Spray drying of elderberry (sambucus nigra l ) juice to maintain its phenolic content

This article was downloaded by: [Moskow State Univ Bibliote] On: 10 December 2013, At: 08:11 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Drying Technology: An International Journal Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/ldrt20 Spray Drying of Elderberry (Sambucus nigra L.) Juice to Maintain Its Phenolic Content a Ramesh Murugesan & Valérie Orsat a a Department of Bioresource Engineering, Faculty of Agricultural and Environmental Sciences , McGill University , Sainte-Anne-de-Bellevue, Quebec, Canada Published online: 19 Oct 2011 To cite this article: Ramesh Murugesan & Valérie Orsat (2011) Spray Drying of Elderberry (Sambucus nigra L.) Juice to Maintain Its Phenolic Content, Drying Technology: An International Journal, 29:14, 1729-1740, DOI: 10.1080/07373937.2011.602485 To link to this article: http://dx.doi.org/10.1080/07373937.2011.602485 PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content This article may be used for research, teaching, and private study purposes Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions Drying Technology, 29: 1729–1740, 2011 Copyright # 2011 Taylor & Francis Group, LLC ISSN: 0737-3937 print=1532-2300 online DOI: 10.1080/07373937.2011.602485 Spray Drying of Elderberry (Sambucus nigra L.) Juice to Maintain Its Phenolic Content ´ Ramesh Murugesan and Valerie Orsat Downloaded by [Moskow State Univ Bibliote] at 08:11 10 December 2013 Department of Bioresource Engineering, Faculty of Agricultural and Environmental Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada Spray drying was studied with Elderberry (Sambucus nigra L.) juice using a Buchi B-290 spray dryer Different inlet temperatures ranging from 70 C to 120 C and two feed flow rates of 180 ml/hr and 300 ml/hr were considered for the experiment The operating parameters were optimized in terms of total phenolic content retention, color, and powder recovery The inlet temperature of 80 C with feed flow rate of 180 ml/hr gave high phenolic content retention with good color but lower recovery of the dried powder, i.e., less than 50% To increase the recovery percentage during the drying process, the elderberry juice was spray dried with five different wall materials, i.e., soya milk powder, soya protein powder, isolated soya protein, gum acacia, and maltodextrin Wall materials were evaluated in terms of total phenolic content retention, color of the powder, and mass recovery percentage The gum acacia and maltodextrin gave better results and high recovery percentage, i.e., more than 70% The best three combinations were stored under three different storage conditions in three different packagings to monitor the stability of the phenolic content and color of the powder Keywords Antioxidants; Color measurement; Fruit powder; Polyphenols; Recovery INTRODUCTION Large quantities of fruits and vegetables are produced worldwide; however, due to their large water content, they are prone to microbial contamination and chemicalenzymatic reactions, which lead to spoilage of these fresh commodities.[1] Due to their perishable nature, postharvest losses of fruits and vegetables are higher when compared to pulses and cereals To reduce the losses due to the microorganism’s deterioration, the moisture content or water activity of the food products must be brought to a safer, lower level Drying generally refers to the removal of moisture from materials During the drying process, the moisture level of the product is brought down by evaporation or sublimation or any other moisture migration phenomenon ´ Correspondence: Valerie Orsat, Department of Bioresource Engineering, Faculty of Agricultural and Environmental Sciences, 21111 Lakeshore Road, Macdonald Campus, McGill University, ´ Sainte-Anne-de-Bellevue, Quebec, Canada H9X 3V9; E-mail: valerie.orsat@mcgill.ca Drying of food materials is the best method for storing products for longer periods as compared to other preservation methods and it is widely used,[2] even though drying processes are the most energy-consuming preservation methods.[3] The spray-drying process is one of the drying processes, which is used not only for drying purposes but also used for encapsulation, and many food manufacturing processes use spray drying to convert liquid food products such as juices into a powder form.[4] Most food industries, especially dairy industries, use spray drying as a preservation technique to increase the storability of the products by reducing water activity Spray drying is also used in the pharmaceutical industry to dry heat-sensitive materials and to enhance the flow properties of the dried powder materials.[5,6] Spray-drying food process applications have contributed significantly in our daily lives We use a lot of products which have been manufactured by spray drying such as fruit powders, instant coffee, milk powder, powdered cheese, instant soups, sweeteners, etc.[7] Spray drying is one of the most commonly used encapsulation techniques by the food industry[8,9] and one of the oldest known methods, since the 1930s, to encapsulate flavors using gum acacia.[10] Because of its energy efficiency, relative ease of operation, and minimal process duration, spray drying is considered as an alternative to freeze drying and can be used for larger-scale productions with readily available equipment in the market.[11,12] The main benefit is that spray drying can be useful to produce stable and functional products.[6,13] Due to the short contact times with heat during spray drying, higher amounts of the functional properties such as flavor, color, and other nutrients are retained in the final products.[14,15] From an engineering point of view, we can describe spray drying as an effective process which converts a fluid feed into its powder form in a single operation.[16] The spray dryer converts fluid feed into solid particles by spraying them into a hot air drying medium The spray-drying process generally consists of several stages involving atomization, mixing of spray and drying gas, evaporation, and 1729 Downloaded by [Moskow State Univ Bibliote] at 08:11 10 December 2013 1730 MURUGESAN AND ORSAT separation.[6] The spray-drying process is a process that has complex equipment interactions, process parameters, and product parameters that have a significant effect on the final product quality The final product quality mainly depends upon the spray dryer operating parameters.[17] Spray drying is an important drying process to produce powders and it mostly produces amorphous materials rather than crystalline materials.[18] The production of crystallites is principally dependent upon the drying conditions, i.e., inlet air temperature, pressure, etc.[19] The main objective of drying fruit juices is to produce a material which has higher shelf life with higher stability along with ease of handling.[16] The spray-drying process produces a good quality final product with low water activity and reduced weight, resulting in easier storage and transportation The final product’s physicochemical properties mainly depend on feed flow rate, particle size, viscosity, spray dryer temperature, pressure, and type of atomizer.[20] Spray-drying processed materials can be classified into sticky products and non-sticky products.[4] Spray drying is often selected as it can process material very rapidly while providing control of the particle size distribution.[21] Often carriers or wall materials are used in spray drying to minimize the damage to the functional components such as polyphenolic compounds, vitamins, minerals, etc Gum acacia and maltodextrin are well known and commonly used wall materials or carriers in drying of fruit juices Gum acacia is an efficient encapsulating material because of its high water solubility, lower viscosity, and capability of oil-in-water emulsification.[22,23] Gum acacia is a complex polysaccharide that mainly contains galactose, arabinose, rhamnose, glucuronic acids, and a smaller fraction of protein,[24–26] and this protein content governs the functional properties of gum acacia.[27] A lot of research has been conducted using gum acacia for its encapsulation functionality.[28–33] Maltodextrin is a popular encapsulating material next to gum acacia Maltodextrin is mostly added to reduce the stickiness during the spray-drying process as the addition of maltodextrin increases the glass transition temperature.[4] Maltodextrin consists of a chain of D-glucose units connected with glycosidic bonds (1!4).[34] Maltodextrins are classified as a function of the length of the chain expressed as Dextrose Equivalents (DE) ranging between and 20 Maltodextrin with various dextrose equivalents has been used to spray dry a variety of fluids such as mango, blackcurrant, apricot, and raspberry.[1,31,35] Proteinous compounds such as soya milk powder, soya protein powder, skim milk powder, etc., are also used by some researchers[1,5] to find alternative wall materials or partially replace carriers like gum acacia as gum acacia is costly and market supplies are at times unpredictable Elderberry fruit belongs to the wild berry category and is predominantly grown in Europe and North America Elderberries have been traditionally used for medicinal purposes Elderberries have been reported useful for the treatment of many diseases like asthma, colds, constipation, arthritis, etc.[36] As a food, elderberries are mainly used for the production of juice and concentrates; however, they are also used to manufacture syrup, wine, jelly, pie filling, desserts, cakes, candies, etc.[36] The color pigments derived from elderberry can be used in many food commodities and beverages as coloring agents and nutritional supplements The color pigments from elderberry have high anthocyanin content[37] and the anthocyanin content in elderberry fruit is higher than in strawberries and bilberries Elderberry has a high anthocyanin content of 863 mg=l.[38] The elderberry’s anthocyanin belongs to the category of cyanidin anthocyanins Cyanidin-3-sambubioside and cyanidin-3-glucoside are the two major anthocyanins in elderberry and contribute around 85% of the total anthocyanins present in the fruit,[39] making them an attractive nutritional supplement in many foods Spray drying is an ideal process to produce an elderberry powder with high nutritional and color functionality Elderberry juice was spray dried in this study to produce elderberry powder of high quality In this study, three soya products were tested along with other well-known carriers like maltodextrin and gum acacia to understand the efficacy of these materials in preserving the phenol content and color of elderberry juice Soya milk powder, isolated soya protein, soya protein powder, gum acacia, and maltodextrin were used as carriers in the spray-drying experiment MATERIALS AND METHODS Elderberry Juice Preparation The fully ripened elderberry fruits were manually harvested in 2009 from a farm located in Franklin, Quebec, Canada Harvested elderberry fruits were immediately transported to the laboratory and manually cleaned by running cold water to remove any dirt and foreign materials The fruits were stored at refrigeration temperature (4 C) before juice extraction The total soluble solid content of the fruit was used as an indicator for the fruit maturity Fully ripened fruits were carefully selected for the juice extraction The fruits were brought up to room temperature before juice extraction A commercial juice extractor was used to extract the juice from the thawed fruits The extracted juice was filtered twice using muslin cloth to remove seeds and skin particles The juice was spray dried immediately without any delay The total soluble solids content of the fruit juice ranged from 10 to 13 Brix and pH ranged from 3.9 to 4.1 1731 SPRAY DRYING OF ELDERBERRY JUICE Downloaded by [Moskow State Univ Bibliote] at 08:11 10 December 2013 Reagents and Standards Sodium Carbonate (anhydrous), Folin–Ciocalteu reagent, Gallic acid (anhydrous), and de-ionized water were required in this experiment All reagents and chemicals used in the experiment were of analytical quality and purchased from Fisher Scientific International, Inc Wall Materials Five wall materials were tested: Spray dried gum acacia (also known as gum arabic) from Importers Service Corporation, New Jersey, USA; Malto-dextrin (Excelvin1 with DE of 4-7) from Distrivin, Quebec, Canada; Isolated soya protein from Bob’s Red Mill natural foods, Milwaukee, USA; Soya protein powder (purely bulkTM), and Soya milk powder (purely bulkTM) from Verve Naturals, Guelph, Canada, were used as wall materials in the experiment All wall materials used in the research were tested in terms of their interactions with the polyphenols present in the fruit juice All wall materials were added at the total juice solids to wall materials ratio of 5:1, 5:2, 5:3, 5:4 and 1:1 (weight basis) The wall materials were blended with fruit juice using an electric blender for 10 of homogenizing for all samples The homogenized juice was spray dried immediately without any delay Spray Drying Equipment A laboratory mini spray dryer (Buchi – B290) was used in the experiment This laboratory spray dryer had the drying capacity of kg H2O=hr The maximum inlet temperature that can be used with this spray dryer is 220 C The minimum atomizing pressure requirements of the spray drying process using this laboratory spray dryer range from 5À8 bars This range was adopted from the manufacturer specification from Buchi Corporation Various particle sizes can be produced from the spray dryer according to the operating pressure and atomizer flow speed The unit was operated at 5.5 bars atomizer pressure with an aspiration gas flow rate of 35 m3=hr, while the feed flow was operated at either 180 or 300 ml=hr Total Phenolic Content (TPC) Determination The phenolic content of the spray-dried powder was measured by recommended Folin-Ciocalteu’s method.[40] The total polyphenolic content estimation method was used in the experiment without doing any modification of the method The absorbance was measured at 765 nm using a spectrophotometer (BIOCHROM – Ultrospec 1000TM) gram of fruit powder was used in each analysis Deionized water was used as a dissolving medium The whole experiment was carried out at room temperature Gallic acid was used as a standard for the validation and the results were correlated with a standard Gallic acid curve, which has a standard linear correlation coefficient (R) of 0.9997 and the results were expressed in milligram equivalents of Gallic acid (GAE) per g of spray-dried elderberry powder Color Measurement Color of spray-dried powder was measured using a chromameter (MINOLTATM) g of the fruit powder was used to measure the color The chromameter works with the principle of measuring reflected light and expressing in three coordinates L, a, b Light beam from the chromameter was passed through the powder and the reflected light was measured by using L, a, b coordinates The L value indicates the darkness or lightness of the product The a value indicates redness or greenness, while the b value designates yellowness or blueness of the sample The hue angle is an indicator that denotes the exact color of the material The hue angle denoted ranges of color starting from dark red color to light magenta in the color axis The hue angle was calculated from the following formula: Hue angle ¼ tanÀ1 ða=bÞ Mass Recovery Percentage Determination Recovery percentage of the spray-drying process was calculated by mass balance The initial dry matter in the juice, with and without wall materials, was determined by hot air oven A known quantity of juice was dried in the oven at 120 C for 24 hours to quantify initial dry matter 100 ml of the fruit juice was spray dried for each experiment The spray-dried powder weight was measured at the end of each trial and total mass recovery percentage during the spray-drying process was calculated using the following formula: (Initial dry mater in juice(g) Mass recovery % ¼ À (Leftover powder mass  100 in spray dryer (g)) Initial dry matter in juice (g) The leftover mass of powder in the above formula indicates the powder, which was not recovered during the spray-drying process In other words, this is the powder that was sticking to the drying chamber and other parts of the dryer Actual Phenol Content (APC) Determination To evaluate each wall material, as an encapsulating material, a new parameter named actual phenol content was used The actual phenol content is a parameter dependent of mass recovery percentage and total phenol content 1732 MURUGESAN AND ORSAT This parameter was calculated to determine the actual efficiency of the wall material as the mass recovery percentage and total phenol content depend on the type of wall materials and their ratio to total solid content of the juice The actual phenol content was calculated using the following formula: Downloaded by [Moskow State Univ Bibliote] at 08:11 10 December 2013 Actual phenol content, (mg GAE/g) ¼ Total phenol; ðmgGAE=gÞ Â Mass recovery percentage ð%Þ Statistical Analysis All the experiments were conducted in three replicates Mean values of the replicates are presented A two-way Analysis of Variance (ANOVA) was carried out with the confidence level of 95% (P 0.05) to determine the significant effect of using different wall materials and their ratio to total solid content of the juice in the spray-drying process SAS (Windows version 9.2) software was used for the statistical analysis and Microsoft Excel (Windows version 12) was used to interpret the results Storage Studies The best three combinations of different wall materials in terms of total phenol content of spray-dried powder were stored in three different storage conditions with three different packagings for 90 days, to study the stability of the phenolic content and color of the powder The three storage conditions were as follows: a Room temperature (20 C) with light (1739 lux) – (LRT) b Room temperature (20 C) without light (dark) – (DRT) c Refrigerated (5 C) without light (dark) – (REF) and three packaging material as follows: a paper bag b polythene bag c polythene bag – vacuum packed At the end of the storage period the samples were analyzed for total phenol content and color The values were compared with the original values RESULTS AND DISCUSSION Optimization of Inlet Temperature and Feed Flow Rate The inlet temperature and feed flow rate of the spray dryer were optimized for elderberry juice drying All other spray-dryer parameters, such as aspiration gas flow rate and air pressure, were not changed during the experiment These values were reported in section 2.4 The spray drying equipment has no control over outlet air temperature Six inlet temperatures, i.e., 70, 80, 90, 100, 110, and 120 C, and two feed flow rates, i.e., 180, 300 ml=hr, were tested To optimize the feed flow rate and temperature, the spray-drying experiment was carried out for all possible combinations The flow rate and the inlet temperature were optimized based upon the total phenolic content of the fruit powder The total phenolic content was measured as per the method mentioned in section 2.5 The loss of the phenolic content increased with the increase of inlet temperature For example, the total phenols content in elderberry powder spray dried at 120 C was around 10% lower when compared to control but it was only 6% lower with the inlet temperature of 100 C at the feed flow rate of 180 ml=hr (Table 1) These results are in accordance with previous research,[41] which observed that the total phenolic content of wild elderberry did not change significantly during the juice concentration process at the temperature of 40 C; however, they found significant loss (25%) of phenolic content during blanching at a temperature of 70 C for 10 min.[41] This significant 25% loss is likely due to the thermo-sensitivity of the fruit juice and the high temperature maintained for longer duration In the case of spray drying, our fruit juice was subjected to a higher temperature; however, for only a few seconds, which may lead to a reduced loss in the phenolic content of the juice Mass recovery percentage was calculated for each experiment and the results were interpreted Generally, mass recovery percentage was decreased with increase of feed flow rate at the same air inlet temperature For example, at 120 C the recovery percentage was 48.11% in 180 ml=hr flow rate but it was decreased to 38.97% in 300 ml=hr feed flow rate The lower mass recovery percentage was mainly caused by stickiness of the product It might be as a result of inefficient moisture removal during 300 ml=hr as the heat input per ml of feed input was lower when compared to 180 ml=hr Table presents overall changes in total phenolic content due to feed flow rate and inlet temperature Similarly, results were reported for the spray drying of chicory root inulin,[18] where the mass recovery of the spray drying was decreased with an increase of feed flow rate, with lower air inlet temperature In that TABLE Optimization of inlet temperature and feed flow rate Mass recovery, % Inlet Loss of temperature,  C phenol content, % 180 ml=hr 300 ml=hr 70 80 90 100 110 120 2.51 Ỉ 0.12 2.65 Ỉ 0.05 5.21 Ỉ 0.07 6.29 Ỉ 0.15 8.69 Æ 0.11 10.3 Æ 0.03 28.22 42.34 43.68 46.12 46.89 48.11 19.53 34.2 36.19 37.25 38.11 38.97 1733 SPRAY DRYING OF ELDERBERRY JUICE Downloaded by [Moskow State Univ Bibliote] at 08:11 10 December 2013 FIG Total phenolic content in spray-dried powder with different wall materials study, they achieved only 6.2% recovery at 142 C inlet temperature; however, increasing the inlet temperature to 198 C, to increase the heat input to the feed load, resulted in 30.7% mass recovery for the same feed flow rate.[18] These results were in accordance with findings of the current research The 80 C inlet temperature at 180 ml=hr inlet flow rate gave better phenolic content retention and color with, however, lower mass recovery percentage than at higher temperature In this combination, the loss of phenolic content was around 2.65% with a recovery of 42.34% However, at the same inlet temperature, i.e., 80 C, with 300 ml=hr feed flow rate resulted in a recovery of only 34.2% Hence the feed flow rate was fixed to 180 ml=hr for the rest of the experiment, to ensure product recovery, with an inlet temperature of 80 C to ensure phenol content retention All wall material experiments were conducted with 180 ml=hr feed flow rate and 80 C inlet temperature Spray Dried Elderberry Powder Properties – Total Phenolic Content Phenolic compounds in fruits and vegetables are vastly distributed and they provide color and flavor to fruits and vegetables.[42] Polyphenols can provide good antioxidant activity and help to prevent various cancer and cardiovascular diseases However, polyphenols are a group of antioxidants highly sensitive to degradation at high temperatures.[43] For example, high-temperature drying versus low-temperature drying has been shown to significantly influence the loss of the polyphenolic content in plums.[44] Similar results were obtained with drying of red grape pomace.[45] Grape peels dried at 140 C and 100 C experienced greater loss in polyphenolic content when compared to peels dried at 60 C Similar results were also reported with sorghum.[46] Hence, it is very important to control process temperature, such as drying medium input temperature, to preserve a material’s total phenolics during processing The study of the total phenol content in spray-dried elderberry juice as a function of wall materials is presented in Figure The highest phenolic content was found at 1:1 ratio of gum acacia with 48.1 mg GAE=g while the lowest phenolic content was found at 5:1 ratio of gum acacia with 35.2 mg GAE=g The total phenolic content of the elderberry powder, obtained using maltodextrin as wall material, showed a different trend when compared to gum acacia The phenolic content did not increase in all cases with the increase of maltodextrin concentration For example, the phenolic content increased with the ratio increase from 5:1 to 5:2 but it decreased for ratio changes from 5:2 to 5:3 (Table 2) In general, the gum acacia produced better phenolic content retention when compared to maltodextrin and all other soya products Similar findings were reported in many studies; for example, gum arabic and rice starch, along with gelatin, were used as encapsulating materials for ascorbic acid.[47] The inlet and outlet temperatures of the spray drying were maintained at 150 C and 80 C, respectively Gum arabic encapsulated ascorbic acid appeared to be more stable and produced better morphology as compared to rice starch encapsulated ascorbic acid and it showed higher retention, even in higher relative humidity as compared to rice starch encapsulation In another study, gum acacia and soluble polysaccharides had good oxidative resistance when used as encapsulating materials to encapsulate arachidonic acid with ascorbic acid The spray drier inlet and outlet temperatures TABLE Percentage increase or decrease of total phenolic content of fruit powder with the increase of concentration of wall materials Concentration increment 5:1 5:2 5:3 5:4 to to to to 5:2 5:3 5:4 1:1 Soya milk powder Soya protein powder Isolated soya protein Gum acacia Maltodextrin 7.75 4.08 2.11 7.19 4.08 4.66 À2.66 À3.87 9.48 7.60 1.14 À0.23 6.63 8.27 4.64 10.40 4.09 À3.23 3.59 À0.97 1734 Downloaded by [Moskow State Univ Bibliote] at 08:11 10 December 2013 FIG MURUGESAN AND ORSAT L value of spray-dried powder with different wall materials were set at 200 C and 100–110 C.[48] The spray encapsulation of bixin, a pro-carotenoid found in annatto (Bixa orellana L.), was studied[49] with air inlet and outlet temperatures maintained at 180 C and 130 C Gum arabic was a better encapsulating materials over maltodextrin as it was to times more stable than maltodextrin For linoleic acid encapsulation, gum acacia performed better when compared to maltodextrin in terms of encapsulation efficiency, size, stability, and oxidation resistance.[50] Published research has even suggested to use a mixture of gum acacia and maltodextrin for better encapsulating properties For example, cardamom oleoresins were encapsulated using gum arabic, maltodextrin, and modified starch and showed that 4=6, 1=6, 1=6 proportion blends can all effectively encapsulate the material However, gum arabic was found to be the better wall material as compared to other wall materials when all are used alone.[51] The inlet and outlet temperatures of the spray dryer were maintained at 178 Ỉ and 120 Ỉ 5 C For pepper oleoresin encapsulation, gum arabic was the best encapsulating material over modified starch in an experiment where the inlet and outlet temperatures were maintained at 178 Ỉ and 110 Ỉ 5 C.[52] As presented in Figure 1, we can clearly visualize the increase of the phenolic content as the ratio of fruit juice to wall material changed from 5:1 to 1:1 However, the percentage increase of phenolic retention was not uniform (Table 2) Interestingly, the increase of some wall material concentrations even decreased the phenolic content when compared with immediate lower concentration of same wall material For example, the increase in maltodextrin concentration from 5:2 to 5:3 reduced the phenolic content of the final fruit powder by 3.23% Soya products results were different from gum acacia and maltodextrin results For example, the total phenolic content retention of the spray-dried powder increased with increasing soya protein powder concentration, until a maximum was reached, after which the total phenolic content started decreasing with the increase in wall material (Figure 1) The total phenolic content was around 35.3 mg GAE=g of fruit powder at the wall material ratio of 5:1 and it increased to up to 38.6 mg GAE=g of fruit powder with the total solids to wall material ratio of 5:3 and the percentage increase was around 4% in each case (Table 2) However, the total phenolic content decreased with the further increase of wall material beyond 5:3; for example, the phenolic content of the fruit powder decreased from 37.6 to 36.2 mg GAE=g with total solids to wall material ratio of 5:4 and 1:1, respectively This indicates that there is a maximum quantity of soya protein powder that can be added to yield a benefit in the phenolic content retention Similarly, when using isolated soya protein as a carrier, the increase in phenolic content was rapid from 5:1 to 5:2 with a jump from 36.3 mg GAE=g to 40.1 mg GAE=g of fruit powder; however, beyond the 5:3 ratio, the total phenolic content of the fruit powder remained almost stable at the value of 43 mg GAE=g of fruit powder This further supports that there is a maximum concentration of wall material that brings an increase in phenolics retention and that an increase of concentration of isolated soya protein beyond the 5:3 ratio (to 5:4 or 1:1) may only bring a very minimal increase in the total phenols retention in the fruit powder In summary, the current study indicates the potential use of soya products as an alternative to gum acacia and maltodextrin for the retention of phenolics during spray drying Among the soya products tested, soya milk powder and isolated soya protein powder produced better retention of phenolic compounds when compared to soya protein powder Nonetheless, gum acacia gave the highest yield in phenolic content retention Spray-dried Elderberry Powder Properties – Powder Color (L Value and Hue Angle) Anthocyanins are the compounds responsible for the red or purple color of fruits.[53] The major anthocyanins present in elderberry are all cyanidin glycosides, which mostly include 3-sambubioside, 3-glucoside, 3-sambubioside-5-glucoside and 3,5-diglucoside The anthocyanin content ranges from 200 to 1000 mg= 100 g fresh weight[54] and among these pigments 3-sambubioside were found to be more stable when compared to other pigments in elderberry fruit.[55] Like most polyphenols, anthocyanins are sensitive to temperature The anthocyanin content in blueberries was significantly decreased during high-temperature drying.[56] Plums (Prunus domestica) were dried in an oven with different temperatures (55, 75, and 95 C) and duration combinations It was found that the drying process adversely affected the anthocyanin content of the fruit and its final color.[42] Downloaded by [Moskow State Univ Bibliote] at 08:11 10 December 2013 SPRAY DRYING OF ELDERBERRY JUICE In the current study, the color of the powder was measured using a chromameter and the values were presented in terms of ‘‘L,’’ ‘‘a,’’ and ‘‘b.’’ The darkness of the powder, expressed by the L value, is presented in Figure Lower L value indicates darkness while a higher L value indicates lightness of the material The hue angles were calculated using ‘‘a’’ and ‘‘b’’ color values and are presented in Figure All the wall materials diluted the color of the powder Isolated soya protein produced lowest L value found at ratio of 5:1 while the highest L value was found with maltodextrin at 1:1 ratio The L value increased with the increase of the wall material concentration In each case the lowest L value was found at lowest concentration of the wall material (5:1) and highest L value was found at the highest wall material concentration (1:1) The highest change or increase in L value (10.47%) was found with maltodextrin when the concentration increased from 5:1 to 5:2 The decrease in darkness of the powder is higher for all soya products as compared to gum acacia and maltodextrin However, the decrease in the darkness of fruit powder was not necessarily an indicator of loss of quality, but rather an indication of a dilution effect from the wall materials For example, the highest L value (thus lighter color) was found at 1:1 ratio of maltodextrin, while its total phenol content was 41.4 mg GAE=g of powder, an average retention value This indicates that the L value could not solely be used as a quality indicator of the powder The hue angle of the powder was calculated with a and b values and the hue angle of the powder increased with the increase of concentration of the wall material (Figure 3) The lowest hue angle was found at 5:3 ratio of maltodextrin and the highest was found at 1:1 ratio of soya protein powder A less pronounced increase in the hue angle with the concentration increase of wall material was found with maltodextrin The hue angle value stayed at around 270 regardless of increase in concentration of maltodextrin This indicates that the maltodextrin had negligible effect on the hue angle of the fruit powder FIG Hue angle of spray-dried powder with different wall materials 1735 In the group of soya products, the soya milk powder and soya protein powder affected the hue angle significantly when compared with isolated soya protein The hue angle behaved in a more erratic manner when using isolated soya protein as a wall material The hue angle initially decreased with the ratio increase from 5:1 to 5:2; however, beyond the 5:2 ratio, the hue angle increased with an increase of the concentration of the isolated soya protein powder On the other hand, soya protein powder, soya milk powder, and gum acacia increased the hue angle with the increase of their concentration (Figure 3) Spray-dried Elderberry Powder – Mass Recovery Percentage and Actual Phenolic Content Recovery The mass recovery percentage using gum acacia was significantly affected by the wall material concentration (Figure 4) The highest mass recovery was found at 5:1 ratio with a percentage recovery of 80.1% and the lowest was found at 1:1 ratio with 72.8% These values are far better than for all wall materials from the soya origin (soya milk powder, isolated soya protein, and soya protein powder) Nonetheless, the mass recovery percentage increased following the same pattern where the recovery percentage decreased with the increase of wall material (gum acacia) concentration The mass recovery percentage of spray-dried powder with maltodextrin was highest when compared to all other wall materials tested in the experiment The highest recovery was around 82% found at the ratio of 5:4 and the lowest recovery was found at 5:2 ratio with 77.9% Due to its high mass recovery percentage, the total phenol recovery was high when maltodextrin was used as a wall material The actual recovery in terms of total phenol of the elderberry powder was calculated by multiplying the mass recovery percentage with the total phenol content of the elderberry powder (Figure 5) The highest actual phenol content was found at the ratio of 5:4 with 34 mg GAE=g FIG Mass recovery percentage of spray-dried powder with different wall materials 1736 MURUGESAN AND ORSAT TABLE Two-way ANOVA – Total phenol content versus product ratio and wall material Source DF SS MS F P Ratio Wall material Error Total 4 16 24 186.295 25.692 66.087 278.074 46.5738 6.423 4.1304 11.28 1.56 0.234 TABLE Two-way ANOVA – Recovery versus product ratio and wall material Downloaded by [Moskow State Univ Bibliote] at 08:11 10 December 2013 FIG Actual phenolic content in spray-dried powder with different wall materials of fruit powder and the lowest phenol content of 31.2 mg GAE=g of fruit powder was found at the ratio of 5:1 (Figure 5) All soya products expressed a decrease in mass recovery with an increase in their concentration With soya milk powder, the highest recovery of 68.9% was obtained at the lowest ratio of 5:1 (total juice solids: wall material) The main reason for lower mass recovery percentage is due to the stickiness of the soya products Thus, an increase in wall material concentration increased the stickiness of the spray-dried powder The fruit=wall material powder tends to stick to the walls of the drying chamber and cyclone, which leads to a lower product recovery The highest phenol content was only 27.2 mg GAE=g in actual recovery, which is much lower, namely 40.74% when compared to the original phenolic content of 45.9 mg GAE=g of fruit powder This lower recovery prevents the use of the soya milk powder as a wall material for elderberry juice spray drying Similar results were obtained for the other soya products Due to the lower mass recovery, the actual phenolic content was low and resulted in a total phenolic content of less than 23.9 mg GAE=g of fruit powder This indicates that the soya protein powder or isolated soya protein did not adequately assist the drying of elderberry juice as it decreased the efficiency of the drying by increasing the stickiness of the elderberry powder Overall Impact and Significance of Wall Material and their Concentration on Total Phenolic Content, Recovery, and Color Parameters (L, a, B) The two-way ANOVA results are presented in Tables 3– testing the significance of the wall materials and their combinations as their effect varied with according responses For example, the choice of wall material was not a significant factor in the total phenol content retention while the ratio of the wall material to total solids was significant (P < 0.01) In general, the combination of wall Source DF SS MS F P Ratio Wall material Error Total 4 16 24 332.93 2165.2 314.27 2812.4 83.233 541.299 19.642 4.24 27.56 0.016 TABLE Two-way ANOVA – L-color versus product ratio and wall material Source DF SS MS F P Ratio Wall material Error Total 4 16 24 76.808 77.981 22.091 176.881 19.2021 19.4953 1.3807 13.91 14.12 0 TABLE Two-way ANOVA – a-color versus product ratio and wall material Source DF SS MS F P Ratio Wall material Error Total 4 16 24 86.618 26.796 8.358 121.772 21.6546 6.699 0.5224 41.46 12.82 0 TABLE Two-way ANOVA: b-color versus product ratio and wall material Source DF SS MS F P Ratio Wall material Error Total 4 16 24 0.8518 63.7885 8.6234 73.2637 0.213 15.9471 0.539 0.4 29.59 0.809 SPRAY DRYING OF ELDERBERRY JUICE Downloaded by [Moskow State Univ Bibliote] at 08:11 10 December 2013 material and their ratio were the deciding factors affecting the recovery percentage (P < 0.05), and color values (P < 0.01) Storage Stability of the Total Phenol Content and Color of Spray-Dried Elderberry Powder The spray-dried elderberry powders were stored under three different storage conditions and packed in three different packing materials as described in section 2.10 The spray-dried powders were stored to monitor the stability of total phenolic content and color Only three wall materials were considered for the storage studies, namely gum acacia, maltodextrin, and soya milk powder These wall materials and their ratio were selected from the spray-drying experiment Best actual phenolic content of the spray-dried powder was used as a deciding factor for choosing the wall materials and their ratios The selected ratio of total solids to wall materials were for gum acacia, 1:1; for maltodextrin, 5:4; and for soya milk powder, 1:1 (Total solids: wall material) All the samples were kept in storage for ninety days The initial phenolic content and color parameters L, a, b were measured After ninety days the final phenolic content and color parameters were measured and compared with the initial values Total Phenol Content The changes in the total phenolic content during storage are presented in Figure Gum acacia had the best results followed by maltodextrin in phenolic content retention during storage The lowest loss in phenolic content of 1.8% was found under the vacuum packing stored under refrigerated condition (REF) using gum acacia as a wall material On the other hand, the soya protein powder resulted in the highest decrease in phenolic content with 29.2% loss found in the polythene packing stored in presence of light FIG Total phenolic content (TPC) for different wall materials following storage 1737 For gum acacia, all the packing stored at room temperature with presence of light (LRT) showed higher loss with 14.6% for polythene packing and 10.6% for vacuum packing, while the paper packing showed a lower decrease in phenolic content with only 5.3% This lower decrease might be due to the lower light penetration into the spray-dried powder through the paper opacity Physical appearance in terms of granulation and powder flowability in the fruit powder was assessed visually During the storage period, the elderberry powder did not become sticky and maintained its free-flowing nature This indicates that the gum acacia did not have any adverse effects on the spray-dried powder in terms of lumps’ formation or stickiness With maltodextrin fruit powder, the polyethylene and vacuum packings, stored under light at room temperature conditions, showed lower loss in phenolic content when compared to the respective packing types with gum acacia fruit powder Interestingly, the highest loss in phenolic content was found in paper packing, which was stored with absence of light, indicating that contact with oxygen was the most important factor affecting the decrease in phenolic content for the maltodextrin spray-dried powder rather than degradation due to light Even though, the maltodextrin showed results similar to gum acacia (second best in terms of phenolic retention), the physical character of the powder was not equivalent to the gum acacia spray-dried powder as it became sticky and lumpy with loss of its free-flowing nature during the storage period at room temperature (with or without light); however, this behavior did not occur in the powder stored under refrigerated condition with polythene packing This implies that the maltodextrin can be used to spray dry the elderberry juice, but the final product should be stored under refrigerated condition with polythene packing to prevent caking of the powder Soya milk powder did not produce better results when compared to maltodextrin and gum acacia Regardless of packing type and storage conditions, the soya-based powder expressed high decrease in phenolic content when compared to the other two wall materials during the storage period The percentage losses in phenolic content ranged from 7.7 to 29.2% (Figure 6) The highest decrease in phenolic content of 29.2% was found in the polythene packing stored in presence of light The physical character of the spray-dried powder with soya milk powder was poor and the spray-dried powder lost its free-flowing nature during the storage period The caking of the spray-dried powder was found in all storage conditions regardless of packing material This indicates that the elderberry juice spray dried with soya milk powder could not be adequately stored Powder Color – L Value and Hue Angle Following storage, the L value was measured and the hue angle was calculated from the a and b color values 1738 MURUGESAN AND ORSAT Downloaded by [Moskow State Univ Bibliote] at 08:11 10 December 2013 FIG L value for different wall materials following storage The overall L value and hue angle for different storage conditions are shown in Figures and The L values ranged from 34.14 to 48.94 when gum acacia was used as wall material Highest L value was found in the vacuum packing stored with presence of light and the lowest L value of 34.14 was found in spray-dried powder stored in polythene packing under refrigerated condition (absence of light), where the darker sample had a lower decrease in phenol content around 4.2% This high L value indicated the lightness of the powder color, indicating a loss of color in the presence of light The hue angle of the gum acacia fruit powder was higher in storage conditions of refrigeration and room temperature with absence of light when compared to presence of light The values ranged from 303.17 to 307.17 The lowest hue angle was found with paper packing stored under light with a value of 270.65 The L value of the maltodextrin-elderberry powder ranged from 31.76 to 51.8 The highest L value of 51.8 (lightest sample) was found with the vacuum packing stored under refrigerated condition This result is the opposite of what was experienced with gum acacia where the lowest L value FIG Hue angle for different wall materials following storage was expressed in vacuum packing under refrigerated storage conditions However, in maltodextrin, the lowest L value was found with polythene packing stored with absence of light The total phenolic content loss was moderate at 11.8% This implies that the L value does not have any direct relation in the analysis of storage stability for maltodextrin as it had in gum acacia Maltodextrinelderberry powder hue angle values ranged from 270.13 to 306.73 and the hue angles were almost the same in all storage conditions regardless of packaging type and storage conditions, except for the paper packing with absence of light (refrigerated condition and room temperature), which resulted in the higher hue angle of 306.73 and 305.73, indicating the color sensitivity of the maltodextrin powder to oxygen In soya milk-elderberry powder, the L values ranged from 26.45 to 47.18 and hue angle ranged from 270.26 to 316.77 The lowest L value of 26.45 was found with paper-packed powder stored in the dart at room temperature, indicating the protection of the color pigment with the opacity of the packing under dark storage conditions The highest hue angle was found with paper-packing storage with absence of light and lowest hue angle was found with vacuum packing in the same storage condition SUMMARY AND CONCLUSION The elderberry juice was spray dried with five different wall materials, gum acacia, maltodextrin, soya protein powder, soya milk powder, and isolated soya protein Initially, the spray-drying process was optimized for the elderberry juice in terms of inlet temperature and feed flow rate The inlet temperature of 80 C and 180 ml=hr feed flow rate were found to be the optimum parameters for elderberry juice spray drying in terms of product mass recovery and phenolic retention The five different wall materials were tested in the ratios ranging from 5:1 to 1:1 (total solids to wall material ratio) Each produced powder material during spray drying was evaluated for total phenol content, color parameters (L value and hue angle), and mass recovery percentage Gum acacia and maltodextrin gave high recovery percentage when compared to powders produced with the soya products, i.e., soya protein powder, soya milk powder, and isolated soya protein Actual phenol content was calculated by multiplying total phenol content to mass recovery percentage Based on highest actual phenol content, three wall materials (gum acacia, maltodextrin, and soya milk powder) were chosen for storage studies to understand the shelf stability of the phenol content and color of spray-dried powder These materials were stored in three different packings under three different storage conditions The refrigerated storage was the best among the three storage conditions in terms of phenolic content retention Downloaded by [Moskow State Univ Bibliote] at 08:11 10 December 2013 SPRAY DRYING OF ELDERBERRY JUICE and physical character (flowability and appearance) of the powder Paper-bag-packaged elderberry powder stored under ambient conditions exhibited high stickiness due to apparent moisture absorption from the atmosphere For that reason, the spray-dried fruit powders should always be packed in air-tight containers to avoid such physical behavior From the storage study, maltodextrin and gum acacia both turned out to be the most suitable wall materials for the elderberry juice spray-drying process with their lower loss of phenol content when compared to soya milk powder However, gum acacia was overall the most suitable wall material in terms of mass recovery percentage, total phenol content retention, and color of the powder as the gum acacia walled elderberry powder was less prone to absorb moisture from the air when compared to maltodextrin product The color stability of both acacia gum and maltodextrin products was better when compared to soya products REFERENCES Cano-Chauca, M.; Stringheta, P.C.; Ramos, A.M.; Cal-Vidal, J Effect of the carriers on the microstructure of mango powder obtained by spray drying and its functional characterization Innovative Food Science & Emerging Technologies 2005, 6(4), 420–428 Hawlader, M.N.A.; Uddin, M.S.; Ho, J.C.; Teng, A.B.W Drying characteristics of tomatoes Journal of Food Engineering 1991, 14(4), 259–268 Ratti, C Hot air and freeze-drying of high-value foods: A review Journal of Food Engineering 2001, 49(4), 311–319 Bhandari, B.R.; Datta, N.; Howes, T Problems associated with spray drying of sugar-rice foods Drying Technology 1997, 15(2), 671–684 ´ ´ ´ ´ Rodrıguez-Hernandez, G.R.; Gonzalez-Garcıa, R.; Grajales-Lagunes, A.; Ruiz-Cabrera, M.A.; Abud-Archila, M Spray-drying of cactus pear juice (Opuntia streptacantha): Effect on the physicochemical properties of powder and reconstituted product Drying Technology 2005, 23(4), 955–973 ´ Re, M.I Formulating drug delivery systems by spray drying Drying Technology 2006, 24(4), 433–446 Nath, S.; Satpathy, G.R A systematic approach for investigation of spray drying processes Drying Technology 1998, 16(6), 1173–1193 Reineccius, G.A The spray drying of food flavors Drying Technology 2004, 22(6), 1289–1324 ´ Re, M.I Microencapsulation by spray drying Drying Technology 1998, 16(6), 1195–1236 10 Shahidi, F.; Han, X.Q Encapsulation of food ingredients Critical Reviews in Food Science and Nutrition 1993, 33(6), 501–547 11 Jafari, S.M.; Assadpoor, E.; He, Y.; Bhandari, B Encapsulation efficiency of food flavours and oils during spray drying Drying Technology 2008, 26(7), 816–835 ´ 12 Chavez, B.E.; Ledeboer, A.M Drying of probiotics: Optimization of formulation and process to enhance storage survival Drying Technology 2007, 25(7), 1193–1201 13 Liu, C.P.; Liu, S.D Low-temperature spray drying for the microencapsulation of the fungus Beauveria bassiana Drying Technology 2009, 27(6), 747–753 14 Shiga, H.; Yoshii, H.; Nishiyama, T.; Furuta, T.; Forssele, P.; Poutanen, K.; Linko, P Flavor encapsulation and release characteristics of spray-dried powder by the blended encapsulant of cyclodextrin and gum arabic Drying Technology 2001, 19(7), 1385–1395 1739 15 Kuts, P.S.; Samsonyuk, V.K Enhancement of spray drying of thermosensitive materials Drying Technology 1989, 7(1), 35–45 16 Roustapour, O.R.; Hosseinalipour, M.; Ghobadian, B An experimental investigation of lime juice drying in a pilot plant spray dryer Drying Technology 2006, 24(2), 181–188 17 Chegini, G.R.; Khazaei, J.; Ghobadian, B.; Goudarzi, A.M Prediction of process and product parameters in an orange juice spray dryer using artificial neural networks Journal of Food Engineering 2008, 84(4), 534–543 18 Toneli, J.; Park, K.; Negreiros, A.; Murr, F Spray-drying process optimization of chicory root inulin Drying Technology 2010, 28(3), 369–379 19 Chiou, D.; Langrish, T.A.G.; Braham, R Partial crystallization behavior during spray drying: Simulations and experiments Drying Technology 2008, 26(1), 27–38 20 Tonon, R.V.; Brabet, C.; Hubinger, M.D Influence of process conditions on the physicochemical properties of acai (Euterpe oleraceae ¸ Mart.) powder produced by spray drying Journal of Food Engineering 2008, 88(3), 411–418 ´ ´ ´ 21 Obon, J.M.; Castellar, M.R.; Alacid, M.; Fernandez-Lopez, J.A Production of a red-purple food colorant from Opuntia stricta fruits by spray drying and its application in food model systems Journal of Food Engineering 2009, 90(4), 471–479 22 Glicksman, M Gum arabic In Food Hydrocolloids; Glicksman, M., Ed.; CRC Press: Boca Raton, FL, 1983 23 McNamee, B.F.; O‘Riorda, E.D.; O’Sullivan, M Emulsification and microencapsulation properties of gum arabic Journal of Agricultural and Food Chemistry 1998, 46(11), 4551–4555 24 Anderson, D.M.W.; Howlett, J.F.; McNab, C.G.A The amino acid composition of the proteinaceous component of gum arabic (Acacia Senegal (L.) Willd.) Food Additives and Contaminants 1985, 2(3), 159–164 25 Anderson, D.M.W.; Stoddart, J.F Studies on uronic acid materials: Part XV The use of molecular-sieve chromatography in studies on acacia senegal gum (gum arabic) Carbohydrate Research 1966, 2(2), 104–114 26 Street, C.A.; Anderson, D.M.W Refinement of structures previously proposed for gum arabic and other acacia gum exudates Talanta 1983, 30(11), 887–893 27 Randall, R.C.; Phillips, G.O.; Williams, P.A The role of the proteinaceous component on the emulsifying properties of gum arabic Food Hydrocolloids 1988, 2(2), 131–140 28 Kanakdande, D.; Bhosale, R.; Singhal, R.S Stability of cumin oleoresin microencapsulated in different combination of gum arabic, maltodextrin and modified starch Carbohydrate Polymers 2007, 67(4), 536–541 29 Krishnan, S.; Bhosale, R.; Singhal, R.S Microencapsulation of cardamom oleoresin: Evaluation of blends of gum arabic, maltodextrin and a modified starch as wall materials Carbohydrate Polymers 2005, 61(1), 95–102 30 McNamee, B.F.; O‘Riorda, E.D.; O‘Sullivan, M Effect of partial replacement of gum arabic with carbohydrates on its microencapsulation properties Journal of Agricultural and Food Chemistry 2001, 49(7), 3385–3388 31 Minemoto, Y.; Hakamata, K.; Adachi, S.; Matsuno, R Oxidation of linoleic acid encapsulated with gum arabic or maltodextrin by spray-drying Journal of Microencapsulation 2002, 19(2), 181–189 32 Shiga, H.; Yoshii, H.; Nishiyama, T.; Furuta, T.; Forssele, P.; Poutanen, K.; Linko, P Flavor encapsulation and release characteristics of spray-dried powder by the blended encapsulant of cyclodextrin and gum arabic Drying Technology 2001, 19(7), 1385–1395 33 Weinbreck, F.; Minor, M.; de Kruif, C.G Microencapsulation of oils using whey protein=gum arabic coacervates Journal of Microencapsulation: Micro and Nano Carriers 2004, 21(6), 667–679 Downloaded by [Moskow State Univ Bibliote] at 08:11 10 December 2013 1740 MURUGESAN AND ORSAT 34 Righetto, A.M.; Netto, F.M Effect of encapsulating materials on water sorption, glass transition and stability of juice from immature acerola International Journal of Food Properties 2005, 8(2), 337–346 35 Bhandari, B.R.; Senoussi, A.; Dumoulin, E.D.; Lebert, A Spray drying of concentrated fruit juices Drying Technology 1993, 11(5), 1081–1092 36 Jensen, K.; Christensen, L.P.; Hansen, M.; Jorgensen, U.; Kaack, K Olfactory and quantitative analysis of volatiles in elderberry (Sambucus nigra L.) juice processed from seven cultivars Journal of the Science of Food and Agriculture 2001, 81(2), 237–244 37 Netzel, M.; Strass, G.; Herbst, M.; Dietrich, H.; Bitsch, R.; Bitsch, I.; Frank, T The excretion and biological antioxidant activity of elderberry antioxidants in healthy humans Food Research International 2005, 38(8–9), 905–910 38 Vulic, J.J.; Vracar, L.O.; Sumic, Z.M Chemical characteristics of cultivated elderberry fruit, Acta Periodica Technologica 2008, 39, 85–90 39 Goiffon, J.P.; Mouly, P.P.; Gaydou, E.M Anthocyanic pigment determination in red fruit juices, concentrated juices and syrups using liquid chromatography Analytica Chimica Acta 1999, 382(1–2), 39– 50 40 Lee, H.S Phenolic compounds in foods Handbook of food analysis, 2nd ed., L.M.L Nollet, Ed.; Dekker: New York, 2004 ´ 41 Galic, A The polyphenols stability, enzyme activity and physico-chemical parameters during producing wild elderberry concentrated juice Agriculturae Conspectus Scientificus (Poljoprivredna Znanstvena Smotra) 2009, 74(3), 181 42 Raynal, J.; Moutounet, M.; Souquet, J.M Intervention of phenolic compounds in plum technology Changes during drying Journal of Agricultural and Food Chemistry 1989, 37(4), 1046–1050 43 Hamama, A.A.; Nawar, W.W Thermal decomposition of some phenolic antioxidants Journal of Agricultural and Food Chemistry 1991, 39(6), 1063–1069 44 Piga, A.; Del Caro, A.; Corda, G From plums to prunes: Influence of drying parameters on polyphenols and antioxidant activity Journal of Agricultural and Food Chemistry 2003, 51(12), 3675–3681 45 Larrauri, J.A.; Ruperez, P.; Saura-Calixto, F Effect of drying temperature on the stability of polyphenols and antioxidant activity of 46 47 48 49 50 51 52 53 54 55 56 red grape pomace peels Journal of Agricultural and Food Chemistry 1997, 45(4), 1390–1393 Nwanguma, B.C.; Eze, M.O Changes in the concentrations of the polyphenolic constituents of sorghum during malting and mashing Journal of the Science of Food and Agriculture 1996, 70(2), 162–166 Trindade, M.A.; Grosso C.R.F The stability of ascorbic acid microencapsulated in granules of rice starch and in gum arabic Journal of Microencapsulation: Micro and Nano Carriers 2000, 17(2), 169–176 Watanabe, Y.; Fang, X.; Adachi, S.; Fukami, H.; Matsuno, R Oxidation of 6-O-arachidonoyl-ascorbate microencapsulated with a polysaccharide by spray-drying Lebensmittel-Wissenschaft undTechnologie 2004, 37(4), 395–400 Barbosa, M.I.M.J.; Borsarelli, C.D.; Mercadante, A.Z Light stability of spray-dried bixin encapsulated with different edible polysaccharide preparations Food Research International 2005, 38(8–9), 989–994 Minemoto, Y.; Hakamata, K.; Adachi, S.; Matsuno, R Oxidation of linoleic acid encapsulated with gum arabic or maltodextrin by spray-drying Journal of Microencapsulation: Micro and Nano Carriers 2002, 19(2), 181–189 Krishnan, S.; Bhosale, R.; Singhal, R.S Microencapsulation of cardamom oleoresin: Evaluation of blends of gum arabic, maltodextrin and a modified starch as wall materials Carbohydrate Polymers 2005, 61(1), 95–102 Shaikh, J.; Bhosale, R.; Singhal, R Microencapsulation of black pepper oleoresin Food Chemistry 2006, 94(1), 105–110 Mazza, G.; Miniati, E Anthocyanins in Fruits, Vegetables, and Grains; CRC Press: Boca Raton, FL, 1993 Bronnum-Hansen, K.; Jacobsen, F.; Flink, J.M Anthocyanin colourants from elderberry (Sambucus nigra L.) Process considerations for production of the liquid extract International Journal of Food Science and Technology 1985, 20(6), 703–711 Drdak, M.; Daucik, P Changes in elderberry (Sambucus nigra) pigments during the production of pigment concentrates Acta Alimentaria 1990, 19(l), 3–7 Lohachoompol, V.; Srzednicki, G.; Craske, J The change of total anthocyanins in blueberries and their antioxidant effect after drying and freezing Journal of Biomedicine and Biotechnology 2004, 5, 248–252  ... and total phenol content depend on the type of wall materials and their ratio to total solid content of the juice The actual phenol content was calculated using the following formula: Downloaded... indication of a dilution effect from the wall materials For example, the highest L value (thus lighter color) was found at 1:1 ratio of maltodextrin, while its total phenol content was 41.4 mg GAE=g of. .. 0.0 5), and color values (P < 0.0 1) Storage Stability of the Total Phenol Content and Color of Spray- Dried Elderberry Powder The spray- dried elderberry powders were stored under three different storage