MINISTRY OF EDUCATION AND TRAINING HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION FACULTY FOR HIGH QUALITY TRAINING Major FOOD TECHNOLOGY Subject PRACTICE OF DAIRY AND RELATED DAIRY PRO.
MINISTRY OF EDUCATION AND TRAINING HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION FACULTY FOR HIGH QUALITY TRAINING Major: FOOD TECHNOLOGY Subject: PRACTICE OF DAIRY AND RELATED DAIRY PRODUCTION Report: Practice of Dairy and Related Dairy Production GROUP Nguyen Thuy Thanh Hien ID: 18116015 Chu Le Thu Huyen ID: 18116017 To Que Phung ID: 18116028 Nguyen Thi Minh Thu ID: 18116038 Tran Bao Thanh Truc ID: 18116040 Semester: – School year: 2021 – 2022 Lecturer: Dr Pham Thi Hoan Class: 18116CLA, Saturday, lesson – 12 Ho Chi Minh City, December 2021 Table of Contents LIST OF FIGURES iv LIST OF TABLES vi LIST OF ABBREVIATIONS .vii EXPERIMENT EVALUATION OF MILK AND RECONSTITUTED MILK QUALITY Abstract 1.1 Introduction 1.2 Materials and methods 1.3 Result and discussion 13 1.3.1 Sensory evaluation of the five samples 13 1.3.2 Milk density 15 1.3.3 Acid titration 15 1.3.4 pH measurement 16 1.3.5 Alcohol test 16 1.3.6 Methylene blue test 17 1.4 Conclusion 18 Reference 18 EXPERIMENT YOGURT PRODUCTION Abstract 2.1 Introduction 2.1.1 Definition of yogurt 2.1.2 Origin of yogurt 2.1.3 Classification 2.1.4 Yogurt consumption situation in some countries around the world 2.2 Materials and methods 2.2.1 Materials 2.2.2 Methods 2.3 Result and discussion 12 2.3.1 Sensory evaluation 12 2.3.2 pH and titratable acidity (TA) measurement 13 2.4 Conclusion 15 Reference 15 EXPERIMENT CHEESE PRODUCTION 18 ii Abstract 18 3.1 Introduction 18 3.1.1 Definition and classification of cheese 18 3.1.2 Mozzarella cheese 19 3.2 Materials and methods 20 3.2.1 Materials 20 3.2.2 Methods 23 3.3 Result and discussion 29 3.3.1 Sensory evaluation 29 3.3.2 Determination of cheese solid yield (CSY) and total solid (TS) of cheese 29 3.3.3 Determination of cheese yield efficiency 30 3.4 Conclusion 31 Reference 31 EXPERIMENT ICE CREAM PRODUCTION 33 Abstract 33 1.1 Introduction 33 4.1.1 Definition of ice cream 33 4.1.2 Origin of ice cream 33 4.1.3 Classification 34 1.2 Materials and methods 34 1.2.1 Materials 34 1.2.2 Methods 36 1.3 Result and discussion 39 4.1.4 Sensory evaluation 39 4.1.5 Determination of overrun 40 1.4 Conclusion 40 Reference 40 iii LIST OF FIGURES Figure 1.1 Sterilled Vinamilk Figure 1.2 Nong Lam pasteurized milk 10 Figure 1.3 Long Thanh pasteurized milk 10 Figure 1.4 Whole cream milk powder 10 Figure 1.5 Balling hydrometer 11 Figure 1.6 How to read a value in a balling hydrometer 12 Figure 1.7 State of unexpired, expired sterilized Vinamilk, Nong Lam milk, Long Thanh milk and reconstituted milk (from left to right) 14 Figure 1.8 Results of methylene blue test for expired and unexpired sterilized Vinamilk 17 Figure 2.2 Yogurt Figure 2.3 The chart on annual yogurt consumption in a certain nation Figure 2.4 Dutch Lady Figure 2.5 Whole cream milk powder Figure 2.6 The starter culture used in this experiment Figure 2.7 The technological process of different set yogurt samples Figure 2.8 Pasteurization of milk after standardizing Figure 2.9 Samples were filled into jars 10 Figure 2.10 pH-meter 11 Figure 2.11 Phenolphtalein chemical structure 11 Figure 2.12 Color transformation during titration 12 Figure 2.13 Yogurt product after cooling within 12 hours made of raw liquid milk (left) and reconstituted milk (right) 12 Figure 2.14 Relationship between pH and titratable acidity of the samples 15 Figure 3.1 Cottage cheese 19 Figure 3.3 Mozzarella cheese 20 Figure 3.4 Nong Lam Milk 20 Figure 3.6 Chemical structure of citric acid 21 Figure 3.7 Citric acid 21 Figure 3.9 Rennet enzyme 22 Figure 3.10 Flow chart of mozzarella cheese processing 23 Figure 3.11 Nong Lam raw liquid milk 24 Figure 3.12 Citric acid 6% addition 24 Figure 3.13 Rennet enzyme addition 25 Figure 3.14 Milk coagulation after 15 minutes 26 Figure 3.15 Diagram of change of milk coagulation 26 Figure 3.16 Curd cutting 27 Figure 3.17 Cheese kneading 28 Figure 3.18 Product in molding 28 Figure 4.1 Ice cream 33 Figure 4.2 VINAMILK UHT non-sugar milk 34 Figure 4.3 Whipping cream Anchor 35 iv Figure 4.4 Egg yolk 35 Figure 4.5 Flow chart of ice cream production 36 Figure 4.6 Egg yolk was stirred by hand beater 37 Figure 4.7 Ice cream machine 38 Figure 4.8 Overrun affects ice cream product 38 Figure 4.9 Hard ice cream 39 v LIST OF TABLES Table 1.1 Gross composition off milk from different mammals Table 1.2 Sensory standards of milk (TCVN 7405:2018) 11 Table 1.3 Results of samples after conducting organoleptic test 14 Table 1.4 Results of milk density 15 Table 1.5 Images of titrated solution 15 Table 1.6 Acidity of milk samples 16 Table 1.7 pH values result 16 Table 1.8 Results of alcohol test for milk samples 16 Table 2.1 Sensory criteria Table 2.2 Physical and chemical criteria Table 2.3 Heavy metal content Table 2.4 Microbiological indicators Table 2.5 Recipe of set yogurt Table 2.6 Sensory properties of surveyed yogurt samples 12 Table 2.7 Color of titratable acidity for the samples 13 Table 2.8 pH and titratable acidity values of surveyed samples 13 Table 3.1 Recipe of Mozzarella cheese 23 Table 3.2 Total solid of milk 29 Table 3.3 Total solid of cheese 30 Table 4.1 Recipe of coffee ice cream 36 Table 4.2 Sensory parameters of edible ices cream 38 Table 4.3 Sensory evaluation of finished product 39 vi LIST OF ABBREVIATIONS BC Before Christ CSY Cheese Solid Yield TA Titratable Acidity TS Total Solid UHT Ultra-High Temperature vii EXPERIMENT EVALUATION OF MILK AND RECONSTITUTED MILK QUALITY Abstract Milk testing and quality control are critical components of every milk processing enterprise, whether small, medium, or big In this experiment, several tests were conducted to assess milk quality from particular sources: Unexpired sterilized Vinamilk and Expired sterilized Vinamilk, Nong Lam pasteurized milk, Long Thanh pasteurized milk and reconstituted milk with 13% total solids As a result, sensory properties of different milk source were different from each other Density of unexpired Vinamilk and reconstituted milk is 1025 kg/m3, that of expired Vinamilk is 1030 kg/m3 Titratable acidity of both expired and unexpired samples are the same 19.26oD, while that of reconstituted milk is 11.28oD pH values of expired and unexpired Vinamilk are 6.89 ± 0.0058 and 7.30 ± 0.0058 for reconstituted milk Alcohol test and methylene blue test proved that all milk samples are well-qualified despite some errors of incomplete reconstitution and external microorganism spoilage 1.1 Introduction Milk is a fluid secreted by the female of all mammalian species, of which there are about 4500 extant species (about 80% of mammalian species are extinct) (Fox, P.F and McSweeney, P.L.H., 1998) Milk is defined as the secretion of the mammary glands of mammals, its primary natural function being nutrition of the young It is derived from lactating mammals such as cows, sheep, goats, horses, buffaloes, etc The principal requirements are for energy (supplied by lipids and lactose and, when in excess, by proteins), essential amino acids and amino groups for the biosynthesis of non-essential amino acids (supplied by proteins), essential fatty acids, vitamins, inorganic elements and water Different kinds of mammals, the chemical components are unsimilar, the differ are present in Table 1.1 Milk is a very complex fluid containing several hundred molecular species (several thousand if all triglycerides are counted individually) The principal constituents are water, lipids, sugar (lactose) and proteins In addition, there are numerous minor constituents, mostly at trace levels, e.g minerals, vitamins, hormones, enzymes and miscellaneous compounds The chemistry of these compounds is generally similar across species but in many cases their structure differs in detail, reflecting evolutionary (Fox, P.F and McSweeney, P.L.H., 1998) Table 1.1 Gross composition off milk from different mammals Milk is often described as the most ‘nearly perfect’ food; although this is true only for the young of the producing or closely related species, the milk of all species is a nutrient rich and well-balanced food (Kon, S K., 1959; du Puis , E M., 2002; Patton, S., 2004 ) However, milk is very susceptible to the growth of micro-organisms, which will cause spoilage if the milk is stored 1.2 Materials and methods 1.2.1.1 Materials ❖ Samples preparation Unexpired sterilized Vinamilk and Expired sterilized Vinamilk (5-month expired milk, but not being opened and stored in refrigerator) from Vietnam Dairy Products Joint Stock Company Figure 1.1 Sterilled Vinamilk Nong Lam pasteurized milk from Nong Lam University, Thu Duc City, Ho Chi Minh City Figure 1.2 Nong Lam pasteurized milk Long Thanh pasteurized milk from LOTHAMILK Joint Stock Company, Bien Hoa City Figure 1.3 Long Thanh pasteurized milk Whole cream milk powder Figure 1.4 Whole cream milk powder From whole milk powder with 4% moisture, preparing 500 mL reconstituted milk with 13% dry matter by dissolving 67.71 g whole milk powder into 432.29 mL boiled 10 Figure 3.17 Cheese kneading Figure 3.18 Product in molding ❖ Brining The curd is then extruded into a mold in which it is pre-cooled before being salted in brine Salting of Mozzarella cheese is carried out using cool brine Mozzarella cheese can also be dry salted or pre-salted just after cooking, in this case a diluted brine should be used as stretch water, in order to avoid salt loss during stretching The main advantage of dry salting is avoiding risks of contamination by yeast or mold that can occur when using brine (Barbano D.M.,1994) It also makes it possible to obtain a homogeneously salted product, with positive consequences for the functional properties Depending on the time it is carried out, pre-salting can yield a salty whey that has substantially increased amounts of lactoferrin (Blaschek et al, 2007) ❖ Drying Mozzarella cheese was dried at room temperature to evaporate the salt solution 28 3.2.2.3 Analysis methods ❖ Sensory evaluation Sensory evaluation of cheese for various attributes (flavor, texture, color) ❖ Determination of cheese solid yield (CSY) and total solid (TS) of cheese mTS cheese 3.1 %CSY = × 100% mTS milk With: mTS cheese (g) is mass of cheese after drying; mTS milk (g) is mass of milk after drying %TS = mTS cheese × 100% minitial cheese 3.2 With minitial cheese (g) is initial mass of cheese before drying After creating a mass of mozzarella cheese, weighing samples with grams per sample Taking a sample that is completely dried to constant weight and then calculating with the above formula to get the total solid mass of the cheese From there, calculating cheese solid yield (CSY) and total solid (TS) of cheese ❖ Determination of cheese yield efficiency Cheese yield efficiency is the ratio of total weight of collected cheese over the mass of internal milk ingredient mcheese 3.3 %H = × 100% mmilk With: mcheese (g) is mass of cheese; mmilk (g) is mass of milk After creating a mass of mozzarella cheese, weighing and record the mass Applying the formula above, calculating cheese yield efficiency 3.3 Result and discussion 3.3.1 Sensory evaluation The finished cheese, lightly salted, is white, soft with a very lively surface sheen and has unique property of stretchability 3.3.2 Determination of cheese solid yield (CSY) and total solid (TS) of cheese ❖ Cheese solid yield (CSY) Three milk samples were prepared in g each crucible Table 3.2 Total solid of milk Sample Initial weight of crucible + liquid milk (g) 29.73 35.17 29.59 Average Weight of crucible + milk after drying (g) 26.19 31.70 26.64 29 𝐦𝐓𝐒 𝐦𝐢𝐥𝐤 (g) 1.54 1.57 1.55 1.55 ± 0.015 Table 3.3 Total solid of cheese Sample Initial weight of Weight of crucible + crucible + cheese cheese after drying (g) (g) 29.51 27.21 29.63 31.98 29.32 31.63 Average 𝐦𝐓𝐒 𝐜𝐡𝐞𝐞𝐬𝐞 (g) 2.30 2.35 2.31 2.32 ± 0.026 From equation 3.1: mTS cheese 2.32 %CSY = × 100% = × 100% = 149.68% mTS milk 1.55 Total solids in cheese is higher than that of milk due to curding texture and protein content after coagulating ❖ • • • Total solid (TS) of cheese Total solid of cheese: mTS cheese = 2.32 (g) Initial mass of cheese: mcheese = (g) From equation 3.2: mTS cheese 2.32 %TS = × 100% = × 100% = 46.40% minitial cheese According to Kosikowski (1982), total solids of Mozzarella is 51.42% ± 1.32, while total solids of modified method from Khartoum Dairy Products Company (KDPC) is 54.52% ± 2.84 Such differences may be attributed to chemical composition of raw material The result is lower than previous articles, however, it was nearly similar to the values found by Coppola et al (1995); El Koussy et al (1995) and Fernandez and Kosikowski (1986) who reported 46%, 47.82% and 49.5% respectively 3.3.3 Determination of cheese yield efficiency • Total weight of collected cheese (g): mcheese = 101.93 (g) • Mass of milk ingredient (g): mmilk = 1519.2 (g) • From equation 3.3: 101.93 100 = 6.71% 1519.20 When cows' or goats' milk, or a combination of both, was used in the manufacturing of cheese, the yield varied between 5% and 16% (Hayaloglu, 2017) The results revealed that utilizing the Kosikowski (1982) technique and the modified method used by Khartoum Dairy Products Company (KDPC) (Owni & Sana, 2009), fresh Mozzarella cheese yielded 13.2% and 11.65%, respectively In the KDPC technique, mozzarella cheese made from heated milk had a greater average production (13.2) than mozzarella cheese made from raw milk, which had an average yield of 11.65 Heat treatment of milk led in greater protein and mineral salt retention in cheese curd, according to Patel et al (1986) As a result, the total solids content of the cheese rose, %H = 30 as did the yield Furthermore, it was discovered that agitation during the manufacturing of Mozzarella cheese (Kosikowski, 1982 technique) improved whey drainage and reduced the loss of tiny cheese particles in the whey Therefore, our experiment had much low cheese yield in comparison This result can be inferred that fresh Mozzarella cheese made from various milk of varying chemical composition (fat, protein, total solids, ash, lactose content) has different cheese yield and method for cheesemaking is a significant factor 3.4 Conclusion Yield may signify productive success in practical terms in the dairy industry, and it's a useful tool for optimizing the process and the company's cost-benefit balance The yield of dairy products is affected by a number of factors, the most important of which are those connected to the technical quality of milk These are directly connected to the animals (genetics, nutrition, physiological, and health state) or the raw material processing (hygiene conditions, procedures employed, and so on) Yield varies primarily based on the processing method (stretching time), the raw material (industrial or natural yeast), and the features of the finished goods, especially for stretched-curd cheeses Therefore, cheese solid yield, total solids and cheese yield efficiency of Mozzarella need to be determined to find out factors that affect cheese processing As a result, dairy efficiency in mozzarella production is highly linked to processing parameters and milk characteristics Reference Barbano D.M., Yun J.J., Kindstedt P.S., Mozzarella cheese making by a stirred curd, no brine procedure, J Dairy Sci 77 (1994) 2687–2694 Blaschek K.M., Wendorff W.L., Rankin S.A., Survey of salty and sweet whey composition from various cheese plants in Wisconsin, J Dairy Sci 90 (2007) 2029–2034 Brandsma, R L., & Rizvi, S S H (2001) Manufacture of Mozzarella cheese from highly-concentrated skim milk microfiltration retentate depleted of whey proteins, International Journal of Food Science and Technology, 36(6), 611– 624 doi:10.1046/j.1365-2621.2001.00507.x Coppola, R., E Sorrention, L cinquanta, M Lorrizzo and L Grazia, 1995 Shelf life of mozzarella cheese samples packaged without liquid and stored at different temperatures Italian J Food Sci., 7: 351-359 Fernandez, A and F.V Kosikowski, 1986 Low moisture Mozzarella cheese from whole milk retentates of ultrafiltration J Dairy Sci., 69: 2011-2017 Hayaloglu, A A (2017) Cheese Varieties Ripened Under Brine In E Ltd (Ed.), Cheese: Chemistry, Physics and Microbiology Elsevier Ltd.: Elsevier Ltd Kosikowski, F.V., 1977 Cheese and Fermented Milk Foods 2nd Edn., Edwards Brothers Inc., Ann Arbor, MI., pp: 448 Lambert, Paula “Mozzarella Cheese” Sally's Place Media Holdings Retrieved April 1, 2008 31 Owni, O A O E., & Sana, E O (2009) Evaluation of Chemical Composition and Yield of Mozzarella Cheese Using Two Different Methods of Processing Pakistan Journal of Nutrition, 8, 684-687 Patel, G.C., S.H Vyas and K.G Upadhyay, 1986 Evaluation of mozzarella cheese made from buffalo milk using direct acidification technique Int J Dairy Sci., 39: 394-403 persianutab.com (2020) Citric acid in mozzarella cheese TS Lâm Xuân Thanh – Giáo trình cơng nghệ chế biến sữa sản phẩm từ sữa, p147, 2003 32 EXPERIMENT ICE CREAM PRODUCTION Abstract Ice cream is a dairy-based aerated treat that is frozen before serving It is a liquid and solid microcrystalline network It comprises air cells entrapped in a liquid phase, as well as other components such as proteins, fat globules, stabilizers, sugar, soluble and insoluble ions In this experiment, recipe with egg yolk (lecithin, an emulsifier source) was prepared to determine sensory quality and overrun of hard ice cream product The finish product was delicious, met almost all good quality However, the overrun value is 133.33% which is too low to commercial products 1.1 Introduction 4.1.1 Definition of ice cream Ice cream is a sweetened frozen meal that is commonly consumed as a snack or dessert It is produced from milk or cream and is flavored with a sweetener, either sugar or a substitute, and a spice, such as chocolate or vanilla, or with fruit, such as strawberries or cherries It can also be prepared by combining flavored cream base and liquid nitrogen In addition to stabilizers, food coloring is sometimes used To integrate air voids and prevent noticeable ice crystals from forming, the mixture is chilled below the freezing point of water and agitated The end result is a smooth, semi-solid foam that becomes solid at extremely low temperatures (below 2°C) As the temperature rises, it becomes more bendable Figure 4.1 Ice cream 4.1.2 Origin of ice cream Although there are various accounts concerning the history of frozen desserts, their origins are unknown According to some reports, ice cream-like dishes originally appeared in Persia around 550 BC, (Marks and Gil, 2010), while others believe that the Roman Emperor Nero used ice obtained from the Apennine Mountains to create the first sorbet blended with honey and wine Although sorbets are said to have originated in Persia, (Weir et al, 2010) some sources claim that ice cream started in the Mongol Empire and spread to China throughout its development (Clarke and Chris, 2004) In 1774, a guy named Phillip Lenzi stated in New York that he would be selling confections such as ice cream In 1812, Dolly Madison served it In 1776, the first ice 33 cream shop in America opened in New York City The term "iced cream" was derived from the phrase "iced tea." Nowadays, ice cream comes in a variety of flavors other than vanilla 4.1.3 Classification According to (Lâm Xuân Thanh, 2003), there are many different types of ice cream They differ in nutritional composition, color, taste, appearance People base on the main ingredients to classify ice cream into groups: • • • • Ice cream is made from milk Ice cream is made from milk and vegetable oil Ice cream made from fruit juice, with added milk Ice cream is made from water, sugar and jam On the market today, ice cream made from milk with added vegetable oil accounts for 80-90% of total ice cream production 1.2 Materials and methods 1.2.1 Materials 4.1.3.1 Milk Figure 4.2 VINAMILK UHT non-sugar milk Distributor: VINAMILK Vietnam Dairy Products Joint Stock Company Head office: 10 Tan Trao, Tan Phu Ward, District 7, Ho Chi Minh City, Vietnam Milk is used for one purpose, which is to add fat to ice cream Milk fat is used in the form of whole milk powder, raw milk, cream of milk, butter or anhydrous milk fat (AMF) Fat plays a very important role in ice cream because it creates a smooth texture, makes ice cream long to melt and stimulates taste 4.1.3.2 Sugar and instant coffee Sugar offers a pleasant taste, enhances thickness, and bulkiness, but excessive usage can change ice cream into a mushy structure above a solid content of roughly 42 percent Instant coffee aims at flavor formation 34 4.1.3.3 Whipping cream Anchor Figure 4.3 Whipping cream Anchor Distributor: FONTERRA BRANDS CO., LTD (VIETNAM) Head office: Bitexco Financial Building, No 02, Hai Trieu Street, Ben Nghe Ward, District 1, Ho Chi Minh City, Vietnam Cream with a high fat content is particularly effective at retaining air The whipped in air bubbles are stabilized by the fat globules in the cream Whipped cream does not stay steady for long; within a few hours, it will have crumbled visibly Fat has a positive impact on body, texture, palatability, taste intensity, emulsion formation, and melting point maintenance If the fat level exceeds a certain use concentration, the ice cream melts quicker, as well as the instability and aggregation of fat droplets Higher overflow causes collapse of air cells and, as a result, structural contraction Cream is richer than milk, has an ivory color, and a velvety feel When churning it up to produce ice cream, the fat makes the ice cream texture grow thicker and richer than when you use milk 4.1.3.4 Egg yolk Figure 4.4 Egg yolk Emulsifiers are added to ice cream during the production process to smoothen the texture and ensure even distribution of air cells The most frequent emulsifiers used in ice cream facilities are mono and di-glycerides Emulsifiers are employed in amounts of no more than 0.2 % by weight Polysorbate and sorbitan tristearate at concentrations of up to 0.1 % are currently considered safe in dairy products In this experiment, ice cream was manufactured with egg yolk as an emulsifier 35 It is quite important in dishes and aids in the mixing of different flavors for desirable qualities The inclusion of egg yolks raises the price of ice cream It adds a nice flavor to ice cream, but if the egg product has any bad flavor, it is immediately apparent in ice cream with egg The protein and lecithin complex in egg yolks is particularly desired in mixes with minimal total solids and produced with butter oil or butter • Advantages: ▪ Delicate characteristic flavor ▪ Texture and body improvement ▪ Viscosity increase ▪ Improved whipability • Disadvantage: Off flavor in egg yolk detectable in final product 1.2.2 Methods 1.2.2.1 Ice cream processing Figure 4.5 Flow chart of ice cream production Table 4.1 Recipe of coffee ice cream Ingredients Weight Egg yolk (egg) Sugar (g) 25 Unsweetened milk (mL) 156 36 Instant coffee (g) Whipping cream (mL) 94 1.2.2.2 Explanation of the process ❖ Preparation Firstly, ingredient includes: egg yolk (1 egg), whipping cream (94 mL), UHT milk (156 mL), sugar (25g), instant coffee (1 g) Egg yolk was stirred by hand beater Figure 4.6 Egg yolk was stirred by hand beater ❖ Mixing Stirring well until the mixture is completely dissolved ❖ Homogenization The word “homogenize” means "to make or render homogeneous" while homogeneous means "having the same composition, structure, or character throughout" (Dhankhar, 2014) From that, the purpose of homogenizing is to provide a non-separating form of a product by the application of high pressure, which can easily separate or ‘tear’ fat globules in cream emulsion ❖ Pasteurization A process in which packaged and non-packaged foods (such as milk and fruit juice) are treated with mild heat, usually to less than 100°C (212°F), to eliminate pathogens and extend shelf life The process is intended to destroy or deactivate organisms and enzymes that contribute to spoilage or risk of disease, including vegetative bacteria, but not bacterial spores (95°C for 10 minutes) This experiment was used this step at 85oC in 15 mins to cook egg yolk and eliminate microorganism in the mixture ❖ Mixing and freezing This step was conducted in an ice cream machine to mix vigorously the mixture in low temperature When the ice cream reaches the machine will signal and turn off the machine Take out the ice cream and put it in the fridge to freeze 37 Figure 4.7 Ice cream machine 1.2.2.3 Analysis methods ❖ Sensory evaluation According to TCVN 7402 : 2004 of Edible ices cream – Technical requirements: Table 4.2 Sensory parameters of edible ices cream Criteria Requirement Color Milky white color or typical color of additional ingredients Odor, taste Characteristic for each type of product, no strange smell or taste State Frozen, not melted ❖ Determination of overrun Overrun is the term for the percent of the expansion of ice cream achieved from the amount of air incorporated into the product during the freezing process The air included during the freezing process accounts for the majority of the increased volume The amount of air that should be integrated relies on the mix's composition and how it's processed, and it's regulated to ensure that the ice cream has the right body, texture, and palatability A white, fluffy ice cream will result from too much air, whereas a soggy, heavy ice cream would result from too little air Figure 4.8 Overrun affects ice cream product • Method of implementation: 38 After the ingredients are mixed and pasteurized, the mixture is measured for volume, recording data Then put the mixture in the freezer for a period of hours After completion, the product is frozen, take it out and measure it again Recording data The overrun is calculated by volume: Va − Vi ×100% Vi % Overrun = Where: Vi: The volume of ice cream mix before freezing process Va: The volume of ice cream after freezing process The general rule is that the mixtures with a high total solids content show a higher rate of air incorporation than those with a lower total solids content Typically, the overrun amount should be to times the total solids of the ice cream mixture 1.3 Result and discussion 4.1.4 Sensory evaluation Figure 4.9 Hard ice cream Table 4.3 Sensory evaluation of finished product Criteria Evaluation Color Milky white color, has a little ivory yellow Odor: desirable Odor, taste Taste: fatty, delicious No strange smell or taste State Frozen 39 4.1.5 Determination of overrun The volume before mixing of the cream is 300 mL After freezing, the finished product has a volume of 400ml From the above data overrun is calculated as following: 400 % Overrun = ×100% ≈ 133.33% 300 With the desired end product being a hard ice cream, the ingredients contribute to the firmness of the cream structure and maximum retention of cream for the maximum amount of time With an overrun rate of 133.33%, the level to form ice cream is not high This indicates that the quality of the resulting cream product has an unsatisfactory texture, remaining as a milky liquid There are many reasons to explain such as low freezing time, ice cream machine equipment running at low capacity, etc 1.4 Conclusion In order to achieve a standard for ice cream, high-quality ice cream in each category In a few minutes the cream should easily whip up to form a firm and homogeneous product, containing 50 to 60% (v/v) of air, corresponding to 100 to 150% overrun (Walstra, Wouters, & Geurts, 2006) Therefore, the overrun rate of our result needs to be at least 150% for the manufacturer to make the finished product with the needs of the consumer and gain benefits Reference Marks, Gil (17 November 2010) Encyclopedia of Jewish Food Weir, Caroline, Weir, Robin (2010) Ice Creams, Sorbets & Gelati:The Definitive Guide p Clarke, Chris (2004) Science of Ice Cream Royal Society of chemistry p Dhankhar, P (2014) Homogenization fundamentals IOSR Journal of Engineering, 4(5), TS Lâm Xn Thanh – Giáo trình cơng nghệ chế biến sữa sản phẩm từ sữa, p.111, 2003 P Walstra, Pieter Walstra, Jan T M Wouters, Tom J GeurtsDairy – Science and Technology, 2005, 200-201 Syed QA, Anwar S, Shukat R, et al Effects of different ingredients on texture of ice cream J Nutr Health Food Eng 2018;8(6):422-435 40 41 42 ... Springer Science & Business Media p 191 TS Lâm Xn Thanh – Giáo trình cơng nghệ chế biến sữa sản phẩm từ sữa, p137, 2003 Choi, Y J., Jin, H Y., Yang, H S., Lee, S C., & Huh, C K (2016) Quality... (2020) Citric acid in mozzarella cheese TS Lâm Xuân Thanh – Giáo trình cơng nghệ chế biến sữa sản phẩm từ sữa, p147, 2003 32 EXPERIMENT ICE CREAM PRODUCTION Abstract Ice cream is a dairy-based aerated