TEA, COFFEE, COCOA AND CHOCOLATE PROCESSINGS

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TEA, COFFEE, COCOA AND CHOCOLATE PROCESSINGS

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MINISTRY OF EDUCATION AND TRAINING NONG LAM UNIVERSITY – HO CHI MINH CITY FACULTY CHEMICAL ENGINEERING AND FOOD TECHNOLOGY  TEA, COFFEE, COCOA AND CHOCOLATE PROCESSINGS GROUP 3 MEMBERS January 20.

MINISTRY OF EDUCATION AND TRAINING NONG LAM UNIVERSITY – HO CHI MINH CITY FACULTY: CHEMICAL ENGINEERING AND FOOD TECHNOLOGY  TEA, COFFEE, COCOA AND CHOCOLATE PROCESSINGS GROUP - MEMBERS Võ Nguyễn Thục Trinh Bùi Thiên Lộc Nguyễn Thu Hiền Đỗ Hồng Ánh Mai Đỗ Thị Yến Ly Đỗ Thành Trung January 2022 - Ho Chi Minh city TABLE OF CONTENT TABLE OF CONTENT INTRODUCTION PART 1: ANTIOXIDANTS IN TEA, COFFEE AND COCOA AND THEIR CHANGES DURING PROCESSING I Antioxidants in tea, coffee, and cocoa Tea Coffee 10 Cocoa 17 II Changes of antioxidants in tea, coffee, cocoa during processing 19 Tea 19 Coffee 23 Cocoa 27 PART 2: FAT IN COCOA – THEIR CONTRIBUTION TO CHOCOLATE PROCESSING 32 I Fat in cocoa 32 II Contribution of cocoa butter to chocolate processing 34 III Some cocoa butter alternatives are used in processing 35 CONCLUSION 39 REFERENCES 41 INTRODUCTION Antioxidants are substances that can prevent or slow damage to cells caused by free radicals, unstable molecules that the body produces as a reaction to environmental and other pressures Antioxidants counter the development of free radicals within the body They carry out a process called free radical scavenging, which means they come through the body tissues and consume free radicals This means that rejuvenating effects of correctly roasted coffee doesn’t just come from the caffeine that wakes you up when you’re sleepy By drinking healthy coffee, tea, or cocoa you are restoring your cells and protecting them from the damaging (yet hard-to-avoid) effects of daily life Tea remains the most consumed drink in the world after water, well ahead of coffee, beer, wine, and carbonated soft drinks An accumulated number of population studies suggests that consumption of green and black tea beverages may bring positive health effects High levels of flavonoids in tea can protect cells and tissues from oxidative damage by scavenging oxygen-free radicals Chemically, the flavonoids found in green and black tea are very effective radical scavengers The tea flavonoids may therefore be active as antioxidants in the digestive tract or in other tissues after uptake A substantial number of human intervention studies with green and black tea demonstrates a significant increase in plasma antioxidant capacity in humans approximately 1h after consumption of moderate amounts of tea (1-6 cups/d) There are initial indications that the enhanced blood antioxidant potential leads to reduced oxidative damage to macromolecules such as DNA and lipids Tea flavonoids are potent antioxidants that are absorbed from the gut after consumption Tea consumption consistently leads to a significant increase in the antioxidant capacity of the blood Beneficial effects of increased antioxidant capacity in the body may be the reduction of oxidative damage to important biomolecules The seeds of the tropical tree Theobroma cacao L are used to make cocoa beans Because of the high concentration of bioactive chemicals, such as catechins, epicatechins, and procyanidins, which are antioxidants Not only in the food industry, but also in the pharmaceutical and cosmetic industries, they are in high demand Cocoa beans have a substantially higher antioxidant content per serving than black tea, green tea, or red wine, according to Lee et al (2003) Interest in these cocoa components has risen in recent years as a result of their potential health benefits To prevent or delay cellular damage, cocoa antioxidants can either quench free radicals or chelate transition metal ions, limiting their ability to form reactive oxygen species They also have a number of physiological characteristics that help them avoid diseases Catechins (flavan-3-ols) (37 percent), anthocyanins (4 percent), and proanthocyanidins (58 percent) are the three primary categories of antioxidants (polyphenols) found in cocoa (Theobroma cacao L.) and cocoa products (Wollgast & Anklam, 2000) Coffee is very rich in antioxidants — including the hidroxycinnamic acid family (caffeic, chlorogenic, coumaric, ferulic, and sinapic acids) as well as other biologically active chemicals having antioxidant potential, such as caffeine, nicotinic acid, trigonelline, cafestol, and kahweol During processing, the antioxidant profile of coffee changes due to the degradation of native antioxidants and the formation of new ones Thus, the antioxidant capacity of coffee is related to the presence of both natural constituents and compounds formed during processing (roasting) (Vignoli et al., 2011) Low water activity and high temperatures favor the development of Maillard reactions (MR), and the formation of MR products between proteins and carbohydrates (Borrelli et al., 2004) Cocoa nibs contain about 55% butter, which accounts for about 30% of the finished chocolate Saturated fatty acids are found at the 1,3-position and oleic acid is found at the 2-position in cocoa butter triglycerides Talbot (1999) found that oleic (34%), stearic (36%), and palmitic acid (27%) fatty acids are present, along with polar lipids, sterols, and tocopherols, depending on growing conditions and provenance Chocolate melts at temperatures ranging from 23 to 37oC due to its basic glyceride makeup Form V (β2) of the lipid crystal is the most desirable in chocolate manufacture and dominates in well-tempered chocolate Whole cocoa beans are used to make cocoa butter The beans are fermented before being dried for use in chocolate production To make cocoa nibs, the beans are roasted and separated from their hulls The cocoa nibs are ground to make cocoa mass, which becomes liquid at temperatures above the melting point of cocoa butter and is referred to as cocoa liquor or chocolate liquor To separate the cocoa butter from the non-fat cocoa solids, the chocolate liquor is squeezed Deodorization of cocoa butter is occasionally done to remove strong or unpleasant flavors Cocoa butter is used in chocolate to keep sugar particles suspended and lubricated Although cocoa butter reduces the viscosity of melted chocolate, it has little flavor of its own and hence does not contribute significantly to the flavor of chocolate Cocoa butter has a variety of distinct qualities that make it a highly sought-after fat For technological and economic reasons, cocoa butter alternatives such as cocoa butter equivalents (CBEs), cocoa butter substitutes (CBSs), and cocoa butter replacers (CBRs) can partially replace cocoa butter in chocolate manufacture PART 1: ANTIOXIDANTS IN TEA, COFFEE AND COCOA AND THEIR CHANGES DURING PROCESSING I Antioxidants in tea, coffee, and cocoa Tea Tea, made from the leaves of the Camellia sinensis plant, is one of the world's most popular beverages It has been consumed on a daily basis Nonfermented green tea, semifermented oolong tea, and fully fermented black tea are the three varieties Fresh tea leaves are steamed or pan-fried to prepare green tea, which inactivates enzymes and inhibits the oxidation of tea polyphenols These chemical compounds act as antioxidants, which control the damaging effects of free radicals in the body By stealing electrons from DNA, free radicals can cause mutations that raise LDL cholesterol or change cell membrane traffic, both of which are damaging to human health Though green tea is thought to be higher in polyphenols than black or oolong (red) teas, studies demonstrate that, with the exception of decaffeinated tea, all plain teas have similar amounts of these compounds, but in varying quantities Green tea has the most epigallocatechin-3 gallate, while black tea contains the most theaflavins; studies have shown that both have health benefits Herbal teas contain polyphenols as well, however the amount varies greatly depending on the plant Tea consumption has been linked to a lower risk of chronic illnesses including cardiovascular disease and cancer in epidemiological studies There are also laboratory research that show tea intake has health benefits The polyphenol chemicals in tea are thought to be responsible for these benefits The most abundant polyphenols in green tea are catechins Theaflavins and thearubigins, which are generated by the oxidation and polymerization of catechins during fermentation, are the major colours in black tea Despite accounting for up to 60% of the dry weight of black tea extract, the chemistry of thearubigins remains unknown • Flavonoids Polyphenols, also known as flavonoids, are most likely one of the factors that contribute to tea's health benefits Flavonoids are plant secondary metabolites that may be separated into six groups depending on the structure and conformation of the heterocyclic oxygen ring (C ring) of the basic molecule: flavones, flavanones, isoflavones, flavanols, flavanols, and anthocyanins (Fig 1) fAvanols and favonols are the two primary types of favonoids found in tea Different quantities of tea samples were extracted with varying solvents for varied durations of time at different temperatures, resulting in different extraction efficiencies After acid hydrolysis, the content of flavonols in green tea leaves ranged from 0.83 to 1.59, 1.79 to 4.05, and 1.56 to 3.31 g kg-1, while the content of flavonols in black tea leaves ranged from 0.24 to 0.52, 1.04 to 3.03, and 1.72 to 2.31 g kg-1 for myricetin, quercetin, and kaempferol, respectively Figure Basic structure of flavonoids • Catechins Many different types of polyphenols and catechins may be found in tea Catechins are the most abundant Catechins are molecules with a C6-C3-C6 carbon structure and two aromatic rings, A and B, that belong to the flavonoids group Figure The basic structural formulas of tea catechins Seven different types of catechins are contained in the tea plant, as well as traces of additional catechin derivatives There are two types of catechins: free catechins and esterified or galloyl catechins Catechins may be found in all areas of the tea plant; about 15–30 percent can be detected in the tea shoots, and the second and third leaves have high catechin contents Catechin content is highest in August when the light of the sun is the strongest The synthesis of free catechins declines over time, whereas galloyl catechins rise Catechins are abundant in the bud and higher leaves Details that, Zaprometov investigated the synthesis of tea catechins C was found in the four primary catechins when CO2 was absorbed with the tea leaves for two hours Figure The structural formulas of catechins • Polyphenolic catechins in green tea The polyphenolic catechins which is an antioxidant in green tea (Camellia sinensis) They are quite abundant Green tea consumption may reduce the risk of cardiovascular disease (CVD) and nonalcoholic fatty liver disease (NAFLD) (NAFLD) In green tea, catechins contain antioxidant and anti-inflammatory properties, which help to reduce oxidative stress reactions linked to CVD Considering the low bioavailability of dietary catechins, the antioxidant effects of green tea catechins are expected to be mediated by indirect pathways Green tea is good anti-inflammatory properties, which are mediated in part by its antioxidant properties, inhibit nuclear factor kappa B (NFB) activation, and NFB-dependent pro-inflammatory responses Figure Chemical structures of the predominant catechins found in green tea Green tea catechins include both catechin and epicatechin forms Gallated catechins include epigallocatechin gallate (EGCG), gallocatechin gallate (GCG), epicatechin gallate (ECG), and catechin gallate (CG) The major non-gallated catechins are epicatechin (EC), catechin (C), epigallocatechin (EGC), and gallocatechin (GC) • Theaflavins Theaflavins, which give black tea its vivid red color, have a benzotropolone skeleton that is generated by the co-oxidation of two catechins, one with a victrihydroxyphenyl moiety and the other with an orthodihydroxyphenyl structure The qualities of black tea, including as color, 'mouthfeel,' and the degree of tea cream development, are all influenced by theaflavins Their structures have been thoroughly investigated Theaflavin, theaflavin 3-gallate, theaflavin 30 -gallate, and theaflavin 3,30-digallate (Figure 5) are four primary theaflavins in black tea that are formed by oxidative coupling between EC and EGC, EC and EGCG, ECG and EGC, ECG, and EGCG, respectively Figure Structures of major theaflavins in tea The roasting of the cocoa beans at 150°C led to a considerable decrease in the total phenolic content The application of humid air for the roasting of cocoa beans effectively reduced the losses of phenolic compounds This phenomenon can be explained by the formation of the protective layer of water (present in humid air) on the surface of samples that reduced the access of oxygen into the seeds The greatest decrease in total phenolic content was observed when cocoa beans were roasted at 150°C and the lowest RH (RH=0.3%) This finding is in accordance with the fact that phenolic compounds are easily degraded and/or become bound to polymer structures at high temperatures in the presence of oxygen Roasting under mentioned above conditions resulted in total phenolics losses ranging from 2.4 to 15.2% Roasting: superheated steam roasting and convectional roasting The total phenol content of cocoa beans during convection roasting and superheated steam roasting at different temperatures (150℃, 200℃ and 250℃) for 10 − 50 The highest loss may occur due to high oxidation during the convectional method because of the presence of oxygen during the roasting process Whereas the lowest loss may due to the absence of oxygen when roasted by the superheated steam method Effect of oxidative enzymes might be another factor to reduce antioxidant properties in convection method roasting with superheated steam caused the lower loss of total phenolics than conventional roasting of cocoa beans The highest antioxidants were observed in roasted during superheated steam at 150℃ for 10 and lowest at 250℃ for 50 during convectional roasting Superheated steam roasting could be more appropriate and flexible than the convectional method because the higher total phenol and antioxidant properties are preserved using the same temperature and time This method takes short time to achieve the optimum roasting characteristics whereas the conventional method takes too long that may contribute the loss of antioxidant properties of the products 29 Figure 15 Changes in the total phenol content (TPC) of cocoa beans during convection and superheated steam roasting at different temperatures (150oC, 200oC, and 250oC) for 10-50 30 Roasting: vacuum roasting During vacuum roasting of cocoa powder (45.6 and 60.8 cmHg) at temperatures ranging from 100 to 120°C the limited content of oxygen in the roasting space slowed down the oxidative degradation of catechins The low oxygen in the roasting space caused low oxidation of catechin which made degradation of catechin slow However, there was also a possibility of the degradation of procyanidin or proanthocyanidin (precursors), as both were the constructors of catechin compound which made the synthesis rate always higher than the degradation rate As the roasting space was vacuum, the roasting process and many of its components occurred faster On the other hand, in non-vacuum roasting, high concentration of oxygen could possibly make catechin oxidation fast Vacuum roasting of 60.8 cmHg at 100° C for 25 minutes produced the highest percentage of catechin concentration of cocoa powder The increased temperature to beyond 100° C for the length of more than 25 minutes would reduce the catechin concentration of cocoa powder The increased catechin in cocoa powder during vacuum roasting occurred due to the degradation of procyanidin (either in form of dimer, trimer or tetramer) The effect of roasting on the antioxidant properties of cocoa beans → Depends on the balance between the thermal degradation of naturally occurring phenolic compounds and the formation of new antioxidants, such as polymeric pigments and Maillard reaction products The phenolic content and antioxidant activity of roasted cocoa beans can be increased by thermal processing at lower temperatures with humid air Alkalization The pH change caused by the addition of alkaline agents influenced the total polyphenols content in the produced cocoa powder It has turned out that natural cocoa powders (pH 5.39–5.76) showed higher levels of antioxidative capability and total content of polyphenols Alkalization causes high losses of polyphenols (over 60% loss of total polyphenols content) and changes their composition The greatest losses are observed for epicatechin and catechin (up to ca 98% and 80%, respectively) Further degrees of alkalization lead to a noticeable decrease in polyphenol content These changes may be ascribed to the oxidation and polymerization of polyphenols under alkaline conditions 31 PART 2: FAT IN COCOA – THEIR CONTRIBUTION TO CHOCOLATE PROCESSING I Fat in cocoa The fat in cocoa (cocoa butter) is neutral in flavor Of the caloric content in typical whole beans, about 50 – 60 percent comes from cocoa butter Cocoa butter is a light-yellow fat that is characterized by the smell and flavor of chocolate and is one important compound used in chocolate production which helps the dispersion of the acid composition of cocoa butter consists of a high proportion of saturated fat mainly consists of palmitic acid and stearic acid CB also contains trace amounts of caffeine and theobromine, which are phenolic compounds Thus, natural antioxidant contents that recognized to have many therapeutic properties, are important compounds of Cacao Butter The molecular structure of cocoa butter provides insight into both the complexity of the fat and its physical properties, as well as aiding in the explanation of some of the reasoning behind some cocoa quality assessments in general Chemically, cocoa butter is not a single type of fat, but rather a group of fats known as triglycerides These vary greatly in composition, but all have a similar underlying structure: three separate chains of fatty acids, each attached (or entered) to one of the three carbon atoms of a former glycerol molecule The basic structure of a triglyceride is depicted in Figure 16 Figure 16 Triglyceride structure 32 Fatty acid and Triglyceride It is a solid fat at ambient temperature due to the fatty and composition that are palmitic acid (27%), stearic acid (36%), oleic acid (34%) and the position of fatty acid in triglyceride composition They are in majority symmetric triglycerides with oleic acid at the position that are palmitic-oleic-palmitic, palmitic- oleic-stearic, stearic-oleicstearic Its fatty acids and triglycerides compositions confer high melting point, solid fat content and give desirable texture to Cacao Butter when it is used in chocolate manufacturing Table Cocoa butter fatty acids composition (%) according to some countries (Lipp, Anklam, 1998) Table Cocoa butter triglycerides composition (%) according to some countries (Podlaha et al, 1984) P: Palmitic acid, O: Oleic acid, S: Stearic acid, A: Arachidic acid Phytosterols The phytosterols are bioactive compounds that are in majority of beta sitosterol, campesterol, stigmasterol, brassicasterol, cholesterol contained in cacao butter Table Phytosterol composition of Cocoa butter ((Staphylakis, Gegiou; 1985) 33 Tocopherol One of the bioactive compounds is tocopherol It is an entity of vitamin E recognized like a strong and natural antioxidant detected in the fat of cacao It was found to be dominated by the β-tocopherol, followed by γ-tocopherol, while the amount of αtocopherol was found to be insignificant Physico-Chemical Properties Cocoa butter is a multi-dimensional and multifunctional butter because of its high amounts of glycerol-linked saturated fatty acids forming triglycerides whose oleic acid is attached in position Cocoa butter is solid at room temperature (25oC) and begins to melt from body temperature (33-34oC) The indexes of saponification, iodine, peroxide, and acid influence cacao butter chemical properties Table 10 Physico-chemical properties of Cocoa butter (Jahurul et al., 2013) II Contribution of cocoa butter to chocolate processing Cocoa butter is used in chocolate to suspend and lubricate sugar particles Cocoa butter reduces the viscosity of melted chocolate, but it has little flavor of its own and hence does not contribute considerably to chocolate flavor Cocoa butter has a number of distinguishing characteristics that make it a very desirable fat: At room temperature, cocoa butter hardens to a brittle consistency If cocoa butter was not brittle, chocolate would not have its characteristic snap When cocoa butter sets, it contracts dramatically The contraction of coca butter as it crystallizes makes it possible for the confectioner to release chocolate easily from molds once it is set Cocoa butter is used to improve the texture of the chocolate and gives it that melt-inyour-mouth characteristic To get the desired mouthfeel, manufacturers utilize varied amounts of cocoa butter The taste of cocoa butter varies depending on its origin Manufacturers will have to consider the cocoa butter's flavor 34 In industrial chocolate manufacturing, crystallization of cocoa butter (alone or in chocolate) contains two steps: pre-crystallization by tempering to create seeds and secondary crystallization by cooling to allow the seeds to grow out The purpose of tempering chocolate is to pre-crystallize the cocoa butter in it, which is important to make your chocolate ready for processing During tempering, the cocoa butter in the chocolate takes on a stable crystalline form This guarantees a perfect finished product with a satin gloss and a hard snap It also makes the chocolate contract during cooling, which makes it easier to unmold If chocolate is simply melted (between 40 and 45 °C) and then left to cool down to a suitable working temperature, the finished product will not be glossy If you make the small effort of bringing your chocolate to the right working temperature properly, you are guaranteed to get the desired end result And that’s what we mean by tempering: bringing chocolate up to the right working temperature while making sure that the crystalline structure of the cocoa butter in it is stable the three key principles for proper tempering are time, temperature, and movement One of the typical properties of cocoa butter is the occurrence of substantial quantities of 2-oleyl glycerides of palmitic and stearic acid (POP, POS, SOS) These triglycerides are mainly responsible for providing the valuable crystallization and melting characteristics so essential in providing sharp melting at body temperature in chocolate confectionery This particular melting behavior provides a cooling effect in the mouth, the typical ‘mouth feeling’ while eating a high-quality chocolate Thus, the substitution of cocoa butter is crucial in several respects: the melting behavior has to be very similar to cocoa butter in order to achieve the same ‘mouth feeling’ and, if cocoa butter is only to be substituted in parts, the addition of the fat must not alter severely the crystallization and the melting behavior of cocoa butter III Some cocoa butter alternatives are used in processing There were, and are, strong efforts to replace cocoa butter in part for chocolate production for technological and economic reasons Such cocoa butter alternatives are the so-called cocoa butter equivalents (CBEs), cocoa butter substitutes (CBSs) and cocoa butter replacers (CBRs) These are mostly mixtures of various vegetable fats (often modified) and can consist of palm and palm kernel oil, illipé fat, shea butter, sal fat and kokum butter In addition, a large variety of other vegetable oils can be used Cocoa butter equivalent (CBEs) Cocoa butter equivalent (CBEs): non-lauric (not containing lauric acid) plant fats, which are similar in their physical and chemical properties to cocoa butter and mixable with it in every amount without altering the properties of cocoa butter • Cocoa butter extender (CBEX): subgroup of CBEs not mixable in every ratio with cocoa butter • Cocoa butter improvers (CBIs): similar to CBEs, but with higher content in solid triglycerides; used for improving soft cocoa butters The compositions of the most common cocoa butter equivalents (CBEs) are described in separate sections Palm oil, palm mid-fractions, and related products, illipe (Shorea stenoptera) fat, shea (Butyrospermum pa&ii) butter, sal (Shorea robusta) fat, 35 kokum (Garcinia indica) butter, and some commercially available mixtures blended from various, sometimes processed, vegetable fats are among them Palm oil, fractions and related products (Elaeis guineensis) Palm oil can be divided by fractionated crystallisation into a fraction of palm olein and palm stearin using different processes These fractions may then be used for further processing such as interesterification Illipé (Shea stenoptera) There is some confusion in the literature about the correct labelling of illipt fat and sal fat, respectively Illipk is also called Borneo tallow, engkabang or tenkgawang tallow This fat is obtained from the seed kernels of a number of trees that grow in Borneo, Java, Malaysia, the Philippines, and other localities of this area However, the most important species from which the fat is obtained is Shorea stenoptera Shea butter (Butyrospermum purkii) Shea butter is often also called Karite butter, Galam butter and by other native names It is obtained from the seeds of a tree mainly found in West Africa As the fruits can be harvested only after 15 years, farming is not economically viable Sal fat (Shea robusta) Sal fat is also called Borneo tallow or tenkgawang tallow This fat is obtained from the seed kernels of a number of trees that grow in Borneo, Java, Malaya, Philippines and other localities of this area However, there is some confusion in the literature between Shorea robusta, Shorea stenoptera and Madhuca longifolia They are all referred to as borneo tallow, sometimes even illipe, depending on the date of publication Kokum fat The formulations in Table 11 were used to make both milk and dark chocolate products CB was substituted at various levels, such as 5, 10, 15, and 25% fat for milk chocolate, yielding 1.6, 3.26, 4.9, and 8.2 percent by weight of the product, respectively, and 10, 15.8, and 20% fat for dark chocolate, yielding 3.16, 5.0, and 6.32 percent by weight of the product, respectively All the ingredients were mixed with about 50% of added CB and passed through a three-roll refiner (Pascal, England), three times, keeping the distance between the rollers and number of passes constant for all the batches The mass was then conched by adding the remaining CB and lecithin for h at 50–55oC The mass after conching was taken for viscosity measurement The mass was then tempered by manually cooling to about 27oC with stirring followed by reheating to 30–31oC and then moulding The samples were kept refrigerated for further analysis 36 Table 11 Formulations of chocolate with added kokum fat The addition of kokum fat to chocolate changes the texture Both dark and milk chocolate have a similar firmness The influence was determined by measuring the temperature at 30 degrees Celsius kokum fat incorporation Figure 16 shows that both black and milk chocolate are equally hard as the amount of kokum in the samples increased, so did the number of samples Chocolate's fat content increased, resulting in a stronger impact Milk chocolate has a strong flavor These findings suggest that kokum fat, even in modest quantities, boosts the immune system of chocolate's hardness, which allows it to be utilized in hotter environments and climates Figure 17 Effect of kokum fat addition on the texture of dark and milk chocolate measured at 30oC 37 These findings show that kokum fat has a lot of potential as a cocoa butter improver The fat, such as illipe or shea fats, might be used up to 5% by weight of the product, which is the allowed limit in several European countries, to strengthen the hardness of CB and chocolate so that it can be stored at high temperatures, such as in summer or tropical areas Cocoa butter replacers (CBRs) Cocoa butter replacer (CBR): non-lauric fats with a distribution of fatty acid similar to cocoa butter, but a completely different structure of the triglycerides; only in small ratios compatible to cocoa butter The fatty acid composition of some non-identified commercially available cocoa butter replacers is summarized in Table 12 with the corresponding triglyceride composition in Table 13 Table 12 Fatty acid composition (area %) of some non-identified, commercially available cocoa butter replacers (Nikolova-Damyanova and Amidzhir, 1992) Table 13 Triglyceride composition (area%) of some non-identified, commercially available cocoa butter replacers (NikolovaDamyanova and Amidahir, 1992) 38 Cocoa butter substitutes (CBSs) The fatty acid composition of a cocoa butter substitute made by selective hydrogenation and fractionation of palm olein is described in Leong and Lye (1992) The procedure yielded a stearin fat fraction suitable for commercial coating fat However, it was not possible to remove the waxy tail from the product completely The fatty acid composition of clearly identified cocoa butter substitutes is given in Pongracz (1982) and Paulicka (1976) As a lauric CBS, the fatty acid composition is dominated by the content of lauric acid (approx 50%) and myristic acid (approx 20%) The fatty acid composition of seven cocoa butter substitutes made from different vegetable fats is given in Table 14 Table 14 Fatty acid composition (wt%) of seven commercially available CJSs made from different vegetable oils and fats (Paulicka, 1976) CBS from sal fat (Shorea robusta), Palm kernel oil, and other oils and fats Sal fat can also be used for the production of a cocoa butter substitute Palm kernel oil is obtained from the kernels of the palm, Elaeis guineensis It is similar to coconut fat but contains more oleic acid Besides the fats described above, the use of a wide variety of plant fats is proposed in the literature Those fats are proposed as CBAs either directly or after appropriate fractionation or interesterification Due to numerous references no attempt was made to state explicitly the composition of fatty acids, triglycerides or the unsaponifiables for each fat individually CONCLUSION Green tea is made by steaming or pan-frying fresh tea leaves, which inactivates enzymes and limits the oxidation of tea polyphenols These chemical molecules function as antioxidants, limiting the harmful effects of free radicals in the body Polyphenols, also known as flavonoids, are most likely one of the reasons influencing tea's health benefits Though green tea is supposed to be richer in polyphenols than black or oolong (red) teas, studies show that, with the exception of decaffeinated tea, all plain teas have equal levels of these compounds in variable ratios Green tea has the most epigallocatechin-3 gallate, while black tea contains the most theaflavins both have been found to offer health benefits in studies 39 Individual catechins, theaflavins, and flavonols alter with each processing phase of green and black tea leaves Individual flavonol concentrations vary throughout leaf processing based on aglycone type and glycosylated form The roasting process, in particular, enhanced catechin concentration in green tea, especially EGCG and ECG, whereas catechins were dramatically decreased in black tea owing to oxidation and conversion to theaflavins after the fermentation stage Drying multi-steps were also revealed to be a component that impacts the growth of flavonoids in tea processing Coffee also includes a variety of useful chemical compounds, including antioxidants, fiber, and melanoidins Coffee contains a lot of antioxidants from the hidroxycinnamic acid family (caffeic, chlorogenic, coumaric, ferulic, and sinapic acids), as well as other physiologically active compounds with antioxidant properties as caffeine, nicotinic acid, trigonelline, cafestol, and kahweol The concentration of natural antioxidants was significantly reduced as a consequence of the thermal treatments, the overall antioxidant properties of the food products were maintained or even enhanced by the development of MRPs The seeds of the tropical tree Theobroma cacao L are used to make cocoa beans Because of the high concentration of bioactive substances, such as antioxidants catechins, epicatechins, and procyanidins Not only are they in great demand in the food industry, but they may also quench free radicals or chelate transition metal ions, decreasing their potential to form reactive oxygen species and thereby preventing or delaying cellular damage They also have a number of physiological characteristics that protect them from ailments including coronary heart disease, cancer, and neurological problems Fermentation, drying, roasting, and alkalization are some of the most significant stages in the processing of cocoa beans since they lead to the development of a variety of beneficial properties in chocolate However, these beneficial changes may be followed by reactions that drastically lower the amount of polyphenolic compounds These unfavorable impacts might be mitigated by standardizing agricultural practices at the start of the supply chain and enhancing the production process at critical stages of cocoa bean pre-treatment Cocoa butter is the only continuous fat phase in chocolate and is therefore responsible for the dispersion of the other constituents Efforts have been made to find an alternative (such as CBSs, CBEs, CBRs and other oils and fats) to cocoa butter and to replace parts of the cocoa butter in chocolate, for economic and technological reasons The major methods for modification of the fats are fractionated crystallisation and interesterification of the fat as well as selectively breeding the plants 40 REFERENCES Komes, D., & Bušić, A (2014) Chapter - Antioxidants in Coffee In V Preedy (Ed.), Processing and Impact on Antioxidants in Beverages (pp 25-32) Academic Press https://doi.org/https://doi.org/10.1016/B978-0-12-4047389.00003-9 Narita, Y., & Inouye, K (2015) Chapter 21 - Chlorogenic Acids from Coffee In V R Preedy (Ed.), Coffee in Health and Disease Prevention (pp 189-199) Academic Press https://doi.org/https://doi.org/10.1016/B978-0-12-4095175.00021-8 Sridevi, V., Giridhar, P., & Gokare, R (2011) Evaluation of roasting and brewing effect on antinutritional diterpenes-cafestol and kahweol in coffee Global J Med Res, 11, 1-7 Kim, Y., Goodner, K L., Park, J.-D., Choi, J., & Talcott, S T (2011) Changes in antioxidant phytochemicals and volatile composition of Camellia sinensis by oxidation during tea fermentation Food chemistry, 129(4), 13311342 Lee, M.-K., Kim, H.-W., Lee, S.-H., Kim, Y J., Asamenew, G., Choi, J., Lee, J.-W., Jung, H.-A., Yoo, S M., & Kim, J.-B (2019) Characterization of catechins, theaflavins, and flavonols by leaf processing step in green and black teas (Camellia sinensis) using UPLC-DAD-QToF/MS European Food Research and Technology, 245(5), 997-1010 Manir, M M., Kim, J K., Lee, B.-G., & Moon, S.-S (2012) Tea catechins and flavonoids from the leaves of Camellia sinensis inhibit yeast alcohol dehydrogenase Bioorganic & medicinal chemistry, 20(7), 2376-2381 Alimuddin, S (2018) Changes in phenol level and antioxidant activity of cocoa beans during fermentation and roasting Journal of Food Research, 7(4), 23-29 Oracz, J., & Nebesny, E (2016) Antioxidant properties of cocoa beans (Theobroma cacao L.): influence of cultivar and roasting conditions International Journal of Food Properties, 19(6), 1242-1258 Urbańska, B., Derewiaka, D., Lenart, A., & Kowalska, J (2019) Changes in the composition and content of polyphenols in chocolate resulting from pretreatment method of cocoa beans and technological process European Food Research and Technology, 245(10), 2101-2112 10 Yuwono, S., Estiasih, T., & Santoso, U (2012) The Change of Catechin Antioxidant during Vacuum Roasting of Cocoa Powder Nutrition & Food Sciences 11 Zzaman, W., Bhat, R., Abedin, M Z., & Yang, T A (2013) Comparison between superheated steam and convectional roasting on changes in the phenolic compound and antioxidant activity of cocoa beans Food Science and Technology Research, 19(6), 949-956 12 MN Zaprometov, AL Kursanov Figiologia Rastenii 5:51–61, 1958 K Iwasa Biosynthesis of catechins in tea plant Bulletin of the National Res Inst of Tea 13:101–126, 1977 M Kito, H Kokura, J Izaki, K Sasaoka Theanine, a precursor 41 of the phloroglucinol nucleus of catechins in tea plants Phytochem 7:599–603, 1968 13 Leung, L K., Su, Y., Chen, R., Zhang, Z., Huang, Y., & Chen, Z.-Y (2001) Theaflavins in black tea and catechins in green tea are equally effective antioxidants The Journal of nutrition, 131(9), 2248-2251 14 Sang, S (2016) Tea: Chemistry and Processing In B Caballero, P M Finglas, & F Toldrá (Eds.), Encyclopedia of Food and Health (pp 268-272) Oxford: Academic Press 15 Wang, H., Provan, G J., & Helliwell, K (2000) Tea flavonoids: their functions, utilisation and analysis Trends in Food Science & Technology, 11(4), 152-160 doi:https://doi.org/10.1016/S0924-2244(00)00061-3 16 Bruno, R S., Bomser, J A., & Ferruzzi, M G (2014) Chapter - Antioxidant Capacity of Green Tea (Camellia sinensis) In V Preedy (Ed.), Processing and Impact on Antioxidants in Beverages (pp 33-39) San Diego: Academic Press 17 Svilaas A., Sakhi A.K., Andersen L.F., Svilaas T.E.C., Ström E.-C., Jacobs D.R (2004): Intakes of antioxidants in coffee, wine and vegetables are correlated with plasma carotenoids in humans Journal of Nutrition, 134: 562– 567 18 Castillo M.D., Ames J.M., Gordon M.H (2002): Effect of roasting on the antioxidant activity of coffee brews Journal of Agricultural and Food Chemistry, 50: 3698–3703 19 Richelle M., Tavazzi I., Offord E (2001): Comparison of the antioxidant activity of commonly consumed polyphenolic beverages (coffee, cocoa, and tea) prepared per cup serving Journal of Agricultural and Food Chemistry, 49: 3438– 3442 20 Hernandez J.A., Heyd B., Irles C., Valdovinos B., Trystram G (2007): Analysis of the heat and mass transfer during coffee batch roasting Journal of Food Engineering, 78: 1141–114 21 Stadler R.H., Varga N., Hau J., Vera F.A., Welti D.H (2002a): Alkylpyridiniums Formation in model systems via thermal degradation of trigonelline Journal of Agricultural and Food Chemistry, 50: 1192–1199 Stadler R.H., Varga N., Milo C., Schilter B.F., Vera F.A., Welti D.H (2002b): Alkylpyridiniums Isolation and quantification in roasted and ground coffees Journal of Agricultural and Food Chemistry, 50: 1200–1206 22 Afoakwa, E J C s., & technology Wiley-Blackwell, H., NJ, USA (2011) Cocoa cultivation, bean composition and chocolate flavour precursor formation and character 23 Jalil, A M M., & Ismail, A J M (2008) Polyphenols in cocoa and cocoa products: is there a link between antioxidant properties and health? , 13(9), 21902219 24 Mazor Jolić, S., Radojčić Redovniković, I., Marković, K., Ivanec Šipušić, Đ., Delonga, K J I j o f s., & technology (2011) Changes of phenolic compounds and antioxidant capacity in cocoa beans processing 46(9), 1793-1800 42 25 CISSE, V., & YEMİŞÇİOĞLU, F (2019) Cacao Butter and Alternatives Production Cukurova Tarım ve Gıda Bilimleri Dergisi, 34(1), 51-60 26 Lipp, e M., & Anklam, E (1998) Review of cocoa butter and alternative fats for use in chocolate—part A Compositional data Food Chemistry, 62(1), 7397 27 Maheshwari, B., & Yella Reddy, S (2005) Application of kokum (Garcinia indica) fat as cocoa butter improver in chocolate Journal of the Science of Food and Agriculture, 85(1), 135-140 43 ... of caffeine, Vignoli et al (2011) reported high correlations between antioxidant capacity of coffee brews and caffeine Similarly, López-Galilea et al (2007) reported a significant correlation... oxide species (Gliszczyńka-Świgło and Sikorska, 2004) The presence of tocopherols in coffee oil was reported for the first time by Folstar et al (1977) Among tocopherols, two main tocopherols (α-... Arabica and Robusta coffee beans, both green and roasted (Alves et al., 2010) Ogawa et al (1989) reported vitamin E mean content in coffee brew of 7±3μg/100ml The content of α-tocopherol in roasted

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