211099351
The Kinetics of Total Phenolic Content and Monomeric Flavan-3-ols during the Roasting Process of Criollo Cocoa
Cocoa beans are the main raw material for the manufacture of chocolate and are currently gaining great importance due to their antioxidant potential attributed to the total phenolic content (TPC) and the monomeric flavan-3-ols (epicatechin and catechin). The objective of this study was to determine the degradation kinetics parameters of TPC, epicatechin, and catechin during the roasting process of Criollo cocoa for 10, 20, 30, 40, and 50 min at 90, 110, 130, 150, 170, 190, and 200 °C. The results showed a lower degradation of TPC (10.98 ± 6.04%) and epicatechin (8.05 ± 3.01%) at 130 °C and 10 min of roasting, while a total degradation of epicatechin and a 92.29 ± 0.06% degradation of TPC was obtained at 200 °C and 50 min. Reaction rate constant (k) and activation energy (Ea) were 0.02–0.10 min−1 and 24.03 J/mol for TPC and 0.02–0.13 min−1 and 22.51 J/mol for epicatechin, respectively. Degradation kinetics of TPC and epicatechin showed first-order reactions, while the catechin showed patterns of formation and degradation.
52177365
The effect on bioactive components and characteristics of chocolate by functionalization with raw cocoa beans.
Chocolate manufacturers often develop their own original blends of cocoa beans, which, after processing, will give an unique sensory properties to their chocolates. In recent years, there has been a trend in the production of an increasing amount of low-processed or unprocessed food. Therefore, we carried out the research in which we obtained and analyzed chocolates with different blends of cocoa liquors prepared from roasted and unroasted cocoa beans of Criollo and Forastero varieties.Studies have shown that viscosity and yield value increased and hardness of chocolates lowered with the increase content of cocoa liquor from unroasted beans. Chocolates with cocoa liquor from roasted beans were characterized by the largest ability to scavenge DPPH radicals. Antioxidant activity determined by the ORAC-FL method increased with increasing polyphenol content in the chocolates. Type of the cocoa liquor used induced minor changes in the polyphenol and fatty acid composition. Asparagine was determined at the highest concentration, followed by alanine, glutamine, and serine. The concentration of acetic acid was the higher the higher the content of unroasted beans. The increased content of cocoa liquor from unroasted beans caused the color of the chocolate to brighten, more red and yellow. All tested chocolates were characterized by good organoleptic properties and microbial stability.
64325947
Formation of aromatic compounds precursors during fermentation of Criollo and Forastero cocoa
There are three main genetic varieties of cocoa (Theobroma cacao L) used in chocolate making: Forastero, Trinitario and Criollo, which are distinguished by their aroma, an attribute that determines their quality. Criollo cocoa is of the highest quality and is used in the manufacture of fine chocolates because of its fruity aroma. The aroma of Criollo cocoa is defined by volatile compounds such as pyrazines and aldehydes, which are formed during roasting of the bean, from aroma precursors (reducing sugars and free amino acids) that are generated inside the bean via enzymatic reactions during fermentation; for this reason, fermentation is the most important process in the value chain. This review discusses the production of aroma precursors of Criollo and Forastero cocoa by studying the kinetics of spontaneous fermentation and the role of starter cultures to produce aroma precursors. Fine aroma precursors produced in the pulp during the fermentation phase will migrate into the bean when it's permeability is improved and then retained during the drying phase. Diffusion of aroma precursors into the cocoa bean may be possible, this process is mathematically characterized by the coefficient of molecular diffusion D, which describe the process of mass transfer via Fick's Second Law. The current state of knowledge is analyzed based on existing research and reports some gaps in the literature, suggesting future research that will be necessary for a better understanding of cocoa fermentation.
100254297
From the raw seed to chocolate: Volatile profile of Blanco de Criollo in different phases of the processing chain
•Volatiles are present in raw cacao and are developed during the processing chain.•Pyrazines, esters, alcohols and acids are important quality descriptors of chocolate.•PCA and HCA evidenced patterns of emission based on the production phase.•It's the first characterization of the volatiles in the whole cacao processing chain.•Volatile analysis can be a simple and effective tool to evaluate processing phases.
102148964
The influence of the roasting process conditions on the polyphenol content in cocoa beans, nibs and chocolates
Abstract The process of roasting is a significant step in cocoa bean processing. Heating results in the formation of many advantageous features of beans, such as taste, color, texture. However, these positive changes can also be accompanied by reactions reducing the content of bioactive compounds such as polyphenols. It is therefore important to select the appropriate roasting process conditions (time, temperature, humidity and flow rate of air), as well as fineness of the beans. The article describes the research on the influence of roasting parameters (temperature, roasting time, air flow rate and relative humidity) on the kinetics of changes in the content of phenolic compounds in whole beans and in cocoa nibs of different particle size. Additonally, chocolates were obtained from cocoa liquor prepared from cocoa beans roasted as whole beans as well as from fraction of cocoa nibs of middle particle size. LC–MS/MS analysis of phenolic compounds in the roasted beans, nibs and chocolates showed that the degradation of these compounds in beans and nibs was lower when they were roasted in air with increased relative humidity. The greatest degradation of compounds both in whole beans and nibs was observed for epicatechin and procyanidin B2, regardless of the roasting conditions applied. There were no differences as the course of degradation of polyphenolic compounds in beans and nibs, roasted under constant and non-constant process parameters. The loss of flavanols in the process of chocolate preparation was not high.
4596946
Impact of roasting on the flavan-3-ol composition, sensory-related chemistry, and in vitro pancreatic lipase inhibitory activity of cocoa beans.
Roasting is an important cocoa processing step, but has been reported to reduce the polyphenol content in the beans. We investigated the impact of whole-bean roasting on the polyphenol content, aroma-related chemistry, and in vitro pancreatic lipase (PL) inhibitory activity of cocoa under a range of roasting conditions. Total phenolics, (-)-epicatechin, and proanthocyanidin (PAC) dimer - pentamer content was reduced by roasting. By contrast, roasting at 150 °C or greater increased the levels of catechin and PAC hexamers and heptamers. These compounds have greater PL inhibitory potency. Consistent with these changes in PAC composition and this previous data, we found that roasting at 170 °C time-dependently increased PL inhibitory activity. Cocoa aroma-related compounds increased with roasting above 100 °C, whereas deleterious sensory-related compounds formed at more severe temperatures. Our results indicate that cocoa roasting can be optimized to increase the content of larger PACs and anti-PL activity, while maintaining a favorable aroma profile.
84335422
Influence of roasting conditions on the biogenic amine content in cocoa beans of different Theobroma cacao cultivars
Abstract The objective of this study was to investigate how roasting process conditions affected the content of biogenic amines in cocoa beans of different Theobroma cacao varieties. The raw cocoa beans were roasted at four different temperatures (ranging from 110 °C to 150 °C) and three different air humidities (0.3% to 5.0%). Roasting process may significantly modify the profile and levels of biogenic amines. Tyramine was the most abundant amine in raw cocoa beans, followed by tryptamine and 2-phenylethylamine. Serotonin and dopamine were presented only in small amounts. However, it was found that roasted cocoa beans contained mainly 2-phenylethylamine, followed by tyramine, tryptamine, serotonin and dopamine. Parameters of roasting have a significant effect on the levels of each amine in all types of roasted beans. The highest amount of biogenic amines was observed in the samples roasted at the highest temperatures and in the air with increased humidity. In addition, the results revealed that the cacao cultivars significantly affect the levels of biogenic amines.
23335770
Determination of antioxidant capacity and phenolic content of chocolate by attenuated total reflectance-Fourier transformed-infrared spectroscopy.
Antioxidant capacity and phenolic content of chocolate, containing different amounts of cacao (35-100%), were determined using attenuated total reflectance (ATR)-Fourier transformed-infrared (FT-IR) spectroscopy (4000-550cm(-1)). Antioxidant capacities were first characterized using DPPH (2,2-diphenyl-1-picrylhydrazyl) and ORAC (oxygen radical absorbance capacity) assays. Phenolic contents, including total phenol and procyanidins monomers, were quantified using the Folin-Ciocalteu assay and high performance liquid chromatography coupled with photodiode array detector (HPLC-DAD), respectively. Five partial least-squares regression (PLSR) models were constructed and cross-validated using FT-IR spectra from 18 types of chocolate and corresponding reference values determined using DPPH, ORAC, Folin-Ciocalteu, and HPLC assays. The models were validated using seven unknown samples of chocolate. PLSR models showed good prediction capability for DPPH [R(2)-P (prediction)=0.88, RMSEP (root mean squares error of prediction)=12.62μmol Trolox/g DFW], ORAC (R(2)-P=0.90, RMSEP=37.92), Folin-Ciocalteu (R(2)-P=0.88, RMSEP=5.08), and (+)-catechin (R(2)-P=0.86, RMSEP=0.10), but lacked accuracy in the prediction of (-)-epicatechin (R(2)-P=0.72, RMSEP=0.57). ATR-FT-IR spectroscopy can be used for rapid prediction of antioxidant capacity, total phenolic content, and (+)-catechin in chocolate.
94613964
Non enzymatic browning during cocoa roasting as affected by processing time and temperature
Abstract Non enzymatic browning (NEB) kinetics were studied at 125, 135 and 145 °C during a cocoa beans roasting process aimed to reach a final moisture content of 2 g 100 g −1 . Colour lightness and hue angle decreased with roasting time following a first and a zero order kinetic, respectively. Moisture content being equal, high temperature-short time (HTST) roasting processes minimized the extent of browning reaction. Melanoidins increased with roasting time following an asymptotic kinetic. Moisture content being equal, HTST processes maximized the melanoidins formation. The energy of activation of melanoidin formation (132 kJ mol −1 ) was higher than those of colour changes and polyphenol oxidation (between 60 and 80 kJ mol −1 ), thus NEB during roasting is not solely dependent on Maillard reaction occurrence. Hydroxymethylfurfural (HMF) increased exponentially with roasting time but its final content was low (0.1–0.8 g kg −1 ). HTST processes minimized the HMF formation, which was not temperature dependent and was influenced by concentration.
208761485
Optimization of chromatographic separation and classification of artisanal and fine chocolate based on its bioactive compound content through multivariate statistical techniques
ABSTRACT In this study, multivariate statistical techniques were used to evaluate concentrations of bioactive compounds such as theobromine, catechin, epicatechin, and caffeine in artisanal and fine chocolate using high-performance liquid chromatography (HPLC). The compound separation optimization step was carried out using a central composite design with three variables. The optimized variables were the initial percentage of methanol in the mobile phase, gradient time and flow rate. The optimal conditions were: initial methanol percentage of 0% (starting with 100% of 0.1% (v/v) acetic acid solution), changing to 100% of methanol in 9.85 min, with a flow rate of 0.74 mL min−1. The optimized procedure was validated and applied to the analysis of artisanal and fine chocolates with varying cocoa content. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to discriminate the samples based on the cocoa content present in the chocolates. Samples containing a high percentage of cocoa solids were separated from those containing a low percentage of cocoa solids due to their high concentrations of methylxanthines and flavonoids. Theobromine, catechin, epicatechin and caffeine concentrations in all samples ranged from 1.6 mg g−1 to 13.9 mg g−1, 0.047 mg g−1 to 0.60 mg g−1, 0.048 mg g−1 to 1.68 mg g−1 and 0.6 mg g−1 to 1.52 mg g−1, respectively. A comparison with data found in the scientific literature showed that artisanal and fine chocolate with a high cocoa content can be a good source of stimulant substances such as caffeine and antioxidant compounds such as catechin and epicatechin.
23797829
Cocoa and chocolate flavonoids: implications for cardiovascular health.
This paper offers a review of current scientific research regarding the potential cardiovascular health benefits of flavonoids found in cocoa and chocolate. Recent reports indicate that the main flavonoids found in cocoa, flavan-3-ols and their oligomeric derivatives, procyanidins, have a variety of beneficial actions, including antioxidant protection and modulation of vascular homeostasis. These findings are supported by similar research on other flavonoid-rich foods. Other constituents in cocoa and chocolate that may also influence cardiovascular health are briefly reviewed. The lipid content of chocolate is relatively high; however, one third of the lipid in cocoa butter is composed of the fat stearic acid, which exerts a neutral cholesterolemic response in humans. Cocoa and chocolate contribute to trace mineral intake, which is necessary for optimum functioning of all biologic systems and for vascular tone. Thus, multiple components in chocolate, particularly flavonoids, can contribute to the complex interplay of nutrition and health. Applications of this knowledge include recommendations by health professionals to encourage individuals to consume a wide range of phytochemical-rich foods, which can include dark chocolate in moderate amounts.
208546353
Bioactive amines and phenolic compounds in cocoa beans are affected by fermentation.
Cocoa is the target of increased scientific research as it is one of the richest source of bioactive compounds. The formation of bioactive amines and their changes in cocoa beans during seven days of traditional fermentation was investigated for the first time. In addition, total phenolic compounds, anthocyanins contents and the scavenging capacity against ABTS radical were determined to monitor the fermentation process. Only two biogenic amines (tryptamine and tyramine) and two polyamines (spermidine and spermine) were detected in cocoa beans during fermentation. Fermentation was characterized by three stages: i) high levels of tryptamine, phenolics, and scavenging capacity; ii) high contents of spermine, total biogenic amines and total polyamines; and iii) the highest spermidine levels and total acidity, but the lowest total phenolic compounds and anthocyanins contents. The scavenging capacity of cocoa beans during fermentation correlated with total phenolic compounds and anthocyanins contents.
96788029
Effect of roasting on the radical scavenging activity of cocoa beans
The free-radical scavenging activity of cocoa samples subjected to different roasting treatments has been determined. The samples (raw, pre-roasted and roasted) were separated into four molecular weight fractions per sample (>30, 30–10, 10–5, and <5 kDa). The free-radical scavenging activity was determined with the DPPH• (1,1-dipheny-2-picrylhydrazyl), and ABTS•+ [2,2’-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)] free-radical scavenging assays for all samples. Both tests were compared in terms of sensitivity and measurement precision, at different reaction times. Comparing the results from each test, the free-radical scavenging activity trends were similar for each fraction but with notable differences in the sensitivity of the assays. Analysis of the concentration of reducing substances, such as water soluble phenolics, melanoidins, carbohydrates, etc, in these fractions by the photometric Folin–Ciocalteu assay, showed a similar pattern to the free-radical scavenging activity trend. Moreover, this comparison showed that there were significantly (P < 0.05) more reducing substances and free-radical scavenging activity in the 10–5 kDa roasted cocoa bean fraction.
20582210
Phenolic content and antioxidant capacity of hybrid variety cocoa beans.
Cocoa (Theobroma cacao L.) is a major, economically important, international crop and has been associated with several nutritional benefits including high antioxidant capacity. New cocoa hybrids have been developed in Ghana that exhibit resistance to pest damage during storage. The aim of this work was to assess the phenolic content and antioxidant capacity of these new hybrids in comparison to more traditional cocoa varieties. Total extractable phenolics were similar in all the four hybrids tested ranging from 69.9 to 81.6FAEg(-1). These levels were very similar to that extracted from traditional beans (73.8±2.5FAEg(-1)). The "phenolic profile" was determined by HPLC. A total of 25 peaks was observed but there were only minor differences in this profile between traditional and hybrid bean extracts. Antioxidant capacity was determined using the FRAP assay and traditional beans were found to possess 12.4μmolTEg(-1). In comparison the hybrid beans had antioxidant capacities ranging from 21.6 to 45.5μmolTEg(-1), and these were significantly higher than in the traditional beans for three out of the four hybrids. Since the phenolic and antioxidant levels and in these hybrid varieties were either similar to, or higher than, that obtained from traditional beans, the introduction of these new varieties would be unlikely to impact detrimentally on these nutritional components of the beans.
83124453
Analysis of total phenols and other oxidation substrates and antioxidants by means of Folin-Ciocalteu reagent
Publisher Summary This chapter discusses the analysis of total phenols and other oxidation substrates and antioxidants by means of Folin-Ciocalteu reagent. Analyses of the Folin-Ciocalteu (FC) type are convenient, simple, and require only common equipment and have produced a large body of comparable data. Under proper conditions, the assay is inclusive of monophenols and gives predictable reactions with the types of phenols found in nature. Because different phenols react to different degrees, expression of the results as a single number—such as milligrams per liter gallic acid equivalence—is necessarily arbitrary. Because the reaction is independent, quantitative, and predictable, analysis of a mixture of phenols can be recalculated in terms of any other standard. The assay measures all compounds readily oxidizable under the reaction conditions and its very inclusiveness allows certain substances to also react that are either not phenols or seldom thought of as phenols (e.g., proteins). Judicious use of the assay—with consideration of potential interferences in particular samples and prior study if necessary—can lead to very informative results. Aggregate analysis of this type is an important supplement to and often more informative than reems of data difficult to summarize from various techniques, such as high-performance liquid chromatography (HPLC) that separate a large number of individual compounds .The predictable reaction of components in a mixture makes it possible to determine a single reactant by other means and to calculate its contribution to the total FC phenol content. Relative insensitivity of the FC analysis to many adsorbents and precipitants makes differential assay—before and after several different treatments—informative.
93175198
Isocratic elution system for the determination of catechins, caffeine and gallic acid in green tea using HPLC
Abstract A simple high performance liquid chromatographic analysis for tea catechins, caffeine and gallic acid with an isocratic elution system was developed. The separation system consisted of a C18 reversed-phase column, an isocratic elution system of methanol/water/orthophosphoric acid, and an UV detector. This method is ideally suited for rapid, routine analysis for the determination of catechins in green tea with good repeatability and accuracy of results. Furthermore, this method can be applied to all kinds of tea and tea products, and is especially useful for the determination of (+)-catechin, which was regarded as being in too low a concentration to detect, and (−)-gallocatechin gallate, which was regarded as a measure for heat treatment for green tea.
27684549
Kinetics of aflatoxin degradation during peanut roasting.
This study investigated aflatoxin degradation during peanut roasting. First, peanuts contaminated with three initial aflatoxin concentrations (35, 332 and 695μg/kg) were roasted at 180°C for up to 20min. The percentage of aflatoxin degradation after 20min were 55, 64 and 81% for peanuts contaminated with aflatoxin at 35, 332 and 695μg/kg, respectively. This difference was statistically significant (p<0.05), showing that initial concentration influences aflatoxin reduction. Thereafter, peanut samples contaminated with an initial aflatoxin concentration of 85μg/kg were roasted at 160, 180 and 200°C for 5, 10, 15, 20 and 25min, then residual concentrations of aflatoxin were determined. Roasting at 160, 180 and 200°C resulted in an aflatoxin reduction of 61.6, 83.6 and 89.7%, respectively. This study has provided quantitative data reinforcing the fact that roasting alone is not enough to control aflatoxins in peanuts.
19419825
Temperature influences epimerization and composition of flavanol monomers, dimers and trimers during cocoa bean roasting.
Cocoa consumption is suggested to promote many health benefits, since cocoa is a rich source of flavanols; but amounts and profiles of flavanols depend strongly on the bean type, origin and manufacturing process. Roasting is known as a crucial step in technical treatment of cocoa, which leads to flavanol losses and modifications, especially the epimerization of (-)-epicatechin to (-)-catechin. This study monitors the influence of cocoa bean roasting on the composition of flavanol monomers to trimers, with special focus on epimerization, which was quantified for procyanidin dimers, and also observed for trimers for the first time. Five dimeric and two trimeric potential epimerization products were detected and the extent of epimerization during cocoa roasting was shown to be a function of temperature. The data also showed remarkable variations in the change of flavanol content. The quantified flavanols decreased about 50% in Java beans and increased about 30% in Ivory Coast beans, despite being roasted under equal conditions.
96944351
Review on polyphenols in Theobroma cacao: changes in composition during the manufacture of chocolate and methodology for identification and quantification
Abstract Polyphenols have become an intense focus of research interest because of their perceived health-beneficial effects, such as anti-carcinogenic, anti-atherogenic, anti-inflammatory, anti-microbial, etc. Polyphenols in green and black tea, grape seeds, grapes and (red) wine have raised much attention but chocolate has not been investigated intensively up to now. This review is concerned with polyphenols in Theobroma cacao, the change in composition and quantity during fermentation, drying, and the manufacture of chocolate, as well as with analytical methods for isolation, characterisation and quantification. Cocoa beans are rich in polyphenols in particular catechins and proanthocyanidins. However, a sharp decrease in quantity occurs during fermentation and drying of cocoa beans and further retention has been reported during roasting. Characterisation and in particular quantification of polyphenols in chocolate has only been developed relatively recently. This work reviews further on the literature on the available methodology for analysis, quantification, isolation, purification, and structure elucidation of polyphenols in cocoa components and other commodities. Concerning the analytical methods main emphasis is put on HPLC as it is usually the method of choice due to its high resolution, high efficiency, high reproducibility and relatively short analysis time without restriction on sample volatility. Moreover, HPLC can be coupled to a variety of detectors such as UV–Vis, photodiode array (PDA), fluorescence, electrochemical (ECD), and mass spectrometry (MS). However, TLC as a screening method and capillary electrophoresis (CE) as a promising tool is taken into consideration as well. The characterisation and quantification of the polyphenol composition is amongst the first steps to be done to evaluate a putative contribution of chocolate to human health.
202888019
Changes in methylxanthines and flavanols during cocoa powder processing and their quantification by near-infrared spectroscopy
Abstract Variation in methylxanthines (theobromine and caffeine) and flavanols (catechin and epicatechin) was studied in a large set of cocoa powders (covering different origins, processing parameters and alkalisation levels). The content of these compounds was established by high-performance liquid chromatography (HPLC), whose results showed that the alkalisation process lowered the content of all analytes, whose loss was more evident in flavanols. Therefore, the determination of these analytes in a huge set of samples allowed not only better knowledge of the concentration variability in natural commercial cocoas from different origins, but also the understanding of the effect that industrial alkalisation has on these contents. The feasibility of reflectance near-infrared spectroscopy (NIRS) combined with partial least square (PLS) to non-destructively predict these contents, was also evaluated. All the analytes were generally well predicted, with predictions for methylxanthines (R2P 0.819–0.813 and RMSEP 0.068–0.022%, and bias 0.005 and 0.007 for theobromine and caffeine, respectively) and for flavanols (R2P 0.830–0.824; RMSEP 8.160–7.430% and bias −1.440 and −1.034 for catechin and epicatechin, respectively). Thus NIRS could be an alternative fast reliable method for the routine assessment of these analytes in the cocoa industry.
85232919
Epicatechin Content in Fermented and Unfermented Cocoa Beans
As determined by high performance liquid chromatography, (-)- epicatechin concentrations among freshly harvested beans of verified genetic origin ranged from 21.89–43.27 mg/g of dry defatted samples. Fermented beans showed much lower concentrations (2–10 mg). During fermentation, a trend towards decrease in (-)-epicatechin content was observed. Commercial beans from areas with reputations for shipping well-fermented products contained lower levels of (-)-epicatechin than beans from regions where fermentation is less extensive.
43065278
Impact of fermentation, drying, roasting, and Dutch processing on epicatechin and catechin content of cacao beans and cocoa ingredients.
Low molecular weight flavan-3-ols are thought to be responsible, in part, for the cardiovascular benefits associated with cocoa powder and dark chocolate. The levels of epicatechin and catechin were determined in raw and conventionally fermented cacao beans and during conventional processing, which included drying, roasting, and Dutch (alkali) processing. Unripe cacao beans had 29% higher levels of epicatechin and the same level of catechin compared to fully ripe beans. Drying had minimal effect on the epicatechin and catechin levels. Substantial decreases (>80%) in catechin and epicatechin levels were observed in fermented versus unfermented beans. When both Ivory Coast and Papua New Guinea beans were subjected to roasting under controlled conditions, there was a distinct loss of epicatechin when bean temperatures exceeded 70 °C. When cacao beans were roasted to 120 °C, the catechin level in beans increased by 696% in unfermented beans, by 650% in Ivory Coast beans, and by 640% in Papua New Guinea fermented beans compared to the same unroasted beans. These results suggest that roasting in excess of 70 °C generates significant amounts of (-)-catechin, probably due to epimerization of (-)-epicatechin. Compared to natural cocoa powders, Dutch processing caused a loss in both epicatechin (up to 98%) and catechin (up to 80%). The epicatechin/catechin ratio is proposed as a useful and sensitive indicator for the processing history of cacao beans.
94382893
Changes of phenolic compounds and antioxidant capacity in cocoa beans processing
A number of studies have shown that the consumption of cocoa and chocolate products has positive health effects on humans. The object of this research was to monitor changes of total and individual phenolics and antioxidant capacity during the cocoa bean manufacturing. The loss of cocoa phenolics and their antioxidant activity vary with the degree of technological process. The process of roasting and cocoa nib alkalisation had the major influence on phenolic compounds as well as on antioxidant capacity. The roasting treatment resulted in 14% loss of the total phenolics content, while alkalisation resulted in 64% loss of total phenolics content. Procyanidins B1 and B2 as well as ())-epigallocatechin were the unstable components, while caffeic acid derivate showed the greatest stability in all technological process. Furthermore, PCA showed that phenolic contents, antioxidant capacity and non-fat cocoa solids parts of the samples were classified in groups according technological conditions.
56573187
Methylxanthine and catechin content of fresh and fermented cocoa beans, dried cocoa beans, and cocoa liquor
The theobromine and catechin content can affect the quality of cocoa liquor and is influenced by cacao variety, production area (PA), and fermentation, as well as the method of drying beans (FDB) and cocoa liquor production (CLP). This study examined variations in methylxanthine and catechin levels in fresh and fermented cocoa beans, dried cocoa grains, and in cocoa liquor from Trinitario, Criollo, and Forastero cacao varieties. A total of 123 cocoa bean samples from three Peruvian PAs at different altitudes, Tingo Maria (TM), San Alejandro (SA), and Curimana (CU), were evaluated. The theobromine (Tb) and caffeine (Cf) contents in fresh cocoa beans were affected by both cocoa type and PA. The caffeine content was higher in Trinitario cacao than in Criollo and Forastero varieties (p ≤ 0.05). The Tb and CF contents decreased in dry cocoa grain and was affected by FDB (p ≤ 0.05) (1.449 ± 0.004 to 1.140 ± 0.010 and 0.410 ± 0.03 to 0.165 ± 0.02 g Tb and C, respectively, per 100 g dry weight). Cocoa beans from Tingo Maria, which has the highest altitude, had higher Tb and CF contents than those from other PAs. The catechin (C) and epicatechin (EC) contents were affected by the FDB and CLP, and were highest in fresh cocoa beans from the Tingo Maria area (range: 0.065 ± 0.01 to 0.020 ± 0.00 g C/100 g). The C and EC contents decreased during FDB and CLP (0.001 g C/100 g of cocoa liquor). Taken together, these results show that higher concentrations of Tb, Cf, C, and EC are present in fresh cocoa beans. Moreover, the cocoa variety influenced cocoa liquor quality. Overall, cocoa from the Tingo Maria PA had the most desirable chemical composition.
91740028
Biological functions of epicatechin: Plant cell to human cell health
Abstract Research on epicatechin as a potential nutraceutical has gained huge interest due to its critical biological functions and ease of availability. Several in vitro and in vivo studies have been carried out to explore its therapeutic potential and have shown excellent biological effects. In spite of its wide range of biological activity, poor bioavailability and instability in in vivo system have limited its application. One of our studies on nanoformulation of catechin rich extract suggested enhanced antioxidant activity and in vitro bioavailability. In this review, we have provided information on the discovery of epicatechin in plants and its role in the protection of plant. Additionally, information on the biological activities of epicatechin in animals and human is discussed. Article also showcases factors that influence pharmacokinetics and bioavailability of epicatechin. An ample coverage on the scope and applications of nanotechnology in the bioavailability enhancement and biological effects are duly emphasized.
22174825
Survey of commercially available chocolate- and cocoa-containing products in the United States. 2. Comparison of flavan-3-ol content with nonfat cocoa solids, total polyphenols, and percent cacao.
A survey of a broad range of chocolate- and cocoa-containing products marketed in the United States was conducted to provide a more detailed analysis of flavan-3-ol monomers, oligomers, and polymers, which can be grouped into a class of compounds called procyanidins. Samples consisted of the three or four top-selling products within the following six categories: natural cocoa powder, unsweetened baking chocolate, dark chocolate, semisweet baking chips, milk chocolate, and chocolate syrup. Composite samples were characterized for percent fat (% fat), percent nonfat cocoa solids (% NFCS), antioxidant level by ORAC, total polyphenols, epicatechin, catechin, total monomers, and flavan-3-ol oligomers and polymers (procyanidins). On a gram weight basis epicatechin and catechin content of the products follow in decreasing order: cocoa powder > baking chocolate > dark chocolate = baking chips > milk chocolate > chocolate syrup. Analysis of the monomer and oligomer profiles within product categories shows there are two types of profiles: (1) products that have high monomers with decreasing levels of oligomers and (2) products in which the level of dimers is equal to or greater than the monomers. Results show a strong correlation (R(2) = 0.834) of epicatechin to the level of % NFCS and also very good correlations for N = 2-5 oligomers to % NFCS. A weaker correlation was observed for catechin to % NFCS (R(2) = 0.680). Other analyses show a similar high degree of correlation with epicatechin and N = 2-5 oligomers to total polyphenols, with catechin being less well correlated to total polyphenols. A lesser but still good correlation exists between the calculated percent cacao (calcd % cacao) content, a proxy for percent cacao, and these same flavanol measures, with catechin again showing a lesser degree of correlation to calcd % cacao. Principal component analysis (PCA) shows that the products group discretely into five classes: (1) cocoa powder, (2) baking chocolate, (3) dark chocolate and semisweet chips, (4) milk chocolates, and (5) syrup. PCA also shows that most factors group closely together including the antioxidant activity, total polyphenols, and the flavan-3-ol measures with the exception of catechin and % fat in the product, which group separately. Because catechin distribution appears to be different from the other flavan-3-ol measures, an analysis of the epicatechin to catechin ratio was done, indicating there is a >5-fold variation in this measure across the products studied. The cocoa-containing products tested range from cocoa powder with 227.34 +/- 17.23 mg of procyanidins per serving to 25.75 +/- 9.91 mg of procyanidins per serving for chocolate syrup. These results are discussed with respect to other studies on commercial products, the bioavailability of the flavanols, and the possible role of processing on the amount of catechin in products.
103340614
Physicochemical Changes of Cocoa Beans during Roasting Process
During cocoa beans roasting, there are physicochemical changes that develop the chocolate quality attributes. Roasting systems have a particular influence on the development of these characteristics, and the effects of operation variables for each system must be evaluated. The objective of this study was to evaluate the effect of roasting time and temperature in a rotatory system on cocoa beans physicochemical parameters of quality as moisture, water activity, pH, total acidity, color , total phenolic content (TPC), and DPPH radical capacity. Cocoa beans were roasted as a function with a central rotatable design with 22 + 5 central points and 4 axial points ( 1.414, 1, 0, +1, and +1,414) and a response surface methodology was applied. Temperature and time levels were 110–170°C and 5–65 minutes, respectively. The effect of the variables was nonlinear and modeled with a second-order response polynomial. Roasting time and temperature presented a significative effect ( ) on the response variables except for both TPC and DPPH radical capacity in aqueous extract.
39843328
(-)-Epicatechin mediates beneficial effects of flavanol-rich cocoa on vascular function in humans.
Epidemiological and medical anthropological investigations suggest that flavanol-rich foods exert cardiovascular health benefits. Endothelial dysfunction, a prognostically relevant key event in atherosclerosis, is characterized by a decreased bioactivity of nitric oxide (NO) and impaired flow-mediated vasodilation (FMD). We show in healthy male adults that the ingestion of flavanol-rich cocoa was associated with acute elevations in levels of circulating NO species, an enhanced FMD response of conduit arteries, and an augmented microcirculation. In addition, the concentrations and the chemical profiles of circulating flavanol metabolites were determined, and multivariate regression analyses identified (-)-epicatechin and its metabolite, epicatechin-7-O-glucuronide, as independent predictors of the vascular effects after flavanol-rich cocoa ingestion. A mixture of flavanols/metabolites, resembling the profile and concentration of circulating flavanol compounds in plasma after cocoa ingestion, induced a relaxation in preconstricted rabbit aortic rings ex vivo, thus mimicking acetylcholine-induced relaxations. Ex vivo flavanol-induced relaxation, as well as the in vivo increases in FMD, were abolished by inhibition of NO synthase. Oral administration of chemically pure (-)-epicatechin to humans closely emulated acute vascular effects of flavanol-rich cocoa. Finally, the concept that a chronic intake of high-flavanol diets is associated with prolonged, augmented NO synthesis is supported by data that indicate a correlation between the chronic consumption of a cocoa flavanol-rich diet and the augmented urinary excretion of NO metabolites. Collectively, our data demonstrate that the human ingestion of the flavanol (-)-epicatechin is, at least in part, causally linked to the reported vascular effects observed after the consumption of flavanol-rich cocoa.
10762024
Impact of fermentation, drying, roasting and Dutch processing on flavan-3-ol stereochemistry in cacao beans and cocoa ingredients
This paper reports a systematic study of the level of flavan-3-ol monomers during typical processing steps as cacao beans are dried, fermented and roasted and the results of Dutch-processing. Methods have been used that resolve the stereoisomers of epicatechin and catechin. In beans harvested from unripe and ripe cacao pods, we find only (-)-epicatechin and (+)-catechin with (-)-epicatechin being by far the predominant isomer. When beans are fermented there is a large loss of both (-)-epicatechin and (+)-catechin, but also the formation of (-)-catechin. We hypothesize that the heat of fermentation may, in part, be responsible for the formation of this enantiomer. When beans are progressively roasted at conditions described as low, medium and high roast conditions, there is a progressive loss of (-)-epicatechin and (+)-catechin and an increase in (-)-catechin with the higher roast levels. When natural and Dutch-processed cacao powders are analyzed, there is progressive loss of both (-)-epicatechin and (+)-catechin with lesser losses of (-)-catechin. We thus observe that in even lightly Dutch-processed powder, the level of (-)-catechin exceeds the level of (-)-epicatechin. The results indicate that much of the increase in the level of (-)-catechin observed during various processing steps may be the result of heat-related epimerization from (-)-epicatechin. These results are discussed with reference to the reported preferred order of absorption of (-)-epicatechin > (+)-catechin > (-)-catechin. These results are also discussed with respect to the balance that must be struck between the beneficial impact of fermentation and roasting on chocolate flavor and the healthful benefits of chocolate and cocoa powder that result in part from the flavan-3-ol monomers.
90695954
Thermal stability of catechin and epicatechin upon disaccharides addition
Summary 
Influence of sucrose and trehalose addition on epimerisation and thermal degradation of catechin and epicatechin have been studied. Sucrose addition accelerated epimerisation of catechin and epicatechin at 80 and 100 °C. Addition of trehalose had protective effect on epimerisation of catechin and epicatechin. Considering thermal degradation, it was confirmed that thermal degradation of catechin and epicatechin follows the first-order kinetics. Increasing the temperature causes shorter half-lives of catechin and epicatechin. Addition of sucrose had negative effect on catechin stability. However, in samples with epicatechin, sucrose impact was temperature dependent. Trehalose addition had positive impact on preventing catechin and epicatechin degradation almost doubling the half-life of studied compounds. Data presented in this study could help to predict chemical conversions of investigated phenolics in various food systems and to prolong their shelf life in thermally processed foods.
39215878
Assessment of flavanol stereoisomers and caffeine and theobromine content in commercial chocolates.
Assessment of the flavanol composition of 41 commercial chocolates was by HPLC-DAD. Among individual flavonols ranged from 0.095 to 3.264mgg(-1), epicatechin was the predominant flavanol accounting for 32.9%. Contrary to catechin, epicatechin was a reliable predictive value of the polyphenol content. Conversely the percentage of theobromine used as a proxy measure for nonfat cocoa solids (NFCS) was not a good predictor of epicatechin or flavanol content. In a further chiral analysis, the naturally occurring forms of cocoa flavanols, (-)-epicatechin and (+)-catechin, was determined joint the occurrence of (+)-epicatechin and (-)-catechin due to the epimerization reactions produced in chocolate manufacture. (-)-Epicatechin, the most bioactive compound and predominant form accounted of 93%. However, no positive correlation was found with% cocoa solids, the most significant quality parameter.
31775977
Physicochemical properties and antioxidant capacity of raw, roasted and puffed cacao beans.
The antioxidant capacity and attributable bioactive compounds of puffed cacao beans were investigated. Roasting was carried out at 190°C for 15min and puffing was performed at 4-7kgf/cm(2). Cacao beans puffed at 4kgf/cm(2) showed the highest total polyphenols (23.16mgGAE/gsample) and total flavonoids (10.65mgCE/gsample) (p<0.05). As the puffing pressure increased, the amount of total polyphenols and total flavonoids decreased. The antioxidant capacity of cacao beans reflected the total polyphenols and flavonoids measured. The quantities of theobromine, catechin, epicatechin, and procyanidin B2 were higher in cacao beans puffed at 4kgf/cm(2) than in roasted cacao beans. Puffed cacao beans received a good sensory score in flavor, but sourness increased as puffing pressure increased. Thus, these results suggest that, in cacao bean processing, puffing could be an alternative to roasting, which provide a rich taste and high antioxidant capacity.
42407866
Biological activities of (-)-epicatechin and (-)-epicatechin-containing foods: Focus on cardiovascular and neuropsychological health.
Recent studies have suggested that certain (-)-epicatechin-containing foods have a blood pressure-lowering capacity. The mechanisms underlying (-)-epicatechin action may help prevent oxidative damage and endothelial dysfunction, which have both been associated with hypertension and certain brain disorders. Moreover, (-)-epicatechin has been shown to modify metabolic profile, blood's rheological properties, and to cross the blood-brain barrier. Thus, (-)-epicatechin causes multiple actions that may provide unique synergy beneficial for cardiovascular and neuropsychological health. This review summarises the current knowledge on the biological actions of (-)-epicatechin, related to cardiovascular and brain functions, which may play a remarkable role in human health and longevity.
94036315
Changes in the flavan-3-ols, anthocyanins, and flavanols composition of cocoa beans of different Theobroma cacao L. groups affected by roasting conditions
Abstract
In the present study, the effect of roasting conditions on the individual flavan-3-ols, anthocyanins, and flavanols content of cocoa beans of five different Theobroma cacao L. groups was studied. The raw cocoa beans were roasted at four different temperatures (110, 120, 135, and 150 °C) and three different relative air humidities (0.3, 2.0, and 5.0 %). The great variations in the contents of both total and individual phenolic compounds among the different studied cocoa groups were observed. In general, the cocoa beans of the Forastero group from Brazil exhibited the highest content of individual flavan-3-ols, anthocyanins, and flavanols, while the samples of the Trinitario type from Papua New Guinea had the lowest polyphenols levels. Roasting significantly affected the profile and levels of the flavan-3-ols, anthocyanins, and flavanols in cocoa beans. The changes depended upon the different cocoa types evaluated and their processing conditions. A decrease in epicatechin, procyanidin B, procyanidin C1, both anthocyanins, and quercetin glycosides was observed in all of the five cocoa groups tested after roasting. This reduction coincided with the increase in catechin and quercetin contents in roasted cocoa beans from the five cocoa groups.
24458051
Flavanols, proanthocyanidins and antioxidant activity changes during cocoa (Theobroma cacao L.) roasting as affected by temperature and time of processing.
The effect of roasting on the content of flavanols and proanthocyanidins and on the antioxidant activity of cocoa beans was investigated. Cocoa beans were roasted at three temperatures (125, 135 and 145 °C), for different times, to reach moisture contents of about 2 g 100 g(-1). Flavanols and proanthocyanidins were determined, and the antioxidant activity was tested by total phenolic index (TPI), ferric reducing antioxidant power (FRAP) and total radical trapping antioxidant parameter (TRAP) methods. The rates of flavanol and total proanthocyanidin loss increased with roasting temperatures. Moisture content of the roasted beans being equal, high temperature-short time processes minimised proanthocyanidins loss. Moisture content being equal, the average roasting temperature (135 °C) determined the highest TPI and FRAP values and the highest temperature (145 °C) determined the lowest TPI values. Moisture content being equal, low temperature-long time roasting processes maximised the chain-breaking activity, as determined by the TRAP method.
2365904
The kinetics of polyphenol degradation during the drying of Malaysian cocoa beans
The main objective of the study was to determine the kinetics of the polyphenol oxidation reaction in cocoa beans during air drying at various air temperatures and humidities. The temperatures used were between 40 and 60 °C and the relative humidities were between 50 and 80%. The higher the temperature and relative humidity of the drying air, the lower the amount of polyphenol residue in the cocoa beans, because of enzymatic oxidation of polyphenols. At higher drying temperatures, non-enzymatic oxidation of polyphenols could also occur. Computer simulation results gave rate constants for the polyphenol oxidation reaction (k 1 ) and the condensation reaction (k 2 ), at various air conditions, in the range of 0.055-0.200 and 0.136-0.155 h -1 respectively. The activation energies obtained for the polyphenol oxidation reaction were in the range of 27 800-30 312 J K -1 mol -1 . The reaction kinetics of the enzymatic browning reaction fitted a pseudo first-order reaction.
93626417
The Drying Kinetics and Polyphenol Degradation of Cocoa Beans
This study investigated the kinetics of drying and polyphenol degradation during hot air and sun drying of cocoa beans. Hot air drying was carried out using a constant humidity-controlled (50% relative humidity) oven at temperature range of 60–80C, and sun drying was carried out by exposing the beans under direct sunlight. Several semi-theoretical models were used to model the kinetics of moisture diffusion and it was found that the Page and Logarithmic models were able to provide good prediction. A first-order reaction kinetics was used to predict the polyphenol degradation process with rate constants ranging from 0.011/h to 0.052/h. Activation energy for polyphenol degradation was determined at 8.97 kJ/mol using the Arrhenius equation. Effective diffusivity during drying was found within the order of magnitude (10−12–10−10 m2/s) reported in most drying literatures. 
 
Practical Applications 
The understanding of moisture diffusion is important in dryer design especially in the determination of effective diffusivities during drying. Polyphenols are important antioxidants that are beneficial to human health. By investigating the polyphenol degradation kinetics, this helps to link the reactions with moisture diffusion kinetics.
98439607
Kinetic modeling of phenolic compound degradation during drum-drying of apple peel by-products
Abstract The apple peel, a by-product of apple processing, has a high total phenolic content (TPC); however, these compounds can be highly thermosensitive and unstable. Therefore, the aim of this study was to determine the degradation kinetics of the TPC in apple peels during drum-drying as a stabilization and recovery method. Apple peels (Granny Smith) were dried at 110, 120, 130 or 140 °C for 250 s with a constant drum clearance (0.2 mm). TPC degradation exhibited first-order kinetics and their retentions at the end of the process were 73.13% at 110 °C, 57.28% at 120 °C, 43.40% at 130 °C and 21.10% at 140 °C. Finally, empirical models were significantly fitted to predict the TPC as the apple peels reached a certain level of dehydration, which may be useful from the processing standpoint and validate the use of drum-drying as a process tool for the recovery of apple industrial wastes.
99646316
Kinetics of hot air roasting of cocoa nibs and product quality
Cocoa beans are widely used in the manufacturing of various food and beverage products such as chocolates, powdered drink, cookies, confectioneries, and others. Processing plays a vital role in governing the final flavor profile of cocoa beans especially during roasting. The current studies aimed to determine the transport properties of cocoa nibs during roasting and also to investigate the quality of roasted cocoa nibs. Cocoa nibs were roasted at temperatures of 120, 130, and 140 °C inside a hot air convective oven. Kinetics analyses showed that overall rates of sensible heating (from T = 27 to 100 °C) were in the range of 5.1–9.5 °C/min as compared to overall rates of effective roasting (from T = 100 °C onwards) in the range of 0.9–1.4 °C/min. The observed moisture content profiles followed the typical exponential decay as commonly explained by the Fick's second law of diffusion. The dependency of thermal and moisture diffusivities with temperatures could be described using quadratic and Arrhenius models, respectively. It was determined that the average order of magnitude for moisture diffusivity was 10−10 m2/s as compared to 10−9 m2/s for thermal diffusivity. High roasting temperature had a negative impact on cocoa polyphenols where greater degradation was observed. Sensory evaluation showed that cocoa liquor produced from the higher temperature treatment (T = 140 °C) had the highest cocoa flavor. 
 
Practical applications 
Information on the roasting kinetics and moisture/thermal diffusivities are important design parameters for cocoa roaster. Changes in flavor quality during roasting are important in governing the development of flavor in the finished chocolate products. Therefore, the current studies contribute knowledge to the cocoa industry for both equipment and chocolate manufacturers.
93584299
Effect of thermal treatment on phenolic compounds from plum (prunus domestica) extracts – A kinetic study
Abstract The effect of thermal treatment on the degradation of the polyphenolic compounds in plum extract was investigated in the range of 70–110 °C by means of fluorescence spectroscopy and spectrophotometric techniques. The fluorescence results suggested that plum extract represents a multicomponent system with different fluorescence species. The heating of plum extract resulted in structural changes that led to a significant decrease in fluorescence intensity at higher temperature when the solutions were excited at 300 nm, whereas, when excited at 410 nm, significant increase in fluorescence intensity was measured in the temperature range of 70 and 110 °C. Degradation rate constants were estimated using a first order kinetic model. Temperature dependence of the degradation rate constants were expressed according to the Arrhenius model. The total monomeric anthocyanins showed the highest degradation in comparison to other polyphenols, as well as to antioxidant activity.
1278000
Kinetic and thermodynamic compensation. A current and practical review for foods.
Kinetic and thermodynamic compensations have been reported in many chemical, physical, biological and food processes. Kinetic compensation can be found for any process and when it takes place, it gives information about the reaction mechanism and whether the reaction is controlled by enthalpy or entropy. It consists of the linear relationship between the logarithm of the frequency factor (lnk0) and the activation energy (Ea), both previously obtained from the Arrhenius equation for different values of an environmental variable (e.g. pH, concentration of any substance not involved in the process, pressure, water activity, etc.). A mathematical consequence of kinetic compensation is the isokinetic temperature, this being the temperature at which the kinetic constant should be the same regardless of the environmental variable. Thermodynamic compensation can be found for any process involving an equilibrium and consists of the linear relationship between the variation of enthalpy and entropy, both previously obtained from the Van't Hoff equation for different values of an environmental variable. A mathematical consequence of thermodynamic compensation is the isoequilibrium temperature, this being the temperature at which the equilibrium constant should be the same regardless of the environmental variable. According to the transition state theory, some kinetic constants can be related to the equilibrium constant of the initial equilibrium stage between the reagents and the transition state. For these cases, it can be concluded that both compensations are related mathematically and therefore not only does the existence of one kind of compensation imply the existence of the other, but the isokinetic and isoequilibrium temperatures should both be the same, or at least very close to each other. However, there is no reason that forces the linearities that cause either kind of compensation. So, some processes have shown these linear relationships while others have not. Moreover, some authors have reported that, due to the fact that the estimates of the parameters for the couples lnk0-Ea and ΔH≠-ΔS≠ being correlated with each other, there is a statistic compensation that consists of the propagation of experimental errors, and this effect has to be considered before concluding kinetic and/or thermodynamic compensations. This work reviews how to deal with kinetic and thermodynamic compensations physically, mathematically and statistically, prior to a second part that reviews the food processes for which one or both of these compensations have been studied.
90777174
Thermal stability of phytochemicals, HMF and antioxidant activity in cape gooseberry (Physalis peruviana L.)
Cape gooseberry is a fruit recognised for having relevant contents of health-promoting compounds. Changes in the content of phytochemicals (ascorbic acid, β-carotene, catechin and epicatechin), hydroxymethylfurfural (HMF) and antioxidant activity of this fruit were studied at various temperatures and times. Ascorbic acid degradation was described by a first order reaction. β-carotene was not degraded and followed an isomerization reaction from 80 °C onwards. Formation of HMF was described with a consecutive zero together with a first order reaction model. The contents of catechin and epicatechin increased at 40 °C. More than three competing reactions did not allow to make kinetic modelling. Antioxidant activity followed fractional first order conversion model. Comparison with kinetics found in other fruits showed that health-promoting compounds of cape gooseberry are relatively more stable to heat treatment. This makes cape gooseberry suitable for the preparation of foods (jam, juices and dehydrated fruit) with relevant health-promoting compounds contents.