Effect of traditional and oven roasting on the physicochemical properties of fermented cocoa beans

Antioxidant activity, physico-chemical properties, and bioactive compounds of Nigella sativa seeds and oil impacted by microwave processing technique

Strongly anti-oxidant and medicinal, Nigella sativa L (NS) is utilized in conventional medicine to address a range of illnesses, including gastrointestinal, inflammatory and rheumatic illnesses. This study was carried out to investigate the effects of microwave processing on the physico-chemical properties of Moroccan-grown Nigella sativa seeds and oils, as well as to investigate the antioxidant qualities of black cumin oils under conditions of accelerated oxidation. The study's specific goal was to ascertain the effects of varying microwave power levels (500 and 750 W) and roasting times (5, 10, and 15 min) on the black cumin oils' quality indices, fatty acid and sterol content, carotenoid and chlorophyll levels, mineral profile, tocopherol amount, and overall antioxidant activity. To this end, the seeds of black cumin were roasted at two power levels (500 and 750 W) and for three different periods (5, 10, and 15 min) in a microwave oven. The obtained results show that the duration and the processing power did not significantly influence the amount of sterols and fatty acids. In contrast, the quality indices, physico-chemical properties, carotenoid and chlorophyll contents, mineral profile, and tocopherol amount were influenced by the microwave processing. A significant decline in the antioxidant activity was recorded from 45.01 ± 0.81 % (unroasted cumin seeds) to 4.32 ± 0.91 % (750 W/5 min). Based on these findings, the black cumin oil preparations should be handled carefully and the oil must be protected once extracted. The stability and preservation of antioxidants are crucial steps against pro-oxidant and inflammatory conditions that could favour cellular senescence and accelerate aging processes.

Analysis of the Sensory Profile and Physical and Physicochemical Characteristics of Amazonian Cocoa (Theobroma cacao L.) Beans Produced in Different Regions

The cocoa tree (Theobroma cacao L.) has seeds that after processing become a valuable agricultural commodity in the world. In Brazil, the state of Pará located in the Eastern Amazon is the main producer, accounting for more than 53% of the national production. Although the region is the largest producer, no studies are found in the literature containing data on the sensory quality of the beans. Thus, the purpose of this study is to establish the sensory profile of Amazonian cocoa from the main cocoa-producing regions of the Eastern Amazon (Lower Tocantins River, Northeast, West, Southeast and Trans-Amazon). The sensory profile was established from the Quantitative Descriptive Analysis (QDA), in addition to using an affective test to verify consumer preference for the chocolates produced. Physical, physicochemical and bioactive compound evaluations were carried out. Beans from different regions had a similar sensory profile; however, it was possible to observe some differences in certain descriptor terms. In the physical evaluation, the samples presented an acceptable commercial standard, and the humidity was within the values established by the legislation. It was found that the post-harvest and/or processing parameters had no influence on the quality attributes of cocoa beans.

Phenolic content and oxidative stability of chocolates produced with roasted and unroasted cocoa beans

The aim of this study was to produce chocolate using roasted (RB) and unroasted cocoa beans (URB). The effect of roasting on the total phenolic content (TPC), antioxidant activity [2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ferric reducing antioxidant power (FRAP), and cupric ion reducing antioxidant capacity (CUPRAC) values], phenolic compounds, caffeine, oxidative stability [free fatty acid, peroxide, conjugated dienes, conjugated trienes, and thiobarbituric acid reactive substances (TBARS)], Fourier transform infrared (FTIR), and differential scanning colorimetry (DSC) analysis of both cocoa beans and chocolate samples were analyzed. According to the results, the TPC of URB (24.96 mg gallic acid equivalent (GAE)/g sample) was higher than roasted beans (21.32 mg GAE/g sample). Similar results were also seen in the TPC of chocolate samples. Although roasting did not affect the DPPH scavenging activity and caffeine content of cocoa beans, it decreased FRAP and CUPRAC values. (-)-Epicatechin and chlorogenic acid values were higher in unroasted bean and chocolate samples, but the amount of gallic acid increased with the roasting process. Free fatty acid, peroxide, conjugated dienes, conjugated trienes, and TBARS results of unroasted samples were lower than roasted ones, indicating better oxidative stability. The melting temperatures of cocoa beans changed with roasting while it was similar between chocolate samples. Composition of the beans and the chocolate samples were qualitatively determined with FTIR.

Effect of different reheating processes and conditions on the nutritional, functional, and microbiological properties of cow meat

The objective of this study was to evaluate the effect of different reheating methods and conditions on the proximate composition, mineral content, oil quality, and functional and microbiological properties of cow meat. For this, a survey was carried out to identify the reheating methods used in the community. For this study, 8.6 kg of raw beef was used and group 1 (500 g) served as raw control. The remaining 8.1 kg was boiled for 30 min in 5 L of water. Four hundred grams of boiled beef was removed and served as cooked control (group 2). The remaining 3688 g was divided into four groups of 922 g, which were, respectively, divided into subgroups of 307 g. The four sets of subgroups were, respectively, reheated by boiling, frying, microwaving and oven roasting for 3 days. Reheating was done three times a day and samples were collected at the end of each day for further analysis. Changes in proximate composition, mineral content, oil quality, functional properties, and microbiological count were evaluated using standard methods. Results showed that frequent reheating of food was the most used preservation method of cooked food, and boiling and steaming were the most used methods. Reheating time significantly reduces the protein, mineral content, and oil quality of cow meat in general. For the functional properties, reheating methods/conditions generally increased the water-holding capacity, loose and packed bulk densities as well the pH of the meat. Reheating by frying increased the porosity and Hausner ratio of the meat powder while all the reheating treatments reduced the swelling capacity and titratable acidity of cow meat powder. Generally, the reheating methods and duration significantly reduced the bacterial count of cow meat powder. Cow meat should not be reheated for more than 2 days in order to preserve its physiochemical properties.

Chemical Composition, Fatty Acid Profile, and Optimization of the Sacha Inchi (Plukenetia volubilis L.) Seed-Roasting Process Using Response Surface Methodology: Assessment of Oxidative Stability and Antioxidant Activity

This study aimed to optimize the roasting conditions for sacha inchi (Plukenetia volubilis L.) seeds using the central composite design (CCD) of the response surface methodology (RSM). The antioxidant activity and oxidation indicators (peroxide and TBA values) were assessed, along with the impact of roasting on the fatty acid profile and chemical characterization of the seeds using gas chromatography. The results demonstrated that roasting partially increased the indicators of lipid oxidation in the oil extracted from roasted seeds, as well as the antioxidant activity of the seeds. The optimal roasting conditions were determined using CCD and RSM, resulting in an optimized temperature of 134.28 °C and 18.84 min. The fatty acid contents were not significantly affected by the roasting intensity, whereas a higher presence of amino acids was found in the seeds roasted at 140 °C for 15 min. In conclusion, it is suggested that the optimal roasting conditions for enhancing amino acid presence, improving antioxidant activity, and maintaining oxidative stability in sacha inchi seeds fall within the temperature range of 134-140 °C and a roasting duration of 15-20 min.

Forastero and Criollo cocoa beans, differences on the profile of volatile and non-volatile compounds in the process from fermentation to liquor

Cocoa bean fermentation is an important process because during this process, aroma compounds are produced, the astringency decreases, and the embryo dies. The fermentation processes of the Criollo and Forastero types have been studied separately without comparing them at the same time and in the same place. The aim of this work was to determine differences in the profile of volatile and nonvolatile compounds of Criollo and Forastero cocoa from the fermentation process to the final stage of obtaining the liquor. The experiments were carried out at the same time in the Maya region. Volatile compounds were determined by HS-SPME GC-MS (headspace solid phase-microextraction with gas chromatography-mass spectrometry). Sugars, organic acids, and alkaloids were determined by ultrahigh-performance liquid chromatography (UHPLC-PDA/UV). Criollo cocoa liquor was defined by the volatile and nonvolatile compounds such as acetic acid, phenylethyl alcohol, benzaldehyde, 2-phenylethyl acetate, acetophenone and 3-methylbutanal., which are associated with sour, honey, almond, flowery and chocolate aroma. Forastero cocoa liquor was represented with a significant difference by acetic acid, isobutyl acetate, 2,3-diethyl-5-methylpyrazine and ethyl octanoate and these could provide aroma descriptors such as sour, fruity and nutty. This study characterized for the first time the dynamics of volatile compounds during the fermentation, drying, and roasting stages and in the final cocoa liquor of Criollo and Forastero from cocoa beans of the same origin.

Effects of roasting on alkylpyrazin compounds and properties of cocoa powder

The volatile flavor compounds are the most important indicators of the quality of cocoa beans, among which pyrazines are considered as the main and key groups affecting the cocoa flavor. In cocoa processing, roasting is an important stage in the technical treatment of cocoa and has a significant impact on chemical properties of cocoa and its flavor. The present study aimed to assess the impact of roasting (temperature and time) on alkyl pyrazines, as key flavor compounds, via gas chromatography-mass spectrometry. Additionally, other properties, including color, polyphenols, chemical properties, and sensory attributes of cocoa powder were investigated. The results indicated that with the change in roasting time and temperature, these properties changed significantly. The cocoa powder roasted at 140 °C for 40 min had the highest browning index value (OD460/OD525), tetramethylpyrazine to trimethylpyrazine (TMP/TrMP) ratio, and sensory evaluation score and the lowest polyphenol content compared to the other samples.

Quality Evaluation of Fair-Trade Cocoa Beans from Different Origins Using Portable Near-Infrared Spectroscopy (NIRS)

Determining cocoa bean quality is crucial for many players in the international supply chain. However, actual methods rely on a cut test protocol, which is limited by its subjective nature, or on time-consuming, expensive and destructive wet-chemistry laboratory procedures. In this context, the application of near infrared (NIR) spectroscopy, particularly with the recent developments of portable NIR spectrometers, may represent a valuable solution for providing a cocoa beans' quality profile, in a rapid, non-destructive, and reliable way. Monitored parameters in this work were dry matter (DM), ash, shell, fat, protein, total polyphenols, fermentation index (FI), titratable acidity (TA) and pH. Different chemometric analyses were performed on the spectral data and calibration models were developed using modified partial least squares regression. Prediction equations were validated using a fivefold cross-validation and a comparison between the different prediction performances for the portable and benchtop NIR spectrometers was provided. The NIRS benchtop instrument provided better performance of quantification considering the whole than the portable device, showing excellent prediction capability in protein and DM quantification. On the other hand, the NIRS portable device, although showing lower but valuable performance of prediction, can represent an appealing alternative to benchtop instruments for food business operators, being applicable in the field.

Box fermentation and solar drying improve the nutrient composition and organoleptic quality of chocolate from cocoa beans

Chocolate is a well-liked and popular food product made from the cocoa bean. The objective of this research was to evaluate the effects of box fermentation and solar drying of cocoa bean on chocolate quality. Fermentation was carried out in a perforated wooden box for 168 h with periodic turning after every 48 h. The succession of microorganisms during fermentation and total microbial count were monitored. Both the fermented and unfermented samples were solar dried. During drying the change in weight of the beans, amount of solar radiation, and ambient wind speed of the atmosphere were measured. The approximate nutrient (crude protein, crude fat, total ash, crude fiber, and carbohydrate) and phytochemical (phenol) contents of the dried cocoa beans were evaluated. Sensory properties of chocolate, produced from the two samples (box fermented and dried as well as unfermented and dried) were compared. The initial temperature of the fermenting cocoa mash was 30°C. It rose to 46°C by the 96th h of fermentation and sharply declined to 38°C by the 120th h. Candida, Pseudomonas and Staphylococcus spp were probable organisms identified with the fermenting mass at the initial stage of the fermentation. Lactic acid bacteria dominated after 72 h. Bacillus spp was also observed until the 168th h. Solar drying of unfermented bean lasted for 4 days, while that of fermented bean lasted for 3 days. Fermentation increased the crude protein, total ash and carbohydrate contents of the cocoa beans. It also improved the appearance, and aroma of chocolate from the cocoa beans.

The impact of roasting on cocoa quality parameters

Roasting is an essential process in cocoa industry involving high temperatures that causes several physicochemical and microstructural changes in cocoa beans that ensure their quality and further processability. The versatility in roasting temperatures (100 - 150 °C) has attracted the attention of researchers toward the exploration of the effects of different roasting conditions on the color, proximal composition, cocoa butter quality, concentration of thermolabile compounds, formation of odor-active volatile organic compounds, generation of melanoidins, production of thermal processes contaminants in cocoa nibs, among others. Some researchers have drowned in exploring new roasting parameters (e.g., the concentration of water steam in the roasting chamber), whilst others have adapted novel heat-transfer techniques to cocoa nibs (e.g., fluidized bed roasting and microwaves). A detailed investigation of the physicochemical phenomena occurring under different cocoa roasting scenarios is lacking. Therefore, this review provides a comprehensive analysis of the state of art of cocoa roasting, identifies weak and mistaken points, presents research gaps, and gives recommendations to be considered for future cocoa studies.

Dark chocolate: An overview of its biological activity, processing, and fortification approaches

Dark chocolate gets popularity for several decades due to its enormous health benefits. It contains several health-promoting factors (bioactive components - polyphenols, flavonoids, procyanidins, theobromines, etc, and vitamins and minerals) that positively modulate the immune system of human beings. It confers safeguards against cardiovascular diseases, certain types of cancers, and other brain-related disorders like Alzheimer's disease, Parkinson's disease, etc. Dark chocolate is considered a functional food due to its anti-diabetic, anti-inflammatory, and anti-microbial properties. It also has a well-established role in weight management and the alteration of a lipid profile to a healthy direction. But during the processing of dark chocolate, several nutrients are lost (polyphenol, flavonoids, flavan 3 ol, ascorbic acid, and thiamine). So, fortification would be an effective method of enhancing the overall nutrient content and also making the dark chocolate self-sufficient. Thus, the focus of this review study is to gather all the experimental studies done on dark chocolate fortification. Several ingredients were used for the fortification, such as fruits (mulberry, chokeberries, and elderberries), spices (cinnamon), phytosterols, peanut oil, probiotics (mainly Lactobacillus, bacillus spices), prebiotics (inulin, xanthan gum, and maltodextrin), flavonoids, flavan-3-ols, etc. Those fortifications were done to raise the total antioxidant content as well as essential fatty acid content simultaneously reducing total calorie content. Sometimes, the fortification was done to improve physical properties like viscosity, rheological propertiesand also improve overall consumer acceptance by modifying its bitter taste.

Use of molecular networking to identify 2,5-diketopiperazines in chocolates as potential markers of bean variety

2,5-diketopiperazines are cyclic dipeptides found, among others, in chocolate. Although those compounds are contributing greatly to its pleasant bitterness, they can also be seen as interesting markers of cocoa beans processing. To evaluate the influence of bean variety and processing technology on the quantity of 2,5-diketopiperazines formed in chocolates, HPLC-MS/MS analyses were conducted, and a molecular network was built with the MS² data. This approach eases the identification of 2,5-diketopiperazines within complex datasets and allows to visualize the chemical diversity of all samples. Using this methodology, 33 dark chocolates were analysed. 18 different diketopiperazine were identified and quantified. Among them, cyclo(L-ile-L-val), cyclo(L-leu-L-ile) and cyclo(L-phe-L-phe) were, to the best of our knowledge, detected for the first time in chocolate. The molecular network allows the clear visualization of differences between samples. The principal component analysis revealed the clustering of small batch chocolate samples according to bean variety, suggesting that bean genotype has a strong influence on the 2,5-diketopiperazines content of bean-to-bar chocolates, regardless of the degree of roasting or the technological process used by the small producers. The presence of two unique diastereoisomers in the classical chocolates bought in the supermarket indicates that the beans have probably undergone a more intense heat treatment. This study proposes the use of 2,5-diketopiperazines as potential markers of cocoa beans variety, as well as an indicator of post-harvest processing and processing technology, and highlights the potential of the molecular networks in the field of food and drink innovation as a promising tool to understand the complex chemistry of flavours.

Effect of boiling and oven roasting on some physicochemical properties of sunflower seeds produced in Far North, Cameroon

The effects of different processing methods on proximate composition, total phenolic content, antioxidant activity, lipid oxidation, and mineral contents of sunflower seeds produced in Far North Region of Cameroon were evaluated. Mean moisture, ash, lipid, protein, fiber, and carbohydrate contents of raw sunflower seeds were 6.60%, 2.55%, 44.65%, 20.17%, 4.08%, and 21.25%, respectively. The changes in moisture, ash (excepted in boiled samples), lipid, protein, fiber, and carbohydrate (excepted in roasted samples) were found to be significant for all cooking methods. Ash and lipid contents of samples roasted at 120°C were found to be significant when compared with other cooking methods. Antioxidant activity increased with treatment. After processing, the acid, peroxide, and thiobarbituric acid values increased significantly, whereas iodine value decreased. The roasting process improved the induction time, and samples roasted at 120°C were found to have the highest induction time (2.29 ± 0.09 hr). Raw sunflower seeds were good sources of potassium (K), magnesium (Mg), calcium (Ca), iron (Fe), zinc (Zn), and manganese (Mn). Increase in contents of Ca, Mg, Zn, Cu, and Fe was observed during processing. Roasting compared with boiling appeared to be the best cooking method of sunflower seeds concerning nutrient content, antioxidant stability, and lipid stability.

Traceability of polyphenols in cocoa during the postharvest and industrialization processes and their biological antioxidant potential

Noncommunicable diseases, the leading cause of mortality around the world, are responsible for approximately 75% of premature adult deaths (ages 30-69). To tackle this issue, a healthy diet based on functional foods, including cocoa and its derivatives, has been increasingly promoted. The polyphenols present in cocoa have been of interest due to their antioxidant potential and their possible protective role in the context of noncommunicable diseases, such as diabetes and cardiovascular conditions. However, during cocoa postharvest and industrialization, the concentration of these bioactive compounds is reduced, possibly affecting their health-promoting properties. Therefore, this paper reviews in the literature in this field to find the total polyphenol content in cocoa during the postharvest and industrialization processes in order to define concentration ranges as a reference point for future research. In addition, it discusses in vitro and in vivo studies into the biological antioxidant potential of cocoa and its derivatives. This review covers publications in indexed databases from 2010 to 2020, their data were processed and presented here using box plots. As a result, we identified the concentration ranges of polyphenols depending on the type of matrix, treatment and country, as well as their relationship with the main bioactive compounds present in cocoa that are associated with their possible antioxidant biological potential and health-related benefits.

Chemical and biological properties of cocoa beans affected by processing: a review

Cocoa (Theobroma cacao L.) is widely cultivated in tropical countries. The cocoa beans are a popular ingredient of confectionery. Cocoa beans contain various chemicals that contribute to their bioactivity and nutritional properties. There has been increasing interest in developing cocoa beans for "healthy" food products. Cocoa beans have special combination of nutrients such as lipids, carbohydrates, proteins and other compounds of biological activities. The bioactive phytochemicals include methylxanthines, polyphenols, biogenic amines, melanoidins, isoprostanoids and oxalates. These phytochemicals of cocoa are related to various in vivo and in vitro biological activities such as antioxidation, anti-cancer, anti-microbial, anti-inflammation, anti-diabetes, cardiovascular protection, physical improvement, anti-photoaging, anti-depression and blood glucose regulation. The potential of bioactive compounds in cocoa remains to be maximized for food and nutritional applications. The current processing technology promotes the degradation of beneficial bioactive compounds, while maximizing the flavors and its precursors. It is not optimized for the utilization of cocoa beans for "healthy" product formulations. Modifications of the current processing line and non-conventional processing are needed to better preserve and utilize the beneficial bioactive compounds in cocoa beans.

An overview of conventional and emerging techniques of roasting: Effect on food bioactive signatures

Roasting is a food processingtechnique that employs the principle of heating to cook the product evenly and enhance the digestibility, palatability and sensory aspects of foods with desirable structural modifications of the food matrix. With the burgeoning demand for fortified roasted products along with the concern for food hygiene and the effects of harmful compounds, novel roasting techniques, and equipment to overcome the limitations of conventional operations are indispensable. Roasting techniques employing microwave, infrared hot-air, superheated steam, Revtech roaster, and Forced Convection Continuous Tumble (FCCT) roasting have been figuratively emerging to prominence for effectively roasting different foods without compromising the nutritional quality. The present review critically appraises various conventional and emerging roasting techniques, their advantages and limitations, and their effect on different food matrix components, functional properties, structural attributes, and sensory aspects for a wide range of products. It was seen that thermal processing at high temperatures for increased durations affected both the physicochemical and structural properties of food. Nevertheless, novel techniques caused minimum destructive impacts as compared to the traditional processes. However, further studies applying novel roasting techniques with a wide range of operating conditions on different types of products are crucial to establish the potential of these techniques in obtaining safe, quality foods.

Effect of Fermentation, Drying and Roasting on Biogenic Amines and Other Biocompounds in Colombian Criollo Cocoa Beans and Shells

The composition of microbiota and the content and pattern of bioactive compounds (biogenic amines, polyphenols, anthocyanins and flavanols), as well as pH, color, antioxidant and reducing properties were investigated in fermented Criollo cocoa beans and shells. The analyses were conducted after fermentation and drying (T1) and after two thermal roasting processes (T2, 120 °C for 22 min; T3, 135 °C for 15 min). The fermentation and drying practices affected the microbiota of beans and shells, explaining the great variability of biogenic amines (BAs) content. Enterobacteriaceae were counted in a few samples with average values of 10³ colony forming units per gram (CFU g⁻¹), mainly in the shell, while Lactobacillus spp. was observed in almost all the samples, with the highest count in the shell with average values of 10⁴ CFU g⁻¹. After T1, the total BAs content was found to be in a range of 4.9÷127.1 mg kg⁻¹_DFW; what was remarkable was the presence of cadaverine and histamine, which have not been reported previously in fermented cocoa beans. The total BAs content increased 60% after thermal treatment T2, and of 21% after processing at T3, with a strong correlation (p < 0.05) for histamine (ß = 0.75) and weakly correlated for spermidine (ß = 0.58), spermine (ß = 0.50), cadaverine (ß = 0.47) and serotonine (ß = 0.40). The roasting treatment of T3 caused serotonin degradation (average decrease of 93%) with respect to unroasted samples. However, BAs were detected in a non-alarming concentration (e.g., histamine: n.d ÷ 59.8 mg kg⁻¹_DFW; tyramine: n.d. ÷ 26.5 mg kg⁻¹_DFW). Change in BAs level was evaluated by principal component analysis. PC1 and PC2 explained 84.9% and 4.5% of data variance, respectively. Antioxidant and reducing properties, polyphenol content and BAs negatively influenced PC1 with both polyphenols and BA increasing during roasting, whereas PC1 was positively influenced by anthocyanins, catechin and epicatechin.

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.

Effect of Roasting on the Phytochemical Properties of Three Varieties of Marble Vine (Dioclea reflexa) Using Response Surface Methodology

This study assessed the optimum roasting conditions on the phytochemical properties of three varieties of Dioclea reflexa seeds using response surface methodology. Roasting conditions were varied using temperature (110°C~200°C) and time (10~40 min). Phytochemical components (phenolics, tannin, flavonoids, cardiac glycoside, and steroids) of the seeds were screened and estimated. The study showed that availability of phytochemical activities was heat-dependent. An increase in roasting temperature beyond 110°C for 10 min resulted in a decrease in total phenolic (TP) and flavonoid (TF) contents. However, prolonged durations of roasting favored increased amounts of TP and TF in dark and light varieties. Total sterol, tannin, and cardiac glycoside contents increased with increasing roasting temperature and time. The desirability of the models were 0.76, 0.74, and 0.72 for black, dark brown, and light brown, respectively. The coefficients of regression (R2), ranged from 0.66 to 0.98 signifying accuracy of the model. The following models (cubic, quadratic, and 2 factor interaction) were significant (P≤0.05). We found that roasting time influenced the phytochemical properties of D. reflexa to a greater extent than temperature. The optimum roasting temperature and time was found to beat 110°C, 35 min, 40 min, and 32 min in black, dark brown, and light brown varieties, respectively. Roasting conditions significantly affects the phytochemical contents of three varieties of D. reflexa seed flour (P<0.05). Therefore, D. reflexa holds the potential to be used in development of functional foods and in therapeutic applications to promote health.

Effect of boiling and roasting on the physicochemical properties of Djansang seeds (Ricinodendron heudelotii)

This study was aimed at determining the effect of boiling and roasting on physicochemical properties of Djansang seeds. Dried Djansang seeds were divided into three groups: one group was boiled for 5, 10, and 15 min; another group was traditionally roasted for 5, 10, and 15 min, and the last group was left unprocessed and served as the control. Polyphenols were extracted from the processed seeds using the maceration method, and their content and antioxidant activity were evaluated. Oils were extracted from the dried seeds by Maceration method, and the quality was analyzed by determining their peroxide value (PV), thiobarbituric acid value (TBA), iodine value (IV), and acid value (AV). The changes in proximate composition and mineral content of the processed samples were also evaluated using standard methods. Results showed that traditional roasting significantly decreases (p < .05) the polyphenol content and antioxidant activity of Djansang seeds as compared to boiling. The analysis of oil showed that traditional roasting and boiling significantly reduce the quality of Djansang seed oil (PV: 10.85-38.49 meq O2/kg; TBA: 1.80-3.20 ppm; AV: 0.28%-0.82%; and IV: 104.27-98.11 g I2/g for roasted samples, and PV: 10.85-27.52meq O2/kg; TBA: 1.45-2.28 ppm; AV: 0.56%-0.96%; and IV: 105.87-102.96 g I2/g for boiled samples) compared to the control (PV: 9.96 meq O2/kg; TBA: 1.01 ppm; AV: 0.11%; and IV: 104.83 g I2/g) and that traditionally roasted samples were the most affected. The proximate and mineral composition of Djansang was also affected during processing. Boiling for 5 and 10 min (BNS 5 min and 10 min) and traditional roasting for 5 min (TRNS 5 min) appear to be the best processing methods of Djansang for production of Djansang-based foods like Djansang sauce.

Comparison of the Total Polyphenol Content and Antioxidant Activity of Chocolate Obtained from Roasted and Unroasted Cocoa Beans from Different Regions of the World

The polyphenol content of cocoa beans and the products derived from them, depend on the regions in which they are grown and the processes to which they are subjected, especially temperature. The aim of the study was to compare the total content of polyphenols and antioxidant activity of chocolates obtained from roasted and unroasted cocoa beans. The chocolates produced from each of the six types of unroasted beans and each of the five types of roasted beans were investigated. The seeds came from Ghana, Venezuela, the Dominican Republic, Colombia and Ecuador. The highest total polyphenol content was determined in cocoa beans originating from Colombia and in the chocolates obtained from them. A higher content of total polyphenols was found in unroasted cocoa beans, which indicates the influence this process had on the studied size. The ability to scavenge free DPPH radicals was at a high level in both the beans and the chocolates produced from them, irrespective of the region where the raw material was grown. A positive correlation between the total polyphenol content and the ability to scavenge free radicals was found.