Bean Cotyledons Research Articles

Effect of cooking treatment on the formation mechanism and physicochemical properties of mung bean (Vigna radiata L.) paste

For the formation of mung bean paste, heat treatment is required where different process conditions will affect the degree of the denatures. The protein on the exterior surface of the cotyledon cells encapsulates the starch particles, thereby triggering the disintegration and relation of pectin present in the intercellular spaces between the mung bean cotyledon cells, namely the resultant to form mung bean paste. The optimum processing conditions of mung bean paste were investigated by response surface methodology using three levels (such as soaking time, cooking temperature, and time) of response surface analysis. Complete information on the physical properties and microstructure with color changes during the cooking of mung beans was established to observe the changes in the color of mung beans after cooking. The results showed that a high yield (65%) mung bean paste with minimally damaged starch (1.5%) was obtained by soaking at 30 °C for 2 h and cooking at 110 °C for 40–50 min. To the best of our knowledge, no study has investigated the formation mechanism and physicochemical properties of mung bean paste. Various physicochemical changes in mung beans were analyzed to reveal the production of mung bean paste under optimal conditions, which will help factories precisely control the production quality of mung bean paste-based foods.

Air-drying characteristics of fresh and pretreated (African Oil Bean) <I>Pentaclethra macrophylla benth.</i> cotyledons

Processing of African Oil Bean Cotyledons (AOBC), a valuable source of protein has been a bottleneck because of the associated drudgery. In addition, the shelf life of the processed bean is very short; the cotyledon turns green shortly during storage due to putrefaction. On the basis of the above, there is a need to produce shelf-stable cotyledons which could be rehydrated when needed. Three portions were separately soaked in each solution of sodium chloride (3 %), sodium meta-bisulfite (300 ppm), ascorbic acid (300 ppm) for 1h, and one portion were subjected to natural fermentation for three days, while the other was used as control. All the samples (single and double cotyledons) were oven-dried at 50, 60, 70, and 80o C to constant weight. The dehydration rate of AOBC decreased gradually until the water activity of the oil bean cotyledon reduced to less than one. Moisture diffusivity increased from 4.9061×10-10 – 2.091 × 10-9 m2/s, and varied with drying temperature, thickness, and pretreatments. Midilli and Kucuk model (R2 = 0.9702 - 0.9940) showed a better fit than other drying models. Effective moisture diffusivity is direct of the samples is reliant on air-drying temperature and can be described by the Arrhenius equation. The activation energy of drying of the African Oil Bean cotyledon was in the range of 10.29 – 27.12 kJ/mol. Finally, the addition of preservatives proved to be highly effective on the drying rate and the other studied parameters as well as the shelf stability of the AOBC.

Targeted hydrothermally induced cell biopolymer changes explain the in vitro digestion of starch and proteins in common bean (Phaseolus vulgaris) cotyledons.

Digestion of macro-nutrients (protein and starch) in pulses is a consequence of the interplay of both extrinsic (process-related) and intrinsic (matrix-dependent) factors which influence their level of encapsulation and physical state, and therefore, their accessibility by the digestive enzymes. The current work aimed at understanding the consequences of hydrothermally induced changes in the physical state of cell biopolymers (cell wall, protein, and starch) in modulating the digestion kinetics of starch and proteins in common beans. The hydrothermal treatments were designed such that targeted microstructural/biopolymer changes occurred. Therefore, bean samples were processed at temperatures between 60 and 95 °C for 90 minutes. It was demonstrated that these treatments allowed the modulation of starch gelatinization, protein denaturation and cell separation. The specific role of hydrothermally induced starch gelatinization and protein denaturation, alongside enhanced cell wall permeability on the digestion kinetics of common bean starch and proteins is illustrated. For instance, bean samples processed at T > 70 °C were marked by higher levels of starch digestibility (Cf values above 47%) compared to the partially (un-)gelatinized samples (processed at T ≤ 70 °C) (Cf values below 35%). Similarly, samples processed at T > 85 °C exhibited significantly higher levels of protein digestibility (Cf values above 47%) resulting from complete protein denaturation. Moreover, increased permeability of the cell wall to digestive enzymes in these samples (T > 85 °C) increased levels of digestibility of both gelatinized starch and denatured proteins. This study provides an understanding of the potential use of hydrothermal processing to obtain pulse-based ingredients with pre-determined microstructural and nutritional characteristics.

Pengaruh waktu induksi dan ZPT terhadap pertumbuhan kalus kotiledon kacang panjang (Vigna unguiculata subsp. sesquipedalis)

Yard-Long bean plants are an agricultural commodity that has great potential to be developed because they are easy to cultivate, their market share is also quite high but there are still problems in meeting the need for sufficient seeds and they are still susceptible to pests and disease. Therefore, efforts need to be made to increase production and induce variations. One method that can be used is tissue culture for the induction of somaclonal variations and/or the formation of transgenic plants. This study aims to determine the effect of variations in callus initiation time and the effect of Plant Growth Regulators (PGR) administration on the growth of long bean cotyledon explant callus. Seed sterilization was carried out using detergent, 10% sodium hypochlorite, 70% alcohol and sterile distilled water. The results of the research showed that variations in callus initiation time on MS media with the addition of 2,4-D PGR and the use of several variations of PGR in subcultures were able to initiate callus and influence callus size, callus color, and the percentage of browning of Yard-long bean cotyledon explants. Callus initiation time of 4 weeks with a combination of 2 ppm BAP concentration with 0.1 ppm IAA produced the largest callus size and brownish white callus color. The addition of PGR during subculture had a smaller browning percentage than the treatment without PGR.

Chemical and microstructural characterization of easy- and hard-to-cook Jack bean (Canavalia ensiformis (L.) DC.) collections

Differences in the microstructure and the chemical composition of pectic polymers were investigated from three Jack bean collections with different hard-to-cook (HTC) levels, as confirmed by the optimal cooking time analysis. These collections showed different cell and starch granule sizes, where the hardest-to-cook bean (Jombang collection) had the smallest maximum cell perimeter (285 μm), the smallest starch granule perimeter (98 μm), and the highest frequency of small intercellular space indicating more linkage in the middle lamella. No significant difference was observed in the frequency of small intercellular spaces between Malang and Cilacap despite having different optimal cooking times. Jack bean cotyledon cell walls were mainly composed of insoluble polysaccharide rich in arabinose and galactose. The beans contained high covalently bound pectin fractions (NEF) ranging from 78% to 83%. Higher bound phenolics (ferulic acid) were found with the increase in the optimal cooking times of the collections. Overall, the findings suggest the occurrence of cell wall linkage and highlight the importance of ferulic acid pectin crosslink in HTC Jack bean. This study could help develop strategies to reduce cooking time to promote the utilization of Jack bean.

The Drying Kinetics and CFD Multidomain Model of Cocoa Bean Variety CCN51.

The CCN51 cocoa bean variety is known for being highly resistant to diseases and temperature variation and for having a relatively low cultivation risk for the producers. In this work, a computational and experimental study is performed to analyze the mass and heat transfer within the bean when dried by forced convection. A proximal composition analysis is conducted on the bean testa and cotyledon, and the distinct thermophysical properties are determined as a function of temperature for an interval between 40 and 70 °C. A multidomain CFD simulation, coupling a conjugate heat transfer with a semiconjugate mass transfer model, is proposed and compared to the experimental results based on the bean temperature and moisture transport. The numerical simulation predicts the drying behavior well and yields average relative errors of 3.5 and 5.2% for the bean core temperature and the moisture content versus the drying time, respectively. The moisture diffusion is found to be the dominant mechanism in the drying process. Moreover, a diffusion approximation model and given kinetic constants present a good prediction of the bean's drying behavior for constant temperature drying conditions between 40 and 70 °C.

Bean softening during hydrothermal processing is greatly limited by pectin solubilization rather than protein denaturation or starch gelatinization

The rate liming step of bean softening during cooking was evaluated. Red kidney beans (fresh/non-aged and aged) were cooked at different temperatures (70–95 °C) and their texture evolution established. Softening of beans (loss of hard texture) with cooking and increasing cooking temperature was evident at ≥ 80 °C more so for non-aged than aged beans, evidencing hard-to-cook development during storage. Beans at each cooking time and temperature were subsequently classified into narrow texture ranges and bean cotyledons in the most frequent texture class evaluated for the extent of starch gelatinization, protein denaturation and pectin solubilization. During cooking, starch gelatinization was shown to precede pectin solubilization and protein denaturation, with these reactions progressing faster and to a greater extent with increasing cooking temperature. At 95 °C for instance (practical bean processing temperature), complete starch gelatinization and protein denaturation is attained earlier (∼10 and 60 min cooking, respectively and at comparable time moments for both non-aged and aged beans) than plateau bean texture (∼120 and 270 min for non-aged and aged beans)/plateau pectin solubilization. The extent of pectin solubilization in the cotyledons was consequently most correlated (negatively, r = 0.95) with and plays the most significant role (P < 0.0001) in directing the relative texture of beans during cooking. Ageing was shown to significantly retard bean softening. Protein denaturation plays a less significant role (P = 0.007) while the contribution of starch gelatinization is insignificant (P = 0.181). Thermo-solubilization of pectin in bean cotyledons is therefore the rate limiting step of bean softening towards attaining a palatable texture during cooking.

Advancement in Genomics and Molecular Marker Technologies for Breeding of Faba Bean with Low Vicine-convicine Content: A Review

Faba bean (Vicia faba L.), is a popular legume crop due to its high protein content (22-38.2%), dietary fibre (12%), medicinal and nutritional values and environmental benefits. It is considered as an excellent source of protein, particularly in developing countries where people cannot afford to buy meat. It also has antioxidant, anti-inflammatory, antiviral, anticancer, anti-diabetic and anti-atherosclerotic effects. But the presence of some key anti-nutritional factors, such as vicine and convicine, tannins, phytic acid etc. restricts the potential utilization of this crop as food and feed. Vicine and convicine are the thermostable, glucosidic aminopyrimidine derivatives that accumulate in the cotyledons of faba bean during seed development and maturity and cause “Favism” or haemolytic anaemia upon consumption by individuals having deficiency of glucose 6-phosphate dehydrogenase enzyme. As globally millions of people are genetically predisposed to such condition, it is highly desirable to eliminate these compounds from faba bean without compromising yield and other quality characteristics. In this review, we have highlighted the recent advancement in the field of genomics and molecular marker technologies for an easy and efficient selection of faba bean with low vicine and convicine content and the strategies to deploy these efficient tools in the future molecular breeding programs in faba bean.

Novel insights into the role of the pectin-cation-phytate mechanism in ageing induced cooking texture changes of Red haricot beans through a texture-based classification and in situ cell wall associated mineral quantification

Utilization of common beans is greatly hampered by the hard-to-cook (HTC) defect induced by ageing of the beans under adverse storage. Large bean-to-bean variations exist in a single batch of beans. Therefore, a texture-based bean classification approach was applied in this detailed study on beans with known textures, to gain in-depth insights into the role of the pectin-cation-phytate mechanism in relation to the texture changes during subsequent cooking of Red haricot fresh and aged beans. For the first time, a correlation between the texture (exhibited after cooking) of a single bean seed before ageing (fresh) and its texture after ageing was established. Furthermore, scanning electron microscopy coupled with energy dispersive spectrometry (SEM-EDS) based in situ cell wall associated mineral quantification revealed that the cell wall associated Ca concentration was significantly positively correlated with the texture of both fresh and aged cooked Red haricot bean cotyledons, with ageing resulting in a significant enrichment of Ca at the cell wall. These additional Ca cations originate from intracellular phytate hydrolysis during ageing, which was shown to affect the texture distribution of aged beans during cooking significantly. The relocation of the mineral cations from the cell interior to the cell wall occurs mainly during storage rather than subsequent soaking of the cotyledons. In addition, the pectin-cation-phytate hypothesis of HTC was further confirmed by demethylesterification of the cell wall pectin and increased pectin-Ca interactions upon ageing of the cotyledons, finally leading to HTC development of the cotyledon tissue.

Cell wall polysaccharide changes and involvement of phenolic compounds in ageing of Red haricot beans (Phaseolus vulgaris) during postharvest storage

Cell wall material was isolated from selected non-aged and aged Red haricot bean cotyledons using a texture-based classification approach. Pectin-depleted residual cell wall fractions were obtained by sequential pectin extraction and were characterized to investigate in situ cell wall related molecular changes upon ageing during adverse storage of the beans. Particularly, involvement of phenolic compounds in cell wall strengthening during the ageing process, resulting in the hard-to-cook defect, was evaluated. Results show that ageing induces substantial changes at a cell-wall-structural level in the Aged sample compared to the Non-aged sample, with mainly vanillin, 4-hydroxybenzoic acid and 4-hydroxybenzaldehyde covalently bound with sugar side-chains of pectin and/or involved in lignification-like mechanisms. FT-IR spectroscopy coupled with chemometric analysis reveals that lignin-like phenolic-cell wall polymers, which are known to reinforce cell wall structure, are present in the cell wall polysaccharide network of the Aged sample, and are therefore contributing factors to the hard-to-cook development during Red haricot bean ageing.

Physiochemical and thermal characterisation of faba bean starch

The structure and physicochemical properties of starch isolated from the cotyledon and hull of faba beans and from wheat (as reference) were examined using 16 different methods. The amylose content in faba bean cotyledon and hull starch was 32% and 36%, respectively, and that in wheat starch was 21%. The faba bean cotyledon and hull starch were structurally alike both displaying C-polymorphic pattern, a similar degree of branching and similar branch chain length distributions. Wheat starch had a significantly greater prevalence of short amylopectin chains (DP < 12) and a higher degree of branching. Granules in both faba bean starches exhibited surface cracks and were more homogenous in size than the smoother wheat starch granules. Gelatinisation temperature was higher for the faba bean starches, likely as an effect of high amylose content and longer starch chains delaying granular swelling. Cotyledon starch produced pastes with the highest viscosities in all rheological measurements, probably owing to larger granules. Higher prevalence of lipids and resistant starch reduced the viscosity values for hull starch. For all starches, viscosity increased at faster heating rates. During the rheological analyses, the samples were exposed to different instruments, heating rates and temperatures ranges, differing from standard rheological procedures, which could help predict how different processing techniques effect the final starch textures.Graphical abstract

Calcium transport and phytate hydrolysis during chemical hardening of common bean seeds

In this study, two chemical bean seed hardening methods were used to investigate the changes in cooking behavior associated with Ca2+ transport and phytate hydrolysis to better understand their role in the pectin-cation-phytate hypothesis. The texture evolution of fresh and hardened red kidney beans was evaluated, hardening being induced by soaking or in a CaCl2 solution (0.01 M, 0.05 M, 0.1 M) or sodium acetate buffer (0.1 M, pH 4.4, 41 °C). The beans soaked in a CaCl2 solution at higher concentrations or in sodium acetate buffer for a longer time exhibited a delayed cooking behavior. This study also explored the bio-chemical changes (calcium content in different bean substructures, phytate content and the pectin degree of methylesterification (DM) in the cotyledons) occurring in the beans during chemical hardening and cooking. The Ca2+ concentrations in the whole beans and cotyledons of beans soaked and cooked in CaCl2 solutions significantly increased while inositol hexaphosphate IP6 content showed no significant changes. This indicates that the delayed texture drop in this case results from the influx of exogenous Ca2+ in the cotyledons and seed coats during cooking while the IP6 was not hydrolyzed and did not release endogenous Ca2+. For beans soaked in sodium acetate buffer, phytate profiling showed increased hydrolysis of IP6 with longer soaking time, suggesting the migration of endogenous Ca2+ released from phytate hydrolysis contributing to the delayed cooking of these beans. These results indicate that both an exogenous Ca2+ influx during soaking and cooking and an endogenous Ca2+ replacement resulting from phytate hydrolysis can play an important role in the hardening of beans. In neither of the cases, a significant change in pectin DM was observed during chemical hardening, therefore limiting the delayed cooking to the role of Ca2+ transport. The outcome of both cases is inline with the basic principles of the pectin-cation-phytate hypothesis whereby pectin DM changes are hardly involved and different mechanisms of release/transport are involved.

Nutritious novel snacks from some of cereals, legumes and skimmed milk powder

This study was aimed to prepare and evaluate six different snacks included control (Yellow corn, PC) and five formulas (P1, P2, P3, P4, and P5) based on local available ingredients snacks (cereal s: yellow corn, wheat flour and broken rice and legumes: faba bean cotyledons and decorticated parched chickpea). Chemical composition, mineral elements, amino acid composition, in vitro protein digestibility (IVPD), C-PER and energy value in addition to sensory evaluation were determined of the snacks. Different extrudates were stored at RT up to 6 months since peroxide value was determined . Data revealed that protein content was increased of different products as: 14.9, 15.5, 12.7, 14.4 and 13.0 % in P1, P2, P3, P4, and P5, respectively compared to 6.89 % in the control product (PC).It was also shown that the total essential amino acids increased significantly and reached 46.87 g / 100 g protein (P4) compared to 40.24 in the control (PC).Denaturation of proteins during the extrusion processing increased the IVPD from 77.8% (PC) up to 89.3% (P4). Data also revealed that the complementing between cereal and legume and supplementing with dried skimmed milk improved all of minerals content, energy and C-PER in all snacks, Energy reached 381.16 compared to 345.65 kcal /100 g.(PC), while the C-PER reached 1.72 (P5) compared to 1.25 (PC). The sensory evaluation of the products was also conducted and it turned out that all of them were highly acceptable. The peroxide number also showed the high storage ability of the products under test up to 6 months at RT.

The moisture plasticizing effect on enzyme-catalyzed reactions in model and real systems in view of legume ageing and their hard to cook development

This study aims to understand the role of storage conditions (temperature, T and moisture content) in the reactions involved in the cation-pectin-phytate hypothesis, postulated to cause the Hard-to-cook (HTC) defect in beans as influenced by the plasticizing effect of moisture (glass transition ( T g ) concept). The enzyme catalysed reactions, demethylesterification of pectin and hydrolysis of phytic acid, were monitored respectively in simplified pectin and phytic acid/protein model systems. In addition, both reactions were studied in a real system, red kidney bean cotyledon during storage at 35 °C and different relative humidity conditions (6%, 54%, 66%, 72% and 82%) for 15 weeks. The T g -moisture relation of the model systems and the bean cotyledon were established by Dynamic Mechanical Thermal Analysis (DMTA). The T g -line, fitted using the Gordon-Taylor equation, was combined with the moisture sorption isotherm to create a stability diagram. The stability diagram obtained can be used to ascertain the biochemical stability during post-harvest ageing of beans. Results displayed that there was significant hydrolysis of phytic acid in the phytic acid/protein model system and the real system when stored above their glass transition values. On the other hand, in the model system the pectin degree of methylesterifcation (DM) did not significantly change during storage. In the real system, significant, although small, changes of the DM were noted when T - T g > 20 °C. An examination of the glass transition lines revealed that the reactions were influenced by the plasticizing effect of moisture. • The reactions in the cation-pectin-phytate hypothesis were studied in model and real systems. • Hydrolysis of phytic acid is controlled by glass transition. • Glass transition lines of red kidney bean cotyledon and its' cell wall polymers were created. • DMTA based T g lines are better suited for explaining (bio)chemical stability rather than TMCT. • Stability map supports in establishing suitable post-harvest storage conditions.

Flavan-3-ols Monomer and Oligomer, and Flavor Profiles of Chocolates Produced from Fermented Cocoa Beans under Different Roasting Degree in Taiwan

Taiwan cocoa beans were fermented in a wooden box by natural occurring microorganisms for seven days. Six types of chocolate were manufactured from the fermented cocoa beans under different roasting degree. The fermentation parameters including the count of microorganisms, fermenting mass temperature, pH value of the pulp and cotyledons of cocoa bean along with the fermentation time were determined. Furthermore, the flavan-3-ols monomer and oligomer (FMO) of chocolates were determined by normal phase HPLC and the volatile aroma compounds of the six types of chocolate were analyzed by electronic nose to identify the important flavors and odors. Primary component analysis (PCA) was performed to distinguish the flavor profiles among the chocolates. The sensory assessment was conducted to evaluate the organoleptic properties of the six types of chocolate and their overall acceptability. The results showed that the total amount of FMO and proanthocyanidins in the chocolate both decrease with the intensity of the roasting degree of cocoa beans. Twenty-three important volatile aroma compounds were identified by electronic nose analysis. Differences in the amount of each compound were determined in the investigated chocolate and these are expected to cause sensory differences among the six types of chocolate. As a result, chocolates produced from beans under medium roasting condition (130°C and 25min) rated the highest score of overall acceptability among the chocolates. It was significantly higher than those of chocolate produced from light roasting beans. On the other hand, chocolate produced from cocoa bean under light roasting degree was retained more content of the bioactive compounds and could be a potent candidate of health functional food. PCA was successful to discriminate the flavor profiles of the six types of chocolate produced from beans under different roasting degree and could be used as a tool to recognize the origin of chocolate product. These results of this study could provide an important approach for producing chocolate products with desired flavor properties and bioactive compounds that have positive benefits for human health.

Studying the influence of mungbean use on the structure-forming indicators of meat-plant systems based on veal, pork, chicken meat

This paper reports a study into the use of germinated mungbean as a promising raw material influencing the structure-forming indicators of meat systems during the production of meat-vegetable sausages. The content of iodine in the germinated mungbean and its anatomical parts has been examined using solutions of potassium iodide. A change in the phytic acid content and size of phytin globoloids has been established in mungbean malt depending on germination conditions. The influence of flour from germinated mungbean on the moisture-binding, moisture-retaining, fat-retaining abilities, as well as on the pH of meat systems based on veal meat, pork, chicken has been investigated. The reported set of studies is important as the defined patterns could make it possible to devise technologies for meat-vegetable sausages, to expand the range of enriched meat products. The result of this study has established that the degree of biotransformation of iodine into beans is influenced by the protein content in the native beans. Almost 90...95 % of iodine is accumulated in the cotyledons of beans in the protein fraction, 5...10 % ‒ in sprouts and roots. The rational range of potassium iodide concentrations in the germination solution is 76.5 g per 1,000 cm3, over 48 hours. Prolonging the germination time leads to microbiological damage to the bean mass. The germination process affects the reduction of phytic acid content, which is confirmed by a decrease in the diameter of phytin globoloids. It is rational to use in meat systems based on pork meat and veal meat 10 % of the developed flour by reducing meat raw materials. With this ratio of formulation ingredients, the maximum increase in the moisture-binding, moisture-retaining, and fat-retaining capacities of these meat systems is achieved. In the meat systems based on chicken meat, it is possible to increase a replacement part of up to 15 %. The reported set of studies is useful and important because it could form the basis for devising the technologies of meat-vegetable sausages to meet the needs of different segments of consumers

Why is phloem sap nitrate kept low?

Since the first description of phloem sap composition nearly 60 years ago, it is generally assumed that phloem sap does not contain nitrate and that there is little or no backflow of nitrate from shoots to roots. While it is true that nitrate can occasionally be absent from phloem sap, there is now substantial evidence that phloem can carry nitrate and furthermore, transporters involved in nitrate redistribution to shoot sink organs and roots have been found. This raises the question of why nitrate may or may not be present in phloem sap, why its concentration is generally kept low, and whether plant shoot-root nutrient cycling also involves nitrate. We propose here that phloem sap nitrate is not only an essential component of plant nutritional signaling but also contributes to physical properties of phloem sap and as such, its concentration must be controlled to ensure proper coordination of plant development and nutrient transport. This article is protected by copyright. All rights reserved.

The Influence on Phenolic, Aroma Compounds, Rheological and Sensory Properties of Chocolates by Different Strains Inoculated Fermentation

Four designed cocoa fermentations were conducted in separated wooden boxes with different strains inoculum. One was spontaneous fermentation with natural occurring microorganisms, another was inoculated with Saccharomyces cerevisiae, another was inoculated with Lactobacillus plantarum, and the other was inoculated with Acetobacter aceti. The experimental parameters, including the fermenting cocoa mass temperature, the pH value, the total acidity of the pulp and cotyledons of cocoa beans, along with the fermentation time were determined. Furthermore, the phenolic compounds (flavanols and procyanidins DP1-10) of chocolates were determined by normal phase HPLC. In addition, the rheological, textural properties, and color parameters of the chocolates were measured. Meanwhile, the electronic nose was used to analyze the aroma compounds of the investigated chocolates and the principal components analysis (PCA) was conducted to distinguish the flavor profiles among the chocolates. The consumer sensorial assessment was carried out to evaluate the organoleptic properties of chocolates and their overall acceptability. The quality of chocolates produced by the defined inoculum varied with each other with the exception of the FP and PAC content. Different inoculated fermentation methods affected the rheological, textural properties, and color parameters of the end product chocolates. Furthermore, they influenced the types and numbers of aroma compounds generated during fermentation. However, the impact is mainly on their levels of aroma compounds. From sensory point of view, chocolates produced from inoculated Acetobacter aceti BCRC12324 during fermentation had the highest score point of overall acceptability among the investigated chocolates. The high levels of 2-methylbutanal content occurred in this chocolate could be an adequate reply of this finding. The quality of chocolate from fermentation with Lactobacillus plantarum B0091 inoculum was similar to the others, but some properties such as rheological, textural, and flavor profiles were inferior and less pronounced, leading to a slightly poorer response by the sensory panel. PCA successfully discriminates the aroma profiles into four groups, providing a better visualization of the variation among the chocolates produced by the different strains. This attempt to manipulate the strains during cocoa fermentation is a new approach in Taiwan chocolate industry. By controlling the starter culture of fermentation properly, we could improve the quality and flavor profiles of chocolate with a consistent and more reliable production.

Evaluation of storage stability of low moisture whole common beans and their fractions through the use of state diagrams

A material science approach was explored towards understanding storage stability of common dry bean seeds. State diagrams of powders from distinct bean varieties were generated through determination of their glass transition temperatures (Tgs) using differential scanning calorimetry. Confronting the state diagrams with dry matter-temperature combinations during storage facilitated establishing the link between the relative position of the bean storage conditions along the Tg line and extent of hard-to-cook (HTC) development. Generally, Tg increases with dry matter content of the bean powders implying stability at increasingly higher temperatures attributed to the reduced plasticizing effect of water. Whereas Tg lines of powders of the different bean varieties were very similar, distinct differences were observed for the powders of bean substructures. At a given moisture content, the Tg of the cotyledon material was lower than that of the seed coat material and the Tg values of the whole bean powders were dominated by the cotyledon material. Cooking time analysis showed that whole beans stored above their Tg developed the HTC defect, this extent being correlated with the difference between storage temperature and Tg value. Considering the HTC development rate, (R-value, rate of change in cooking time with storage time over a period of 0–4 months or at 0 months of storage) the higher the difference between the storage temperature and the Tg value, the faster the change in cooking time during storage. Exploring the role of the major polymer components of bean cotyledon revealed that at a given moisture content, the cell wall material showed the lowest Tg values compared to the protein and starch isolates (Tg cell wall < Tg protein < Tg starch isolate). Confronting these values with the HTC development rates (change of cooking time with storage time) supports involvement of the cell wall material and probably protein changes in the development of this defect.

Influence of two anti-fungal Lactobacillus fermentum-Saccharomyces cerevisiae co-cultures on cocoa bean fermentation and final bean quality.

The growth of filamentous fungi during the spontaneous cocoa bean fermentation leads to inferior cocoa bean quality and poses a health risk for consumers due to the potential accumulation of mycotoxins. We recently developed anti-fungal cultures with the capacity to inhibit the growth of mycotoxigenic filamentous fungi on cocoa beans. However, it is not clear how these anti-fungal cultures affect the fermentation process and cocoa bean quality. For that, the anti-fungal co-cultures, Lactobacillus fermentum M017-Saccharomyces cerevisiae H290 (A) and Lb. fermentum 223-S. cerevisiae H290 (B), were applied to 180-kg box fermentations in Honduras in three time-independent replications each including a spontaneous control fermentation. The comparison of inoculated and spontaneous fermentation processes revealed that the co-cultures only marginally affected the fermentation process and cocoa bean quality. Microorganisms reached maximal levels of 6.2–7.6 log CFU/g of yeasts and acetic acid bacteria and 7.9–9.5 log CFU/g of lactic acid bacteria during all fermentations and led to maximal metabolite concentrations in bean cotyledons of 4–12 mg/g ethanol, 2–6 mg/g lactic acid and 6–14 mg/g acetic acid. The fermentation and drying processes resulted in 38–90 mg epicatechin equivalents/g in the cotyledons of dried beans. However, the co-cultures led to up to ten times higher mannitol levels in cotyledons of inoculated beans compared to beans during spontaneous fermentation, and caused a slower fermentation process, detectable as up to 8–12 °C lower temperatures in the centre of the fermenting pulp-bean mass and up to 22% lower proportions of well-fermented beans after drying. Co-culture B–with Lb. fermentum 223 –led to improved cocoa bean quality compared to co-culture A–with Lb. fermentum M017 –, i.e. cocoa beans with 0.5–1.9 mg/g less acetic acid, 4–17% higher shares of well-fermented beans and, on a scale from 0 to 10, to 0.2–0.6 units lower astringency, up to 1.1 units lower off-flavours, and 0.2–0.9 units higher cocoa notes. Therefore, the anti-fungal co-culture B is recommended for future applications and its capacity to limit fungal growth and mycotoxin production during industrial-scale cocoa bean fermentation should be investigated in further studies.