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Background: Stretchability is the most important sensory textural attribute considered by consumers of pounded yam. It is important both for the processor during pounding and for the consumer during consumption to measure this attribute while screening large populations of yam genotypes intended for advanced breeding and eventual adoption. Texture determined by sensory evaluation and consumer perception is time consuming and expensive. It can be instrumentally mimicked by texture analyser, thereby providing an efficient alternative screening tool. Results: Two instrumental methods (uniaxial extensibility and lubricated squeezing flow) were applied to assess the extensional properties of pounded yam. In order to evaluate the accuracy, repeatability and discrimination of the methods, six yam genotypes with contrasting extensional properties, previously evaluated by 13 panellists in terms of stretchability and moldability and by 99 participants randomly selected in terms of overall liking, were used. Both methods allowed the discrimination of different genotypes as a function of extensional properties. Principal components showed that the genotypes were grouped within separate components associated with specific sensory attributes and their related instrumental texture parameters. Moreover, significant correlations were found between uniaxial extensibility textural attributes, bi-extensional viscosity and consumer overall liking. However, the sensory attributes were not significantly correlated with instrumental data and consumer overall liking. Conclusion: Bi-extensional viscosity and uniaxial extensibility attributes can be used to discriminate and screen yam genotypes for their strechtability characteristics.

International audience; Germination is a traditional process and a re-emerging trend in healthy foods, resulting a progressively increase in scientific research on their nutritional traits and phytochemical contents. This review examines the physiological and biochemical changes during the germination sensu stricto in pulses, taking into consideration the genotype, environmental conditions, hormone control, and the metabolic transition from seed to seedling. Germination sensu stricto is achieved as soon as elongation of the radicle, implies heterotrophy metabolism; further thermal processing is needed before consumption. In contrast, seedlings production requires a long period of imbibition and can provide a ready-to-eat food product. Furthermore, proteins, carbohydrates, minerals, vitamins, and antinutritional compounds of pulses are described. Impacts of food processing, such as soaking, germination, and cooking, in nutritional and antinutritional values are also evaluated. The association of soaking, germination, and cooking increases the nutritional values of pulses by increasing protein/starch digestibility and vitamins content and by decreasing antinutritional compounds. The final plant-based product allows versatility in formulation to produce novel food products and/or ingredients with better nutritional content. This can encourage the scientific community, industry, and government to invest in research and development to increase germinated pulse-based food, to replace other products, or to develop new ones.

BACKGROUND: Boiled yam key quality attributes typical for West African consumers are: crumbly, easy to break, and sweet taste. New yam varieties are being developed but high or medium throughput tools to assess the required quality traits and their range of acceptance are limited. This study assessed the acceptance thresholds of these quality attributes and established the predictive models for screening yam varieties that meet the required consumers' preferences. RESULTS: Overall liking was associated with sweet taste, crumbly and easy to break (r values 0.502, 0.291 and -0.087, respectively). These parameters and selected biophysical parameters highly discriminated the boiled yam varieties. Crumbly texture and easy to break were well-predicted by penetration force and dry matter, whereas sweet taste by dry matter and sugar intensity. A high crumbliness and sweet taste are preferred (sensory scores above 6.19 and 6.22 for crumbly and sweet taste, respectively, on a 10 cm unstructured line scale), while a too high easiness to break is disliked (sensory scores ranging from 4.72 to 7.62). Desirable biophysical targets were between 5.1 and 7.1 N for penetration force, dry matter around 39% and sugar intensity below 3.62 g/100g. Some improved varieties fulfilled the acceptable thresholds, and the screening was improved through the deviation from optimum. CONCLUSION: The acceptance thresholds and the deviation from optimum for boiled yam assessed through the instrumental measurements are promising tools for yam breeders.

Ablo is a rice-based bread consumed in Southern Benin. We investigated the impact of pre-cooking conditions and starch characteristics on dough and Ablo physical properties. The solid-like behavior of doughs measured by rheological sweep tests appears significantly negatively correlated to Ablo quality; above a starch gelatinization level (7-8 %), the solid-like behavior of the doughs increased sharply and the fluidity decreased, leading to Ablo of poor quality. A comparison between three rice cultivars tends to show that rice with low amylose content and/or gelatinization temperature gives dough with higher fluidity and Ablo with lower density. In addition, a specific rheological test for measuring simultaneously dough expansion and rheological properties during heating has been developed. It shows that whatever the rice variety, thermal expansion of proofed dough begins and is followed by a dough/crumb transition. This innovative rheological test could be used for studying dough/crumb transition for other types of breads.

Thermal treatment applied during the cooking of pulses leads to denaturation and even aggregation of the proteins, which may impact protein digestibility. Thermal transitions of lentil, chickpea, and bean proteins were studied using differential scanning calorimetry (DSC). Protein-enriched samples were obtained by dry air classification of dehulled seeds and were heated to 160 °C, with water contents ranging from 0.2 to 4 kg/kg on a dry basis. The DSC peaks of the resulting endotherms were successfully modeled as overlapping Gaussian functions. The denaturation temperatures were modeled as a function of the temperature according to the Flory–Huggins theory. The modeling allows for the calculation of the degree of protein transition for any temperature and moisture condition. The denaturation diagrams reflect the different protein compositions of lentil, chickpea, and bean (particularly the 11S/7S globulin ratio). Chickpea proteins were more thermally stable than those from lentil and bean. Proteins underwent an irreversible transition, suggesting that unfolding and aggregation were coupled.

Seeds of Parkia biglobosa, also called African locust bean seeds (ALBSs), are used to produce a condiment by subjecting them to cooking, alkaline fermentation, and drying. The objective of this work was to monitor the evolution of the composition of ALBS during spontaneous fermentation. Results showed that the seeds at initial time contained mainly proteins (45%) and lipids (36%). During fermentation, the conversion of this initial composition took place to produce ammonium, free amino acids, and short-chain fatty acids (SCFAs) that accounted for 2%, 10%, and 1.5% dry basis, respectively, which explains the typical flavor of fermented ALBS. This release was also concomitant with biogenic amine production. Along with ammonium and SCFA release, pyrazines were the major volatile organic compounds. Composition modulation was well represented by a Verhulst equation in which the dynamic could be modified by the initial composition of the seed, the pre-cooking step, and the fermentation conditions (temperature and aeration). Practical applications: For nutritional and sustainability reasons, re-integration of vegetable in general and legumes, in particular in our diet, is a current trend. However, only dish that are appealing to consumers are concretely adopted. Fermentation of legumes is interesting in more than one way. It does not involve heat, so thermolabile molecules can be preserved and the financial and energetic costs are low. Biological interesting molecules are produced from the metabolism of microorganisms, and among them, volatile organic compounds that contribute to enhance the flavor of legume dishes. Soumbala is a meal and/or condiment obtained from the fermentation of African locust bean (Parkia biglobosa) seeds (ALBSs), a legume widely spread in west Africa. The final typical sensory properties are known to be due to the alkaline fermentation step by Bacillus species. This paper presents the kinetics of release of various compounds during spontaneous fermentation that may impact the sensory and nutritional properties of the final product. More precisely, the dynamic of the production of free amino acids, free fatty acids, volatile compounds, and biogenic amines are presented and discussed to give insights into the succession of important reactions to control the sensory and nutritional qualities of fermented ALBS (FALBS). This paper shows that further research are necessary to better understand and control the quality of not only FALBS but also similar protein-rich legumes to modulate the quality of the final products.

Prioritizing sensory attributes and consumer evaluation early in breeding trials to screen for end-user preferred traits could improve adoption rates of released genotypes. In this study, a lexicon and protocol for descriptive sensory analysis (DSA) was established for sweetpotato and used to validate an instrumental texture method for which critical values for consumer preference were set. The study comprised several phases: lexicon development during a 4-day workshop; 3-day intensive panel training; follow-up virtual training, evaluation of 12 advanced genotypes and 101 additional samples from two trials in 2021 by DSA and instrumental texture analysis using TPA double compression; and DSA, instrumental texture analysis and consumer acceptability tests on 7 genotypes in on-farm trials. The established sweetpotato lexicon comprising 27 sensory attributes enabled characterization and differentiation of genotypes by sensory profiles. Significant correlation was found between sensory firmness by hand and mouth with TPA peak positive force (r = 0.695 and r = 0.648, respectively) and positive area (r = 0.748, r = 0.715, respectively). D20, NAROSPOT 1, NASPOT 8, and Umbrella were the most liked genotypes in on-farm trials (overall liking = 7). An average peak positive force of 3700 gf was proposed as a minimum texture value for screening sweetpotato genotypes, since it corresponded with at least 46 % of consumers perceiving sweetpotatoes as just-about-right in firmness and a minimum overall liking of 6 on average. Combining DSA with instrumental texture analysis facilitates efficient screening of genotypes in sweetpotato breeding programs.

International audience; A first modeling approach was used to understand the behavior of folate in cowpea seeds during soaking at different temperatures (30 degrees C, 60 degrees C and 95 degrees C). Folic acid, 10-formylfolic acid, 5-methyltetrahydrofolate, and 5-formyltetrahydrofolate were quantified in both the seeds and the soaking water during the process. A 2D-axisymmetric seed soaking simulator was then built considering these 4 folate vitamers to simultaneously describe diffusion, oxidation and interconversion of the single vitamers. The model adjustments revealed the predominance of folate diffusion at 60 degrees C and 95 degrees C (apparent diffusivity 2-3 x 10(-11) m(2) s-(1))whereas at 30 degrees C enzymatic interconversions of all vitamers into 5-methyltetrahydrofolate were observed (reaction rate of 8.0 x 10(-5) s(-1) for 5-formyltetrahydrofolate). The results of this study allow us to recommend a preliminary soaking step to retain folate in seeds and to improve the bioavailability of folates for human nutrition.

Folate is a fundamental vitamin for metabolism in plants and humans. A modelling approach has been developed to characterize the reactivity of folates in cowpea seeds during germination at 30 °C, using a water-to-seed ratio of 1:1 (w/w). For this purpose, the concentrations of folic acid, 10-formylfolic acid, 5-methyltetrahydrofolate, 5-formyltetrahydrofolate and tetrahydrofolate were determined in seeds during germination times up to 96 h. Two reaction models were sequentially built and adjusted to experimental data to describe changes in concentration in cowpea seed during two germination phases: before 14 h and after 48 h. Results showed intense enzymatic interconversion of all folate vitamers into 5-methyltetrahydrofolate before 14 h of germination and high enzymatic production of 5-methyltetrahydrofolate, 5-formyltetrahydrofolate and tetrahydrofolate after 48 h of germination. This study suggests that a long germination process could be more beneficial than soaking to increase the production of bioavailable folates within the seed for human consumption.

The aromatic quality of chocolate requires the use of cocoa with high aromatic potential, this being acquired during the fermentation of cocoa beans. Traditional fermentation is still often carried out on a small scale with wild strains of yeasts and acetic bacteria and under poorly controlled conditions leading to cocoa quality ranging from best to worst. This study is the first part of a project aiming to control quality of cocoa to produce high aromatic quality chocolate by using a mixed starter of selected strains of yeast and acetic bacteria and by controlling the conditions of fermentation. To achieve this objective, a mathematical model of the alcoholic fermentation of cocoa beans has been developed. The growth, glucose consumption and ethanol production of Saccharomyces cerevisiae LM strain in synthetic broth were modeled for the most important intrinsic (pH, glucose, ethanol, free nitrogen and oxygen levels) and extrinsic (temperature, oxygen level) fermentation parameters. The model was developed by combining the effects of individual conditions in a multiplicative way using the gamma concept. The model was validated in liquid synthetic medium at two different inoculation levels 104 and 106 CFU/mL with an increase in temperature that recorded during spontaneous fermentations. The model clearly shows that the level of inoculation and the speed of the increase in temperature clearly drive yeast growth, while other factors including pH and ethanol, free nitrogen and oxygen levels have no significant impact on yeast growth.

International audience; Soumbala is made from African locust bean seeds (Parkia biglobosa), a legume widely spread in west Africa. It is a lipid and protein-rich condiment obtained by three main steps: cooking, fermentation and drying. Ten different analysis were made on AFLBS samples at each step with a particular focus on protein and lipid fates. Results showed that cooking decreased markedly the carbohydrate content leaving mainly proteins and lipids as substrates for fermentation. During this step, 20% of the proteins were converted into free amino acids, mainly glutamic acid and tyrosine. Significant biogenic amines release occurred and reached 50 mg per 100 g of dried ALBS. Di-glycerides and fatty acids increased markedly and represented 11% and 7% of the total lipids of dried ALBS. These results give a complete view of the nutritional characteristics of dried ALBS, its benefit but also its defects that arise during fermentation and not suppressed by the subsequent processing steps.

International audience; Cooking-induced conversion of starch, the major carbohydrate in pulses, is crucial for the digestibility of the seed. The gelatinization-melting transition of lentil, bean and chickpea starches was studied using Differential Scanning Calorimetry at different temperatures (T values ranged from 20 to 160 ◦C) and water contents (X from 0.2 to 3 kg kg 1 db). Gelatinization and melting endotherms were successfully modeled as two desummed Gaussian functions. This modeling enabled to generate the degree of starch conversion for any T and X conditions, a valuable indicator that could be used in predictive cooking models. As previously reported for melting, the temperature of gelatinization was found to depend on moisture in a way that can be modeledusing the FloryHuggins equation. The results suggest that starch undergoes melting transition irrespective of water content. The similar starch conversion diagram for the three pulses suggest that starches have similar thermal behavior.

Rice is the staple cereal in Senegal. Despite the many policies implemented over the last decade, Senegalese consumers still prefer imported over local rice. To understand this preference, this study compares consumer acceptability of three local rice samples versus two imported rice samples. Two focus groups and a consumer test with 120 women were carried out in the city of Saint‐Louis in Senegal. The results concerning consumption habits showed that about 85% of the surveyed women consume rice at least once a day (at lunch). The hedonic test showed that consumers appreciated all five rice samples, but the most liked samples were obtained from industrial processing of either local or imported whole and fragrant rice. The least liked sample was a local semi‐industrial rice, including 50% broken grains. The results of the just‐about‐right (JAR) test and check‐all‐that‐apply (CATA) test showed that the sensory descriptors such as white color, well‐cooked, and homogeneous grain size had an influence on the consumers’ choice of rice samples. However, the most important selection criteria were the homogeneous size of the rice grains, the absence of impurities, both of which are directly linked to the milling conditions, and fragrance, which is related to the variety. The origin of the rice samples did not influence the consumers’ choice. This study showed that local rice can compete with imported rice if processing is improved in some small‐scale rice mills., The article compares the consumer acceptability of local rice versus imported rice. The sensory descriptors influencing the choice of the consumers were identified. Local rice can compete with imported rice.

International audience; The aim of this study was to develop an instrumental method for measuring the texture of French fries and correlated it with sensory measurements. For seven samples of French fries with different crispness levels, a cone penetrometer test was conducted simultaneously with microphone recording of sound emissions. A descriptive sensory analysis was also performed on these samples. The results showed that the number of sound peaks, the linear distance of sound peaks, the area under the sound-displacement curve and the mean sound pressure were strongly positively correlated (r ≥ 0.80; P-value

The endogenous alpha-galactosidase activity of cowpea seeds was characterized and modelled assuming Michaelian behavior. The aim is to use the resulting knowledge to optimize alpha-galactoside degradation during the soaking-cooking process. In this study, the alpha-galactosidase enzyme from Wankoun cowpea was extracted and its enzymatic activity was analyzed as a function of temperature, pH and the presence of some inhibitors. Enzymatic activity was optimal around 35 °C and a pH of 5.8. Activation and inactivation energy was evaluated at 50 ± 3 and 103 ± 9 kJ.mol−1, respectively. The strongest inhibitor was galactose with an inhibition constant KI of 0.28 ± 0.03 mM. Incubation of the enzyme extract with alpha-galactosides revealed a 10-h lag phase in the early stages that could be due to low pH, the action of inhibitors including galactose and the biosynthesis of alpha-galactosides. After the lag phase, the degradation of each alpha-galactoside occurred without the appearance of any intermediary product. The degradation of alpha-galactosides was observed with a Km of 1.7 ± 0.3 mM for raffinose; 3.6 ± 0.6 mM for stachyose and 15.9 ± 0.1 mM for verbascose. A long soaking step around 35 °C is suggested to maximize the alpha-galactosides enzymatic degradation.

This paper describes a mixed fermentation model made by assembling block hosting models for the growth of lactic acid bacteria (Lactobacillus plantarum) and a yeast strain (Pichia kluyveri), metabolic production and the physical-chemical changes which occur during the fermentation of gowe. The growth model for P. kluyveri was developed on a synthetic medium following the gamma concept taking into account the effect of pH, temperature, concentrations in glucose, lactic acid and ethanol. Additional parameters for the previously defined L. plantarum growth model were also determined (glucose and ethanol concentrations). The model was validated in three different gowe processing conditions. Even if the model underestimates LAB growth, it explains what occurs in the product and enables in silico extrapolation to various fermentation conditions. The predicted hydrolysis rates of native and gelatinised starches showed that increasing malt content is not an efficient way to increase the sweetness of gowe in contrast to increasing the level of pre-cooking. The builing-block model developed in this study could be applied to many other fermented foods and particularly to non-alcoholic but acid and sweet cereal based beverages.

Ablo is a rice or maize-based steam-cooked bread-like product, very popular in Benin, Togo and Ghana. This study optimized the processing steps of rice ablo using response surface methodology. The effect of precooking (proportions of flour and water, duration), kneading (wheat level, duration), fermentation (yeast level, temperature, duration) conditions to dough (gelatinization level, fluidity, proofing) and ablo (ethanol content, pH, density, cooking expansion, firmness, alveolar structure) properties were studied. It was demonstrated that ablo texture can be controlled by the fluidity of the fermented dough. Fluid fermented dough (at least 0.5 cm/s) expands adequately during steam-cooking and results in a less dense ablo in line with commonly consumed ablo. The optimal dough fluidity comes from a low gelatinization level of the precooked dough (less than 20%) and an intense fermentation (high yeast dose and long fermentation). Surprisingly, dough proofing appears to have no effect on final ablo expansion.

Gowe is a very popular traditional fermented and non-alcoholic cereal beverage in Benin. The purpose of the present study was to characterize the physical-chemical properties, nutritional and anti-nutrient composition, microbiological safety and mycotoxin occurrence in the various types of gowe. Six to nine samples from four types of technologies were analyzed for the various aspects of quality. Proximate composition, physical properties (particle size, viscosity), nutritional (amino-acid profile) and anti-nutritional (tannin, phytate, and cyanide levels) properties of gowe resulting from the different traditional processes are quite similar except for the physical properties, the differences of which originate from the raw materials and the diverse cooking conditions. The main hazard of traditional gowe are potential mycotoxin contamination, and presence of cyanogenic compounds, which are linked to raw material contamination and the malting step, and occurrence of E. coli and Enterobacteriacae (gowe is free from other pathogens), linked to inappropriate handling and to the packaging material. The main defects are low α-amylase activity of malt linked to poor control of the malting process, low content of several essential amino-acids in the raw materials and which is deteriorated by the cooking step. Several potential solutions are discussed for paving the way for upgrading and re-engineering this process.

International audience; Mare milk has been consumed for thousands of years in Central Asia and neighbouring regions. Its composition is similar to human milk, but different from cows’ milk. Fermentation with lactic acid bacteria and yeasts leads to the production of a traditional drink called qymyz. Qymyz, which is a symbol of good health, is a central part of the national cuisine and of the traditional cycle of horse husbandry, as well as playing a role in the cultural identity of Central Asian people. Mare milk, along with qymyz, has been reported to have a wide range of therapeutic effects. In this article, the authors have compiled information on mare milk composition, qymyz production and the therapeutic effects of mare milk and its products.

International audience; This study aimed to identify the microstructural parameters of the crust which can explain the crispness of French fries. The French fry microstructure was visualized by X-ray micro-computed tomography (XMT). Analysis of the images provided information on the pore size distribution, global porosity of the French fries and local porosity of the crust region. The results revealed that prefrozen French fries do not practically undergo any volume shrinkage during frying. The total porosity created in French fries corresponds to the volume of water loss during frying. The difference between hot-air fried and deep-fat fried French fries was mainly related to the pore diameter and pore size distribution in the crust. Principal component analysis between the sensory and morphometric parameters showed that the volume of small pores (diameter < 0.15 mm) and the span of the pore size distribution in the first millimetres of the crust correlated with the crispness of the product (r > 0.85, P value < 0.05). Thus, a French fry is crispier if the pores generated in the crust have a small median diameter (diameter < 0.2 mm), as well as a large dispersion of pore diameters.

A cytohistological investigation was performed to better understand the structural alterations of cowpea seeds in relation with soaking. Thin sections obtained from seeds soaked at 30 °C, 60 °C and 95 °C were treated to specifically visualize starch, proteins, cellulose and pectin. Micropyle behavior as well as water uptake and dry matter loss were also monitored. A Soaking at 30 °C induced slight alteration of parenchymatous cells of cotyledons, whereas drastic alterations were observed at 60 °C and intense alterations at 95 °C. All these structural modifications of cells could explain losses of nutrients and antinutritional factors at the highest soaking temperature (95 °C). The size of the apertures in the micropyle sections varied depending on both soaking temperature and time. At 30 °C and 60 °C, the micropyle aperture enabled notable water uptake by seeds. At 95 °C, water was entirely taken up through the testa. These results show that models describing nutrients losses and water uptake should account for these structure changes during soaking of legumes.

International audience; One of the most frequently consumed sorghum food in Mali is a thick porridge, known as to. Many grain traits contribute to its firmness and color, which are the most important qualities for consumers. These traits are related to chemical composition, physical properties, but also grain size, shape, glume adherence and color, pericarp thickness, or the presence of a testa. Quantitative trait loci for to consistency, to color, 16 grain traits, as well as day to flowering and grain yield, were investigated in two elite breeding populations, involved in a marker assisted selection program. A total of 51 and 71 QTLs were detected for P114 and P118, respectively. Several QTLs with high R-2 corresponded to major genes segregating in the populations such as the Z gene for pericarp thickness, the B2 and B1 genes for testa presence, the P gene for anthocyanin, and a QTL for flowering time. Many QTLs with moderate effect were detected for grain attributes associated to to quality, without showing antagonism between grain quality and yield. The results of this study will contribute to producing new varieties combining grain productivity and grain quality favorable alleles, through the use of marker assisted selection.

International audience; This chapter provides a state-of-the-art review of the diversity and dynamics of consumer demand with respect to the eating quality of rice worldwide. Quality includes both tangible measurable factors (rice characteristics) and the context of consumption. The main sensory attributes evaluated around the world are described, and their relationship with the diversity of consumer demand is discussed. Instrumental methods for predicting quality measured on either raw or cooked grains are reviewed. The changes that occur in the rice grain during cooking are described along with a modeling approach able to predict the changes and their spatial distribution in the rice grain during cooking. This approach can be used to link consumer demand with cooking conditions and grain quality.

White Kenley is a traditional stiff dumpling produced from fermented dehulled maize grains in Ghana. The physico-chemical modifications which occur during combination of various steeping (12, 30 and 48 h) and fermentation (0 h, 12 h and 24 h) times were assessed to study the impact of these unit operations on the quality of white kenkey . Water uptake by soaked grains and the release of metabolites were followed during grains steeping and particle size distribution after milling was determined. Steeping time exceeding 24 h was required to produce a fine wet milled flour while water uptake was completed after 8–10 h. This was parallel to hydrolysis of proteins and/or hemicelluloses which occurred after 16 h. Changes in acidity and glucose content were determined in the grain after steeping and in the dough after fermentation. The texture of the kenkey was determined using a texture analyzer. Increases in acidity were higher during dough fermentation than in steeping. Stickiness of the white kenkey decreased consistently with steeping time. Principal Component Analysis showed that a combination of long steeping and short fermentation times gives white kenkey with low stickiness (and high fineness), low acidic taste and low fermented odour.

International audience; The thickness of grain pericarp, the outer layer of the kernel, is an important breeding criterion for sorghum. This cereal is mainly used through traditional processing in family-based food systems in many regions of the world. We investigated in this study how pericarp thickness could be predicted by Near Infrared Reflectance Spectroscopy (NIRS), a fast and non-destructive measurement method that is commonly used to measure physico-chemical parameters of sorghum grains, and how this trait also influences the prediction of those parameters. We showed that, using a classification approach, it was possible to discriminate thick from thin pericarp whole grain samples with a good accuracy and that the proportion of thin and thick grains in mixed samples could also be predicted. In addition, pericarp thickness had a significant effect on the calibration performance for other grain parameters indicating that the pericarp can distort spectral information of whole grain samples. As a practical consequence, we suggest to develop separate whole grain calibration models for thin and thick pericarp samples, combined with a two-steps prediction approach to improve the accuracy of whole grain NIRS calibrations for grain quality parameters in sorghum.

This work describes the formulation of a functional yogurt-like product based on fermented maize with added phytosterols and its oxidative stability during cold storage. The technological challenge was to stabilize 3.5% esterified phytosterols (between 2 and 3 g of free sterols) in a low-fat emulsion and to preserve the obtained product throughout processing and storage. The natural bioactive compounds: lutein, zeaxanthin, β-cryptoxanthin, β-carotene and γ-tocopherol were detected in the yogurt, and remained stable during 12 days of refrigeration. Higher content of C18:1 n-9 and C18:3 n-3 (six and ninefold, respectively) were obtained in samples with phytosterols. This was desirable from a nutritional point of view, but at the same time it induced lipid oxidation that was 1.4-fold higher in the product with phytosterols than in the controls. The use of a multivariate approach served to find descriptors which were related to treatments, and to explain their behavior over time. Fil: Descalzo, Adriana María. Instituto Nacional de Tecnología Agropecuaria; Argentina. Universidad de Morón; Argentina Fil: Rizzo, Sergio Aníbal. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Los Alimentos; Argentina. Universidad de Morón; Argentina Fil: Servent, Adrien. Centre de Coopération Internationale en Recherche Agronomique pour le Développement; Francia. Université de La Reúnion; Francia Fil: Rossetti, Luciana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Los Alimentos; Argentina Fil: Lebrun, Marc. Université de La Reúnion; Francia. Centre de Coopération Internationale en Recherche Agronomique pour le Développement; Francia Fil: Pérez, Carolina Daiana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Los Alimentos; Argentina Fil: Boulanger, Renaud. Université de La Reúnion; Francia. Centre de Coopération Internationale en Recherche Agronomique pour le Développement; Francia Fil: Mestres, Christian. Centre de Coopération Internationale en Recherche Agronomique pour le Développement; Francia. Université de La Reúnion; Francia Fil: Pallet, Dominique. Université de La Reúnion; Francia. Centre de Coopération Internationale en Recherche Agronomique pour le Développement; Francia Fil: Dhuique-Mayer, Claudie. Université de La Reúnion; Francia. Centre de Coopération Internationale en Recherche Agronomique pour le Développement; Francia

A 1D mechanistic model was developed to describe water, deformation, amylose transport and starch gelatinization inside rice grains during cooking. Four migrating species were considered: two water populations according to the state of the starch, soluble amylose and an insoluble solid phase network. Three coupled mass transport PDE were formulated assuming diffusional mass transport and using a Lagrangian-Eulerian framework. The model integrates the convective effect of a water flux on the transport of soluble amylose. Rice grain deformation was the result of both water-induced swelling and erosion of the surface of the solid phase, assuming a zero-order kinetic process. The model was adjusted on a milled Chil-bo rice cultivar steeped in excess water at 75 °C and 95 °C. After 30 min at 95 °C, which is the standard cooking time, water uptake, leaching of soluble amylose and the amount of eroded material were 3.15 kg kg−1 db, 5.0% and 15.5% (w/w) respectively. Using the predicted distribution of species within the grain, the model could help to control the texture of cooked rice. (Resume d'auteur)

Gowe is a traditional fermented Beninese soft cooked paste made from a blend of malted and non-malted cereals that is diluted with water/ice and sugar just before consumption as a thirst-quenching drink. Major differences in the processes used for the preparation of gowe, which includes natural lactic fermentation, result in variable quality. Acidity and free sugar content have been linked to the process parameters but also to the type of strains that can be used for inoculation. The aim of this study was to investigate the starch degradation mechanism in relation with the activity of degrading enzymes during the preparation of gowe and enzyme impact on the quality (sugar content and viscosity) of the final product. Our results point to a key role for malt α-amylase and its susceptibility to acidic conditions in the sequence of the preparation process and in the final quality of gowe. Pre-cooking and inoculation speeds up and increases acidification of the product thereby favoring its safety, but reduces the final free sugar content and increases the final viscosity of gowe, which are both organoleptic defects of the product.

Sensory profile of gowe beverage was established with 10 gowe samples by 22 semitrained panelists. Besides, consumer study was performed on four representative gowe samples with 141 African ordinary consumers using a modified quantitative descriptive analysis. Gowe samples significantly differed (P 0.05). The principal component analysis plot revealed the effects of raw material and process: Sorghum gowe was differently scored from maize gowe samples (P

Gowé is an acidic beverage obtained after simultaneous saccharification and fermentation (SSF) of sorghum. A previous paper focused on modeling the growth of lactic acid bacteria during gowé processing. This paper focuses on modeling starch amylolysis to build an aggregated SSF model. The activity of α-amylase was modeled as a function of temperature and pH, and the hydrolysis rates of both native and soluble starch were modeled via a Michaelis-Menten equation taking into account the maltose and glucose inhibition constants. The robustness of the parameter estimators was ensured by step by step identification in sets of experiments conducted with different proportions of native and gelatinized starch by modifying the pre-cooking temperature. The aggregated model was validated on experimental data and showed that both the pre-cooking and fermentation parameters, particularly temperature, are significant levers for controlling not only acid and sugar contents but also the expected viscosity of the final product. This generic approach could be used as a tool to optimize the sanitary and sensory quality of fermentation of other starchy products.

Resume Dans les pays occidentaux, une consommation de glucides atteignant 50 a 55 % des apports energetiques totaux est recommandee. Le riz a une place legitime dans ces recommandations grâce a ses nombreux avantages nutritionnels. Par contre, dans les regions ou le riz peut constituer jusqu’a 50 % de la base alimentaire, il est important de comprendre l’impact de la variete, des procedes de transformation et la cuisson du riz sur la reponse glycemique, la disponibilite des micronutriments et les potentielles contaminations en metaux lourds. Cette revue s’interesse a l’impact de la composition du grain et des procedes de transformation et de cuisson sur les proprietes nutritionnelles du riz.

Gowe is a traditional Beninese fermented red sorghum beverage made from a blend of malted and precooked nonmalted flour. The main objective of this work was to evaluate the degradation of starch during the production of gowe and to characterise the organic acid and sugar profiles of the product obtained using starter cultures. Inoculation was performed with strains of Lactobacillus fermentum or Weissella confusa and of Kluyveromyces marxianus or Pichia anomala used singly or in combination. Size exclusion chromatography revealed that starch was hydrolysed into high molecular weight dextrins (DP over 35), oligosaccharides and glucose, mainly due to the malting and precooking steps. Glucose was the main free sugar, and lactic acid was the main organic acid. The choice of the inoculation strain directly influenced the acidity but also indirectly the sugar content of the resulting gowe and will thus affect consumer acceptability. (Resume d'auteur)

Akpan is a traditional ready-to-drink fermented yoghurt-like cereal beverage consumed in urban and rural areas in Benin. With the aim of adapting the product to new local and export markets, this work maps African and European consumer preferences for different types of Akpan. RESULTS A sensory profile of Akpan was created and consumer tests were conducted with 103 consumers of African origin and 74 consumers of European origin. Consumer acceptance was significantly correlated with fermented odour (r = −0.94) and milky taste (r = 0.92–0.97) attributes. Cluster analysis revealed different behaviour by African and European consumers with respect to acceptability of Akpan; European consumers did not like the sour taste and African consumers liked an intense sweet milky taste. CONCLUSION This study provides information on how Akpan, and other fermented yoghurt-type cereal products, could be adapted to African and European consumer preferences. © 2014 Society of Chemical Industry. (Resume d'auteur)

Gowe is a sweetish paste of malted, fermented, and cooked sorghum and/or maize flour, consumed in its pure state, but preferentially as a beverage after homogenizing with water, sugar, milk, and ice. A survey was carried out at different localities in the traditional gowe producing areas to investigate the diversity of the processing techniques, consumers¿ characteristics, and the quality attributes. Producers and sellers were women exclusively while consumers cut across all classes of age, socio-cultural groups, and educational levels. Gowe varied in cereal and processing techniques, with maize and sorghum being used either singly or in combination (maize/sorghum ratio varying from 1 to 3) through four processes. Apart from the alternative process which leaves out the malting step, gowe processing techniques aim at producing sweetish and acidic tasting products through malting, saccharification, and fermentation. A principal component analysis plot of quality criteria of gowe indicated that the preference of consumers was directly associated with the perceptions of producers.

An isothermal model of rice cooking process was developed that accounts for the impact of starch phase transition on water transfer and swelling, using an arbitrary Lagrangian–Eulerian framework. Two water populations were distinguished: water in native starch and excess water absorbed by starch since it starts to gelatinize. The model was solved by FEM. Water apparent diffusivities in native and gelatinized starch were 3.6 × 10 −10 and 2.8 × 10 −10 m 2 s −1 respectively. The model was validated on the Chil-Bo rice cultivar using experimental water uptake and microscopy measurements of the gelatinization front. At 50 °C, 75 °C and 95 °C, the volume gains were 0.3, 4.8 and 8.3 m 3 m −3 respectively. The model adequately reproduces swelling as its extent corresponds to the amount of water absorbed (±4% v/v). Both water and gelatinization profiles over time would be of tremendous benefit for the optimization of cooked rice properties such as texture.

A global model of the lactic fermentation step of gowe was developed by assembling blocks hosting models for bacterial growth, lactic acid production, and the drop of pH during fermentation. Commercial strains of Lactobacillus brevis and of Lactobacillus plantarum were used; their growth was modeled using Rosso’s primary model and the gamma concept as a secondary model. The optimum values of pH and temperature were 8.3 ± 0.3, 44.6 ± 1.2 °C and 8.3 ± 0.3, 3.2 ± 37.1 °C with μmax values of 1.8 ± 0.2 and 1.4 ± 0.1 for L. brevis and L. plantarum respectively. The minimum inhibitory concentration of undissociated lactic acid was 23.7 mM and 35.6 mM for L. brevis and L. plantarum, respectively. The yield of lactic acid was five times higher for L. plantarum than for L. brevis, with a yield of glucose conversion to lactic acid close to 2.0 for the former and 0.8 for the latter. A model was developed to predict the pH drop during gowe fermentation. The global model was partially validated during manufacturing of gowe. The global model could be a tool to aid in the choice of suitable starters and to determine the conditions for the use of the starter.

An improved iodine colorimetric method based on ammonium-buffered pH 9 solution (NH4Cl-KI) is reported. The method produces blue color and measures apparent amylose contents (AC) of nonwaxy rice, using potato amylose standard, and results in values similar to those observed when using differential scanning calorimetry (DSC), based on the exotherm of amylose-lipid complex formation, which has no amylopectin and lipid interference. Using the iodine colorimetric method, waxy rice had AC values of 2-3%, while undefatted, milled rice samples had AC values similar to those observed using the DSC method, probably because interference from amylopectin-iodine and amylose-lipid complexes cancelled each other. Using the iodine-NH4I method, AC values for five nonwaxy rice varieties were identical to DSC values, while AC values for the iodine colorimetric method with acetate buffer were not identical to DSC values when amylose alone was used as the standard. Using an amylose-waxy rice standard, the ammonium buffer method resulted in 4 nonwaxy rice varieties with AC values identical to DSC values. Iodine-NH4I resulted in 14 AC values identical to DSC values, and AACC International Approved Method 61-03.01 resulted in 7 of 16 rice samples with AC values identical to DSC values. AC determined using DSC and iodine colorimetry, both based on amylose helical complexes, were higher than AC (true amylose plus long-chain amylopectin) determined using high-performance size-exclusion chromatography (HPSEC) of debranched starch and amylopectin. The ammonium buffer method produced a blue color, AC values for nonwaxy rice that were similar to those for the DSC method, and allowed use of undefatted rice samples and an amylose standard alone without waxy rice (amylopectin).

This paper describes the multidimensional features of the texture of cooked rice (in particular the visual aspect and mechanical attributes) determined by sensorial analysis and links these attributes with a wide range of physicochemical characteristics of raw grain (in particular certain cell wall components). Textural classes of cooked rice did not fit classical grain ranking, which is primarily based on shape. For the classification of cultivars, it would be preferable to use chemical characteristics of raw kernels such as amylose content and Tgel (for prediction of firmness), but also protein (adhesiveness and stickiness) and arabinoxylan contents (deformation), which determine the textural properties of cooked rice. Leached amylose has been measured, and the particular role of soluble amylose on the surface behaviour (stickiness and adhesiveness) of the cooked grain is discussed.

Sequências do DNA de uma região em comum de múltiplos indiví­duos de uma população podem revelar polimorfismos que permitem o estudo da evolução do genoma e suas histórias de seleções, migrações e recombinações. Adicionando-se a esses polimorfismos da população informações quanto origem geográfica, viabiliza-se um estudo filogeográfico que permite a elaboração de cenários de evolução após a domesticação; bem como quais eventos (mutações ou recombinações) mais influenciaram a diversidade genética (DG) desta população, para aquela região do DNA em estudo. Por outro lado, a associação desses polimorfismos das sequências com as caracterí­sticas de interesse estabelece um estudo de associação. Neste contexto, este trabalho visou mostrar a aplicação do polimorfismo de sequências de DNA em um estudo de filogeografia e de associação. Para ambos os estudos foram utilizados dezenove segmentos de seis genes candidatos (Sh2, Bt2, Sssl, Ael, Wx e 02) em uma coleção de sorgo (Sorghum bicolor L. Moench), composta por 210 acessos. Os genes Sh2, Bt2, Sssl, Ael e Wx estão envolvidos na sí­ntese do amido e o gene 02 na sí­ntese de proteí­nas de reserva. A DG foi menor nos genes Sh2, Bt2 e Sssl; e maior para Ael, Wx e 02. Os testes estatí­sticos revelaram um elevado número de associações falso-positivas em função da estruturação da coleção, porém foram mantidas várias associações corroboradas pela co-localização com QTLs de sorgo e de milho.

A new and convenient synthesis of 2-acetyl-1-pyrroline (2AP), a potent flavor compound in rice, and its ring-deuterated analog, 2-acetyl-1-d2-pyrroline (2AP-d2), was reported. A stable isotope dilution assay (SIDA), involving headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-positive chemical ionization-ion trap-tandem mass spectrometry (GC-PCI-IT-MS-MS), was developed for 2AP quantification. A divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber was used for HS-SPME procedure and parameters affecting analytes recovery, such as extraction time and temperature, pH and salt, were studied. The repeatability of the method (n=10) expressed as relative standard deviation (RSD) was 11.6%. A good linearity was observed from 5.9 to 779ng of 2AP (r2=0.9989). Limits of detection (LOD) and quantification (LOQ) for 2AP were 0.1 and 0.4ngg-1 of rice, respectively. The recovery of spiked 2AP from rice matrix was almost complete. The developed method was applied to the quantification of 2AP in aerial parts and grains of scented and non-scented rice cultivars. © 2010 Elsevier B.V. This research was funded by the Office National Interprofessionnel des Grandes Cultures (ONIGC) as a part of the “Plan de Relance de la Filiere Riz Camarguaise” project. We thank the Centre Français du Riz (CFR, Arles, France) for providing the rice samples. We also thank Languedoc Roussillon region and Cirad for supporting the doctoral fellowship of the author I. Maraval.

Amylose content is a parameter that correlates with the cooking behavior of rice. It is measured at the earliest possible stages of rice improvement programs to enable breeders to build the foundations of appropriate grain quality during cultivar development. Amylose is usually quantified by absorbance of the amylose-iodine complex. The International Network for Quality Rice (INQR) conducted a survey to determine ways that amylose is measured, reproducibility between laboratories, and sources of variation. Each laboratory measured the amylose content of a set of 17 cultivars of rice. The study shows that five different versions of the iodine binding method are in use. The data show that repeatability was high within laboratories but reproducibility between laboratories was low. The major sources of variability were the way the standard curve was constructed and the iodine binding capacity of the potato amylose used to produce the standard. Reproducibility is much lower between laboratories using a standard curve of potato amylose alone compared with those using calibrated rice cultivars. This study highlights the need to standardize the way amylose is measured, and presents research avenues for doing so.