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Optimization of processing parameters for natural cloudy mango (Mangifera indica L.) juice using pectolytic and cellulolytic enzymes. Abstract-Introduction. Many desirable properties make cloudy fruit juice widely produced according to consumer acceptance. The pulp of mango (Mangifera indica L.), a good source of carbohydrates and water, has many uses including the production of juice. Nowadays, the use of food enzymes has become widespread in the juice industry for various reasons. However, the application of enzymes has not yet been tested in the context of the production of cloudy mango juice, except for the stabilization of nectars. Thus, the aim of our study was to examine and optimize some parameters involved in the enzymatic production of cloudy mango juice. Materials and methods. To achieve our objective, we used Response Surface Methodology (RSM) by combining five factors: time (30-50 min), temperature (35-55°C), pH 4-5.5, Pectinex ® Ultra SP-L (20-40 µL•L-1) and Cellubrix ® L (15-25 µL•L-1). Results and discussion. The study of juice yield, cloud stability and the browning index showed that the coefficients of determination (R 2 values) of these traits with the studied parameters were greater than 0.900. The optimized juice yield, cloud stability and browning index varied with specific values chosen for the five parameters mentioned above. Conclusions. Finally, the use of 30 µL•L-1 Pectinex ® Ultra SP-L and 22 µL•L-1 Cellubrix at 45°C, for 43 min, at pH 5.5, was found to be the optimum set of conditions for processing cloudy mango juice. China / Mangifera indica / fruit juices / processing / colloidal properties / stabilizers / glycosidases / statistical methods Optimisation des paramètres pour le traitement de jus de mangue (Mangifera indica L.) naturellement trouble avec l'emploi d'enzymes pectolytiques et cellulolytiques. Résumé-Introduction. De nombreuses caractéristiques intéressantes ont permis de produire largement des jus de fruits troubles conformes avec l'acceptabilité du consommateur. La pulpe de mangue (Mangifera indica L.), une bonne source d'hydrates de carbone et d'eau, a de nombreuses utilisations dont la production de jus. Aujourd'hui, l'utilisation d'enzymes agroalimentaires est devenue très répandue dans les industries du jus pour diverses raisons. Cependant, l'application d'enzymes n'a pas été encore testée dans le contexte de la production de jus de mangue trouble, si ce n'est pour la stabilisation de nectars. De ce fait, l'objectif de notre étude a été d'étudier, pour optimisation, certains paramètres impliqués dans la production enzymatique de jus de mangue trouble. Matériel et méthodes. Pour atteindre notre objectif, nous avons utilisé la méthodologie de surface des réponses en combinant cinq paramètres : le temps (30-50 min), la température (35-55°C), le pH (4-5,5), et des enzymes tels que Pectinex ® Ultra SP-L (20-40 µL•L-1) et Cellubrix ® L (15-25 µL•L-1). Résultats et discussion. L'étude du rendement en jus, de la stabilité du trouble et de l'index de la coloration brune ont ...

The adsorption of Hibiscus sabdariffa sp. anthocyanins onto a macroporous resin was studied in laboratory experiments. The anthocyanin aqueous extracts obtained from the calyces were used in agitated batch experiments with a macroporous resin. The adsorption kinetics and isotherms of H. sabdariffa anthocyanins on a selected macroporous resin was studied to determine the parameters that have to be optimized to recover the anthocyanins from aqueous extracts of the calyces. The adsorption kinetic experimental data were fit into a pseudo second order kinetic model, which was then used to determine several parameters such as the contact time necessary to reach equilibrium as well as the maximum adsorption capacity. The best fit for the equilibrium adsorption isotherm experimental data was obtained with the Langmuir isotherm model. Based on qualitative and quantitative interpretation of the experimental data, the resin that was tested here appeared to have good adsorption capacity for the anthocyanins even though the necessary time to reach equilibrium was particularly long.Three aspects of the desorption of anthocyanins from the resin were studied: the speed of release of the anthocyanins (desorption kinetics), the extent of the anthocyanin desorption depending on the adsorption contact time and finally, the influence of the mobile phase's characteristics.Practical ApplicationsThe purpose of this work is to facilitate the industrial production of a natural food colorant anthocyanin from H. sabdariffa calyces using a macroporous resin. To attain this, goal values from adsorption experimental data were computed and fit to theoretical adsorption models.The maximum adsorption capacity and the time necessary to reach equilibrium were determined. Qualitative and quantitative interpretation of the experimental data proved that the adsorbent/adsorbate system in study is a favorable process.The desorption of anthocyanins was also studied in order to determine the time necessary to achieve a satisfactory recovery rate, as well as the values of parameters that have a marked influence on the desorption efficiency.The obtained results and the calculated parameters will subsequently be used to plan colorant extraction at a bigger scale.

Several studies have shown that beta‐glucans have positive effects on cholesterol, glucose and insulin metabolism. In this present study we wanted to know whether beta‐glucan contents in cereals and their food forms could influence glycemic indexes (GI). For that purpose, we determined the glycemic indexes of three cereals grown in Africa alleged to display positive effects on diabetes.Samples of fonio, sorghum, and rice as reference, were processed into their porridge and couscous forms and given to 15 Senegalese young adult males (22‐25 of age) for Glycemic indexes assessment following the World Health Organization guidelines. Prior to, beta‐glucan contents in selected cereals were determined in previous studies, and during the trial, total bioavailable sugar was assessed using the Megazyme enzymatic method developed by Mc Cleary.Fonio, which had an overall lower glycemic index (GI =66), contained higher beta‐glucan content than others. Sorghum (GI =72) that ranked second had a higher Beta‐glucan content compared to rice (GI = 95). In addition, this study showed that cereals porridges displayed lower glycemic indexes than their couscous forms, indicative of the fact that food forms may play a critical role in glucose metabolism.Grant Funding SourceUSDA/Institute of Food Science Technology Dakar