This study aimed to determine the total antioxidant capacity of the essential oil (EO) of leaves of Bidens pilosa (Linn. Var. Radita) used as protectant of stored grains in Northern Cameroon. EO was characterized by GC‐FID, antioxidant activity (AA) was determined by combining: evaluation of radical‐scavenging activity, reducing power (RP) and co‐oxidation of β‐carotene methods. Tests were carried out on crude and stored EO kept for two weeks at 31.48 ± 2.88°C and 58.56 ± 6.78% relative humidity. These conditions are the same as those of grain storage. GC analyses enabled the identification of 27 compounds, representing around 97.57% of the total oil contents. The major constituents of the EO were α‐pinene (14.7%), ε‐caryophyllene (13.5), and β‐ocimene (12.8%). The AA of the crude and stored EO are proportional to the concentrations and time of exposition. Exposed at the day light, this EO inhibit 77.4–18.69% for the DPPH system, 59.55–19.14% for RP method and 91.88–21.8% for β‐carotene‐linoleate model system, respectively, from crude and 15 days storage EO at 20 mg L−1. For the EC50 values, β‐carotene method is excellent and in the decreasing order of DPPH method, PR with 2.52 mg L−1, 2.77 mg L−1 and 4.13 mg L−1, respectively, for the crude oil. The ET50 were 1.59 days for the RP method and 2.88 days DPPH system and β‐carotene‐linoleate model system at 20 mg L−1. These results showed that the EO of B. pilosa leaves exhibits AA that might be an added value for this EO preventing stored products from pest attacks.

This study aimed to evaluate the effects of dehulling and boiling on the physico-chemical, functional and pasting properties of two varieties of Mucuna bean flours. Dried beans sample was soaked in distilled water and divided into two sets from which one was manually dehulled. The dehulled and undehulled beans were boiled followed by drying and milling into flours. A third set of flour was obtained by direct milling of whole dry beans. The results revealed that the proximate composition changed significantly (p \ 0.05) with boiling and dehulling while variety generally had little effects. Protein (range 25.6-31.2 %), total sugar (range 46.5-51.1 %) and lipid (range 1.5-7.2 %) levels increased significantly (p \ 0.05) with dehulling, and decreased with boiling. In reverse the ash (range 1.7-4.6 %), polyphenols (range 0.82-5.32 %), phytates (0.83-1.64 %) and L-Dopa (range 94.03-611.12 mg/100 g) contents decreased with dehulling and boiling. The particle size of flour was also shown to increase with boiling and decrease with dehulling. The combined changes in physical and chemical properties induced significant modification in the functional and pasting properties of the flour as attested by the highly significant (p \ 0.01) correlations observed. In this respect protein and total sugar levels in the flour were positively correlated with the water absorption capacity, water solubility index, foaming capacity and foaming stability. The pasting viscosity was positively correlated with the phytic acid and L-Dopa levels in the flour.

Extraction conditions for maximum values of protein yield, protein content, sugar content and dry matter of vegetable milk extracts from dehulled Mucuna cochinchinensis bean flour and whole Mucuna cochinchinensis bean flour were investigated using response surface methodology. A Central Composite Design (CCFD) with three factors: temperature (25 to 95°C); extraction time (6 to 74 min.) and water to flour ratio (6 to 24 mL/ g) were used. Data analysis showed that all the factors significantly (p < 0.05) affected the responses variables. The optimal conditions determined for extraction were temperature 63-66°C, water to flour ratio 12-13 mL/g and extraction time of 57-67 min. At these optimum points the protein and sugar contents, extraction yield of protein and dry matter were respectively 14.0 g/100 mL, 4.8 g/100 mL, 53.8 g/100 g, 12.1 g/100 g for vegetable milk produced from dehulled M. cochinchinensis bean flour and 6.4 g/100 mL, 3.5 g/100 mL, 50.0 g/100 g and 8.0 g/ 100 g for vegetable milk extracted from whole M. cochinchinensis bean flour milk. The optimal condition was -Vegetable milks from whole and dehulled mucuna seeds flours were successfully produced by optimization using a central composite design; -Second polynomial models were established to significantly describe the variation in protein content and yield as a function of extraction time, temperature and water to flour ratio; -The protein content, protein yield and dry matter of the milk increased as the extraction time increase, while increase followed by decrease was observed when temperature and ratio increased; -Optimal conditions determined by superposition of response contours plot and by using desirability function did not varied significantly with dehulling; treatment; -The protein content of milk produced at optimal condition was 14 % for dehulled mucuna flour and 6.4 % for whole mucuna flour, while no consistent differences were observed on protein yield, dry matter and carbohydrates content. 145-157 DOI 10.1007145-157 DOI 10. /s13197-015-1765 verified at the optimum points for model validation and the response values were not significantly different from the predicted values.

Extraction conditions for maximum values of polyphenol content, flavonoid content, total reducing power and DPPH free radical scavenging of vegetable milk extract from dehulled Mucuna cochinchinensis flour and whole M. cochinchinensis flour were investigated using response surface methodology (RSM). A Central Composite Design with three factors: temperature (25-95°C); extraction time (6-74 min) and water to flour ratio (6-24 mL/g) were used to study the response variables. Data analysis showed that all the factors significantly (p \ 0.05) affected the responses variables. Desirability function showed that the optimal conditions were 55-59°C for extraction temperature, water to flour ratio of 16-17 mL/g and an extraction time of 57-67 min. At these optimum points the polyphenol content, flavonoid content, total reducing power and DPPH free radical scavenging were respectively 113.5, 32.77, 0.78 g/100 mL, 82.14 %, for dehulled M. cochinchinensis milk and 138.2, 42.46, 0.8 g/100 mL, 73.14 % for vegetable milk extracted for whole M. cochinchinensis flour. In addition, the overall optimum regions for dehulled and whole mucuna milk had a desirability of 0.91-1. The optimal condition was verified at the optimum points for model validation and the response values were not significantly different from the predicted values.

No abstract