Peptidomics Analysis of Soy Protein Hydrolysates-Antioxidant Properties and Mechanism of their Inhibition of the Oxidation of Palm Olein during Frying Cycles.

This study determined for the first time the structure of the peptides (i.e., peptidomics) in soy protein hydrolysates and elucidated their effects on an oil's oxidative stability during frying cycles. The oil investigated was palm olein during 0, 4, 8, and 12 frying cycles of plantain banana chips. Proteins were extracted and hydrolyzed with two proteases. Trypsin hydrolysate (HTRY) exhibited higher anti-radical activity (DPPH, 70.2%) than the control (unhydrolyzed proteins, 33.49%) and pepsin hydrolysate (HPEP, 46.1%) at 200 µg/mL. HPEP however showed a 4.6-fold greater reduction of ferric ions (FRAP) while also possessing a higher peroxyl radical scavenging ability (716 ± 30 µM Trolox Eq/g) than HTRY (38.5 ± 35 µM Trolox Eq/g). During oil oxidative stability tests, HPEP improved the oxidative stability of the palm olein oil after 8 and 12 frying cycles, characterized by lower concentrations of hydroperoxides, and carbonyl and volatile compounds. HTRY however exerteda pro-oxidant activity. Structural data from SDS-PAGE and tandem mass spectrometry showed that the mechanism for the greater activity of the pepsin hydrolysate occurred due to unique structural features and a higher percentage of short-chain peptides. This was justified by a 25, 31, and 48% higher contents of tryptophan, histidine, and methionine, respectively (important amino acids with hydrogen atom transfer and electron-donating capacities) in the peptides identified in the pepsin hydrolysate.

Optimization using response surface methodology of the soaking and germination time of two rice varieties (Nerica 3 and Nerica L56) grown in the locality of Dschang (West-Cameroon).

Abstract: One of the solutions to increase children's energy intake is the use of amylase-rich flours. This led us to optimize the fluidification capacity of two paddy rice varieties. For that, the Doehlert plane-type response surface methodology was used to optimize the germinating ability of paddy rice flour (varieties Nerica 3 and Nerica L56) to fluidize cassava-based gruels by using two factors: soaking and germination time. The evaluated response was the flow velocity of the gruels. The optimization result showed that, the optimal soaking time was 48 h for the variety Nerica L56 and 12 h for Nerica 3. Concerning the optimal germination time, it was 135 h for both varieties. These conditions have been found to have the best fluidifying capacities for cassava flour-based gruels. The incorporation of 3 g germinated paddy rice flour (Nerica L56 and Nerica 3) and at optimal conditions, allowed us to obtain high flow velocities of the gruels. They were 100.00 mm/30 s and 210.66 mm/30 s respectively for the varieties Nerica L56 and Nerica 3. These flow velocities were similar to the flow velocities predicted by the model for desirabilities of 0.99 and 1.00. In view of all these results, we could therefore recommend the use of these two varieties of rice produced under these conditions to improving flow velocities, dry matter concentrations and energy bulk of the gruels.

Characterization of corn, cassava, and commercial flours: Use of amylase-rich flours of germinated corn and sweet potato in the reduction of the consistency of the gruels made from these flours-Influence on the nutritional and energy value.

Malnutrition appears in weaning age and is usually due to weaning food which is of low nutritional value. This problem led us to investigate the study of the physicochemical and functional properties of cassava flours and corn flours, and the fluidification of the gruels made from these flours by germinated yellow corn and sweet white potato flours. To do this, the approximate chemical composition, physical and functional properties, and ability of amylase-rich flours to digest the starch in order to reduce consistency were evaluated. From these analyses, it emerges that the chemical composition, and physical and functional properties are influenced by the nature and the treatment undergone by the flours. It appears that the amylase-rich flours that we used at a concentration of 1%-3% during the preparation of the gruels significantly reduced their consistencies. Given their strong liquefying power, this reduction was more marked with germinated corn flour where 1% permits to obtain desired consistency with 21.50 g of DM of bitter cassava flour, thereby multiplying the energy density and nutritional value of this flour by 5.18. It also appears that the action of flours rich in amylases was depending on the concentration, the nature of the flour, its composition, and the treatment undergone. In view of all these results, we can therefore consider the formulation of a weaning food with the consistency, and energy and nutritional value necessary for the proper growth of children.

Effect of Boiling and roasting on lipid quality, proximate composition, and mineral content of walnut seeds (Tetracarpidium conophorum) produced and commercialized in Kumba, South-West Region Cameroon.

The effect of boiling and roasting on the lipid quality, proximate composition, and mineral content of African walnut seeds (Tetracarpidium conophorum) was assessed. Results indicated that the quality of walnut oil significantly (p < .05) reduces with the treatments. Oils extracted from DBWN 60 min (Dried and boiled walnuts 60 min) and FBWN 60 min (Boiled fresh walnuts 60 min) were the most altered. The proximate composition and mineral content of walnut seeds was also significantly affected (p < .05) by the treatments. This study reveals that, thermal processing has significant effects on the nutrients and quality of lipids of walnut oil. DTRWN 60 min (Dried and traditionally roasted walnuts 60 min), DORWN 60 min (Dried and oven roasted walnuts 60 min), and TRFWN 30 min (traditionally roasted fresh nuts 30 min) are the best methods for cooking walnut because they preserve the quality of its lipids and some of the nutrients.