Analysis of the characteristics of foxtail millet during storage under different light environments

Influence of accelerating storage of foxtail millet on the edible and cooking quality of its porridge: An insight into the structural alteration of the in-situ protein and starch and physicochemical properties

This study aimed to elucidate the effect of the accelerating storage (40 °C, 10 weeks) of foxtail millet on the edible and cooking quality of its porridge. The structural alteration of the in-situ protein and starch in foxtail millet, as well as the physicochemical properties were investigated. Both the homogeneity and palatability of millet porridge were significantly improved after 8-week storage of millet, while its proximate compositions remained unchanged. Meanwhile, the accelerating storage increased the water absorption and swelling of millet by 20 % and 22 %, respectively. The morphological studies (using the SEM, CLSM and TEM) revealed that the starch granules in the stored millet became easier to swell and melt, leading to better gelatinization with a higher coverage extension in protein bodies. FTIR results showed that the protein hydrogen bonds in the stored millet became stronger and the starch ordered degree was reduced. Compared to the native foxtail millet, the peak, trough, final, and setback viscosity of the stored sample increased by 27 %, 76 %, 115 % and 143 %, respectively, while the onset, peak, and conclusion temperature increased by 0.80, 1.10 and 0.80 °C, respectively. Besides, the G' and G″ of the stored foxtail millet were significantly higher than its native counterpart.

Optimization of Extrusion Treatments, Quality Assessments, and Kinetics Degradation of Enzyme Activities during Storage of Rice Bran

Over the years, extrusion has been a multi-step thermal technique that has proven to be the most effective process to stabilize rice bran (RB). This study aimed to investigate the effects of extrusion treatment and temperature (15, 25, and 40 °C) on the storage stability, lipid oxidation, peroxidase, and peroxide values, free fatty acids, fatty acid composition, and protein variations of RB over 60 days. The study offers novel insights into the changes in RB’s protein and amino acid compositions during extrusion and storage, which has not been extensively explored in prior research. After extrusion processing, peroxidase activity (POD) and lipase activity (LPS) were significantly reduced. However, peroxide value (PV), free fatty acids (FFA), and malondialdehyde content (MDA) observed a significantly increased by 0.64 mEqO2/kg, 8.3 mg/100 g, and 0.0005 μmol/L respectively. The storage stability of RB after extrusion shows that the POD, LPS, FFA, PV, and MDA were positively correlated with storage duration and temperature. The oleic acid/linoleic acid ratio in processed RB by extrusion had no significant changes during storage. The total and essential/non-essential amino acid ratios showed a downward trend of 5.26% and 8.76%, respectively. The first-order kinetics was the best-fitting model to describe the enzymatic inactivation and degradation of extruded RB during storage. The extrusion treatment did not affect the crude protein and the essential subunits of protein. Overall, the optimized extrusion procedure exhibited promising results in stabilizing the RB.

Investigation on the impact of quality characteristics and storage stability of foxtail millet induced by air cold plasma

The aim of this work was to investigate the effects of dielectric barrier discharge-air cold plasma (DBD-ACP, 15-35 kV, 2-12 min) on the quality of foxtail millets. The L and b* values were evaluated by a digital colorimeter representing that the color of millets was significantly changed at 25 kV for 4-12 min or at 35 kV for 2-12 min. The results were consistent with the change of total yellow pigment in millets, indicating that DBD-ACP damaged the carotenoids if the treatment condition was too high. The activity of lipoxygenase and lipase, involving the oxidation and hydrolysis of lipids of millet, decreased significantly induced by DBD-ACP. For example, the lipoxygenase and lipase activity of Mizhi millet was decreased from 44.0 to 18.7 U g^-1min^-1, 56.0-15.1 U/(mg pro) (p<0.05) after being exposed to 25 kV for 2-12 min, respectively. Changes of color, lipoxygenase and lipase activity, and malondialdehyde content of millets were determined during accelerated storage (40 ± 2°C and 75% Relative Humidity) for 15 days after being treated by DBD-ACP under 15 and 25 kV for 4 min. Results showed that millets treated by DBD-ACP at 15 kV kept a better color with lower malondialdehyde content, and lower lipoxygenase and lipase activity compared to control. This work implied that DBD-ACP is an underlying approach for the storage of foxtail millets.