Metabolic mechanism of nitrogen modified atmosphere storage on delaying quality deterioration of rice grains.

Nitrogen modified atmosphere was an effective way to control pest infestation in grains. In this study, the quality changes of rice during nitrogen modified atmosphere packaging storage (N2-MAPS) were monitored. An un-targeted metabolomics method was used to detect the rice metabolites and explore the mechanism of N2-MAPS for delaying rice deterioration. In this study, two rice species were studied under N2-MAPS and conventional storage at 30 °C for 150 days. The quality changes of rice during storage were monitored. The results showed that N2-MAPS could retard the increase of fatty acid value and amylose content, and defer the decrease of enzyme activities. And N2-MAPS had no significant influence on texture characteristics of rice. The metabolomics results suggested some metabolites and pathways were affected by N2-MAPS and revealed that N2-MAPS could protect rice cells from oxidative damage, maintain cell integrity and stability by regulating the metabolism to delay the rice deterioration.

Effect of Drying Methods on Peanut Quality during Storage.

Storage is an important step after peanut harvest and drying. Many factors could affect the peanut quality during storage. The quality change differences of peanut after being dried by solar radiation and at 35°C, 40°C, 45°C, 50°C during later storage were investigated, including moisture content (MC) and germination percentage (GP) of peanut kernels, acid value (AV), peroxide value (PV), iodine value (IV), vitamin E (VE) content and fatty acid composition (FAC) of extracted peanut oil. And the impact of four storage conditions, air-room temperature (A-RT), air-low temperature (A-LT), vacuum-room temperature (V-RT) and nitrogen-room temperature (N-RT) on peanut quality after 10 months' storage were also studied in this paper. The results revealed that drying conditions had only a little influence on peanut quality during later storage. Peanut dried by solar radiation was more easily oxidized than that dried under other drying conditions. The effects of storage time were much greater. The GP, AV, PV, VE content and FAC, showed significantly changes along with storage. GP and VE content decreased, AV and PV increased, and some linoleic acid was oxidized to oleic acid after 10 months' storage. In addition, A-LT exhibited best performance in keeping peanut quality than A-RT, V-RT and N-RT, which demonstrated that low temperature was more advantageous for peanut storage than controlled atmosphere. These results above would provide useful information and reference for the peanut storage to apply in food industry.

The effect of microwave stabilization on the properties of whole wheat flour and its further interpretation by molecular docking.

In order to stabilize the whole wheat flour and extend its shelf life, microwave was employed to heat the wheat bran to inactivate the lipase in this paper. The effects of microwave heating of wheat bran on the lipase activities, gluten properties, dough properties and storage stability of the stabilized whole wheat flour, and the quality of steamed bread made of stabilized whole wheat flour were investigated. Furthermore, molecular docking was applied to interpret the mechanism. The results showed that microwave can reduce lipase activity, maintain the quality of whole wheat flour dough and steamed bread, and retard rancidity. The molecular docking results displayed that the conformation of the amino acids chains near the lipase catalytic center changed, which made the substrate difficult to enter the catalytic center and prevented the hydrolysis of the fat substrate.