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

Effect of storage temperature on the quality of brown rice revealed by integrated GC-MS and lipidomics analysis

Brown rice is highly nutritious but more susceptible to deterioration without the rice husk's protection. In this study, the mechanism of storage temperature on brown rice quality was investigated based on GC-MS and lipidomics. The results showed that both 15 °C and 20 °C storage retarded the lipids oxidation of brown rice and maintained its texture properties. Moreover, 1-octanol, 1-octen-3-ol, octanal, fitone, 2, 3-dihydrobenzofuran, dodecane, and tridecane were key biomarkers in cooked brown rice flavor. Furthermore, significant correlations between lipid oxidation, texture, and flavor biomarkers were revealed. Notably, the quality of brown rice stored at 15 °C (Fatty acid value = 23.0 mg/100 g) was superior to that at 20 °C (Fatty acid value = 24.3 mg/100 g) due to more effective retardation of glycerophospholipid, glycerolipid, and phospholipid metabolism. This work provided a better understanding of temperature-controlled storage of brown rice and give recommendation for potential commercial applications.

Rice Bran Extraction and Stabilization Methods for Nutrient and Phytochemical Biofortification, Nutraceutical Development, and Dietary Supplementation

Rice is a global staple food crop for nearly half of the world's population. Rice bran along with the germ are essential components of whole-grain rice and have immense potential for enhancing human nutrition. Rice bran has a unique composition and distinct requirements for processing before it can be consumed by humans when compared with other cereal brans. The comprehensive overview and synthesis of rice bran processing include extending the shelf life for functional food product development and extraction of bioactive components. This narrative review highlights established and innovative stabilization approaches, including solvent extraction and enzymatic treatments, which are critical methods and technologies for wider rice bran availability. The nutrient and phytochemical profiles of rice bran may improve with new cultivar development and food-fortification strategies. The postharvest agricultural practices and processing techniques can reduce food waste while also supporting growers to produce novel pigmented cultivars that can enhance nutritional value for human health.

Oxidative Stability and Pasting Properties of High-Moisture Japonica Brown Rice following Different Storage Temperatures and Its Cooked Brown Rice Flavor

The study proposed to investigate the impacts of storage temperatures (15, 20, 25 °C) on the oxidative stability (peroxide value, carbonyl value, malondialdehyde content) and sensory attributes (pasting properties, cooked brown rice flavor) of high-moisture japonica brown rice. According to the findings, the peroxide value, the carbonyl value, and the malondialdehyde content of high-moisture japonica brown rice stored at a temperature of 15 °C exhibited consistently low levels, and the pasting properties were favorable. In addition, 22 out of 51 flavor volatiles were screened as key differential volatile flavor compounds in cooked brown rice via a combination of ANOVA and orthogonal projections to latent structures-discriminant analysis (OPLS-DA). Among them, 3-heptylacrolein had an aroma of fat and mushroom, and its contents were higher at 15 °C and 20 °C. These findings could serve as a valuable reference for storing high-moisture japonica brown rice under low temperature conditions as well as for investigating the flavor characteristics of cooked brown rice derived from this variety.