Effects of the hot air roasting process on brown rice moisturized by water-spraying method

The hard texture of brown rice, attributed to its bran layer, poses significant challenges in improving its palatability. This study investigated the effects of hot-air roasting on the morphological characteristics, thermal properties, and water absorption of brown rice, moisturized using a water-spraying method to enhance texture. Moisture-controlled roasting resulted in a significant difference in the L* values, with the highest observed at 20 % water content. The extent of cracking and fine fissure formation varied with roasting temperature, resulting in increased water absorption. These structural changes subsequently influenced the tan δ value, hardness, and stickiness in the rheological analysis post-cooking. The gelatinization degree significantly increased with higher roasting temperatures and retrogradation effects were noted at 130 °C and 150 °C with a 15 % water content during cooking. Texture and sensory evaluations confirmed an increase in hardness as retrogradation progressed. The observed changes in this study have a profound impact on the textural and sensory attributes of the final cooked product.

Superheated steam processing of cereals and cereal products: A review

The concept of superheated steam (SS) was proposed over a century ago and has been widely studied as a drying method. SS processing of cereals and cereal products has been extensively studied in recent years for its advantages of higher drying rates above the inversion temperature, oxygen-free environment, energy conservation, and environmental protection. This review provides a brief introduction to the history, principles, and classification of SS. The applications of SS processing in the drying, enzymatic inactivation, sterilization, mycotoxin degradation, roasting, and cooking of cereals and cereal products are summarized and discussed. Moreover, the effects of SS processing on the physicochemical properties of cereals and the qualities of cereal foods are reviewed and discussed. The applications of SS for cereal processing and its effects on cereal properties have been extensively studied; however, issues such as the browning of cereal foods, thermal damage of starch, protein denaturation, and nutrition loss have not been comprehensively studied. Therefore, further studies are required to better understand the mechanism of the quality changes caused by SS processing and to expand the fields of application of SS in the cereal processing industry. This review enhances the understanding of SS processing and presents theoretical suggestions for promoting SS processing to improve the safety and quality of cereals and cereal products.

Effect of baking technique for rice wine production and the characteristics of baked rice wine

BACKGROUND

Driven by the requirement to reduce the emission of wastewater in the brewing process, it is necessary to improve and innovate the fermentation technology of Chinese rice wine. In this study, the baking technique used to brew rice wine was explored.

RESULTS

Rice wine was brewed based on baked glutinous rice undergoing different high-temperature stages, designated as baked rice wine (BRW1, BRW2 and BRW3). X-ray diffraction and Fourier transform infrared analysis revealed that baking treatment under 110 °C 0.5 h + 170 °C 30 min relatively changed the crystal properties and short-range molecular order of starch. Compared with the traditional rice wine (RW) from steamed rice, the alcohol content in BRWs was nearly twice that of RW, especially in BRW3. The contents of protein, ascorbic acid and total phenols in BRWs were significantly higher than that in RW. Besides, BRWs presented more abundance in the contents of volatile compounds, free amino acids and certain organic acids, including volatile esters and alcohols and 17 amino acids, which would give rice wine a pleasant aroma and a more comprehensive taste. Furthermore, analysis of the antioxidant capacity indicated a functional difference between RW and BRWs.

CONCLUSION

It was feasible to produce rice wine using baked rice. The baking method allowed for several advantages, including the improvement of alcohol yield, fermentation efficiency, new typicality and stronger antioxidant capacity. This work is expected to provide a foundation for related research. © 2021 Society of Chemical Industry.