Effects of high‐temperature air fluidization (HTAF) on eating quality, digestibility, and antioxidant activity of black rice (Oryza sativa L.)

Abstract

Phytochemical-rich black rice provides health benefits but is not consumed widely because of its poor eating quality. In this study, high-temperature air fluidization (HTAF) was used to improve the eating quality of black rice. The changes in its digestibility and antioxidant activity were also investigated. Fissures appeared on HTAF-treated black rice, and partial starch gelatinization took place. The thermal and pasting properties of black rice starch significantly improved due to the amylose-lipid complex that formed during starch gelatinization; this contributed to the improvement of the eating quality of black rice. In addition, the cooked HTAF-treated black rice showed a lower hardness (748.30 g) and a higher sensory comprehensive score (77.37) than cooked untreated black rice (1320.66 g and 57.09, respectively). Most importantly, HTAF treatment significantly decreased rapidly digestible starch (RDS) and slowly digestible starch (SDS) and increased resistant starch (RS) in black rice. The glycemic index (GI) of black rice was reduced from 88.60 to 85.49, but the antioxidant activity did not significantly decrease.

Physicochemical, Thermal, Crystallographic, and Morphological Properties of Biodynamic Black Rice Starch, and of Residual Fractions From Aqueous Extraction

“…This cereal is mainly composed of starch, together with small amounts of proteins, lipids, fibre, minerals, vitamins and phenolic compounds . According to Li et al, pigmented rice varieties, such as black rice, have received increased attention from researchers in recent years due to their beneficial health properties, which help to reduce the risk of developing chronic ailments such as cardiovascular disease, type II diabetes, obesity, and cancer. Due to these factors they have also become popular with consumers …”

Effect of processing methods and storage on the bioactive compounds of black rice (Oryza sativa L.): a review

“…The high-temperature air fluidization did not significantly alter the anthocyanin content or antioxidant activities of black rice, but it can improve the water absorption performance and the sensory quality of black rice, shorten the optimal cooking time, and lower the GI while also retaining its cyanidin-3-glucoside content, total anthocyanin content, and antioxidant activities. 107,108 Lang et al 109 found that drying black rice in a fluidized bed at high temperatures (100 °C) only decreased the amount of caffeic acid in the free and bound fractions. On the other hand, greater drying temperatures raised starch digestibility and promoted the extractability of ferulic acid in the bound fraction.…”

Genetics, Biochemistry and Biophysical Analysis of Anthocyanin in Rice (Oryza sativa L.)

“…The famous pigmented rice varieties in Korea are dark red Heugjinjubyeo, dark purple Heugnambyeo, dark blue Jakwangdo, red brown Sanghaehyeolla, black purple Hongmi, and dark red-purple Kilimheugmi [130]. The quality of pigmented rice varieties have been improve by employing recent technologies, including genome sequencing, gene expression analysis, gene editing, and omics technologies [102], [131][132][133][134]. High-yield pigmented rice varieties Figure 1.…”