Effects of high-temperature air fluidization (HTAF) on the structural, functional, and in vitro digestive properties of corn

Abstract

The antioxidant activity of corn has been previously demonstrated to increase significantly after high‐temperature air fluidization (HTAF) treatment at 160°C for 60 s. In this study, the structural and functional properties, as well as the in vitro digestibility of corn, were studied under the same conditions. After HTAF treatment, the degree of gelatinization of corn starch increased from 10.79 to 24.60%, which greatly reduced the relative crystallinity of corn starch from 32.17 to 16.15% and transformed corn starch crystals from the A‐type to the A + V‐type. The pre‐gelatinization also caused amylose leaching as reflected by SEM. Meanwhile, the onset and peak gelatinization temperatures increased significantly, whereas the peak, final, setback, and breakdown viscosities of corn starch decreased significantly. Most importantly, after HTAF treatment, the hydrolysis rate of corn starch greatly improved, and the slowly digestible starch (SDS) significantly increased by 4.79% at the cost of resistant starch. Meanwhile, the rapidly digestible starch increased slightly, thereby increasing the glycemic index (GI) of corn by 5.13%. In summary, HTAF treatment could be used as an effective method to improve not only the antioxidant activity but also the digestibility of corn that contains a higher amount of SDS.

High-temperature air­-fluidization-induced changes in the starch texture, rheological properties, and digestibility of germinated brown rice

“…According to the work of Liu et al, the long chains of starch would be degraded by thermal and pressure processing . Therefore, the higher content of amylose in H‐GBR here would be caused by the degradation of loose amylopectin or some branches of amylopectin, as demonstrated in HTAF‐treated corn .…”

“…Compared with hot air, heating by superheated steam would cause agglomeration of grains and serious damage to the starch, according to the research of Srisang et al . Therefore, high‐temperature air fluidization (HTAF) is used more often in the thermal treatment of cereals such as corn and rice . However, only a few studies have applied HTAF to the treatment of GBR, and these studies mostly concentrated upon the cooking and eating properties of GBR .…”

Effects of drying conditions on grain quality: a review

“…Notably, drying is a necessary step to maintain the quality of grains for a longer period, as the harvest is seasonal. Li et al (2017) studied the effects of fluidized bed drying on the structural, functional,…”

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

“…The amylose contents of the untreated and HTAF-treated black rice starch were 13.26 and 12.55%, respectively. The amylose content was determined according to the method of Li et al [17].…”