Effect of increased pressure on the coated layer profile of steamed rice

Relation between textural attributes and surface leachate structural and compositional characteristics of cooked rice

The objective of this study was to evaluate the leachate and textural characteristics of cooked rice, and the correlations between the leachate properties and texture attributes were also investigated. Cooked waxy rice had much higher total solids and amylopectin amount in leachate than the normal and high-amylose rice. For all varieties, the amylopectin chain length of the leachate was similar, excluding Dodam cultivar. The rheological characteristics of the leachate solutions were highly dependent on the amylopectin amount of the leachate. Regarding the textural characteristics, Dodam had the highest hardness and the lowest adhesiveness. The principal component analysis showed substantial differences in leachate and textural characteristics of Korean cooked rice according to its amylose content. The adhesiveness was positively and negatively correlated with amylopectin amount of leachate and the proportion of long amylopectin chains, respectively. These results indicated that the leachate characteristics of cooked rice significantly influenced its textural attributes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01446-3.

Properties of pyrodextrinization corn starch and their inhibitory effect on the retrogradation of fresh rice noodles

This study was aimed to investigate the properties of pyrodextrins under different preparation conditions and the effects of pyrodextrins on the retrogradation of fresh rice noodles. Pyrodextrins were made by heating corn starch with and without lactic acid at 180 °C ranging from 1 to 6 h. The molecular weights of pyrodextrins gradually decreased, whereas the branching degree increased and the chain length shrank with the prolongation of heating time. The changes of acid-heat-treated pyrodextrins were more pronounced than those of dry-heat-treated pyrodextrins under the same treatment time. The acid-heat-treated pyrodextrins displayed higher water solubility and lower viscosity, suggesting that they could no longer gel. These results suggest that starch retrogradation could be limited by pyrodextrins, especially acid-heat-treated pyrodextrins. Then, the pyrodextrins were added to fresh rice noodles and the eating and cooking qualities were examined during storage. After 35 days of storage, the pyrodextrin with acid heating at 180 °C for 4 h showed the most effective inhibition on starch retrogradation and was suitable for fresh rice noodles as an anti-retrogradation agent. The study might supply new perspectives on restraining starch retrogradation and promoting the fresh rice noodle industry.

Bioaccessibility of Glucosylceramide in Rice Based on the Cooking Condition and Cultivar

Glucosylceramide (GlcCer), a major sphingolipid in plants, possesses various food functions, including improvement of intestinal impairments. This study evaluated rice cooking conditions and cultivars based on GlcCer levels transferred into the digestive juice using an in vitro digestion model to investigate the factors related to GlcCer availability. GlcCer levels transferred into the digestive juice were higher in rice gruel than in boiled rice. The GlcCer levels in the digestive juice of boiled rice varied based on the rice cultivar, whereas those in rice gruel had no difference. Thus, GlcCer in rice was not fully utilized via digestion. Further, bioaccessibility was related to the amylose ratio and added water content.

The effect of different tea products on flavor, texture, antioxidant and in vitro digestion properties of fresh instant rice after commercial sterilization at 121 °C

The conventional process of commercial sterilization at 121 °C resulted in undesirable flavor, injured texture and fast starch digestion of fresh instant rice (FIR) with non-dehydration. In this study, tea products, such as instant green tea (IGT), instant black tea (IBT) and matcha (Mat) were chosen as ingredients to improve the quality of FIR. The results showed thatadding tea products endowed FIR with subtle flavors and higher antioxidant capacity. And the data of XRD, FTIR and SEM indicated that the improved texture of FIR with suitable chewiness was attributed to the stability of non-crystal structure. Furthermore, compared with IBT and Mat, IGT increased the ability against digestion from 10.18% to 30.44% and delayed the retrogradation rate from 18.89% to 4.38% evidenced by T₂ values after stored for 14 d. Therefore, adding tea products will be a new way to improve the quality of FIR.