Effect of rice ageing and freeze-thaw cycle on textural properties of cooked rice (Oryza sativaL.) cv. Khao Dawk Mali 105

Improvement of textural and sensory characteristics of aged rice using hydrothermal treatment with xanthan gum

Aged rice (AR) was mildly heated in aqueous dispersions containing different amounts of xanthan gum (Xan) at 60 °C for 1 h, and then dried in a humidity chamber (50 °C, 80% RH) for 12 h. The AR kernels treated without Xan showed a coarse surface with many pores after cooking, whereas the same rice treated with Xan showed a smooth and uniform surface. Prior to the treatment, the cooked AR was harder and less sticky than the cooked fresh rice (FR). The hydrothermal treatment softened the cooked AR although did not change its adhesiveness. The same treatment in the presence of Xan could increase the adhesiveness of AR, making the textural characteristics of AR similar to those of FR. Sensory evaluation revealed that the mild heat treatment in the presence of Xan restored the eating quality and acceptability of cooked AR which had been lost by aging.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01306-0.

The textural properties of cooked convenience rice upon repeated freeze-thaw treatments are largely affected by water mobility at grain level

Brown rice (BR) is a promising source for convenience rice that are mostly stored frozen. However, freezing and thawing may cause deterioration in rice texture quality. To investigate how rice texture is influenced by freeze-thaw cycles, BR, the pretreated BR with partially ruptured bran layer (UER) and white rice (WR) were cooked and treated with repeated freeze-thaw cycles, with their textural properties, variations in moisture distribution and starch structure being measured. Results showed that the repeated freeze-thaw treatment induced a progressive reduction in hardness and stickiness of all cooked rice. The reduced hardness of rice could be explained by the enlarged pore size of starch inside rice under scanning electron microscopy. Moisture migration in WR was the fastest responding to multiply freeze-thaw cycles, followed by UER, while water mobility in BR was slowest. Moreover, WR, BR and UER resulted in a similar extent of amylopectin retrogradation and chains length distribution after repeated freeze-thaw cycles. It indicated similar and minor effect of starch variations on determining the texture of different rice samples against freeze-thawing. Water mobility tended to be a main factor leading to the textural difference of fully gelatinized rice samples. This study focused on the relationship between water distribution and starch retrogradation, providing a better understanding on influences of multiple freeze-thawing on textural quality of cooked rice maintaining different extents of surface layer.

Whole grain rice: Updated understanding of starch digestibility and the regulation of glucose and lipid metabolism

Nowadays, resulting from disordered glucose and lipid metabolism, metabolic diseases (e.g., hyperglycemia, type 2 diabetes, and obesity) are among the most serious health issues facing humans worldwide. Increasing evidence has confirmed that dietary intervention (with healthy foods) is effective at regulating the metabolic syndrome. Whole grain rice (WGR) rich in dietary fiber and many bioactive compounds (e.g., γ-amino butyric acid, γ-oryzanol, and polyphenols) can not only inhibit starch digestion and prevent rapid increase in the blood glucose level, but also reduce oxidative stress and damage to the liver, thereby regulating glucose and lipid metabolism. The rate of starch digestion is directly related to the blood glucose level in the organism after WGR intake. Therefore, the effects of different factors (e.g., additives, cooking, germination, and physical treatments) on WGR starch digestibility are examined in this review. In addition, the mechanisms from human and animal experiments regarding the correlation between the intake of WGR or its products and the lowered blood glucose and lipid levels and the reduced incidence of diabetes and obesity are discussed. Moreover, information on developing WGR products with the health benefits is provided.

Examining the Components of Integrity

The purpose of this paper is to understand the underlying components of integrity and examine its value. The approach is through identifying and expanding on the common values of integrity such as honesty, conscientiousness and principle. There is a need to find a common ground in the sense of giving specific values towards integrity. Current works of literature indicate that there is a gap in assigning the core values of integrity. This information was collected through a semi-structured qualitative interview with 15 experienced participants from a wide range of background and has extensive experience with the fields of integrity. Such samples are from academic experts, government practitioners, representatives of government agencies, and non-governmental organisations. The identified components are then projected and validated through this list of participants. One of the objectives of this study is to understand the components of integrity through the life experience of people who are commonly associated with the areas of "integrity". The common core values of integrity was identified through a process of systematic literature review and summarised in this study. Content analysis of the data identified multiple dimensions and sub-dimensions on integrity. The findings suggest that integrity is more than being honest, conscientious and with principle as other factors are determining factors of being a component of integrity. Values such as responsibility, sincerity, consistency, compliance, conscious, pride, social norms, ruling policies and awareness play a major role in the value of integrity. The paper builds a model of integrity components based on these interpreted values. This paper contributes to the growing interest in the concept of integrity and attempts to streamline the central components of integrity. The studies of integrity are timely contemporary issues which deserve scientific attention. The building of sophisticated models and empirical investigations in their own right are opportunities for society to improve on their understandings of human behaviour. The integrity model provides an opportunity and useful addition for governments, private institutions, and individuals to improve each of their core values towards integrity.