Effect of Parboiling Conditions on Physical and Cooking Quality of Selected Rice Varieties

Effects of distribution, structure and interactions of starch, protein and cell walls on textural formation of cooked rice: A review

The constitution and forms of rice determine its processing and cooking properties and further control the cooked rice quality. As the two main components, starch and protein content correlations and their characteristics have been extensively explored. However, rice is mainly consumed as polished kernels, components distribution, cytoplasmic matrix, and cell walls work together, and the properties of extracted components or flour are difficult to reflect the quality of cooked rice accurately. Thus, this review summarizes the multi-scale structure changes of main components during real rice cooking conditions. The dynamic thermal changes and leaching behaviors in rice kernels are compared with pure starch or rice flour. The in situ changes and interactions of starch granules, protein bodies, and cell walls during cooking are reviewed. Based on this, different textural evaluation methods are compared, and the advantages and disadvantages are pointed out. The oral chewing perception and bionic chewing simulation for textual evaluation have gradually become hot. Both rice quality controllers and eating quality evaluators attempt to establish an accurate quality evaluation system with the increased demand for high-quality rice.

Potential benefits of Rehmanniae Radix after ancient rice-steaming process in promotion of antioxidant activity in rats' health

Rice steam processed product of Rehmanniae Radix (RSRR), one of the processed products of Rehmanniae Radix (RR), is popular as an herbal medicine and food. However, the health-promoting effects and mechanisms of RSRR are still unclear. In this study, 10-week-old Sprague-Dawley female rats were treated with different processed products of RR. No organ coefficient differences were observed between RSRR and the control group, indicating that RSRR did not cause damage to the rats. Compared with other RR products, superoxide dismutase, glutathione, and catalase levels were significantly higher and malondialdehyde levels were significantly lower in the RSRR group, indicating that RSRR exerted a better antioxidant effect. Gene expression analysis showed that hemoglobin genes (Hba-a1, Hba-a2, Hbb-bs, Hbb, Hbq1b, Hbb-b1, and LOC103694857) may be potential biomarkers to evaluate the antioxidant effect of RSRR. Antioxidation-related signaling pathways in GO annotation, including cellular oxidant detoxification, hydrogen peroxide metabolic process, hemoglobin complex, and oxygen binding signaling pathways were significantly enriched, indicating these pathways may represent the antioxidant mechanism of RSRR. To explore the main active compounds primarily responsible for the antioxidant activity of RSRR, UPLC-Q-TOF-MS was used and six components (catalpol, rehmannioside A, rehmannioside D, melittoside, ajugol, and verbascoside) were identified in rat serum. Catalpol and rehmannioside A were predicted to be the major active components by network pharmacology. These results suggested that RSRR exhibits antioxidant activity and has health-promoting properties. This study provides a scientific basis for the antioxidant mechanism and clinical use of RSRR.

Optimization of soaking conditions (temperature and time) on physicochemical properties of selected parboiled rice varieties grown in Eastern Ethiopia

This study aimed to optimize soaking temperature and time for better physicochemical properties of parboiled rice varieties grown in Eastern Ethiopia. Two brown rice varieties (NERICA-4 and NERICA-6) were collected from the Somali Regional Agricultural and Pastoral Research Center in Gode. The experiment was designed to aid the design expert software using box-behnken experimental design of response surface methodology to optimize the effects of soaking temperature (60-70°C) and soaking time (4-6 h). Relevant physical and chemical composition properties of the parboiled rice varieties were investigated using standard methods. Numerical optimization of the responses was performed using design expert software. The results showed that soaking time and temperature significantly (p < .05) influenced the physicochemical quality of studied brown rice varieties. The optimal soaking temperature and time were 65°C and 6 h, respectively, for NERICA-4. Under these conditions, the optimum response variables obtained were 375.37 N, 52 min, 12.3%, 1.24%, 13.86%, 2.17%, 3.2942%, 67.1171%, 343.5 kcal/100 g, 274.72 mg/100 g, 318.35 mg/100 g, and 268.31 mg/100 g for hardness, cooking time, moisture, ash, protein, fat, fiber, carbohydrate, energy, magnesium, and potassium and phosphorous content, respectively. However, 65°C and 5 h were optimum soaking temperatures and time for NERICA-6, giving hardness, cooking time, moisture, ash, protein, fat, fiber, carbohydrate, energy content, magnesium, potassium, and phosphorous of 375.18 N, 52 min, 12.2%, 1.4%, 11.54%, 2.29%, 2.89%, 69.6%, 345.42 kcal/100 g, 156 mg/100 g, 105.9 mg/100 g and 136.9 mg/100 g, respectively. The findings showed that rice varieties, in particular NARICA 4, were processed under optimal parboiling conditions in the study setting for better physical properties, proximate composition, and mineral content.

Rice quality and its impacts on food security and sustainability in Bangladesh

Rice market efficiency is important for food security in countries where rice is a staple. We assess the impact of rice quality on rice prices, food security, and environmental sustainability in Bangladesh. We find that while price varies as expected for most quality attributes, it is unaffected by a broken percentage below 24.9 percent. This reveals a potential inefficiency, considering the average 5 percent broken rate observed in the market. An increase in the broken rate of milled rice within the limits supported by our findings can, ceteris paribus, increase rice rations by 4.66 million a year, or conversely, yield the current number of rice rations using 170.79 thousand fewer hectares and cutting emissions by 1.48 million metric tons of CO2 equivalent. Thus, producing rice based on quality assessment can improve food security and its sustainability.