Variety difference of physicochemical and cooking properties of selected brown rice from Thailand and Malaysia

Abstract

Rice is a major staple food in Thailand and Malaysia. Although brown rice is a highly healthy substitute, preference is very low due to its texture and cooking quality. However, there are some brown rice varieties such as Sungyod (SY), Chiang (CH), Lepnok (LP) from Thailand and long grain specialty 1(LS 1 ) and long grain specialty 2 (LS 2 ) from Malaysian peninsula are commonly consumed in such areas. This study aimed to investigate the physicochemical and the cooking properties of these brown rice to understand the properties for better utilization. Therefore, Rapid visvo analyser (RVA), soaking characteristics, general cooking properties, textural properties and calorific values were measured and compared in 5 varieties of brown rice. Hydration kinetics indicated that LS 1 and LS 2 were faster in water absorption to reach plateau compared to the SY, LP, and CH. The cooking time of these brown rice was in the range from 29 to 35 min. The cooked brown rice had length/breadth (L/B) ratio (2.4 -3.0), water uptake ratio (2.5 -3.0), elongation ratio (1.1 -1.4) and gruel solid loss (3.2 -5.2%). The hardness and the cohesiveness measured from texture analyzer were in the range of 6.75 -15.5 N and 0.13 -0.16. There was a significant variation in RVA pasting property of whole rice flour (p < 0.05). The variations of different properties of brown rice could be considered for the processing of brown rice and its application.

Comparison of the physical properties between Malaysian and Thai Rice

“…The difference in variety in rice grains' hardness is due to the difference in the compact arrangement between rice cultivars of starch granules. The Thai variety may be hard due to its higher content of the bran layer, while lower hardness in Malaysian rice is assumed due to the thin bran layer's likely presence (Chapagai et al, 2020). Besides, the lower hardness level is preferred as it will affect the cooking properties.…”

“…The awareness of physicochemical characteristics of the selected rice (Malaysian & Thai rice) is essentially vital during harvesting crops, transporting and dimensioning the storage process, manufacturing and operating various equipment applied in the main postharvest processing operation (Ghadge & Prasad, 2012). Previously, research was performed on various brown rice and white rice (Chapagai et al, 2020;Sam Lum, 2017). Meanwhile, Thomas et al (2013) reported differences in various brown rice from Thailand and Malaysia.…”

Predicted Glycaemic Index Values of Rice Prepared with Different Cooking Methods

“…It also might be caused by the physiological activities of the mineral, possibly due to the respiration process that subsequently decreases the mineral content in the rice samples (Nur Shafinaz et al 2022). However, some minerals can be volatilized or reduced when heated at high temperatures during the drying process, particularly vitamins B and C (Chapagai et al 2020). This study shows that the storage temperatures indirectly promote the physiological process and affect the ash content of rice samples.…”

“…These results showed that the WR had a relatively higher moisture content than the BR in preparation methods 1 and 3. Since the BR has a high-fibre bran, more water is needed to cook BR, and it is demonstrated that the bran layer inhibits moisture absorption (Chapagai et al 2020). Plus, it may be due to the drying effects of the exothermic reaction of the dehusking procedure (Kim & Lee 2013).…”

Evaluation of final quality of germinated brown rice following steaming and hot-air drying at different temperatures

“…Brown rice is less popular than milled or white rice, despite being higher in lipids, proteins, and vitamins B1 and B2 (Cho and Lim, 2016). It also has certain drawbacks, such as a longer cooking time and a harder cooked texture due to the bran's fiber content (Heinemann et al, 2005;Patil and Khan, 2011;Chapagai et al, 2017;Mohan et al, 2017). The oil content in the bran reduces its shelf life due to rancidity (Parnsakhorn and Langkapin, 2013).…”