Effects of cultivar and aging on parboiled rice properties

Abstract

Background and objectives Parboiled rice is an important commodity, and its properties are affected by parboiling conditions and feedstock properties. This study investigated the impact of cultivar and aging on parboiled rice properties under different parboiling conditions. Findings Regardless of parboiling conditions, cultivar with greater protein content had greater milling yields and cooked rice hardness, and lower deformed kernels and water absorption than low protein content cultivar. Deformed kernel had shown that aging effect was more significant on low protein content cultivar. Cultivar was the most important factor affecting parboiled rice properties and followed closely by soaking and steaming temperatures. Aging accounted for more than 10% of the total variance, and aging generally resulted in increased cooked rice hardness, and decreased deformed kernels, whiteness, pasting viscosities, and soluble solids. Conclusions Parboiled rice prepared from freshly harvested and aged rice displayed different properties. Cultivar with a greater protein content showed to have better protection against severe parboiling condition while preserving desired properties. Aging effect was more evident for rice of a low protein content. Even under different parboiling conditions, parboiled fresh‐harvested and aged rice still resulted in different properties. Significance and novelty The present study suggests the importance of protein content in the cultivar effect and its impact on aging effect.

Physicochemical and cooking quality characteristics of South American rice cultivars parboiled at different steaming pressures

“…At the pressure 0.50, the hardness results of cooked grains indicate that Titan CL exhibit a softer texture compared to the other cultivars. According to a previous study, the amylose content is positively correlated with the hardness of cooked rice (Lii et al, ). Thus, the softer texture found for Titan CL may be a consequence of the lower amylose level.…”

“…Those results may be correlated with the lower DSG obtained for the parboiled rice kernels from Titan CL cultivar in all treatments (Table ). According to Lii, Mauromoustakos, and Wang (), the breaking force of parboiled rice is increased by starch gelatinization and protein denaturation, which may fill the void spaces of the kernels and reduce the fissures. In contrast, the lower DSG negatively affects this physical property, raising the incidence of broken grains.…”

“…Oppositely to the observations made for the broken grain levels, for cooking time the steaming pressure had significant effect ( p < .05) only for Guri Inta CL and Titan CL cultivars. For Guri Inta CL, this behavior may be explained by the severe parboiling conditions, where the denatured proteins may form barriers around the starch granules and restrict swelling, increasing the time required for cooking (Leethanapanich et al, ; Lii et al, ).…”