Exploring Retrogradation Behavior of Commercial Rice Varieties and Physicochemical Properties of Respective Extracted Starch
Ishita Chakraborty, Baishali Das, Indira Govindaraju, Tatsuyuki Yamamoto, Hemanth Noothalapati, Vishwanath Managuli, Nirmal Mazumder
Abstract
High Resolution Image Download MS PowerPoint Slide Current research frequently concentrates on a restricted range of rice cultivars or predominantly investigates indica rice varieties, resulting in a scarcity of data concerning the physicochemical and digestion characteristics of japonica cultivars. The objective of this study is to fill these voids by offering an intricate analysis of commercial japonica rice strains, namely, Nanatsuboshi (NS), Tsuyahime (TH), and Yumepirika (YP), thus enhancing comprehension of their nutritional value and technological capabilities. Analysis of cooking characteristics revealed that YP exhibited the longest minimum cooking temperature (MCT), the highest water uptake ratio (WUR), and the greatest grain elongation ratio (GER), followed by TH and NS. All three types displayed low levels of resistant starch (RS), ranging from 1.4 to 1.6%. Additionally, all three varieties exhibit similar glycemic index (GI) ranging between 74 and 76. The rheological properties of these rice types retrograded at 4 °C revealed significant variations. The study also delved into the physicochemical properties of starch extracted from these rice types, employing techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and differential scanning calorimetry (DSC). YP’s starch exhibited the highest gelatinization temperature (113.19 °C), whereas NS had the lowest (75.99 °C). The research aimed to uncover potential health benefits by examining the rheological, structural, and physicochemical traits. This research offers potential for addressing health issues related to high glycemic carbohydrates and enhancing the versatile use of japonica rice.