Analysis Strategy for Assisted Selection of Rice Eating Quality by Using Starch Properties

Abstract

<jats:title>Abstract</jats:title> <jats:p>Background Eating quality is the main factor affecting the commodity value of commercial rice. However, its determination relies on sensory evaluations, which require large samples, are easily influenced by subjective factors and are time consuming. In order to make the determination of eating quality more efficient, a set of recombinant inbred lines (RILs) obtained from the hybridization of <jats:italic>indica</jats:italic> and <jats:italic>japonica</jats:italic> rice was used as the test material to analyze the relationship between starch characteristics and the eating quality (EQ) score, from sensory evaluation. An implementation protocol was proposed for starch assisted-selection of eating quality. Results Among the RILs, the values of the measured parameters for amylose content (AC), trough viscosity (TV), final viscosity (FV), breakdown (BD) and setback (SB) were significantly correlated with the EQ values ​​obtained by sensory evaluation. The RILs with higher EQ scores, generally had low AC, TV, FV and SB, but high BD. By normalizing and summing the AC, TV, FV, SB and BD indicators, a comprehensive indicator—viz., the starch properties quality (SPQ)—was established, to assess starch quality. The SPQ value was better correlated with EQ than any of the individually measured parameters, suggesting that the model is valid. This method requires much smaller rice samples than sensory evaluations, i.e., three grams of milled rice flour. Conclusions Therefore, the SPQ indicator is a rapid, objective and convenient technique for the rapid assessment of rice eating quality in a large number of crossbreeding progeny, especially early-generation progeny, from which only small samples of rice grains are available.</jats:p>

Evaluation of commercial rice grains present in the Amman market

“…Rice is not cultivated in Jordan, so to meet the needs of consumers, Jordan imports different types of rice from different countries, making quality evaluation a vital step. Cooking and eating quality are the main factors affecting consumer acceptability and, in turn, the economic value of rice [1], [2]. Eating quality is related to different factors, including starch physicochemical properties, chemical composition, dimensions and elongation upon cooking, defects such as chalky rice content, broken rice, and milling degree (the extent of bran removal) [1], [3].…”

“…Cooking and eating quality are usually performed using sensory evaluation of cooked rice. However, this method has several limitations: the texture sensory attributes are not usually clearly defined and standardized [4], the subjective nature of the test, the large sample number and size requirement, and the time-consuming [2]. Another approach to determining the rice-eating quality is studying starch, particularly amylose content, as the primary factor affecting quality.…”

“…Recently, the evaluation of rice eating quality by determining the Rapid Visco Analyzer (RVA) pasting properties has been increasingly adopted by researchers [2], [4], [6], [7], [8], [9]. The principle of the RVA pasting profile relies on measuring rice flour suspension viscosity during heating, holding, and cooling cycles, from which valuable information is drawn, such as pasting temperature, peak viscosity, peak time, trough, setback, and final viscosity [4]; these parameters were found to be correlated with rice eating quality [2].…”