Evaluation of Physicochemical and Cooking Characteristics of Rice (Oryza sativa L.) Landraces of Lamjung and Tanahun Districts, Nepal

Abstract

After the Green Revolution, the increase in the choice of modern varieties at the expense of landraces has become a major cause of varietal loss. The preference, choice, and the economy of rice (Oryza sativa L.) largely depend on its physicochemical and cooking properties, which are found to be superior for landraces than modern varieties. In this study, we assessed and evaluated milled rice of 30 rice landraces on their physicochemical and cooking characteristics which aim to promote the revival of old landraces. Six parameters of physical properties, four parameters of chemical properties, and five parameters of cooking properties were evaluated based on the standard protocols. Significant variations (p<0.05) were found in all the properties that were evaluated. The result showed that the highest milling recovery was found in Indrabeli (75.55%) whereas the lowest was found in Kalo Masino (66.98%) and bulk density ranged from 0.81 g/cm3 to 0.88 g/cm3 showing not much variability. Although most of them were of medium grain type, their 1000 kernel weight varied between 12.62 g and 25.65 g. From the observed chemical properties, Pahelo Anadi (9.73±0.55 mm) showed the highest gel consistency and lowest apparent amylose content (7.23±0.36%). Also, 13% of landraces possessed strong aroma while noble cooking properties were showed by Thakali Lahare Marsi with the highest elongation ratio (2.41±0.05) and by Chiniya with the lowest gruel solid loss (0.033±0.03%) and minimum optimum cooking time (23.45±0.03 min). In the principal component analysis, the first four principal components retained 73.8% of the variance. The first and second principal components were mostly related with the physical and chemical characteristics while the third and fourth principal components were concerned with cooking characters. Superior characters possessed by rice landraces can be further assessed for the breeding programs so that the cultivation of these cherished rice landraces can be enhanced.

Study on physicochemical properties of rice landraces for amylose, gel consistency and gelatinization temperature

“…The majority of the landraces in this study registered soft gel consistency, this could be due to the low level of amylose content since these traits were related to each other (Jan and Subhash, 2020). Rice with soft gel consistency cooks more tenderly and remains soft even after cooling (Pokharel et al, 2020). Similar results of soft GC in most of the genotypes were reported by Bharath et al (2018) and found that rice remains soft after cooking was due to soft GC.…”

“…Most consumers prefer rice with intermediate AC since cooked rice will be soft, flaky with good palatability (Cuevas et al, 2018). Amylose content variation in all levels (low, intermediate and high) in rice landraces was reported by Sahu et al (2017), Taratima et al (2019) and Pokharel et al (2020). This could be due to the variation in genetic level.…”

Multivariate Analysis of Phenotypic Diversity of Rice (Oryza sativa L.) Landraces from Lamjung and Tanahun Districts, Nepal

“…Similar results were obtained by [22] where the first five principal components were found to be significant and contributed 82.9% of the total variation in 31 rice germplasm. In a study of cooking and physicochemical characters using the same landraces, the first four principal components retained 73.8% of the total variance [23]. e proper value measures the importance and contribution of each component to total variance, whereas each coefficient of the proper vectors indicates the degree of contribution of every original variable with the principal component it is associated with [24].…”

Biochemical and Molecular Assessment of Cooking Quality and Nutritional Value of Pigmented and Non-pigmented Whole Grain Rice

“…They also suggested that cultivars with higher ratio of length and width (L:W ratio) show higher degree of milling (DOM). Besides the varietal differences, the type of mill used for milling also highly affects the bran percentage and milling recovery [35][36]. In the present study, the weight of rice bran separated by the polishing method was expressed as DOM.…”