Quality characteristics of noodles made from selected varieties of Sri Lankan rice with different physicochemical characteristics

The physicochemical properties of eight popular Sri Lankan rice varieties (Bg 300, Bg 352, Bg 403, Bg 94-1, Ld 356, Bw 272-6b, At 405 and At 306) and the quality characteristics of noodles made from these varieties of rice were investigated. The physicochemical properties investigated were amylose content (AC), crude protein, fat content, starch properties and amylograph pasting properties. Rice noodles were prepared by gelatinization of dough made with rice flour followed by cold extrusion. Rice noodle samples were evaluated for cooking loss, swelling ratio, tensile strength, extensibility, elastic recovery, firmness and sensory properties. AC of rice varieties ranged from 18.65 +/- 1.19% in At 405 to 30.43 +/- 0.20 % in Bg 94-1. Swelling volume and swelling power were significantly different (p < 0.05) among the rice varieties tested. Amylograph pasting properties of rice varieties showed a significant (p < 0.05) variation for all the pasting parameters. Cooking loss was high in At 405 (19.17 +/- 3.50), and low in Bg 403 (9.19 +/- 0.33). Tensile strength was significantly high for Bg 352 (16.7 +/- 3.4 g) and it was significantly low for At 405 (8.0 +/- 1.7 g). Overall acceptability of rice noodles prepared from At 405 had the significantly lower score and rice noodles from Bg 300 had a significantly higher value. The physicochemical and amylograph pasting properties of rice varieties had a significant influence on the cooking, textural and sensory properties of rice noodles. Amylose content showed significant negative correlation with cooking loss (r = - 0.802, p < 0.001) and significant positive correlation with swelling ratio (r = 0.809, p < 0.001) of noodles. Amylose content showed positive significant correlation with tensile strength, extensibility and elastic recovery at p < 0.05. Rice noodles made from local rice varieties with high amylose content showed desirable quality characteristics.