Physical and cooking qualities of 16 local lowland rice varieties in Phatthalung Province

Abstract

Seed size, shape, color and chalkiness features that involve the milling and cooking qualities indices are the criteria to distinguish for pricing grain and rice product. The purpose of this research was to study the physical and cooking characteristics of lowland rice varieties in southern Thailand for use and add value from recessive traits affecting to low rice quality. Planting 16 varieties of southern rice landraces, 3 repetitions in rainy season at the Phatthalung Rice Research Center. Measurement the grain physical (seed size, shape, chalky and milling quality) and analyzed chemical properties (amylose, gel consistency, alkali test and elongation ratio during cooking) of local rice among 16 varieties. There was found that seed shape as medium (9 varieties) and slender (7 varieties). There were brown rice seed 3 colors (brown, red and white). The highest chalkiness rice found in Bow Nay Mak (2.6%) and Nang Tawng (2.4%) varieties and low milling quality rice varieties were Yah Sai (24.5%), Khao Nang (21.6%) and Bow Nay Mak (20.6%), respectively. Rice had low amylose content (11.5%-19.1%) 6 varieties and medium (20.2%- 23.9%) 10 cultivars, average gel consistency was 76.8 mm. were soft (12 varieties), medium (2 varieties) and hard (2 varieties). All varieties had medium ripening temperature (70-74 °C), except for Bow Nay Mak and Hom Dang varieties, they were classified as low (< 65 °C) and normal rice grain elongation (<1.9 mm). Low-grain quality rice varieties should be selected for value-adding and exploitation of recessive traits while maintaining the diversity of native southern rice varieties to maintain diversity and persistence.