Abstract

                                Widely consumed type of rice in the world with white pericarp and is known as non-pigmented white rice. Recently, pigmented traditional rice varieties have become popular among the consumers due to its dark pigmented pericarp having nutritional value. This type of rice variety is important in determining the digestibility of starch and its Glycemic index (GI). The digestibility of the rice depends on the properties of starch, including its crystallinity and amylose: amylopectin ratio. Hence, the study focuses on the analysis of phyto nutrients in the selected traditional and TNAU released rice varieties to identify the low GI lines. Nutritional analysis of the selected traditional rice genotypes namely Karuppu kavuni, Karun kuruvai (black), Kaattuyanam, Mapillai samba and Kuruvai kalanchiyam and five ruling TNAU released rice varieties (ADT 52, TKM 9,TKM 13, ASD 16 and CO51) has been carried out. Among the selected traditional and TNAU - released rice varieties, Mapillai samba showed the strongest alpha-amylase inhibition (IC50 = 23.15 μg/mL), maximum anthocyanin content (48.37 mg/100g), and phenolic content (45.8 mg/100g), highest total antioxidant activity (51.8% DPPH scavenging activity. Mapillai samba (31) and Kuruvai kalanjiyam (27.5) were identified as low glycemic index lines. Hence, the pigmented traditional rice landraces can be used as a source of functional foods.

Key words : Glycemic index (GI); Pericarp; Digestibility; Total antioxidant activity; Alpha-amylase inhibition