Ratio of Amylose and Amylopectin as indicators of glycaemic index and in vitro enzymatic hydrolysis of starches of long, medium and short grain rice

Abstract

Background: Rice (Oryzasativa L.) is the staple food of over half the world’s population. The major carbohydrate of rice is starch, which is about 72 to 75%. Rice can be classified into three different types: long-grain, medium-grain and short-grain rice based upon their length as compared to their width. Aim of the study was to predict the glycemic index of long, medium and short grain rice based on amylose, amylopectin ratio and to study in vitro hydrolysis of starch of long, medium and short grain rice by salivary and pancreatic amylases and formulate the right type of rice to be consumed by diabetics. Methods: Starches were isolated from long, medium and short grain rice. Amylose and amylopectin from the isolated starches were estimated. Starches isolated were subjected to enzymatic hydrolysis by salivary amylase and pancreatic amylase under optimum in vitro conditions and reducing sugars released after hydrolysis and incubation period of 0, 5, 10, 15, 20 and 30 minutes were estimated by Folin-Wu method. Results were analysed using unpaired t-test and statistical significance was established.Results: Long grain rice was found to have high amylose and low amylopectin content as compared to medium and short grain rice. Long grain rice showed slow release of reducing sugars as compared to medium and short grain rice.Conclusions: Long grain rice because of its high amylose content is a low glycemic food and can be consumed by diabetics. Sustained slow release of reducing sugars given by long grain rice is desirable in diabetics.

Gamma radiation application to rice: Reduced glycemic index in relation to modified carbohydrate observed in FTIR spectra

“…Hence, gamma irradiated rice could be beneficial for lowering blood glucose and can be used in the formulation of diets for diabetics. A comparative study on Indian long, medium, and short-grain rice ( Dipnaik and Kokare, 2017 ) reported that long-grain rice had high amylase, low amylopectin content, and higher Am/Ap ratio (1.12) which results in significantly slower in vitro starch digestibility using salivary and pancreatic amylase enzymes. Thus, the ratio of amylose and amylopectin has been established as the indicator affecting the rate and extent of starch hydrolysis and hence the glycemic response of the food.…”

Seasonal Variation in Starch Accumulation and Starch Granule Size in Cassava Genotypes in a Tropical Savanna Climate

“…On the other hand, Rayong 11 was the lowest for these traits for most planting dates except on 20 April in which it was equal to Kasetsart 50. The genotype with a higher content of amylose and ratio of amylose and amylopectin can be assumed to have a lower glycaemic index [47].…”

Medical nutrition therapy of pediatric type 1 diabetes mellitus in India: Unique aspects and challenges

“…This can be done without affecting the palatability and without making major changes in the patient's eating preferences (Table 1). 10,12‐21 …”

“…This can be done without affecting the palatability and without making major changes in the patient's eating preferences (Table 1). 10,[12][13][14][15][16][17][18][19][20][21] Fiber content of Indian diets can be increased by consuming whole grains (whole wheat, barley, broken wheat), millets, whole pulses (green gram, red gram, chickpea, and kidney beans), vegetables, salads, and fibrous fruits. Addition of dairy products (curd, cottage cheese or paneer), pulses, soybean, and egg can augment the protein content especially in those who cannot afford/do not eat meat, fish, or poultry.…”