Effect of Infrared Pretreatment on the Cooking Characteristics of Traditional Rice Varieties

Abstract

Rice is the staple food of people in several parts of the world and is also second most extensively used up cereal in the world after wheat. As the key dietary source of carbohydrates, it plays a vital role in fulfilling energy requirements and nutrient intakes. The cooking quality of rice is one of the significant factors affecting the consumer acceptability. Freshly harvested rice becomes a sticky mass during the cooking process and only slight swelling is obtained. A good quantity of solids is lost into the cooking water resulting in a thick gruel and there are chances of splitting of rice kernels on sides. Therefore, some pretreatments can be done to improve the cooking quality of rice. In the present study, rice samples were exposed to infrared pretreatment with different power levels and exposure time. Cooking characteristics such as cooking time, grain elongation, water uptake, gruel loss, swelling index, alkali digestion score was analyzed after the treatment. The hardness of cooked rice was also measured. After the treatment it was observed that the rice samples showed higher cooking time and more elongation of grains when exposed to maximum power. Other characteristics namely swelling index, water uptake and gruel loss were also improved after the treatment. Hardness of rice also increased indicating that infrared pretreatment can be used effectively in enhancing the cooking characteristics of rice.