การประยุกต์ใช้อินฟราเรดและไมโครเวฟในข้าวพันธุ์ กข 43 เพื่อเพิ่มปริมาณสตาร์ชต้านทานการย่อยชนิดที่ 3 และมีค่าดัชนีน้ำตาลตํ่า และการพัฒนาผลิตภัณฑ์สําหรับผู้บริโภคที่ควบคุมน้ำหนัก

Abstract

Rice (Oryza sativa L.) is one of the most consumed food staples in major regions of the world, especially in Africa and Asia. In Thailand, most of the population commonly consumes rice every day. Rice can be classified into many types, for example, glutinous us and non- glutinous rice. RD 43 rice, which is originated from crossbreeding between Khoa Jao Hom Suphan Buri and Suphan Buri 1, It has been promoted by the Thai government as it provides medium glycemic index (GI = 57.8). The aims of this study were 1) to investigate the effects of infrared and microwave beating process of RD 43 rice product for increasing resistant starch type 3 and reducing glycemic index, 2) to etamine retrogradation process affecting glycemic index of RD 43 rice, 3) to develop the product form RD 43 rice, which was adjusted to contain low glycemic index, and 4) to examine the consumer acceptance of developed RD 43 rice product. On the condition the rice was autoclave heated at 110 °C for 15 min and restored at 25 °C for 24 hr. The result showed that rice contained the highest resistant starch (0.49 %) and the lowest glycemic index (51.52), the gelatinization was 55.61 % and the retrogradation was 44.39 %. In addition, rice samples were heated by infrared power at 400, 600, and 800 W for 120, 150, and 180 s. The result showed that rice contained the highest RS (0.45±0.16 %) and the lowest pGI (50.37±0.57) by infrared beating at 600 W for 150 s. Futhermore, rice samples were heated by microwave power at 400, 600, and 800 W for 15, 30, and 45 s. The result showed that rice contained the highest RS (0.44±0.01%) and the lowest pGI (52.31±0.23) with microwave beating at 600 W for 30 s. Compared with microwave beating, infrared beating caused lower glycemic index. Therefore, infrared beating was further investigated in retrogradation process. Next, rice samples were retrograded at 5, 10, and 15 °C for 12, 24, and 36 hr. It was found that retrogradation temperatures bad no significantly different effects on total starch content, digestible starch, and resistant starch (p> 0.05). In contrast, retrogradation temperatures had significantly different effects on pGI, degree of gelatinization and retrogradation. When rice was restored at 5 °C there were the lowest pGI (47.24±1.10), the lowest DG (62.01±0.22%) and the highest DR (37.99±0.22%). Additionally, the result showed that retrogradation time affected on pGI. When rice was retrograded at 5 °C for 24 hr., pGI was decreased from 50.37±0.57 to 46.47±0.34 and RS was increased from 0.45±0.16% to 0.53±0.07% Therefore, retrogradation bad affected on increasing RS and reducing pGI in RD 43 rice. In the study of the consumers need, there are two stages including focus groups were divided into three categories as follows: fitness enthusiast, body shaping, and blood glucose level controlling consumers. These 3 groups were interviewed about their food consumption behaviors and needs of frozen food. The collected data were utilized to design surveys for the desires of frozen food products. The 209 participants were asked to participate in the survey. The result showed that they would like to add 21% chicken breast, 30% quinoa, 15% broccoli, and 12% carrot. The participants preferred stir-fried black pepper flavor the most. In addition, the formulation was designed to create proper main ingredient amounts of a product by investigating three factors as follows: RD 43 rice (20-35%) quinoa (3-15%) and water (60-75%) using mixture design. It was found that the optimum formula were 26.68 % of RD 43 rice, 6.75% of quinoa and 66.56% of water. Furthermore, the consumer acceptance (n=204) of the finished product were examined by 9 -point hedonic scale. The result showed that the appearance was 7.40±0.74, color was 7.05±0.76, rice aroma was 6.39±0.93, quinoa aroma was 7.14±0.98, rice flavor was 6.73±0.94, quinoa flavor was 6.81±0.74, softness was 0.96±0.85, hardness was 6.95±0.83, overall liking was 7.10±0.80.the stir-fried chicken with black pepper flavor was 6.98±0.78 and overall vegetable liking was 7.22±0.87. Finally, consumer accepted this finished product at 92.64% and 85.29% of purchased intention.