Optimizing Recipes of Cooked Long-grain Jasmine rice with Sea-tangle Patch (Laminaria japonica) and its Effect on Glycemic Index

Abstract

Thai Jasmine rice (Oryza sativa, long grain Indica var) is very popular in southeastern Asia and China for non-glutinous fluffy texture and fragrant smell. However it has a higher starch digestibility, which leads to the increased glycemic index (GI). Therefore it may require modifying cooking method for diabetes patients. The objectives of this study were to optimize the ratio of Thai Jasmine rice, sea-tangle patch, and olive oil (CLTR) based on consumers’ acceptance. GI of the cooked Thai Jasmine rice (CLR) was measured as a control. Sensory evaluation and response surface methodology were used to determine the optimal ratio. Texture analysis and nutritional evaluation were also performed on the cooked Jasmine rice with sea-tangle patch with optimal recipe. A multiple regression equation was developed in quadratic canonical polynomial models. 26 of trained Chinese panelists in their forties participated. It was found that color, flavor, adhesiveness and glossiness were correlated highly with overall acceptability. Optimal formulation of CLTR was rice 34.8%, sea-tangle 2.8%, water 61.9% and olive oil 0.5%. CLTR had a lower hardness, but higher springiness and cohesiveness compared to CLR. It did however, had the same adhesiveness and chewiness with CLR (p<0.01). The addition of sea-tangle and olive oil delayed retro-gradation of starch in CLTR and also showed the higher level in total dietary fiber, protein and ash contents(p<0.01). The degree of gelatinization, in vitro protein and starch digestibility of CLTR were lower than those of CLR (p<0.01). Based on Wolver’ method, the GI of CLTR (52.9, Inc) was lower compared with co-energy CLR (70.94, Inc), which demonstrated that CLTR is effective in decreasing and stabilizing blood glucose level owing to its lower degree of gelatinization and starch digestibility(p<0.01). Results presented that CLTR could contribute in developing a healthier Thai meal for families and fast-food industry.