Functional and Biological Properties of Sang Yod Rice Bran Hydrolysate Prepared by enzymatic Hydrolysis and Its Application in Rice Pudding Product

Abstract

Sang Yod rice bran (SYRBH) was prepared by enzymatic hydrolysis of Protease G6 and Amyloglucosidase. Application of these two enzymes were either single, sequential or combined digestion. Effects of concentration of the enzyme extract (3, 4 and 5% w/v) and hydrolysis duration (30, 60 and 120 min) on catalytic process and hydrolysate characteristics were investigated. The sequential and combined hydrolysis yielded the hydrolysate with high protein and ẞ-glucan content as well as great value of total phenolic and total anthocyanin contents, relative to that of the process using single enzyme. This condition also improved functional properties of the RBH (water holding, swelling capacity and fat binding capacity). The treatments of extension of hydrolysis time caused the darkening of RBH. The hydrolysate exhibiting the high protein and highest ẞ-glucan content was prepared by using sequential hydrolysis of 5% enzyme concentration and 30 min. The results thus suggest that SYRBH has great composition of bioactive compound with two enzymes sequential hydrolysis as well as short hydrolysis time. Effect of sequential and combined enzymatic hydrolysis yielded the hydrolysate with the high in vitro anti-oxidative activities. The hydrolysis using 5% concentration for 60 min showed highest antioxidant activities. All obtained RBHs exhibited no cytotoxicity on RAW 264.7 cell lines at the maximum concentration of 2000 μg/ml. The RBHs obtained by using sequential and combined with 30 min hydrolysis time showed the best nitric oxide inhibitory in the RAW 264.7 cell with an IC50 of 408 and 973 μg/ml, respectively. Furthermore, The hydrolysis using 5% concentration with 60 min hydrolysis time exhibited the strongest reduction of TNF-α, IL-1ẞ and IL-6 cytokines. Thus, Sang yod rice bran by-product could be used for preparation of RBH strong anti-oxidative and anti-inflammatory activities. SYRBH application as a functional food ingredient to develop the functional rice pudding. The most preference product profile of functional rice pudding as ready-to-eat in plastic cup mixed with cereal/multi-grain and fresh fruit. From consumer sensory evaluation the sample fortified with 5 % SYRBH received the moderately like. The functional rice pudding of one serving size (100g) provide energy at 120 Kcal. Stability of functional rice pudding is being investigated by microbial counts and sensory test during 10 days storage in refrigerator. Fortification of SYRBH in rice pudding thus has the potential to serve as a functional food ingredient that can offer health benefits to consumer.