纤维素酶处理对发芽糙米复配方便米饭食用品质的影响

Effect of cellulase treatment on the edible quality of germinated brown rice mixed convenient rice

发芽糙米的营养价值高于精白米,含有丰富的营养成分,其中膳食纤维、γ-氨基丁酸(GABA)、VB1及VB2含量分别是精白米的4.7倍、4.6倍、4.0倍及2.5倍;但发芽糙米表层含有大量的纤维素、半纤维素及果胶物质,纤维素酶预处理能部分降解这些物质,从而降低发芽糙米的蒸煮糊化温度,改善其食用品质,使其成为可接受的主食。本实验首先选用纤维素酶预处理发芽糙米,然后将发芽糙米与精白米复配蒸煮生产常温无菌包装方便米饭。实验结果表明,纤维素酶预处理的最佳条件为:酶浓度1.0U/mL,酶解温度50℃,酶解时间80 min;发芽糙米与精白米的最佳配比为20∶80~30∶70,发芽糙米与精白米复配米最佳蒸煮工艺为蒸煮米水比1∶1.2,蒸煮压力0.06 MPa,蒸煮时间15 min,此时得到的复配方便米饭感官评价分值最高。

The nutritional value of germinated brown rice is higher than that of refined white rice,and the content of dietary fiber,gamma-aminobutyric acid（GABA）,VB1 and VB2 are4.7,4.6,4.0 and 2.5 times of that of refined rice,respectively.However,there are a lot of cellulose,hemicellulose and pectin substances contained in the surface of germinated brown rice,it is supposed that the addition of cellulase can partially degrade these substances,thus reducing the cooking gelatinization temperature of germinated brown rice and improving its eating quality,making it an acceptable staple food.Cellulase was first used to hydrolyze germinated brown rice,and then the germination of brown rice mixed with refined rice was cooked at room temperature for the production of sterile packaging convenience rice.The results show that the optimal conditions of cellulase pretreatment are：enzyme concentration of 1.0 U/mL,enzymolysis temperature of50 ℃ and enzymolysis time of 80 min;the optimal ratio of germinated brown rice to refined rice is 20∶80 to 30∶70;the highest sensory evaluation score of mixed convenient rice is obtained under conditions of rice to water ratio of 1∶1.2,steaming pressure of 0.06 MPa and cooking time of 15 min.