食盐浓度对熟腌茭白理化性质及品质的影响

以茭白为原料,研究了不同食盐浓度腌制茭白其发酵过程中理化指标(p H、总酸、盐度、亚硝酸盐含量和氨基酸态氮)和微生物指标(细菌、乳酸菌总数)的变化,并对成品的色泽、质地、挥发性风味物质进行了分析。结果表明,3%、5%和8%食盐浓度下腌制的茭白p H分别为3.73、3.18和3.48,酸度分别为13.77、23.67和17.05 g/kg,平衡盐度分别为1.21%、2.51%和3.42%,"亚硝峰"值分别为7.86、11.6和11.79 mg/kg,氨基酸态氮含量分别为0.012、0.027和0.048 g/m L,细菌和乳酸菌数均稳定在107CFU/m L。腌制后茭白的色泽和质地都会有所改变,食盐浓度越低其失色越严重,腌制后茭白的硬度低于新鲜茭白,咀嚼性和内聚性随食盐浓度的升高而增大;三种食盐浓度腌制后茭白均检测到39种挥发性化合物,主要挥发性风味物质为乙醇、2,3-丁二醇、乙酸、乙酸乙酯和苯甲醛等。建议茭白腌制初始食盐浓度为5%。

Effect of Salt Concentration on the Physicochemical Properties and Quality of Cooked-pickling Zizania aquatica L.

The effects of salt concentration on physicochemical properties (pH, total acidity, salinity, nitrite concentration, and amino nitrogen) and microbial populations (total bacteria counts and lactic acid bacteria (LAB)) were investigated during the pickling process of Zizania aquatica L. The color, texture, and volatile flavor compounds of the finished samples were also analyzed. The results indicated that for the pickled products with salinities of 3%, 5%, and 8%, the final pH values were 3.73, 3.18, and 3.48, the acidities were 13.77, 23.67, and 17.05 g/kg, the balanced salinities were 1.21%, 2.51%, and 1.21%, the nitrite peak values reached 7.86, 11.6, and 11.79 mg/kg, and the amino acid nitrogen contents were 0.012, 0.027, and 0.048 g/mL, respectively. The total bacteria counts and LAB were stable around 107 CFU/mL. The color and texture changed after pickling of Z. aquatica L. and decolorization of the final product increased with use of lower salt concentrations during pickling. The hardness of Z. aquatica L. was decreased after pickling, and the chewiness and cohesiveness increased with the increased salt concentration. A total of 39 volatile compounds were found in each of the salt concentrations. The main volatile flavor compounds were ethanol, 2,3-butanediol, acetic acid, ethyl acetate, benzene, and formaldehyde. The initial salt concentration of 5% was suggested.