条斑紫菜乳酸发酵过程中理化因子的演替规律

Succession of physical and chemical factors during lactic acid fermentation of Porphyra yezoensis

以条斑紫菜作为原料,采用老坛水乳酸菌发酵法对紫菜在15、20℃的温度条件下发酵20d,以发酵液中pH、总酸、总糖、氨基酸、蛋白质、盐度以及亚硝酸盐等各理化因子为参数,研究分析紫菜乳酸发酵过程中理化因子的变化规律,揭示紫菜乳酸发酵的可行性。结果显示,发酵液中的pH先下降,后趋于平稳,20℃的发酵液pH下降快,在7 d左右达到最低值2.9,15℃的发酵液在8 d达到最低值3.0;发酵液的总酸含量开始呈上升趋势,后趋于稳定,20℃的上升快,在8 d左右达到最大值0.916 g/100 g,15℃的在10 d左右达到最高值0.856 g/100 g,相对于初始值分别上升了2.2、1.9倍;总糖含量先下降后基本趋于稳定,均在6 d左右下降到最小值0.011、0.013 g/mL,相对于初始值分别下降了48.22%和38.32%;发酵液的氨基酸含量先上升后下降,20℃的在8d左右上升到最大值41.53μmol/mL,相对于检测的初始值上升了68.89%;15℃的在10 d左右达到最大值39.344μmol/mL,上升了84.62%;总蛋白质含量先快速上升后缓慢下降,2个发酵温度均在6 d左右分别达到最大值3.350、3.630 mg/L,分别是检测初始值的3.1、2.8倍;发酵液的盐度基本保持不变;20℃发酵液的亚硝酸盐含量达到峰值的时间早,且含量低,在4 d左右达到峰值6.232mg/L,是初始值的3.8倍,随后开始下降在8 d左右降到3.561 mg/L后趋于平稳;而15℃的亚硝酸盐在6 d左右达到峰值9.645 mg/L,在10 d左右降到最低值5.045 mg/L后呈波动趋势。试验结果旨在为条斑紫菜发酵工艺的研究及紫菜产品深度开发提供理论依据。

In this paper, Porphyra yezoensis was fermented at 15 ℃ and 20 ℃ for 20 days by Lactobacillus fermentation. The p H, total acid, total sugar, amino acid, protein, salinity and nitrite were used as parameters to study the changes of physical and chemical factors in lactic acid fermentation of Porphyra yezoensis and revealed the feasibility of lactic acid fermentation in Porphyra yezoensis. The results showed that the p H of the fermentation broth decreased first and then stabilized. Compared with the fermentation broth at 15 ℃, the pH of fermentation broth decreased faster at 20 ℃ and reached the lowest value of 2.9 in 7 th day. While the pH of fermentation broth at 15 ℃ reached the lowest value of 3.0 in 8 th day; The total acid increased first and then stabilized, the total acid of fermentation broth at 20 ℃ rose faster, reached the maximum value of 0.916 g/100 g in about 8 th day. While the the total acid of fermentation broth at 15 ℃ reached the maximum value of 0.856 g/100 g in 10 th day, rosed 2.2 times and 1.9 times, respectively, compared with the initial value. The total sugar decreased first and then tended to be stable, and decreased to a minimum of 0.011 g/m L and 0.013 g/mL at 6 th day, which decreased by 48.22% and 38.32%, respectively, compared with the initial values. The amino acid increased first and then decreased, the amino acid of fermentation broth at 20 ℃ reached the maximum of 41.53 μmol/m L around 8 th day, relatived to the detection of initial value rosed by 68.89%. While the amion acid content at 15 ℃ reached the maximum of 39.344 μmol/m L in 10 th day, rose by 84.62%. The total protein content increased rapidly first and than slowly decreased, and reached the maximum of 3.350 mg/L and 3.630 mg/L respectively, which were 3.1 times and 2.8 times of the initial value respectively; The salinity of the fermentation broth remained almost unchanged. The nitrite content of the fermentation broth at 20 ℃ reached the peak value earlier and the content was lower, and reached the peak value of 6.232 mg/L at about 4 th day, which was 3.8 times of the initial value, and then decreased to about 3.561 mg/L. While the nitrite of the fermentation broth at 15 ℃ reached the peak value of 9.645 mg/L at about 6 th day, and decreased to the lowest value of 5.045 mg/L at 10 th day. The purpose of this study was to provide a theoretical basis for the study of the fermentation process of seaweed and the deep development of seaweed products.