黄酒米浆水制备农用酵素营养液发酵过程中营养成分的变化

Changes in nutrition components of agricultural Jiaosu nutrient solutions produced from rice milk during fermentation process

黄酒米浆水是黄酒酿造浸米工序中的副产物,属于高浓度有机废水,用之是宝,弃之严重污染环境。采用米浆水代替清水作为配料水,以叶菜类废弃物包括萝卜叶、白菜叶和莴笋叶为植物原料,混合红砂糖,自然发酵制备农用酵素营养液,研究其发酵过程中主要营养组分的变化规律。结果表明,利用黄酒米浆水制备的农用酵素营养液各营养组分在发酵过程中显著高于用清水制备的对照组(P<0.05)。不同植物材料制备的米浆水农用酵素营养液各营养组分变化趋势类似,总糖含量呈下降趋势,钾离子含量呈先升高后降低再升高变化,总氮、总磷、总酸和游离氨基酸含量整体均呈上升趋势;以萝卜叶农用酵素营养液为例,发酵90 d时,总糖含量下降76.68%,总氮、总磷、钾离子、总酸和游离氨基酸总量分别上升40.56%、53.58%、22.83%、33.08%和183.4%;17种游离氨基酸中丙氨酸含量最高,为3 677.4 mg·L^(-1),提高638.6%。不同植物材料制备的农用酵素营养液均含有较丰富的养分,但养分含量差异明显(P<0.05);其中萝卜叶农用酵素营养液发酵各时段总氮、总磷、总糖和总酸含量的平均值较高,分别为4.67mg·m L^(-1)、628.20 mg·L^(-1)、5.22%和13.30 g·L^(-1);萝卜叶农用酵素营养液发酵90 d时游离氨基酸总量最高,为14 157.3mg·L^(-1);莴笋叶农用酵素营养液发酵各时段钾离子含量平均值较高,达到95.22 mmol·L^(-1)。

Rice milk, the byproduct from producing yellow rice wine, is a kind of high concentration organic wastewater that could result in severe water pollution. In this study, changes in main nutrition components of agricultural Jiaosu nutrient solutions, which were fermented using rice milk instead of water and vegetable wastes(including radish leaves, cabbage leaves, and lettuce leaves), mixed with brown sugar as substrate during fermentation process, were investigated. The results showed that: all main nutrition components in solutions produced from rice milk were significantly greater than those of the control group(P<0.05);for solutions produced by different vegetable wastes, the changes of main nutrition components were similar. During fermentation, the contents of free amino acid, total phosphorus, total nitrogen, potassium ion content and total acid showed an increasing trend, while the level of total sugar dropped, potassium ion content rose firstly then decreased and then rose again;for instance, in solutions produced from radish leaves and rice milk after 90 days of fermentation, the total amount of sugar decreased by 76.68 %, whereas the amount of total nitrogen, total phosphorus, potassium ion content, total acid and total free amino acid increased by 40.56 %, 53.58 %, 22.83 %, 33.08 % and 183.4 %, respectively;Alanine increased the most among the 17 free amino acids, grown by 638.6% with the concentration of 3 677.4 mg·L^-1. We also found a significant difference in nutrition components between solutions generated from different vegetable wastes including radish leaves, cabbage leaves, and lettuce leaves(P<0.05);average values of total nitrogen, total phosphorus, total sugar and total acid from radish leaf during fermentation period were around 4.67 mg·mL^-1, 628.20 mg·L^-1, 5.22 % and 13.30 g·L^-1, respectively, which are higher than the levels of other nutrition components. The total free amino acid content in solution after 90 days of fermentation was 14 157.3 mg·L^-1, which was also higher than those of the rest treatments. On the contrary, lettuce leaf Jiaosu nutrient solution had a higher potassium ion content, with the average amount of 95.22 mmol·L^-1 in the period of fermentation.