USDA-ARS, SAA Food Science Research Unit, 322 Schaub Hall, Box 7624, North Carolina State Univ., Raleigh, NC 27695-7624, USA.
J Food Sci. 2010 Apr;75(3):C291-6. doi: 10.1111/j.1750-3841.2010.01558.x.
Waste water containing high levels of NaCl from cucumber fermentation tank yards is a continuing problem for the pickled vegetable industry. A major reduction in waste salt could be achieved if NaCl were eliminated from the cucumber fermentation process. The objectives of this project were to ferment cucumbers in brine containing CaCl(2) as the only salt, to determine the course of fermentation metabolism in the absence of NaCl, and to compare firmness retention of cucumbers fermented in CaCl(2) brine during subsequent storage compared to cucumbers fermented in brines containing both NaCl and CaCl(2) at concentrations typically used in commercial fermentations. The major metabolite changes during fermentation without NaCl were conversion of sugars in the fresh cucumbers primarily to lactic acid which caused pH to decrease to less than 3.5. This is the same pattern that occurs when cucumbers are fermented with NaCl as the major brining salt. Lactic acid concentration and pH were stable during storage and there was no detectable production of propionic acid or butyric acid that would indicate growth of spoilage bacteria. Firmness retention in cucumbers fermented with 100 to 300 mM CaCl(2) during storage at a high temperature (45 degrees C) was not significantly different from that obtained in fermented cucumbers with 1.03 M NaCl and 40 mM CaCl(2). In closed jars, cucumber fermentations with and without NaCl in the fermentation brine were similar both in the chemical changes caused by the fermentative microorganisms and in the retention of firmness in the fermented cucumbers.
来自黄瓜发酵罐场的高盐废水是腌制蔬菜行业面临的一个持续问题。如果能从黄瓜发酵过程中去除 NaCl,就可以大大减少废盐量。本项目的目的是在仅含有 CaCl2 的盐水中发酵黄瓜,以确定在没有 NaCl 的情况下发酵代谢的过程,并比较在 CaCl2 盐水中发酵的黄瓜在随后的储存过程中与在通常用于商业发酵的 NaCl 和 CaCl2 浓度的盐水中发酵的黄瓜的硬度保持情况。在没有 NaCl 的情况下发酵过程中的主要代谢物变化是新鲜黄瓜中的糖主要转化为乳酸,导致 pH 值降至 3.5 以下。当用 NaCl 作为主要腌制盐发酵黄瓜时,也会出现这种情况。在储存过程中,乳酸浓度和 pH 值保持稳定,没有检测到丙酸或丁酸的产生,这表明腐败细菌的生长。在高温(45°C)下储存时,用 100 至 300 mM CaCl2 发酵的黄瓜的硬度保持率与用 1.03 M NaCl 和 40 mM CaCl2 发酵的黄瓜的硬度保持率没有显著差异。在密封的罐中,发酵盐水中含有和不含有 NaCl 的黄瓜发酵在发酵微生物引起的化学变化和发酵黄瓜的硬度保持方面相似。