Montaño A, Sánchez A H, Rejano L, de Castro A
Departamento de Biotecnologia de Alimentos, Instituto de la Grasa (CSIC), Seville, Spain.
Int J Food Microbiol. 1997 Mar 18;35(1):83-90. doi: 10.1016/s0168-1605(96)01232-9.
A mixed culture of Lactobacillus plantarum and Saccharomyces cerevisiae was compared with a single culture of L. plantarum as starter for the fermentation of lye-treated carrots. Using the mixed culture, more than 95% of glucose, fructose and malic acid was consumed after 7 days of fermentation in a brine containing 2.5% w/v NaCl and 0.7% acetic acid, but only 54% of sucrose was degraded. The fermentation products quantified were lactic acid, ethanol and acetic acid and carbon recovery was 88%. Using the single culture of L. plantarum, substrate consumption was lower, and carbon recovery almost 100%. In uninoculated lye-treated carrots, heterofermentative bacteria grew, with the production of considerable amounts of mannitol. In all cases, the stability, sensorial characteristics and carotenoid content of the packed product were studied during 9 months of storage at 30 degrees C, and two different preservation systems were compared: addition of preservatives, approximately 500 and 1000 mg/kg of sorbic and benzoic acid, respectively, and pasteurization at 80 degrees C for 10 min. The pasteurized samples were microbiologically stable during the storage period, while lactic acid bacteria grew in the samples with preservatives. Storage time significantly (P < 0.05) affected the texture and colour parameters (L*, a*, b*) of the carrots, but not the amounts of alpha- and beta-carotene. The type of fermentation had no significant effect on texture, colour parameters or carotenoid content. The preservation method had no significant effect on texture or carotenoid content, but did affect colour (parameter a*). The flavour of carrots fermented by the mixed culture was significantly (P < 0.05) preferred to that of those fermented with a single culture of L. plantarum.
将植物乳杆菌和酿酒酵母的混合培养物与单一的植物乳杆菌培养物作为碱处理胡萝卜发酵的发酵剂进行比较。使用混合培养物时，在含有2.5% w/v氯化钠和0.7%乙酸的盐水中发酵7天后，超过95%的葡萄糖、果糖和苹果酸被消耗，但只有54%的蔗糖被降解。定量的发酵产物为乳酸、乙醇和乙酸，碳回收率为88%。使用单一的植物乳杆菌培养物时，底物消耗较低，碳回收率几乎为100%。在未接种的碱处理胡萝卜中，异型发酵细菌生长，并产生大量甘露醇。在所有情况下，研究了包装产品在30℃下储存9个月期间的稳定性、感官特性和类胡萝卜素含量，并比较了两种不同的保存系统：添加防腐剂，分别约500和1000 mg/kg的山梨酸和苯甲酸，以及在80℃下巴氏杀菌10分钟。巴氏杀菌样品在储存期间微生物稳定，而添加防腐剂的样品中乳酸菌生长。储存时间显著（P < 0.05）影响胡萝卜的质地和颜色参数（L*、a*、b*），但不影响α-和β-胡萝卜素的含量。发酵类型对质地、颜色参数或类胡萝卜素含量没有显著影响。保存方法对质地或类胡萝卜素含量没有显著影响，但对颜色（参数a*）有影响。混合培养物发酵的胡萝卜风味明显（P < 0.05）优于单一植物乳杆菌培养物发酵的胡萝卜。
