Gómez-López Vicente M, Ragaert Peter, Ryckeboer Jaak, Jeyachchandran Visvalingam, Debevere Johan, Devlieghere Frank
Laboratory of Food Microbiology and Food Preservation, Ghent University, Coupure Links, 653-9000 Gent, Belgium.
Int J Food Microbiol. 2007 Jun 10;117(1):91-8. doi: 10.1016/j.ijfoodmicro.2007.02.016. Epub 2007 Mar 6.
Minimally processed vegetables (MPV) have a short shelf-life. Neutral electrolysed oxidising water (NEW) is a novel decontamination method. The objective of this study was to test the potential of NEW to extend the shelf-life of a MPV, namely shredded cabbage. Samples of shredded cabbage were immersed in NEW containing 40 mg/L of free chlorine or tap water (control) up to 5 min, and then stored under equilibrium modified atmosphere at 4 degrees C and 7 degrees C. Proliferation of aerobic mesophilic bacteria, psychrotrophic bacteria, lactic acid bacteria and yeasts were studied during the shelf-life. Also pH and sensorial quality of the samples as well as O(2) and CO(2) composition of the headspace of the bags was evaluated. From the microbial groups, only psychrotrophic counts decreased significantly (P<0.05) due to the effect of NEW, but the counts in treated samples and controls were similar after 3 days of storage at 4 degrees C and 7 degrees C. Packaging configurations kept O(2) concentration around 5% and prevented CO(2) accumulation. pH increased from 6.1-6.2 to 6.4 during the shelf-life. No microbial parameter reached unacceptable counts after 14 days at 4 degrees C and 8 days of storage at 7 degrees C. The shelf-life of controls stored at 4 degrees C was limited to 9 days by overall visual quality (OVQ), while samples treated with NEW remained acceptable during the 14 days of the experiment. The shelf-life of controls stored at 7 degrees C was limited to 6 days by OVQ and browning, while that of samples treated with NEW were limited to 9 days by OVQ, browning and dryness. According to these results, a shelf-life extension of at least 5 days and 3 days in samples stored respectively at 4 degrees C and 7 degrees C can be achieved by treating shredded cabbage with NEW. NEW seems to be a promising method to prolong the shelf-life of MPV.
轻度加工蔬菜（MPV）的货架期较短。中性电解氧化水（NEW）是一种新型去污方法。本研究的目的是测试NEW延长MPV（即切碎的卷心菜）货架期的潜力。将切碎的卷心菜样品浸入含有40mg/L游离氯的NEW或自来水中（对照）长达5分钟，然后在4℃和7℃的平衡改良气氛下储存。在货架期内研究了需氧嗜温菌、嗜冷菌、乳酸菌和酵母菌的增殖情况。还评估了样品的pH值和感官质量以及包装袋顶空的O₂和CO₂组成。在微生物菌群中，由于NEW的作用，只有嗜冷菌计数显著下降（P<0.05），但在4℃和7℃储存3天后，处理过的样品和对照中的计数相似。包装配置使O₂浓度保持在5%左右，并防止了CO₂的积累。在货架期内，pH值从6.1 - 6.2增加到6.4。在4℃储存14天和7℃储存8天后，没有微生物参数达到不可接受的计数。在4℃储存的对照的货架期因总体视觉质量（OVQ）而限制为9天，而用NEW处理的样品在实验的14天内仍可接受。在7℃储存的对照的货架期因OVQ和褐变而限制为6天，而用NEW处理的样品的货架期因OVQ、褐变和干燥而限制为9天。根据这些结果，用NEW处理切碎的卷心菜可分别使在4℃和7℃储存的样品的货架期至少延长5天和3天。NEW似乎是一种延长MPV货架期的有前景的方法。
