Anvarian Amir H P, Smith Madeleine P, Overton Tim W
Bioengineering School of Chemical Engineering The University of Birmingham Birmingham UK.
Present address: National Centre for Food Manufacturing Holbeach Technology Park University of Lincoln Holbeach Lincolnshire UK.
Food Sci Nutr. 2018 Aug 13;6(7):1817-1825. doi: 10.1002/fsn3.756. eCollection 2018 Oct.
Orange juice (OJ) contains numerous compounds some of which are known to play key roles in growth and survival of bacteria. This study aimed to investigate the effects of natural or processing-induced variations in OJ composition on the physiology of . OJ and model OJ (MOJ) samples containing various sugars, organic acids, amino acids, or ascorbic acid were inoculated with K-12 MG1655 in different growth phases. The culturability, viability, and physiology of the cells were investigated during storage using plate counting and flow cytometry. Generally, stationary-phase cells displayed the greatest survival in both MOJ and OJ. Increase in incubation temperature from 4 to 22.5ºC caused a significant decrease in both healthy and culturable cell populations. Supplementation of MOJ with ascorbic acid and amino acids increased both the viability and culturability of the cells. Similar trends were observed in amino acid-supplemented OJ, albeit at a slower rate. In contrast, variations in sugar or organic acid composition had negligible effects on the physiological status of the cells. In summary, natural variation in ascorbic acid or amino acid concentrations could potentially have an adverse effect on the microbiological safety of orange juice.
橙汁（OJ）含有多种化合物，其中一些已知在细菌的生长和存活中起关键作用。本研究旨在调查橙汁成分的天然或加工诱导变化对[此处原文缺失具体对象]生理学的影响。将含有各种糖、有机酸、氨基酸或抗坏血酸的橙汁和模拟橙汁（MOJ）样品接种处于不同生长阶段的K-12 MG1655。在储存期间，使用平板计数和流式细胞术研究细胞的可培养性、活力和生理学。一般来说，稳定期细胞在MOJ和OJ中均表现出最高的存活率。孵育温度从4℃升高到22.5℃导致健康细胞群体和可培养细胞群体均显著减少。向MOJ中添加抗坏血酸和氨基酸可提高细胞的活力和可培养性。在添加氨基酸的橙汁中也观察到类似趋势，尽管速率较慢。相比之下，糖或有机酸组成的变化对细胞的生理状态影响可忽略不计。总之，抗坏血酸或氨基酸浓度的天然变化可能会对橙汁的微生物安全性产生不利影响。
