Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
J Sci Food Agric. 2022 Jun;102(8):3425-3434. doi: 10.1002/jsfa.11690. Epub 2021 Dec 9.
Ready-to-eat fruit and vegetable products have gained tremendous popularity in recent years. The main challenges associated with these minimally processed products are their short shelf life and high food safety concerns. In this study, our goal was to develop an integrated process to both reduce the Salmonella population by >5 log CFU g ) and to reduce polyphenol oxidase activity, followed by quickly cooling the product. We compared the effect of a sequential treatment of dipping in citric acid (CA) followed by cold plasma (CP) treatment on the inactivation of Salmonella Typhimurium, polyphenol oxidase (PPO) activity, browning, total phenolic content and the moisture loss of cut apples during the plasma-integrated low-pressure cooling (PiLPC) process.
The greatest inactivation of Salmonella (5.68 log CFU g ) and the highest PPO inactivation (78%) were observed after dipping cut apples in 5% CA, followed by 3 min of CP treatment. The color of cut apples remained relatively unchanged, with a fresh-like appearance during 7 days of storage at 4 °C after this combined treatment. Although the low-pressure cooling time was increased when samples were pre-dipped in CA, related to those undipped, the moisture loss was reduced by more than 50% during the PiLPC process. No significant reduction in phenolic content was observed during the PiLPC when the samples were pre-dipped in 5% CA.
These results indicate the potential of this integrated process for the inactivation of endogenous food enzymes and bacterial pathogens in fresh-cut apples. © 2021 Society of Chemical Industry.
近年来，即食水果和蔬菜产品越来越受欢迎。这些低加工产品的主要挑战是保质期短和食品安全问题高。在这项研究中，我们的目标是开发一种综合工艺，既能减少沙门氏菌数量（>5 log CFU/g），又能降低多酚氧化酶活性，然后快速冷却产品。我们比较了柠檬酸（CA）浸泡后再进行冷等离子体（CP）处理对减少沙门氏菌 Typhimurium、多酚氧化酶（PPO）活性、褐变、总酚含量和等离子体集成低压冷却（PiLPC）过程中切苹果水分损失的影响。
在 5% CA 中浸泡 3 分钟 CP 处理后，发现沙门氏菌（5.68 log CFU/g）的最大失活和最高 PPO 失活（78%）。经过这种联合处理后，在 4°C 下储存 7 天，切苹果的颜色仍然相对不变，外观新鲜。虽然当样品预先浸泡在 CA 中时，低压冷却时间会增加，但与未浸泡的样品相比，在 PiLPC 过程中，水分损失减少了 50%以上。当样品在 5% CA 中预先浸泡时，PiLPC 过程中酚类含量没有明显减少。
这些结果表明，该综合工艺在减少鲜切苹果中内源性食品酶和细菌病原体方面具有潜力。 © 2021 化学工业协会。
