Dept. of Animal and Food Sciences, Univ. of Delaware, Newark, DE, 19716-2150, U.S.A.
J Food Sci. 2019 Jun;84(6):1494-1500. doi: 10.1111/1750-3841.14613. Epub 2019 May 6.
Strawberry is a healthy fruit with numerous health-benefit compounds. Unfortunately, it is highly perishable and occasionally can be contaminated with foodborne pathogens. The overall goal of this study is to evaluate pulsed light (PL) processing for disinfection of strawberries, extension of shelf life, and preservation of quality attributes and compounds that are beneficial to health. Preliminary screening of PL conditions based on visual appearance of strawberries was conducted, and 3 PL treatments were identified for full evaluation. Salmonella inoculum was artificially deposited onto the skin of strawberries via spot-inoculation or dip-inoculation. The 3 PL treatments slightly reduced the level of inoculated Salmonella on strawberries, ranging from approximately 0.4 to 0.8 log reduction. They also slowed down the visible mold development on strawberries by 2 to 4 days compared with the untreated control. Regarding the natural yeasts and molds, the quality attributes (weight loss and firmness), and the bioactive compounds (total anthocyanin, total phenolics, and total antioxidant activity). The 3 PL treatment showed no significant or negligible difference comparing to the control group. Overall, the 3 PL treatments demonstrated potential in extending the shelf life of strawberries. The quality attributes or the bioactive compounds of strawberries showed no significant or minimal change after these PL treatments. PRACTICAL APPLICATION: Pulsed light (PL) processing for strawberry decontamination and shelf life extension was evaluated. Results demonstrated that PL processing could have the potency to improve strawberry shelf life without significantly affecting the quality and bioactive compounds of strawberries.
草莓是一种健康的水果，含有多种对健康有益的化合物。不幸的是，它极易腐烂，偶尔还会受到食源性致病菌的污染。本研究的总体目标是评估脉冲光（PL）处理对草莓的消毒、延长货架期以及保持对健康有益的质量属性和化合物的作用。我们对基于草莓外观的 PL 条件进行了初步筛选，并确定了 3 种 PL 处理方法进行全面评估。通过点接种或浸泡接种将沙门氏菌接种物人工接种到草莓表皮上。这 3 种 PL 处理方法可使草莓上接种的沙门氏菌水平略有降低，降低幅度约为 0.4 至 0.8 对数减少。与未处理的对照组相比，它们还使草莓上可见霉菌的生长速度减慢了 2 至 4 天。至于天然酵母和霉菌、质量属性（失重和硬度）以及生物活性化合物（总花青素、总酚和总抗氧化活性），这 3 种 PL 处理与对照组相比没有显著或可忽略的差异。总体而言，这 3 种 PL 处理方法在延长草莓货架期方面具有潜力。经过这些 PL 处理后，草莓的质量属性或生物活性化合物没有明显或最小的变化。实用意义：评估了脉冲光（PL）处理对草莓消毒和延长货架期的效果。结果表明，PL 处理有可能在不显著影响草莓质量和生物活性化合物的情况下，延长草莓的货架期。
