Chikhala Tshudufhadzo, Seke Faith, Slabbert Retha M, Sultanbawa Yasmina, Sivakumar Dharini
Department of Horticulture, Tshwane University of Technology, Pretoria West 0001, South Africa.
Phytochemical Food Network Group, Department of Crop Sciences, Tshwane University of Technology, Pretoria West 0001, South Africa.
Foods. 2024 Mar 20;13(6):940. doi: 10.3390/foods13060940.
Due to spoilage microflora and browning, minimally processed fresh-cut fruits have a short shelf life, and over the years, studies have shown the potential of using edible coatings to extend the shelf life and improve the safety of fresh-cut fruits. Recently, there has been a rise in research on the incorporation of probiotics in edible coatings due to the bespoke health and biopreservation benefits they impart. Therefore, in this study, lactobacillus strains ( 75 and ) were incorporated into a xanthan edible coating to enhance color retention, sensory properties, antioxidant retention (ascorbic acid, carotenoids, total phenols), and antioxidant activity (FRAP antioxidant power, ABTS scavenger activity) of fresh-cut cantaloupes and honeydew L. melons during cold storage at 5 C and 85% RH for five days. The edible coating was prepared by mixing 0.5% xanthan gum, 1% glycerol, and 2% citric acid solution with (LAB 75) and bacteria separately, and the final lab count for each strain was made to be 8.0 log CFU/mL. Stable probiotic coatings with ζ-potential of between -39.7 and -51.4 mV and a PdI of 1 were developed, and the incorporation of the probiotic bacteria into the coating was justified using FTIR analysis. The probiotic coatings showed a typical pseudoplastic behavior, in which the viscosity curves fall as the shear rate increases. Thermal stability analysis showed a continuous and multi-step weight reduction in this work, illustrating how the edible coating components interact. The survival of both Lactobacillus strains was recorded on day 5. Both freshly cut melons coated with xanthan and loaded with Lactobacillus strains retained a sufficient quantity of probiotics at the end of storage, while (7 log CFU/g for cantaloupe and 8 log CFU/g for honeydew) retained the highest viability compared to (6 log CFU/g for cantaloupe and 7 log CFU/g for honeydew). In comparison to the coated and uncoated control samples, the inclusion of in xanthan coatings significantly retained the color properties, pigments (total chlorophyll and carotenoids), ascorbic acid, total phenols, and antioxidant activity (FRAP, DPPH, and ABTS). The overall acceptability of fresh cuts of cantaloupe and honeydew melons coated with xanthan gum loaded with was higher than that of other treatments. Thus, xanthan gum loaded with coating is most suitable for reducing postharvest losses in fresh cuts of honeydew melons and cantaloupe, which will help preserve antioxidant and bioactive properties. The xanthan gum loaded with coatings exhibited the highest preservation impact; therefore, it can be recommended for the fresh-cut industry.
由于腐败微生物和褐变问题，最少加工的鲜切水果保质期较短。多年来，研究表明使用可食用涂层有延长鲜切水果保质期并提高其安全性的潜力。最近，由于益生菌带来的定制健康益处和生物保鲜优势，将益生菌加入可食用涂层的研究有所增加。因此，在本研究中，将乳酸菌菌株（75和）加入黄原胶可食用涂层中，以增强5℃、相对湿度85%冷藏5天期间鲜切哈密瓜和白兰瓜的颜色保持、感官特性、抗氧化剂保留（抗坏血酸、类胡萝卜素、总酚）以及抗氧化活性（铁还原抗氧化能力、ABTS清除剂活性）。通过将0.5%黄原胶、1%甘油和2%柠檬酸溶液分别与（LAB 75）和细菌混合制备可食用涂层，每种菌株的最终实验室计数为8.0 log CFU/mL。开发出了ζ电位在-39.7至-51.4 mV之间且多分散指数为1的稳定益生菌涂层，并使用傅里叶变换红外光谱分析证明了益生菌细菌加入涂层的合理性。益生菌涂层表现出典型的假塑性行为（即粘度曲线随剪切速率增加而下降）。热稳定性分析表明在本研究中重量持续且多步减少，说明了可食用涂层成分之间的相互作用。在第5天记录了两种乳酸菌菌株的存活率。用黄原胶包被并接种乳酸菌菌株的两种鲜切瓜在储存结束时都保留了足够数量的益生菌，而（哈密瓜为7 log CFU/g，白兰瓜为8 log CFU/g）相比（哈密瓜为6 log CFU/g，白兰瓜为7 log CFU/g）保留了最高的活力。与包被和未包被的对照样品相比，在黄原胶涂层中加入显著保留了颜色特性、色素（总叶绿素和类胡萝卜素）、抗坏血酸、总酚以及抗氧化活性（铁还原抗氧化能力、二苯基苦味酰基自由基清除能力和ABTS）。用接种了的黄原胶包被的哈密瓜和白兰瓜鲜切部分的总体可接受性高于其他处理。因此，接种了的黄原胶涂层最适合减少哈密瓜和白兰瓜鲜切部分的采后损失，这将有助于保持抗氧化和生物活性特性。接种了的黄原胶涂层表现出最高的保鲜效果；因此，推荐用于鲜切行业。
