Abstract Limited shelf life due to processing associated microbial contamination is one of the major challenging issues with minimally processed ‘Ready to Bake’ (RTB) vegetable products leading to huge post-processing losses. In the current study, three minimally processed vegetables, i.e. tomato, bell pepper and white onion, which are widely used in fast food Industries (FFI), such as pizza and burger as well as in household uses; were studied for their post-processing microbiological profile; and to assess the effect of gamma radiation treatment (0.5–5 kGy) to maintain hygiene during extended storage at low temperature. Prior to radiation treatment, the minimally processed vegetables were packed in low density polyethylene bags (thickness: 50 μm) which is suitable for such agri-produce and compatible to gamma radiation treatment (USA, FDA). Besides, vacuum packaging in multilayerd LDPE bags was optimized for shredded onion. Except tomato, which did not contain any detectable Presumptive Coliform or Yeast and Mold on day 0, the other two cut vegetables were found to have higher load of microbes, i.e., more than 4.0 log CFUg−1 of total aerobic plate count, 3.0 log CFUg−1of each of Yeast and Mold counts (YMC) and Presumptive Coliform (PC) counts. In the radiation treated (2 kGy) vegetables, no PC was detected; even after 20 days of storage; whereas, in the untreated bell pepper, tomato and onion samples PC counts were found to be 4.3 ± 0.1, 3.7 ± 0.2 and 1.7 ± 0.3 log CFUg−1 respectively on day 20 of storage. The data indicated that, the total aerobic plate counts in the 2 kGy irradiated samples were below the permissible limit as per the Food Safety and Standards Authority of India (FSSAI) guidelines. Organoleptic attributes (‘colour’, ‘texture’, ‘flavour’, ‘taste’, and ‘overall acceptability’) of the radiation treated products were found to be well retained even on 20 days of storage. The nutritional adequacy of these products in terms of total energy, fat, protein, carbohydrate, minerals and vitamin content was found to be well retained till the end of the 20 days' storage period. Findings of the study thus establishes the efficacy of gamma radiation treatment in ensuring the safety and quality of minimally processed vegetables for their use in FFI as well as domestic kitchens.

中文翻译：

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伽马辐射处理，以确保即食 (RTB) 蔬菜浇头/填料的微生物安全，并在冷藏期间保持其营养品质

摘要 由于加工相关的微生物污染而导致的有限保质期是最低限度加工的“准备烘烤”（RTB）蔬菜产品的主要挑战问题之一，导致巨大的后加工损失。在目前的研究中，三种最低限度加工的蔬菜，即番茄、甜椒和白洋葱，它们广泛用于快餐行业 (FFI)，例如比萨饼和汉堡以及家庭用途；对其后处理微生物特征进行了研究；并评估伽马辐射处理（0.5-5 kGy）在低温长期储存期间保持卫生的效果。在辐射处理之前，将最低限度加工的蔬菜包装在适用于此类农产品并兼容伽马辐射处理（美国，FDA）的低密度聚乙烯袋（厚度：50 μm）中。此外，多层 LDPE 袋中的真空包装针对洋葱丝进行了优化。除了在第 0 天不含任何可检测到的推定大肠菌群或酵母菌和霉菌的番茄外，其他两种切碎的蔬菜被发现具有更高的微生物负荷，即总需氧菌落总数超过 4.0 log CFUg-1，3.0 log酵母菌和霉菌计数 (YMC) 和推定大肠菌群 (PC) 计数中的每一个的 CFUg-1。在辐射处理（2 kGy）蔬菜中，未检测到 PC；即使在储存 20 天后；而在未经处理的甜椒、番茄和洋葱样品中，在储存的第 20 天，发现 PC 计数分别为 4.3 ± 0.1、3.7 ± 0.2 和 1.7 ± 0.3 log CFUg-1。数据表明，根据印度食品安全和标准局 (FSSAI) 指南，2 kGy 辐照样品中的需氧菌总数低于允许限值。发现经辐射处理的产品的感官特性（“颜色”、“质地”、“风味”、“味道”和“总体可接受性”）即使在储存 20 天后也能很好地保持。发现这些产品在总能量、脂肪、蛋白质、碳水化合物、矿物质和维生素含量方面的营养充足性在 20 天的储存期结束前保持良好。因此，研究结果确定了伽马辐射处理在确保用于 FFI 和家庭厨房的最低限度加工蔬菜的安全性和质量方面的功效。和“总体可接受性”）的辐射处理产品被发现即使在 20 天的储存中也能很好地保留。发现这些产品在总能量、脂肪、蛋白质、碳水化合物、矿物质和维生素含量方面的营养充足性在 20 天的储存期结束前保持良好。因此，研究结果确定了伽马辐射处理在确保用于 FFI 和家庭厨房的最低限度加工蔬菜的安全性和质量方面的功效。和“总体可接受性”）的辐射处理产品被发现即使在 20 天的储存中也能很好地保留。发现这些产品在总能量、脂肪、蛋白质、碳水化合物、矿物质和维生素含量方面的营养充足性在 20 天的储存期结束前保持良好。因此，研究结果确定了伽马辐射处理在确保用于 FFI 和家庭厨房的最低限度加工蔬菜的安全性和质量方面的功效。