Lopes Ana C, Queirós Rui P, Inácio Rita S, Pinto Carlos A, Casal Susana, Delgadillo Ivonne, Saraiva Jorge A
Associated Laboratory for Green Chemistry-Network of Chemistry and Technology (LAQV-REQUIMTE), Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
Department of Applications and Food Processing, Hiperbaric S.A., Calle Condado de Treviño, 6, 09001 Burgos, Spain.
Foods. 2024 Apr 24;13(9):1304. doi: 10.3390/foods13091304.
Nowadays, consumers are more aware of the effects of their diet on their health, and thus demand natural or minimally processed food products. Therefore, research has focused on processes that assure safe products without jeopardizing their nutritional properties. In this context, this work aimed to evaluate the effects of high-pressure processing (550 MPa/3 min/15 °C, HPP) on a fruit salad (composed of melon juice and pieces of Golden apple and Rocha pear) throughout 35 days of storage at 4 °C. For the physicochemical properties analysed (browning degree, polyphenol oxidase activity, antioxidant activity (ABTS assay), and volatile profile), a freshly made fruit salad was used, while for the microbiological tests (total aerobic mesophiles, and yeast and moulds) spoiled melon juice was added to the fruit salad to increase the microbial load and mimic a challenge test with a high initial microbial load. It was determined that processed samples were more microbiologically stable than raw samples, as HPP enabled a reduction of almost 4-log units of both total aerobic mesophiles and yeasts and moulds, as well as an almost 1.5-fold increase in titratable acidity of the unprocessed samples compared to HPP samples. Regarding browning degree, a significant increase ( < 0.05) was observed in processed versus unprocessed samples (roughly/maximum 68%), while the addition of ascorbic acid decreased the browning of the samples by 29%. For antioxidant activity, there were no significant differences between raw and processed samples during the 35 days of storage. An increase in the activity of polyphenol oxidase immediately after processing (about 150%) was confirmed, which was generally similar or higher during storage compared with the raw samples. Regarding the volatile profile of the product, it was seen that the compounds associated with melon represented the biggest relative percentage and processed samples revealed a decrease in the relative quantity of these compounds compared to unprocessed. Broadly speaking, HPP was shown to be efficient in maintaining the stability and overall quality of the product while assuring microbial safety (by inactivating purposely inoculated microorganisms), which allows for longer shelf life (7 versus 28 days for unprocessed and processed fruit salad, respectively).
如今，消费者更加意识到饮食对健康的影响，因此对天然或最低限度加工的食品有了需求。因此，研究集中在确保产品安全而不损害其营养特性的加工过程上。在此背景下，本研究旨在评估高压处理（550兆帕/3分钟/15℃，HPP）对一份水果沙拉（由甜瓜汁、金苹果片和罗查梨片组成）在4℃下储存35天的影响。对于所分析的理化性质（褐变程度、多酚氧化酶活性、抗氧化活性（ABTS法）和挥发性成分），使用的是新鲜制作的水果沙拉，而对于微生物测试（总需氧嗜温菌以及酵母菌和霉菌），向水果沙拉中添加了变质的甜瓜汁以增加微生物负荷，并模拟高初始微生物负荷的挑战性测试。结果表明，经过处理的样品在微生物方面比未处理的样品更稳定，因为HPP能够使总需氧嗜温菌以及酵母菌和霉菌的数量减少近4个对数单位，并且与HPP处理的样品相比，未处理样品的可滴定酸度增加了近一倍半。关于褐变程度，与未处理的样品相比，处理后的样品有显著增加（<0.05）（大致/最大68%），而添加抗坏血酸使样品的褐变减少了29%。对于抗氧化活性，在储存的35天内，未处理和处理后的样品之间没有显著差异。加工后立即确认多酚氧化酶活性增加（约150%），在储存期间，其活性与未处理的样品相比通常相似或更高。关于产品的挥发性成分，发现与甜瓜相关的化合物占相对百分比最大，与未处理的样品相比，处理后的样品中这些化合物的相对含量有所下降。总体而言，HPP被证明在确保微生物安全（通过灭活故意接种的微生物）的同时，能够有效地保持产品的稳定性和整体质量，从而延长保质期（未处理和处理后的水果沙拉分别为7天和28天）。
