a School of Food Science and Engineering, South China University of Technology , Guangzhou 510641 , China.
b Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Center , Guangzhou 510006 , China.
Crit Rev Food Sci Nutr. 2019;59(5):743-757. doi: 10.1080/10408398.2018.1496900. Epub 2018 Dec 30.
As one of the essential parts in human diet, vegetables are important in health keeping and their consumption increases continuously. Due to their highly perishable nature, the shelf life of fresh vegetables is considerably short, due to cellular respiration, microorganism, enzyme reaction, oxidation and so on. Therefore, short- and long-term storages of vegetables are required and various methods and technologies are applied for different commercial goals. For long-term storage, deep frozen storage is one of the most widespread used preservation methods for vegetables, as under temperatures low enough, the rate of most deteriorative reactions and microbial activities are significantly reduced. This review provides a critical comprehensive summary of long-term storage (≥6 months) vegetables under low temperatures (≤ -18 °C), and effects of the storage methods on various quality attributes of vegetables, such as texture, colour, contents of ascorbic acid, chlorophyll and carotenoids. Besides, the impacts of common pretreatments prior to freezing on the subsequent frozen storage are also briefly discussed. The current review shows that although some important biochemical attributes are more or less deteriorated and the quality loss of them is inevitable, a substantial portion of quality attributes appear to be stable during long-term deep frozen storage especially the physical parameters. Meanwhile, pretreatments prior to freezing, such as blanching process, also show significant influence on quality preservation in subsequent storage. Therefore long-term deep frozen storage can be applied as an effective storage method under proper conditions of pretreatments and storage.
蔬菜作为人类饮食的重要组成部分之一，对保持健康起着重要作用，其消费量也在不断增加。由于其高度易腐的特性，新鲜蔬菜的货架期相当短，这是由于细胞呼吸、微生物、酶反应、氧化等原因造成的。因此，需要对蔬菜进行短期和长期储存，并针对不同的商业目标应用各种方法和技术。对于长期储存，冷冻储存是蔬菜最广泛使用的保鲜方法之一，因为在足够低的温度下，大多数变质反应和微生物活动的速度会显著降低。本综述对低温（≤-18°C）下蔬菜的长期储存（≥6 个月）进行了批判性的综合总结，并讨论了储存方法对蔬菜各种品质属性的影响，如质地、颜色、抗坏血酸、叶绿素和类胡萝卜素含量。此外，还简要讨论了冷冻前常见预处理对后续冷冻储存的影响。目前的综述表明，尽管一些重要的生化属性或多或少会恶化，它们的质量损失是不可避免的，但在长期深冷冻藏过程中，大部分品质属性似乎是稳定的，特别是物理参数。同时，冷冻前的预处理，如漂烫处理，对后续贮藏过程中的品质保持也有显著影响。因此，在适当的预处理和储存条件下，长期深冷冻藏可以作为一种有效的储存方法。
