Zhang Chi, Zhou Pengcheng, Mei Jun, Xie Jing
College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China.
Key Laboratory of Aquatic Products High Quality Utilization, Storage and Transportation (Co-Construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Shanghai 201306, China.
Plants (Basel). 2023 Jun 19;12(12):2370. doi: 10.3390/plants12122370.
The strong wind pre-cooling (SWPC), ice water pre-cooling (IWPC), vacuum pre-cooling (VPC), natural convection pre-cooling (NCPC), and slurry ice pre-cooling (SIPC) techniques were used to pre-cool the fresh sweet corn ( L.), and then the pre-cooling treated sweet corn samples were stored at 4 °C for 28 days. During refrigeration, quality indicators, such as hardness, water loss, color, soluble solids content, and soluble sugar, were determined. In addition, oxidation indicators, such as peroxidase, catalase, ascorbic acid-peroxidase activity, and carotene content, were also measured. The results showed that the main problems of sweet corn during cold storage were water loss and respiration. The pre-cooling speed of SWPC is the fastest, and the latent heat of sweet corn can be removed in only 31 min. SWPC and IWPC could reduce the loss of fruit quality, maintain good color and hardness, inhibit the decrease of water, soluble solids, soluble sugars, and carotenoid contents, maintain balance between POD, APX, and CAT, and extend the shelf life of sweet corn. The shelf life of SWPC and IWPC corn reached 28 days, 14 days longer than SIPC and VPC treated samples, and 7 days longer than NCPC treated samples. Therefore, SWPC and IWPC are the appropriate methods to pre-cool the sweet corn before cold storage.
采用强风预冷（SWPC）、冰水预冷（IWPC）、真空预冷（VPC）、自然对流预冷（NCPC）和浆冰预冷（SIPC）技术对新鲜甜玉米（L.）进行预冷，然后将预冷处理后的甜玉米样品在4℃下贮藏28天。在冷藏期间，测定了硬度、水分损失、颜色、可溶性固形物含量和可溶性糖等品质指标。此外，还测定了过氧化物酶、过氧化氢酶、抗坏血酸过氧化物酶活性和胡萝卜素含量等氧化指标。结果表明，甜玉米在冷藏过程中的主要问题是水分损失和呼吸作用。SWPC的预冷速度最快，仅需31分钟就能去除甜玉米的潜热。SWPC和IWPC可以减少果实品质的损失，保持良好的颜色和硬度，抑制水分、可溶性固形物、可溶性糖和类胡萝卜素含量的下降，维持POD、APX和CAT之间的平衡，并延长甜玉米的货架期。SWPC和IWPC处理的甜玉米货架期达到28天，比SIPC和VPC处理的样品长14天，比NCPC处理的样品长7天。因此，SWPC和IWPC是甜玉米冷藏前预冷的合适方法。
