Zheng Yalu, Ma Yan, Ukwatta Ruchika Hansanie, Xue Feng, Li Chen
College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China.
School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China.
Polymers (Basel). 2024 Feb 20;16(5):569. doi: 10.3390/polym16050569.
The food, pharmaceutical, and supply transport storage chain is seeking coolants that come with plastic-free packaging, are nontoxic, environmentally friendly, robust, reusable, and reduce water waste. To meet this demand, a new food coolant based on cornstarch hydrogel was developed and tested using the regeneration method. This study investigated the reusability, water retention, rehydration, and surface cleanliness of the hydrogel, along with its application in freshness retention for fruits. The results of the gel strength and differential scanning calorimetry (DSC) analysis showed that the ideal concentration of cornstarch hydrogel was 8%. Freezing and thawing experiments demonstrated that the hydrogel had the potential to be used as a cooling medium for refrigerated fresh foods. Moreover, the gel strength, scanning electron microscopy images (SEM), DSC, and thermogravimetric analysis (TG) revealed that the freeze-thaw reuse only slightly affected its freezable water content and that its gel strength gradually increased during reuse. Water retention and rehydration tests showed that the hydrogels could be better preserved at -20 °C compared to 4 °C, and the water lost during reuse could be replenished through rehydration. The flexibility in terms of shape and size also allows the hydrogel ice to be used as a customized coolant for various food shapes, as demonstrated by preservation experiments. Additionally, washing the hydrogel after each use can result in a significant reduction in , , and concentrations by 3.03, 3.47, and 2.77 log CFU/hydrogel, respectively. Overall, the new cornstarch hydrogel coolant is a promising alternative to conventional ice, with the potential to serve as a food coolant.
食品、制药和供应运输存储链正在寻找具有无塑料包装、无毒、环保、耐用、可重复使用且减少水资源浪费等特性的冷却剂。为满足这一需求，一种基于玉米淀粉水凝胶的新型食品冷却剂被研发出来，并采用再生方法进行了测试。本研究调查了水凝胶的可重复使用性、保水性、复水性和表面清洁度，以及其在水果保鲜方面的应用。凝胶强度和差示扫描量热法（DSC）分析结果表明，玉米淀粉水凝胶的理想浓度为8%。冻融实验表明，该水凝胶有潜力用作冷藏新鲜食品的冷却介质。此外，凝胶强度、扫描电子显微镜图像（SEM）、DSC和热重分析（TG）显示，冻融再利用仅对其可冻结水含量有轻微影响，且其凝胶强度在再利用过程中逐渐增加。保水和复水测试表明，与4℃相比，水凝胶在-20℃下能得到更好的保存，再利用过程中损失的水分可通过复水补充。形状和尺寸的灵活性也使得水凝胶冰能够作为针对各种食品形状定制的冷却剂，保鲜实验证明了这一点。此外，每次使用后清洗水凝胶可使 、 和 的浓度分别显著降低3.03、3.47和2.77 log CFU/水凝胶。总体而言，新型玉米淀粉水凝胶冷却剂是传统冰块的一个有前景的替代品，有潜力用作食品冷却剂。
