Bleoanca Iulia, Lanciu Andreea, Patrașcu Livia, Ceoromila Alina, Borda Daniela
Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, 800201 Galati, Romania.
Cross-Border Faculty, Dunarea de Jos University of Galati, 111 Domneasca Str., 800201 Galati, Romania.
Membranes (Basel). 2022 Mar 15;12(3):326. doi: 10.3390/membranes12030326.
Edible coatings are important for horticulture crops preservation and reducing food waste. Application of edible coatings followed by low-temperature storage prolongs the storability, preserves quality, and decreases the overall postharvest losses. This study evaluated the efficacy of two nanoemulsions formulae containing thyme essential oil and whey proteins as coatings for zucchini, with the purpose of extending their shelf-life. The nanoemulsions were rheologically evaluated and the formula with guar and arabic gum mix stabilizer (S) showed a better capacity to restructure after strain compared to the formulae with Tween 20 (T). The S coating material had a better capacity to integrate nanoparticles compared to T. However, when applied on zucchini, T coating was more effective in reducing weight loss showing 16% weight loss compared to 21% in S, after 42 days. At the end of storage at 10 °C, the T-coated zucchini had better firmness (p < 0.05) compared with S and both coatings were superior to control (p < 0.05). POD (peroxidase) activity was high in peel at the end of storage when also CAT (catalase) showed a sudden increase. On the 42nd day of storage, the highest enzymes activity (CAT, POD, and APX (ascorbate peroxidase)) was present in the S-coated zucchini peel. The most abundant volatile in T coating was α-pinene and 4-carene in S. Sensory analysis showed that T coating delayed the appearance of senescence while S exhibited surface cracks.
可食用涂层对于园艺作物的保鲜和减少食物浪费至关重要。应用可食用涂层并结合低温储存可延长贮藏期、保持品质并减少总体采后损失。本研究评估了两种含有百里香精油和乳清蛋白的纳米乳液配方作为西葫芦涂层的效果，目的是延长其货架期。对纳米乳液进行了流变学评估，与含有吐温20（T）的配方相比，含有瓜尔胶和阿拉伯胶混合稳定剂（S）的配方在应变后具有更好的重组能力。与T相比，S涂层材料具有更好的整合纳米颗粒的能力。然而，当应用于西葫芦时，T涂层在减少重量损失方面更有效，42天后显示重量损失为16%，而S为21%。在10℃储存结束时，T涂层的西葫芦比S具有更好的硬度（p<0.05），并且两种涂层均优于对照（p<0.05）。贮藏结束时，果皮中的过氧化物酶（POD）活性较高，同时过氧化氢酶（CAT）也突然增加。在贮藏的第42天，S涂层的西葫芦果皮中存在最高的酶活性（CAT、POD和抗坏血酸过氧化物酶（APX））。T涂层中最丰富的挥发物是α-蒎烯，S中是4-蒈烯。感官分析表明，T涂层延缓了衰老的出现，而S则出现了表面裂纹。
