Mohamed Amal M A, Ramaswamy Hosahalli S
Department of Food Science and Agricultural Chemistry, Macdonald Campus of McGill University, 21111 Lakeshore Road, Ste Anne de Bellevue, QC H9X 3V9, Canada.
Foods. 2025 Jul 24;14(15):2598. doi: 10.3390/foods14152598.
Utilizing edible films/coatings promises to extend the shelf life of fruits by controlling various physiological parameters (e.g., respiration and transpiration rates), maintaining firmness, and delaying fruit senescence. The influence of composite-based edible coatings made from sodium or calcium caseinate: carboxymethyl chitosan (75:25) on the postharvest quality of fresh blueberries was assessed over a 28-day storage period, on the basis of weight loss and changes in pH, firmness, color, titratable acidity, soluble solids content, mold and yeast count, and respiration rate. The pH of the blueberries increased over the period of storage, with significant differences observed between uncoated and coated (e.g., pH was 3.89, 3.17, and 3.62 at the end of the storage time for uncoated, Ca 75-1% SO, and Na 75-1% SO, respectively. Desirable lower pH values at the end of storage were obtained with the calcium caseinate formulations. Over the duration of storage, other quality parameters (e.g., firmness) were better retained in coated fruits compared to the uncoated (control) one. At the last storage day, the firmness of the uncoated sample was 0.67 N·mm while the sodium and calcium caseinate was 0.63 and 0.81 N.mm, respectively. Moreover, the microbial growth was reduced in coated fruits, indicating the effectiveness of coatings in preserving fruit quality. The mold /yeast count was 1.4 and 2.3 log CFU/g for CaCa 75-1% SO and NaCa 75-1% SO compared with uncoated with 4.2 log CFU/g. Adding soybean oil to the caseinate-carboxymethyl chitosan composite edible coating has the potential to positively influence retention of various quality parameters of blueberries, thereby extending their shelf life and maintaining overall quality. Further research could explore the optimization of coating formulations and application methods to enhance their effectiveness in preserving fruit quality during storage.
利用可食用薄膜/涂层有望通过控制各种生理参数（如呼吸速率和蒸腾速率）、保持果实硬度以及延缓果实衰老来延长水果的货架期。基于重量损失以及pH值、硬度、颜色、可滴定酸度、可溶性固形物含量、霉菌和酵母菌数量及呼吸速率的变化，评估了由酪蛋白酸钠或酪蛋白钙与羧甲基壳聚糖（75:25）制成的复合可食用涂层在28天储存期内对新鲜蓝莓采后品质的影响。在储存期间，蓝莓的pH值升高，未涂层和涂层蓝莓之间存在显著差异（例如，在储存期结束时，未涂层、Ca 75-1% SO和Na 75-1% SO的蓝莓pH值分别为3.89、3.17和3.62）。酪蛋白钙配方在储存期结束时获得了理想的较低pH值。在整个储存期间，与未涂层（对照）水果相比，涂层水果的其他品质参数（如硬度）保留得更好。在最后一个储存日，未涂层样品的硬度为0.67 N·mm，而酪蛋白酸钠和酪蛋白钙的硬度分别为0.63和0.81 N·mm。此外，涂层水果中的微生物生长减少，表明涂层在保持水果品质方面的有效性。CaCa 75-1% SO和NaCa 75-1% SO的霉菌/酵母菌数量分别为1.4和2.3 log CFU/g，而未涂层的为4.2 log CFU/g。向酪蛋白酸盐-羧甲基壳聚糖复合可食用涂层中添加大豆油有可能对蓝莓各种品质参数的保留产生积极影响，从而延长其货架期并保持整体品质。进一步的研究可以探索涂层配方和应用方法的优化，以提高它们在储存期间保持水果品质的有效性。
