El-Ashaal Eman S, Elshoky Hisham A, El-Sayed Nayera M, El-Kholony Ebtehal A
Nanotechnology and Advanced Material Central Lab, Agricultural Research Center, Giza, 12619, Egypt.
Regional Center for Food and Feed, Agricultural Research Center, Giza, 12619, Egypt.
Sci Rep. 2025 Aug 26;15(1):31384. doi: 10.1038/s41598-025-16756-1.
Strawberries are highly perishable fruits due to moisture loss, intense metabolic activity, and microbial contamination, leading to rapid quality deterioration during storage. In this study, mango seed extract (MSE), a natural antioxidant source, was loaded with chitosan (CS) and carboxymethyl chitosan (CCS) nanoparticles to develop edible coatings for postharvest quality enhancement. Nanoparticles were characterized by dynamic light scattering (DLS) to determine particle size and zeta potential, revealing stable formulations with average sizes of 68.1 nm (CS LM) and 91.3 nm (CCS LM). Antioxidant capacity was assessed using ABTS and DPPH radical scavenging assays, where CCS LM exhibited superior activity (> 92%, p < 0.05) compared to free MSE and CS LM. Antimicrobial properties were evaluated by microbial inhibition tests against Staphylococcus aureus, Escherichia coli, and Candida albicans, showing significant inhibition rates at 800 µg/mL. Storage performance was assessed over 21 days at 2 °C by monitoring weight loss, firmness, color preservation, pH, titratable acidity, and microbial counts. Results demonstrated that CCS LM-coated strawberries had minimal weight loss (5.7%, p < 0.05), retained firmness, and showed reduced bacterial (1.2 log₁₀ CFU/g) and fungal counts (1.3 log₁₀ CFU/g) compared to uncoated fruits. These findings suggest that MSE-loaded CCS nanoparticles, through their antioxidant and antimicrobial functions, offer a promising sustainable strategy to improve the postharvest quality and storage performance of strawberries.
草莓是极易腐烂的水果，因为会出现水分流失、强烈的代谢活动以及微生物污染，导致其在储存期间品质迅速下降。在本研究中，将天然抗氧化剂来源的芒果籽提取物（MSE）负载于壳聚糖（CS）和羧甲基壳聚糖（CCS）纳米颗粒上，以开发用于采后品质提升的可食用涂层。通过动态光散射（DLS）对纳米颗粒进行表征，以确定粒径和zeta电位，结果显示稳定的制剂，平均粒径分别为68.1 nm（CS LM）和91.3 nm（CCS LM）。使用ABTS和DPPH自由基清除试验评估抗氧化能力，其中与游离MSE和CS LM相比，CCS LM表现出更高的活性（> 92%，p < 0.05）。通过针对金黄色葡萄球菌、大肠杆菌和白色念珠菌的微生物抑制试验评估抗菌性能，在800 μg/mL时显示出显著的抑制率。在2°C下通过监测失重、硬度、颜色保持、pH值、可滴定酸度和微生物计数，对储存性能进行了21天的评估。结果表明，与未涂层的果实相比，涂有CCS LM的草莓失重最小（5.7%，p < 0.05），保持了硬度，并且细菌（1.2 log₁₀ CFU/g）和真菌数量（1.3 log₁₀ CFU/g）减少。这些发现表明，负载MSE的CCS纳米颗粒通过其抗氧化和抗菌功能，为提高草莓的采后品质和储存性能提供了一种有前景的可持续策略。
