Department of Horticulture, Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya University, Multan 60800, Punjab, Pakistan.
Department of Horticulture, Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya University, Multan 60800, Punjab, Pakistan.
Int J Biol Macromol. 2024 Jan;256(Pt 1):128429. doi: 10.1016/j.ijbiomac.2023.128429. Epub 2023 Nov 25.
Mango is a climacteric fruit that ripens quickly after harvest due to its climacteric nature. Edible coatings have been reported to delay the ripening of various harvested fruit. The efficacy of the applied edible coatings could be improved by using in combination as a layer-by-layer (LBL) approach. So, the influence of LBL application of chitosan (CH) and carboxymethyl cellulose (CMC) was studied on mangoes during postharvest storage at 15 °C for 20 days. Mangoes were coated with monolayers of CH (1 % w/v) and CMC (1 % w/v) as well as LBL application of CH and CMC and were compared with control. The treatment of mangoes with CH and CMC-based LBL treatment resulted in lower decay percentage and weight loss along with higher total chlorophyll pigments and suppressed total carotenoid accumulation. The LBL application of CH and CMC showed lower activity of chlorophyll degrading such as chlorophyllase (CPS), pheophytinase (Phe), Mg-dechalatase (MGD) and chlorophyll degrading peroxidase (Chl-POD) enzymes as well as reduced changes in b*, a* and L* along with a suppressed increase in ethylene (EP) and CO production (CPR) rates having higher antioxidant such as catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and superoxide dismutase (SOD) enzymes activity. In addition, mangoes coated with LBL treatment of CH and CMC exhibited lower water-soluble pectin (WSP) and higher protopectin (PP) having higher concentrations of chelate soluble (CSP) and sodium carbonate-soluble pectin (SCP). Similarly, LBL-coated mangoes showed significantly higher hemicellulose (HCLS) and cellulose (CLS) contents in contrast with control. It was observed that mangoes coated with CH and CMC-based LBL coating exhibited higher flesh firmness and showed suppressed cellulase (CS), pectin methylesterase (PME), polygalacturonase (PG) and β-galactosidase (β-Gal) enzymes activity. The concentrations of total soluble solids and ripening index were markedly lower and titratable acidity was higher in the LBL-based coating treatment in comparison with control. In conclusion, LBL treatment based on CH and CMC coatings could be used for the delay of ripening and softening of harvested mangoes.
芒果是一种呼吸跃变型果实，采后由于其呼吸跃变特性，果实迅速成熟。已报道可食用涂层可延缓各种收获果实的成熟。通过层层（LBL）方法组合使用，可以提高应用可食用涂层的功效。因此，研究了壳聚糖（CH）和羧甲基纤维素（CMC）的 LBL 应用对 15°C 下贮藏 20 天的芒果的影响。芒果用 CH（1%w/v）和 CMC（1%w/v）的单层以及 CH 和 CMC 的 LBL 应用进行了涂层处理，并与对照进行了比较。用 CH 和基于 CMC 的 LBL 处理的芒果处理导致腐烂百分比和失重较低，总叶绿素色素较高，并抑制了总类胡萝卜素的积累。CH 和 CMC 的 LBL 应用显示较低的叶绿素降解酶活性，如叶绿素酶（CPS）、脱植叶绿素酶（Phe）、Mg-脱胆酸盐酶（MGD）和叶绿素降解过氧化物酶（Chl-POD）酶，以及 b*、a和 L变化较小，同时抑制了乙烯（EP）和 CO 生成率（CPR）的增加，具有较高的抗氧化剂如过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）、过氧化物酶（POD）和超氧化物歧化酶（SOD）酶活性。此外，用 LBL 处理的 CH 和 CMC 涂层的芒果具有较低的水溶性果胶（WSP）和较高的原果胶（PP），具有较高浓度的螯合可溶性（CSP）和碳酸钠可溶性果胶（SCP）。同样，与对照相比，LBL 涂层的芒果表现出较高的半纤维素（HCLS）和纤维素（CLS）含量。观察到用 CH 和 CMC 基 LBL 涂层涂覆的芒果表现出较高的果肉硬度，并表现出抑制纤维素酶（CS）、果胶甲酯酶（PME）、多聚半乳糖醛酸酶（PG）和β-半乳糖苷酶（β-Gal）酶活性。与对照相比，LBL 涂层处理的总可溶性固形物和成熟指数浓度明显较低，可滴定酸度较高。总之，基于 CH 和 CMC 涂层的 LBL 处理可用于延缓收获芒果的成熟和软化。
