Taher Mohamed A, Dawood Dawood H, Selim Mohammed A E, Amin Basma H, Elsherbiny Elsherbiny A
Agricultural Chemistry Department, Faculty of Agriculture, Mansoura University, Mansoura 35516, Egypt.
Agricultural Microbiology Department, Faculty of Agriculture, Mansoura University, Mansoura 35516, Egypt.
Polymers (Basel). 2024 May 28;16(11):1518. doi: 10.3390/polym16111518.
The impact of methyl salicylate (MeSA) or sodium nitroprusside (SNP) in chitosan (CS)/Gum Arabic (GA) mixture on physio-chemical characteristics and antioxidant status during the postharvest ripening of green tomato fruits was studied. CS/GA-MeSA at a 1 mM formulation was the best treatment to retard firmness and titratable acidity (TA) losses. Moreover, this formulation retarded pigmentation progress where it had the lowest significant values of total carotenes (TCs) and lycopene (LYP) contents until the 15th day of the storage period, as well as efficiently faced the rise in malondialdehyde (MDA) levels. Moreover, peroxidase (POD), polyphenol oxidase (PPO), catalase (CAT), and phenylalanine ammonia-lyase (PAL) activities of tomatoes treated with CS/GA-SNP at 2 mM were significantly better than that of control in the primary stages of storage. CS/GA-SNP at a 2 mM formulation showed an extremely high significant content of total polyphenol (TP) in the early stage of storage, while CS/GA and CS/GA-MeSA at 1 and 2 mM accumulated higher significant TP contents than uncoated fruits at the late stage of storage. All formulations were characterized by FTIR spectroscopy. Furthermore, the polymer formulations exhibited strong antifungal activity against and as major pathogens of postharvest tomatoes. Transmission electron microscope (TEM) observations for the mycelia of both fungi treated by CS/GA-MeSA at 2 mM revealed serious ultrastructural damage, including distortion of the cell wall and cell membrane and degradation of cytoplasmic organelles.
研究了水杨酸甲酯（MeSA）或硝普钠（SNP）在壳聚糖（CS）/阿拉伯胶（GA）混合物中对绿熟番茄果实采后成熟过程中理化特性和抗氧化状态的影响。1 mM配方的CS/GA-MeSA是延缓硬度和可滴定酸度（TA）损失的最佳处理方法。此外，该配方延缓了色素沉着进程，在贮藏期第15天之前，其总胡萝卜素（TCs）和番茄红素（LYP）含量的显著值最低，并且有效地应对了丙二醛（MDA）水平的升高。此外，在贮藏初期，用2 mM的CS/GA-SNP处理的番茄的过氧化物酶（POD）、多酚氧化酶（PPO）、过氧化氢酶（CAT）和苯丙氨酸解氨酶（PAL）活性显著优于对照。2 mM配方的CS/GA-SNP在贮藏初期显示出极高的总多酚（TP）含量，而1 mM和2 mM的CS/GA以及CS/GA-MeSA在贮藏后期积累的TP含量比未涂膜果实更高。所有配方均通过傅里叶变换红外光谱（FTIR）进行表征。此外，聚合物配方对采后番茄的主要病原菌 和 表现出很强的抗真菌活性。对用2 mM的CS/GA-MeSA处理的两种真菌的菌丝体进行透射电子显微镜（TEM）观察，发现其超微结构受到严重破坏，包括细胞壁和细胞膜变形以及细胞质细胞器降解。
