PHolysaccharide-based edible coatings are served as an attractive preservation method for postharvest maintenance of most fruits. The current study examined the effect of carboxymethylcellulose (CMC)w CMC- and pectin (Pec)Pec-based edible coatings on titratable acidity (TA), firmness; vitamin C (vit C); total soluble solids (TSS); pH; total phenolics; anthocyanin and flavonoid contents; total antioxidant capacity (based on 1,1-Diphenyl-2-picryl-hydrazyl hydrate (DPPH)); the activities of peroxidase (POD), polyphenol oxidase (PPO) and polygalacturonase (PG) enzymes; and weight loss during , can affect plum fruit quality through cold storage.?
Fruits and vegetables are a great source of antioxidants, anthocyanins, phenolics, some vitamins and nutritional elements [1] which are associated with a reduced risk of chronic health disorders [2][3]. Plums (
Prunus domestica L.) are an important fruit, among the functional foods and nutraceuticals. Plums are a good source of antioxidants. They might help the human body to fight various diseases. However, plums have short postharvest life that results in the loss of valuable and nutritional elements [4]. Plums' quality rapidly declines after harvesting due to their high respiration rate. Consequently, after the transportation and marketing process, they often do not reach consumers at their best status [5][6].
In recent years, applications of safer methods for fruit preservation are of high significance. These safe methods usually have neither side effects on human and animal health, nor negative influences on the environment. Edible coatings are considered as one of the safe strategies. Edible coatings could improve fruit postharvest. So, the application of edible coatings with natural origin such as proteins and polysaccharides has received a growing interest [7][8].
Carboxymethylcellulose (CMC) is a cellulose derivative, anionic, linear, long-chain and high molecular weight compound [10][11]. CMC-based coatings mostly do not have odor, taste, and any toxic or allergic effects. They also are biodegradable, flexible, transparent, oil-resistant, soluble-in-water and slightly permeable to oxygen, CO
2
Pectin (Pec), the main compound of plant cell walls, is a complex high molecular weight polysaccharide with a branching structure [13][14], and an amorphous and colloidal carbohydrate [14]. Pec-based coatings are excellent barriers to O
2
2, in addition to their transparency, oil-resistance, and water solubility. They prevent moisture loss to some extent and eventually maintain the sensory aspects and quality of foods [14][15].
CMC-based edible coatings have been shown to be efficient in preserving the postharvest quality of pear, papaya, mandarin and peach [16][17][18][19]. Pec-based ones preserved the quality of peach, nectarine, fresh-cut apple, and persimmon [20][21][22][23]. Some studies reported the application of edible coatings on plum fruit, including chitosan [24], and carboxymethylcellulose, alone [8] or in combination with irradiation [6].
The current survey reported positive effects of CMC- and Pec-based edible coatings, either alone or in combination with each other, on plum fruit through cold storage in terms of the measured parameters, except weight loss. The coatings especially improved vit C, total phenolics, anthocyanins and flavonoids contents and POD enzyme activity and decreased PPO and PG enzymes activities. CMC at 1% and Pec at 1.5% demonstrated the best results. Additionally, 0.5% Pec + 1.5% CMC is a good combined formulation for the preservation of the nutritional value of plum during postharvest. Thus, the application of CMC and/or Pec and/or their combinations might be considered as a favorable and safe coating approach for extending and improving postharvest qualitative characteristics of plum fruit.
The current survey reported positive effects of CMC- and Pec-based edible coatings, either alone or in combination with each other, on plum fruit through cold storage in terms of the measured parameters, except weight loss. The coatings especially improved vit C, total phenolics, anthocyanins and flavonoids contents and POD enzyme activity and decreased PPO and PG enzymes activities. CMC at 1% and Pec at 1.5% demonstrated the best results. Additionally, 0.5% Pec + 1.5% CMC is a good combined formulation for the preservation of the nutritional value of plum during postharvest. Thus, the application of CMC and/or Pec and/or their combinations might be considered as a favorable and safe coating approach for extending and improving postharvest qualitative characteristics of plum fruit.