Development and characterization of a nanomultilayer coating of pectin and chitosan – Evaluation of its gas barrier properties and application on ‘Tommy Atkins’ mangoes

Abstract

A nanomultilayer coating made of food-grade, bio-based materials (consisting of five nanolayers of pectin and chitosan) was produced. This coating was firstly characterized in terms of the water vapor, oxygen and carbon dioxide permeabilities; these parameters exhibited values of 0.019 ± 0.005 Â 10 À11 , 0.069 ± 0.066 Â 10 À14 and 44.8 ± 32 Â 10 À14 g m/(Pa s m 2), respectively, and are of the same order of magnitude of those found in other nanomultilayer systems. The nanomultilayer system was applied on whole 'Tommy Atkins' mangoes and the layers' adsorption was confirmed by changes in the contact angle of the coated fruits' skin. After 45 d of storage, uncoated mangoes presented a higher mass loss, higher total soluble solids and lower titratable acidity in comparison with coated mangoes. Uncoated mangoes had also a damaged and wrinkled appearance, showing evidence of microbial spoilage, and the flesh exhibited a slightly brownish color, in comparison with the coated mangoes. These results suggest a positive effect of the coating on gas flow reduction and on the consequent extension of the shelf-life of mangoes.

Tommy Atkins mango (Mangifera indica L.) postharvest quality with cassava starch, chitosan and pectin based coatings

“…Supporting this study results, Medeiros et al (2012) indicated that mangos coated with pectin and chitosan had better appearance and lower physiological loss than fruits from control group. One of the reasons for appearance change after harvest is the physiological loss due to transpiration, which may cause fruits to wilt, making them unattractive in market.…”

“…Medeiros et al (2012) coated "Tommy Atkins" mangos with chitosan and pectin coating, kept for 45 days at 4°C and 90% of RH, and observed less physiological loss at 28 days to coated fruits. Cissé et al (2015) also had lower physiological loss as compared to control treatment fruits in mango fruits from Kent cultivar stored for 8 days coated with 1 and 1.5% chitosan.…”

“…Physiological loss of coated fruits is related to an attribute of water vapor barrier. Polysaccharides such as cassava starch, chitosan and pectin are excellent barriers to oxygen and carbon dioxide; however, in isolated forms, they are hydrophilic and have high permeability to water vapor, which differ from each polymer matrix (Medeiros et al, 2012;Cissé et al, 2015). The coating may be optimized by combination with hydrocolloids turns the coatings formation more homogenous (Gao et al, 2013;Castañeda, 2013;Silva, 2015) or with lipidic materials (Xu et al, 2005;Oliveira, 2014).…”

“…According to Medeiros et al (2012), soluble solids content is used as maturity indicators and determines fruit quality, having a great role in its taste. Results showed, in general, that fruits coated with a homogeneous coating of ½ chitosan and cassava starch sustained their soluble solids content, as compared to control fruits group.…”

“…The use of chitosan coatings reduced physiological loss and delayed fruit firmness loss in mangoes during storage (Cissé et al, 2015), such as the use of polysaccharides (methylcellulose, hydroxypropyl cellulose, carboxymethyl cellulose and chitosan) on sustaining citrus fruits quality (Arnon et al, 2014). Another positive effect of polysaccharide coatings (pectin and chitosan) was pointed by the decrease in respiration rate and ethylene production and, as a consequence, extended mango"s shelf life (Medeiros et al, 2012).…”