Interesting properties of LbL coatings for melon and citrus fruits

Edible coatings are a new promising approach for controlling the quality and extending the postharvest shelf-life of food products. To be applicable on fresh agricultural products, edible coatings have to answer a long list of various requirements that single coating material is often unable to satisfy. Layer-by-Layer (LbL) method is based on the alternate deposition of various polymers to produce thin layers on the surface. LbL approach has great potential to control properties and functionality of edible coatings. In the present study, oppositely charged natural polysaccharides, a polyanion alginate or carboxymethyl cellulose combined with a polycation chitosan, were implemented for coating of fresh-cut melons or citrus fruits. The performance of the LbL coatings was compared with single-layer coatings and with a non-coated control. The LbL coating was found to possess the beneficial properties of both ingredients, combining good adhesion to fruit matrix of the inner polyanion layer with beneficial activity of the outer chitosan layer. The bilayer coating slowed down tissue texture degradation. In the case of fresh-cut melons LbL coating effectively inhibits microbial spoilage allowing significant elongation of fruits shelf life. In the case of citrus fruits LbL coating provides increased gloss which is very important parameter for the citrus fruits acceptance. An unexpected benefit of the LbL coating was that its enhanced gas-exchange properties exceeded those of monolayer coatings. As a result, the LbL coating prevented an increase in headspace CO2 and ethanol concentrations, which are the signs of hypoxic stress and off-flavor. ? Original title, complete list of authors and sourcesLayer-by-layer edible coatings of fresh agricultural products anticipated and unexpected effectsE. Poverenov, H.Arnon, S.I. Danino, R. Porat, V. RodovAgricultural Research Organization, The Volcani Center, Bet Dagan, IsraelV Postharvest Unlimited, ISHS International Conference, 10-13 June 2014, Cyprus, http://web.cut.ac.cy/postharvest/ The picture belongs to Naturcover Citrus, by Decco. ? Key wordsPoscosecha?? ?postcosecha?? ?postharvest?? ?na-oes?? ??? ??? ???????? ????? ??? ?post-r?colte?? ????? ?? ??????????? ??? ?na-oogst?? ?post-raccolta?? ?Obr?bka po?? ?p?s-colheita?? ????????????????? ?hasat sonras??? ??? ?Ernte?? ????????????????? ????? ????????????? ?postcollita?? ?poskliz?ov頠 ????? ??? ??? ??? ?nakon branja?? ?pozberov頠 ??? ?obdelovanje zemlje po?? ?post-colleita?? ?????? ??????? ?pascapanen?? ??il?onn postharvest?? ??????? ?p?c ra?as?? ?derliaus apdirbimas po?? ?lepas tuai?? ??? ?? ???????? ?post-recoltare?? ??????? ??????? ???????????????????? ?????????????? ?????????????????? ?sau thu ho?ch?? ?????????????????? ?zangemva kwenkathi yokuvunaC?tricos?? ??? ?citrus?? ?sitrus?? ???????? ????? ??? ?agrumes?? ???????????????? ?????????? ??? ??? agrume?? ?cytrus?? ?c?trico?? ????????????? ?narenciye?? ?????? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ?Mel?n?? ??? ?melon?? ?waatlemoen?? ??????? ???? ?melono?? ??? ????????? ???????? ?meloen?? ?melone?? ??? ??? mel?o?? ??????? ?kavun?? ???????? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ?