Layered Coatings to Control Weight Loss and Preserve Gloss of Citrus Fruit

Abstract

<jats:p>Valencia oranges [<jats:italic>Citrus sinensis</jats:italic> (L.) Osbeck cv. Valencia] and Marsh grapefruit [<jats:italic>Citrus paradisi</jats:italic> Macf.] were treated with single or double layers of coating. In cases where two coatings were applied, the first coating was a moisture-barrier wax; the second was either polyethylene wax or a mixture of shellac and resin ester. The inner coating reduced weight loss, and the outer coating imparted gloss. Fruit gloss, as measured by reflectometer, decreased more rapidly during 1 week at 20C with a single glossy coating than with the same coating applied as a second layer over a wax-based first coating. For citrus fruit, using resin ester or shellac as a high-gloss second coating tended to overly restrict the exchange of O<jats:sub>2</jats:sub> and CO<jats:sub>2</jats:sub>; however, two layers of wax did not.</jats:p>

Lipids and biopackaging

“…In the literature, much work can be found concerning edible films that contain lipids; most of them deal with coating of fresh fruits and vegetables (15)(16)(17)50). The ability to control desiccation and oxidation during carriage and storage (mostly for tropical fruits), to incorporate fungicides for decay control or growth regulators, to improve appearance by imparting shine to the surface, and to control aspects of product physiology all serve to lengthen the market window for commodities with a finite shelf life (51).…”

“…That explains why, in edible films, waxes are the most efficient lipid barriers to water-vapor transfer. Waxes are often used in emulsion for coating fruits and vegetables (14)(15)(16)(17).…”

Fruit cuticle lipid composition and fruit post‐harvest water loss in an advanced backcross generation of pepper (Capsicum sp.)

“…Although there were conflicting reports on whether the pepper fruit stem (a stomatous organ) is also an important path for post‐harvest fruit water loss, previous studies agree that the stem water loss pathway is minor compared with water diffusion through the fruit cuticle (Lownds et al 1993, Diaz‐Perez 1998, Maalekuu et al 2005). Water loss by many kinds of fruit was reduced commercially by the surface application of synthetic‐ or plant‐derived wax coatings to newly harvested fruits (Espelie et al 1982, Drake and Nelson 1990, Hagenmaier and Baker 1995, Saftner 1999). These additional wax coatings have shown promise for improving the storage quality and longevity of fruits by providing an extra barrier to water loss.…”

Shelf‐life extension of peaches through sodium alginate and methyl cellulose edible coatings

“…Coatings have been used extensively on bulky organs to modify internal composition and thereby delay produce ripening (Smith et al, 1987: Banks et al, 1993Baldwin, 1994;Amarante & Banks, 2001), to reduce water loss (Hagenmaier & Baker, 1993;Amarante & Banks, 2001) and to improve the appearance (Hagenmaier & Baker, 1995;Amarante & Banks, 2001). The degree of reduction in water loss and modification of internal atmosphere are greatly affected by the permeance of the coating film (Hagenmaier & Baker, 1995) and the character of the commodity skin (Banks et al, 1993;Hagenmaier & Baker, 1993). Kraght (1966) used waxes on 'defuzzed' peaches to reduce weight loss and have a more attractive appearance.…”