Protective Packaging for Light-sensitive Foods

M.G. PASSARETTI; M.D. NINAGO; M.A. VILLAR

Food Packaging: Innovations and Shelf-Life

CRC Press

Lugar: Boca Ratón, Florida; Año: 2019; p. 1 - 31

Consumer expectations and interests in nutritional aspects and visual appearance, when purchasing food, are important factors that should be taken into account to improve the food industry (Gadioli et al., 2013). Currently, food packaging is strongly linked to material transparency, which must not hide the product but enable its visibility through the packaging (Eldesouky et al., 2015). Nevertheless, many food natural components as well as those added during their preparation are susceptible to light, causing the occurrence of photo-degradative and oxidative reactions (Duncan and Chang, 2012). Foods are exposed to several sources of light during their entire chain of production and commercialization. Some common light sources and their locations are (a) sunlight outdoors (storefronts and windows), (b) incandescent lamps (coolers and storage facilities) and (c) fluorescent lamps (processing areas, displaycases and preparation zones). Foods are also exposed to other sources of light, such as germicidal lamps used in walk-in coolers and storage area rooms to reduce bacterial and mould counts as well as black lights used to detect the presence of insects, rodent excreta and other kinds of contamination. When light strikes a food packaging, it can be reflected off the material surface, absorbed by the packaging material, scattered and absorbed by the food and transmitted through the food. Particularly, light that is absorbed, mainly leads to functionality loss of food compounds (Duncan and Chang, 2012). In most solid foods, light only penetrates the outer layer and so deterioration occurs only at a superficial level. Meanwhile, in liquid foods, light penetration can be greater and their deterioration is more extensive.Foods? light sensitivity depends on many factors, including the strength ofthe light source and type of light that it emits, besides light-source-food distance, exposure time, optical properties of packaging materials, oxygen concentration inside the packaging and storage temperature (Chiste et al., 2010; Duncan and Hannah, 2012; Mestdagh et al., 2005).