Possibilities of Prevention of Light-Induced Quality Loss of Milk

Abstract

The effect of light on milk in different types of packaging materials was studied. Three commercially available packages, viz. carton, plastic pouch and returnable plastic jug were used as well as cartons with inner brown printing, plastic pouches with black pigmented overwrap and plastic jugs pigmented with titanium dioxide. The milk in these packages was exposed to cool white fluorescent light, warm white fluorescent light and cool white lamps provided with plastic ultraviolet shields. The milk was exposed at intensities of 2200 lux and examined for sensory defects as well as losses of riboflavin and ascorbic acid. The colored carton and pigmented pouch pack has a light transmission over the whole visible spectrum of less than 1% and were very effective in preventing light induced changes in the milk. The pigmented plastic jugs were not satisfactory. The use of ultra-violet shields or warm white lights had only a minor influence on light-induced changes.