Influence of Different Light Sources, Illumination Intensities and Storage Times on the Vitamin C Content in Pasteurized Milk


Abstract: The effect of various light sources and illumination intensities on the destruction of vitamin C was determined during the storage of pasteurized milk. For this purpose, raw cow's milk was pasteurized at 72 ^oC for 15 s, and then stored in 2 different refrigerators (4 ± 1^oC) illuminated by fluorescent and tungsten light (normal light) sources with intensities of 1100, 2400 and 5800 lux. As a control group, a pasteurized milk sample was stored at the same temperature under dark conditions. The amount of vitamin C in the milk samples was recorded after 0, 6, 12, 24, 48, 72, 96 and 120 h of storage. Vitamin C contents of the milk samples stored without a light source were higher than those of milk samples stored under the fluorescent and normal lights. As the intensity of light increased, a concomitant loss of vitamin C was observed. Conversely, as storage time increased, the content of vitamin C in the pasteurized milk samples decreased.

Keywords: Pasteurized milk, vitamin loss, vitamin C, storage time

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