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

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 ± 1oC) 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.

Anahtar Kelimeler:

Pasteurized milk, vitamin loss, vitamin C, storage time

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

Keywords:

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

PDF

___

Çakmakçı, S., fiengül, M., Boroğlu, E.: Isıl ifllem ve depolamanın pastörize ve sterilize sütlerde vitamin kayıpları üzerine etkisi. In: Demirci, M., Ed. İçme Sütü, Tekirdağ- Türkiye. 1998; 178-184.
Olsen, J.R., Ashorr, S.H.: An assessment of light induced off- flavors in retail milk. J. Dairy Sci., 1986; 70: 1362-1370.
Kurt, A.: Süt Teknolojisine Girifl. Atatürk Üniv. Yay. No: 493, Erzurum. 1977; 150-152.
Singh, R.P., Heldman, D.R., Kirk, J.R.: Kinetics analysis of light induced riboflavin loss in whole milk. J. Food Sci., 1975; 41: 304-308.
Schröder, M.J.A., Scott, K.J., Bland, M.A., Bishop, D.R.: Flavor and vitamin stability in pasteurised milk in polyethylene coated cartons and in polyethylene bottles. J. Soc. Dairy Technol., 1985; 38: 48-52.
Deger, D., Ashoor, S.H.: Light-induced changes in taste, appearance, odor and riboflavin content of cheese. J. Dairy Sci., 1986; 70: 1371-1376.
Cemeroğlu, B.: Meyve ve Sebze İflleme Endüstrisinde Temel Analiz Metotları. Ankara, Biltav Yayınları. 1992; 325-334.
Minitab.: Minitab Reference Manual, Minitab Inc. USA. 1996.
FAO and WHO: Human Vitamin and Mineral Requirements; Chapter 6: Vitamin C. Report of a joint FAO/WHO expert consultation, Bangkok, Thailand. 2002.
Robertson, G.L., Samaniego, C.M.L.: Effect of initial dissolved oxygen levels on the degradation of ascorbic acid and the browning of lemon juice during storage. J. Food Sci., 1986; 51: 184-187.
Lee, H.S., Nagy, S.: Quality changes and nonenzymic browning intermediates in grapefruit juice during storage. J. Food Sci., 1988; 53:168-172.