Oxidation of cholesterol in butter during storage - effects of light and temperature

Oxidised cholesterol in milk and dairy products

“…According to Finocchiaro et al (1984), the levels of 5,6-epoxycholesterol, 7a-and 7b-hydroxycholesterol were higher in grated Parmesan cheese packaged in glass than the same grated cheese packaged in a cardboard box. Exposure of cheese powders to fluorescent light (1611 lux) for 12 weeks increased the levels of a-epoxide and 7-ketocholesterol, Table 7 COP levels (mg kg À1 fresh product) in stored butter after exposure to light at cooling and room temperature (Hiesberger & Luf, 2000) Butter with the levels being highest after 3 weeks and then decreasing throughout the remaining weeks to about half (Sander et al, 1989b).…”

“…However, at refrigerator temperature, the special light for food significantly accelerated the formation of COPs in comparison to the daylight lamp. Four-day exposure to UV light at room temperature leads to detectable amounts of COPs (Hiesberger & Luf, 2000).…”

Studies on the storage stability of yayik butter

“…Two major flavours are developed from light oxidation; burnt is the sunlight flavour and after longer exposure, the characteristic oxidized flavour (De Man 1999). Hiesberger and Luf (2000) studied the changes in content of various cholesterol oxidation products during storage of butter in extreme storage and different illumination conditions. They determined a remarkable effect on cholesterol oxidation products of light in butter.…”

The effect of process temperature and time on the occurrence of the products of cholesterol oxidation in butter

“…Hiesberger & Luf (2000) also found only a trace of 7‐ketocholesterol in fresh butter. Nourooz‐Zadeh & Appelquist (1988) published results showing that fresh butter from two commercial dairies showed only traces (<0.2 ppm) of 7‐ketocholesterol, but no other cholesterol oxides.…”