Quantification of Cholesterol Oxidation Products In Egg Yolk Powder Spray‐dried with Direct Heating

A direct‐heated spray dryer with an evaporative capacity of up to 7 kg H 2 O/hr was used to identify processing conditions responsible for formation of cholesterol oxidation products (COPS) in spray‐dried egg yolk. Outlet air temperature and nitrogen oxides (NO x ) in the combustion gases were the only conditions that affected COPS levels. At outlet temperature 150°C, total COPS concentrations in the spray‐dried product were 75 ppm at 5 ppm NO x and 213 ppm at 300 ppm NO x . In products dried at 75°C outlet temperature, total COPS concentrations were 21 ppm at 5 ppm NO x and 58 ppm at 300 ppm NO x . In general, individual COPS responded to outlet temperature and NO x in the same manner as total COPS.