Effects of antioxidants and humidity on the oxidative stability of microencapsulated fish oil

The effects of various antioxidants and RH on the oxidative stability of microencapsulated fish oil powder were investigated using PV and thiobarbituric acid tests. The microencapsulation process provided high encapsulation efficiency (greater than or equal to88% of extractable fish oil). Without antioxidants, the encapsulated fat was 10 times more stable against oxidation than the surface fat, as determined by PV. alpha-Tocopherol, which is a lipophilic antioxidant, showed a greater antioxidative effect in both surface and encapsulated fats than ascorbyl palmitate, which is an amphiphilic antioxidant. According to TBARS values, the longest lag period was observed at 0% RH. Addition of >200 ppm alpha-tocopherol in a 10-30% RH range prolonged the oxidative stability of the microencapsulated fish oil powder.