Skipjack roe protein hydrolysate combined with tannic acid increases the stability of fish oil upon microencapsulation

Microencapsulation of fish oil was achieved by spray drying the micro-emulsion, in which skipjack roe protein hydrolysate (SRPH: degree of hydrolysis, 5%) was used as the wall material in the absence or presence of tannic acid (TA) or oxidized tannic acid (OTA). Microcapsule using SRPH had a lower encapsulation efficiency (EE) than those having sodium caseinate-whey protein concentrate (Ca-WPC) as the wall materials (p<0.05). The incorporation of TA or OTA in combination with SRPH yielded spherical encapsulated fish oil with higher EE but lower particle size (p<0.05) than achieved with SRPH alone. Furthermore, the addition of TA retarded lipid oxidation of microcapsule more effectively as indicated by lower peroxide value and thiobarbituric acid reactive substances (TBARS) value during storage at 30°C for 4 weeks, compared with those using only SRPH (p<0.05). Nevertheless, OTA in conjunction with SRPH yielded the higher EE than TA. Therefore, SRPH could serve as an alternative wall material for microencapsulation of fish oil, especially with the aid of TA or OTA.