Microencapsulation by spray drying is a well-accepted technique for fish oil stabilization. However, severe operational conditions during atomisation destabilise the emulsion, leading to capsule collapse and induction of auto-oxidation. Hence, use of food grade cross-linkers to strengthen the wall material and antioxidants to prevent lipid oxidation has been suggested. A promising option in this line is the use of bioactive peptides, which ensure oxidative stability through structural and chemical stabilisation. Present study attempted to compare the efficacy of yellowfin tuna red meat hydrolysate in protecting the core sardine oil, when used as wall and core polymer during encapsulation. Encapsulates were characterised based on morphological and physical parameters, as well as by in vitro digestibility studies. Their storage stability was also compared under accelerated (60 °C), chilled (4 °C) and ambient conditions (28 °C). Tuna protein hydrolysate exhibited significantly higher protective efficacy when used as core polymer rather than in the wall matrix of encapsulates.
Keywords: Antioxidant; Fish oil; Hydrolysate; Microencapsulation; Structural stability; Tuna red meat.