Physical and oxidative stability of fish oil-in-water emulsions stabilized with fish protein hydrolysates

• Published in: Food chemistry 2016-07, Vol.203, p.124-135
• Main Authors: García-Moreno, Pedro J., Guadix, Antonio, Guadix, Emilia M., Jacobsen, Charlotte
• Format: Article
• Language: English
• Subjects: Animals; Antioxidants - chemistry; Dietary Fats, Unsaturated - analysis; Emulsifying Agents - chemistry; Emulsions; Fish Oils - chemistry; Fish protein hydrolysates; Fishes; Food Quality; Hydrolysis; Marine; Muscle Proteins - chemistry; Oil-in-water emulsions; Omega-3; Oxidation-Reduction; Oxidative stability; Pentanols - analysis; Physical stability; Protein Hydrolysates - chemistry; Sardina pilchardus; Sardinops; Scyliorhinus canicula; Subtilisins - chemistry; Water - chemistry
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2016.02.073

•FPH are promising alternative emulsifiers to stabilize fish oil-in-water emulsions.•Sardine hydrolysates with low DH, 3% and 4%, led to more physically stable emulsions.•The previous emulsions were also more oxidatively stable.•Small-spotted catshark hydrolysates showed poor emulsifying properties. The emulsifying and antioxidant properties of fish protein hydrolysates (FPH) for the physical and oxidative stabilization of 5% (by weight) fish oil-in-water emulsions were investigated. Muscle proteins from sardine (Sardina pilchardus) and small-spotted catshark (Scyliorhinus canicula) were hydrolyzed to degrees of hydrolysis (DH) of 3-4-5-6% with subtilisin. Sardine hydrolysates with low DH, 3% and 4%, presented the most effective peptides to physically stabilize emulsions with smaller droplet size. This implied more protein adsorbed at the interface to act as physical barrier against prooxidants. This fact might also be responsible for the higher oxidative stability of these emulsions, as shown by their lowest peroxide value and concentration of volatiles such as 1-penten-3-one and 1-penten-3-ol. Among the hydrolysates prepared from small-spotted catshark only the hydrolysate with DH 3% yielded a physically stable emulsion with low concentration of unsaturated aldehydes. These results show the potential of FPH as alternative protein emulsifiers for the production of oxidatively stable fish oil-in-water emulsions.