Characterization and Profiling of Protein Hydrolysates from White and Red Meat of Tuna (Euthynnus affinis)

Abstract

Tuna is considered as one of the richest source of
fish protein and concentrating these proteins in the
form of hydrolysate finds application in a wide
range of food ingredients and pharmaceutical
products. Protein rich red meat from tuna has
limited use compared to white meat and is usually
processed into products with low market-value
realisation. An effective alternative is the conversion
of this red meat into high value protein hydrolysates.
With a view to this aspect, in the present study
a comparative assessment of hydrolysates derived
from white and red meat of tuna (Euthynnus affinis)
was carried out. Protein hydrolysate was prepared
using 1% (w/w) papain with the hydrolysis time of
60 min under optimal hydrolytic conditions to
obtain tuna white meat protein hydrolysate (TWPH)
and tuna red meat protein hydrolysate (TRPH). The
protein content in tuna red meat and white meat
were 28.34 ± 1.63 and 26.34 ± 0.79%, respectively
whereas protein recovery in their respective hydrolysates
were about 36.87 and 42.14%. Evaluation
of the functional properties of protein hydrolysates
viz., solubility, oil absorption capacity (OAC),
foaming properties and emulsifying properties
revealed that except OAC and Emulsifying Activity
Index, all properties were comparatively higher for
TWPH. However antioxidant studies viz., DPPH
radical scavenging activity, reducing power and
metal chelating activity revealed higher potential for
TRPH compared to TWPH. Further detailed studies
are required with respect to the variations in these properties as intrinsic as well as extrinsic factors can have a major influence on the characteristics of the derived hydrolysates.