Oil Uptake Lessening and Functionality Amelioration of Deep-Fried Fish Fillets Using Egg White Protein Edible Coating

Introduction:

Globally, fried foods are preferred among consumers due to their rapid cooking rates and favourable product attributes. However, consumers are more conscious about their diet and its consequences on well-being. Therefore, the present study aimed to develop a suitable edible coating for reducing fat uptake in deep-fried fish fillets, focusing on protein oxidation after frying.

Methods:

The fresh Labeo rohita fish was chopped into 4x4x2 cm size fillets. The fillets were coated with various concentrations of egg white protein (2.5 to 25% w/v). In this study, analyses of proximate composition, coating pickup, frying yield, protein solubility, WHC, carbonyl content, total sulfhydryl content, texture profile, and cutting force, instrumental colour analysis, and sensory analysis were performed.

Results:

The coating pickup, frying yield, and fat-uptake reduction of the coated fish fillets were found to have increased significantly, from 2.65% to 8.36%, 70.45% to 80.26%, and 9.67% to 48.66%, respectively, with an increase in coating concentrations. Interestingly, the same coatings protected proteins inconsistently from protein oxidation during deep frying, as revealed by total carbonyl content (2.26 to 2.10 nmol/mg protein) and sulfhydryl content (2.16 to 2.28 mol/10⁵ g protein). Furthermore, the WHC (69.58 to 76.73%) and instrumental colour attributes, L* (39.78 to 38.60), a* (9.84 to 12.12), and b*(28.40 to 26.62), change invariably for all coated samples. The hardness, toughness, and cutting force of coated fish fillets were found to have declined significantly (p < 0.05) as the coating concentrations increased. The highest overall acceptance (7.56) was recorded for the fish fillet coated with 15% egg white protein.

Conclusion:

Based on the above results, fish fillets coated with 15% egg white protein show a significant (p<0.05) reduction (48.66%) in fat uptake yet retain their desirable functional properties. Therefore, the present formulation may be recommended for producing healthier fried fish fillets for human consumption.