Emulsification through oil addition on the properties of yellowfin tuna ( Thunnus albacares ) paste

Abstract

In this study, the effects of different amounts of oil addition on the properties of tuna paste were investigated. The whiteness gradually improved with the oil addition. The water holding capacity increased from 0.28 without oil addition to a peak of 0.47 with 15% oil addition before decreasing to 0.21% at 35% oil addition. Changes in properties were measured by a rotational rheometer. Changes in protein secondary structure were evaluated by Fourier transform infrared spectroscopy. The particle size measurements showed that the maximum amount of protein available to bind oil in the emulsification system is ~ 20% and excessive oil will destabilize the system. The oil droplet distribution in the emulsified system was shown by the optical microscope. The differential scanning calorimetry revealed that the oil addition could improve the transfer temperature of actin when the addition amount less than 20%. Overall, plant oil is suggested to improve the rough taste of processed tuna products. Novelty impact statement This work investigates the effects of sunflower seed oil addition on the properties of tuna paste. We found that oil addition greatly changed the properties of tuna paste, such as whiteness, WHC, and rheology properties, thus affecting the taste of tuna paste. The present results showed that adding a suitable amount of oil can improve the property of tuna paste through lipid–protein interaction, thus not only potentially overcoming current limitation of tuna processing technology, but also encourages food processors to produce different forms of tuna products to satisfy consumers with different preferences.