Enhancing muscle physicochemical properties and nutrient distribution in black seabream (Acanthopagrus schlegelii) through dietary linoleic acid supplementation

Abstract

This study investigates the effects of dietary linoleic acid (LA) on the growth, lipid metabolism, muscle nutritional composition, texture characteristics, volatile and non-volatile substances of black seabream (Acanthopagrus schlegelii). Four isonitrogenous and isolipidic diets with LA levels of 5.30 mg/g (LA5.30), 10.51 mg/g (LA10.51), 15.57 mg/g (LA15.58), and 20.01 mg/g (LA20.03) of LA were formulated. A 13-week feeding trial was conducted on black seabream with an initial weight of 6.69 ± 0.01 g. Results indicated that compared with LA5.30 group, dietary LA levels increased the WG and CF. Meanwhile, the contents of LA and n-6 PUFA in liver and muscle significantly increased with increasing dietary LA levels. Hardness and chewiness of black seabream muscle were significantly increased at dietary LA additions of 10.51 mg/g or beyond. Compared with the LA5.30 group, the expression levels of myogenic factors were significantly increased but myostatin was significantly decreased with the increase of dietary LA levels. The results of electronic tongue taste showed that the sweetness value in the black seabream muscle was significantly enhanced in the LA10.51 group while the bitter value was significantly reduced in this group. The composition and relative percentage of volatile substances in muscle also significantly affected by dietary LA levels. In conclusion, dietary LA supplementation could not only improve the growth performance, but also enhance the nutrition and flavor by increasing the nutritional value of muscle, optimizing muscle textural properties, boosting muscle taste, as well as regulating the composition and relative percentage of volatile substances.