# High Dietary Supplementation of Procyanidin-Rich Grape Seed Powders Enhances the Growth Performance and Muscle Crispness of Crisped Grass Carp

## TL;DR

Adding grape seed powder to the diet of grass carp improves their growth and makes their muscle texture crisper.

## Contribution

High-dose grape seed powder supplementation is shown to enhance muscle crispness and growth in grass carp, potentially replacing antibiotics.

## Key findings

- High GSP supplementation increased growth performance and reduced feeding coefficient in grass carp.
- Muscle crispness indicators like ROS content and shear force were significantly higher in the high-GSP group.
- Intestinal microbiota composition changed, with Lactococcus chungangensis linked to improved muscle texture and metabolites.

## Abstract

The muscle crispness of crisped grass carp is triggered by the faba bean-induced ROS reaction. Grape seed powders, which potentially serve as an alternative to antibiotics in the healthful aquaculture of crisped grass carp, are limited to being used as free radical scavengers. In this study, a relatively high daily supplement of procyanidin-rich grape seed powders (GSPs) enhanced the growth performance of crisped grass carp and facilitated muscle crispness, which proved that procyanidin-rich GSPs could replace antibiotics in the aquaculture of crisped grass carp.

A comprehensive analysis was conducted to explore whether feeding inclusion procyanidin-rich grape seed powders (GSPs) affected the faba bean-induced muscle crispness in the aquaculture of crisped grass carp. The procyanidin content in the prepared GSP was 10.40 g/100 g. Additionally, one thousand 1-year-old grass carp with an initial weight of 27 g and an initial length of 12 cm were divided into five groups, including the blank control (basal diet); the positive control (faba bean diet); and the low (faba bean diet supplemented 100 mg/kg GSP), middle (faba bean diet supplemented 500 mg/kg GSP), and high (faba bean diet supplemented 1000 mg/kg GSP) GSP-supplemented groups. After feeding for 60 days, the weight gain rate, specific growth rate, and condition factor were elevated in the high-GSP-supplemented group in comparison with the blank control (p < 0.05), accompanied by a significant decrease in the feeding coefficient (p < 0.05). Meanwhile, a significant increase in muscle ROS content, shear force, gumminess, and chewiness was determined in the high-GSP-supplemented group when compared with the positive group, suggesting that a relatively high daily supplement of GSP facilitated muscle crispness. Moreover, the composition of intestine microbiota was significantly varied between groups with the daily addition of GSP (p < 0.05). Among them, Lactococcus chungangensis was identified as the key biomarker of the high-GSP-supplemented group, which was closely related to the increased muscle ROS content, the modifications in muscle nutritional metabolites (Met, C20:2n6, C20:3n6, C20:4n6, and C22:4n6), and the alterations in muscle texture (gumminess, chewiness, shear force, hardness, and adhesiveness). Based on these results, we believe that a relatively high daily supplement of GSP (1000 mg/kg) facilitated muscle crispness in the aquaculture of crisped grass carp.