# Comparative Analysis of Flesh Quality in Triploid and Allotetraploid Pengze Crucian Carp: Nutritional Composition, Flavor Profile, Texture Properties, and Metabolomics Insights

## TL;DR

This study compares the meat quality of triploid and allotetraploid Pengze crucian carp, revealing differences in nutrition, flavor, and texture that can guide breeding for better fish quality.

## Contribution

The study provides a multidimensional analysis of flesh quality differences between triploid and allotetraploid Pengze crucian carp, linking ploidy to specific nutritional and sensory traits.

## Key findings

- Triploid carp had higher protein and a fresher flavor with fewer fishy odors.
- Allotetraploid carp had more healthy fatty acids, better amino acid balance, and improved tenderness.
- Metabolomics identified 216 different metabolites linked to amino acid and lipid metabolism pathways.

## Abstract

This study compared the flesh quality of triploid and allotetraploid Pengze crucian carp to understand how ploidy affects nutritional and sensory traits. We analyzed their muscle composition, amino acid and fatty acid profiles, flavor compounds, texture, and metabolomics. Results showed that triploids had higher protein content and a fresher flavor with fewer fishy odor compounds. Allotetraploids contained more healthy polyunsaturated fatty acids (including EPA and DHA), a better amino acid balance, and were more tender. Metabolomics revealed 216 different metabolites between the two groups, linked to key pathways like amino acid and lipid metabolism. These findings provide a scientific basis for breeding programs aimed at improving fish quality for consumers.

This study provides a systematic and multidimensional evaluation of flesh quality differences between triploid (T-PZ) and allotetraploid (A-PZ) Pengze crucian carp, addressing a significant gap in genetic improvement of this economically important aquaculture species. By integrating proximate composition analysis, detailed amino acid and fatty acid profiling, volatile flavor compounds, texture characteristics, and non-targeted muscle metabolomics, we delineated the distinct quality attributes associated with each cytotype. The results showed that T-PZ possessed significantly higher crude protein and histidine content, along with a superior flavor profile characterized by lower relative levels of fishy odor-associated aldehydes such as hexanal, heptanal, and nonanal. In contrast, A-PZ exhibited significantly elevated crude lipid, total fatty acid, SFA, MUFA, PUFA, and EPA + DHA contents; a higher essential amino acid index; and improved tenderness indicated by significantly lower hardness and chewiness. Metabolomic analysis identified 216 significantly different metabolites, notably enriched in key pathways including glycine, serine, and threonine metabolism; arginine biosynthesis; and glycerophospholipid metabolism. These comprehensive findings elucidate the complementary nutritional and sensory strengths of the two ploidy forms, thereby establishing a crucial scientific foundation for targeted, quality-driven breeding programs aimed at optimizing flesh quality in Pengze crucian carp for the aquaculture industry.