Page 226 - 《水产学报》2025年第8期

郑家浪，等 水产学报, 2025, 49(8): 089618

Evaluation of Larimichthys crocea quality grades

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ZHENG Jialang , YAN Xiaojun , WU Yuanyuan , WAN Faguo , ZHU Qingling , JIANG Lihua ,
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CHEN Shun , SONG Weihua , XIE Shangwei , WU Jingshu , XU Yongjiu 1
1. National Engineering Research Center of Marine Facilities Aquaculture,
Zhejiang Ocean University, Zhoushan 316022, China;
2. Institute of Nanji Islands National Marine Nature Reserve, Wenzhou 325408, China;
3. Institute of Dongtou Ocean Development Research, Wenzhou 325400, China
Abstract: To evaluate the quality differences of Larimichthys crocea and meet the market's demand for finer quality classifica-
tion, this study developed an evaluation system based on four dimensions: morphology, body color, texture, and nutrition, com-
prising 12 key quality indicators. Morphological evaluation assessed body shape characteristics through fullness index, body
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length-to-height ratio, and geometric morphometric analysis; body color evaluation measured the yellow-blue (b ) and red-
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green (a ) values, as well as lutein content to ensure stability; texture evaluation combined microscopic observation and image
analysis to calculate the muscle fiber area-to-endomysium area ratio, along with total free amino acid content; nutritional evalu-
ation covered moisture, crude fat, ∑n-6 polyunsaturated fatty acids, and the ∑n-3/∑n-6 ratio. A breakpoint regression model
was used to determine the critical values for each indicator, while random forest algorithms were employed to assign weight to
each dimension. Finally, five typical aquaculture areas (A-E zones) with significant market price differences were selected, and
10 professionals conducted sensory evaluations of the fish's morphology, body color, and texture, which were compared with
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objective scoring results. L. crocea was classified into nine grades that D (poor), C (below average), C (average), B (accept-
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able), B (good), A (better), A (excellent), S (superior), and S (extremely superior). The wild L. crocea performed the best in
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morphology (92.66), body color (99.09), texture (99.73), nutrition (99.63), and overall score (97.77, S grade). The E and D
zones showed relatively high performance in each dimension, with scores of morphology (92.01/89.08), body color
(74.15/72.02), texture (86.87/91.60), nutrition (76.17/83.04), and overall scores ranging from 82.35 to 83.94 (A grade). The C
and B zones had moderate scores, with morphology (75.26/75.37), body color (71.91/68.79), texture (77.52/81.56), nutrition
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(82.48/66.87), and overall scores between 73.15 and 76.79 (B /B grade). The A zone scored the lowest in all dimensions, with
morphology (66.87), body color (64.08), texture (50.60), nutrition (58.13), and an overall score of only 59.92 (D grade). Correl-
ation analysis showed strong positive relationships between objective and sensory evaluations of morphology, body color, tex-
ture (R²=0.812-0.952), and market price (R²=0.881-0.907), validating the system’s reliability in reflecting quality and market
value. This study established a quality evaluation model of L. crocea based on morphology, body color, texture, and nutrition,
providing a scientific basis for precise classification of quality grades, standardizing market pricing, and facilitating the realiza-
tion of high-quality L. crocea farming models.
Key words: Larimichthys crocea; quality evaluation; grading; morphology; color; texture; nutrition
Corresponding author: YAN Xiaojun. E-mail: yanxj@zjou.edu.cn

Funding projects: National Key Research and Development Program of China (2023YFD2401900); Nanji National Marine
Natural Reserves Administration (NJKJ2023002); Aquaculture Breeding and Seedling Technology Innovation Center Project of
Zhoushan (2025Y001); Science and Technology Plan of Dongtou District (N2022K04)

https://www.china-fishery.cn 中国水产学会主办 sponsored by China Society of Fisheries
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