Comparative Analysis of Nutritional, Textural, and Sensory Attributes of Butter Crab and Normal Female Mud Crab (Scylla paramamosain): Insights for Market Positioning and Consumer Preference

Abstract

In recent years, the butter crab (BC), a distinctive phenotypic variant of the female mud crab Scylla paramamosain, has garnered increasing market attention due to its perceived superior nutritional and sensory attributes. This study conducted a comprehensive comparative analysis of the nutritional composition, textural properties, and sensory characteristics of BC and normal female mud crab (NFMC). Results showed that the muscle and hepatopancreas of BC contained significantly higher lipid contents (0.77 and 22.14 g/100 g wet weight) and elevated levels of DHA + EPA (18.36% and 12.86% of total fatty acids), which contributed to its characteristic orange-yellow coloration, as reflected by colorimetric values (L* × a* × b* = 30.20 × 4.38 × 16.15). Sensory evaluation revealed that BC exhibited enhanced umami taste and aroma in both muscle and hepatopancreas, corresponding to higher concentrations of umami amino acids (0.75 and 1.95 mg/g wet weight) and aldehydes (35.06% and 34.37% of total volatiles), respectively. In addition, 80% of panelists preferred BC based on visual appearance, indicating its strong consumer appeal. Overall, this study advances our understanding of the biochemical and sensory profiles of BC and NFMC and provides important insights for market positioning of BC in the premium seafood sector.

Keywords: butter crab; normal female mud crab; nutritional profiles; sensory characteristics; texture analysis.

Figure 1

The differences in appearance phenotype and cross-sectional diagram of NFMC and BC. (A) in the arthrodial membrane (arrow) of the legs of NFMC and BC; 3D scatter plot (B) and grouped scatter plot with lines (C) of color parameters in the arthrodial membrane of the legs of NFMC and BC; cross-sectional diagram (D) of NFMC and BC after cooking. Data are expressed as mean ± standard deviation (n = 23). NFMC, normal female mud crab; BC, butter crab; n.s., no significant difference; ** mean p < 0.01, respectively.

Figure 2

The texture of the muscle (A), hepatopancreas (B), and ovaries (C) of NFMC and BC. Data are expressed as mean ± standard deviation (n = 5). NFMC, normal female mud crab; BC, butter crab; n.s., no significant difference; * and ** mean p < 0.05 and p < 0.01, respectively.

Figure 3

Heat map analysis of fatty acid contents (g/100 g total fatty acid) in the muscle, hepatopancreas, and ovaries of NFMC and BC. Data are expressed as mean ± standard deviation (n = 3). NFMC, normal female mud crab; BC, butter crab; M, muscle; H, hepatopancreas; O, ovary; SFA, saturated fatty acids; MUFA, monounsaturated fatty acids; PUFA, polyunsaturated fatty acids.

Figure 4

The results of free amino acids (A–D), umami nucleotides (E), and EUC (F) content in the muscle, hepatopancreas, and ovaries of NFMC and BC. Bitter amino acids include arginine, leucine, isoleucine, methionine, tyrosine, phenylalanine, valine, and tryptophan. Sweet amino acids include glycine, alanine, proline, threonine, and serine. Umami amino acids include aspartic acid and glutamic acid. Umami nucleotides include AMP, CMP, UMP, GMP, and IMP. Equivalent umami concentration (EUC) was devised for quantifying the MSG-like umami intensity [16]. Data are expressed as mean ± standard deviation (n = 3). NFMC, normal female mud crab; BC, butter crab; n.s., no significant difference; * and ** mean p < 0.05 and p < 0.01, respectively.

Figure 5

Radar map (A), principal component analysis (PCA) (B), and bar chart (C–E) of odor response intensity of the E-nose analysis in the muscle, hepatopancreas, and ovaries of NFMC and BC. Data are expressed as mean ± standard deviation (n = 3). NFMC, normal female mud crab; BC, butter crab; M, muscle; H, hepatopancreas; O, ovary; n.s., no significant difference; * and ** mean p < 0.05 and p < 0.01, respectively.

Figure 6

The results of radar map (A), principal component analysis (PCA) (B), and bar chart (C–E) of perceived taste intensity of the E-tongue analysis in the muscle, hepatopancreas, and ovaries of NFMC and BC. Data are expressed as mean ± standard deviation (n = 3). Abbreviations: aftertaste-A, aftertaste astringency; aftertaste-B, aftertaste bitterness; NFMC, normal female mud crab; BC, butter crab; M, muscle; H, hepatopancreas; O, ovary; n.s., no significant difference; * and ** mean p < 0.05 and p < 0.01, respectively.