Summary Fermented minced pepper (FMP) usually suffers from the deterioration of texture quality during fermentation, which can affect sensory and consumer acceptance. In this study, vacuum impregnation (VI) with CaCl2, pectin methylesterase (PME) and CaCl2 and PME (PME + CaCl2 + VI) were compared to improve the texture quality of FMP. FMP treated with PME + CaCl2 + VI showed the relatively intact cells structure after fermentation. In that case, its firmness maintained high level, while water‐soluble pectin (WSP) content was minimum after fermentation. Meanwhile, the molar ratio of most monosaccharides of WSP in PME + CaCl2 + VI treated FMP decreased, while rhamnose (Rha) molar ratio significantly (p < 0.05) increased after fermentation. The high Rha content represents the stability of rhamnogalacturonan‐I linear skeleton of WSP. The negative effect on molecular weight of WSP was delayed by PME + CaCl2 + VI treatment, and its peak area and value increased after fermentation. Atomic force microscope images indicated that PME + CaCl2 + VI treatment could retain the long chain and branch structures, and inhibit the degradation of WSP net‐like structure at some extent. Hence, PME + CaCl2 + VI treatment was effective to improve the texture of FMP and inhibit the solubilisation of WSP via the formation of cross‐linked pectin chains between Ca2+ and demethylesterified pectin.

The cuticle plays an important role for the quality of pepper fruit. However, the molecular mechanism of cuticle formation in pepper fruit remains unclear. Our results showed that the wax was continuously accumulated during pepper development, while the cutin monomer first increased and then decreased. Hexadecanoic acid and 10,16-hydroxyhexadecanoic acid were the main components of wax and cutin, respectively. Combined with transcriptome and proteome, the formation patterns of wax and cutin polyester network for pepper cuticle was proposed. The 18 pairs of consistent expression genes and proteins involved in cuticle formation were revealed. Meanwhile, 12 key genes were screened from fatty acid biosynthesis, biosynthesis of unsaturated fatty acids, fatty acid elongation, cutin, suberine, and wax biosynthesis, glycerolipid metabolism, and transport pathway. This study would provide important candidate genes and theoretical basis for the molecular mechanism of cuticle formation, which is essential for the breeding of peppers.

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