Effect of different pretreatment methods on the quality of fermented mustard

In order to optimize the production process of fermented mustard, the effects of different pretreatment methods of fresh mustard on physicochemical indexes, color parameters, texture, volatile flavor components, and sensory quality of fermented mustard were investigated. Principal component analysis (PCA), orthogonal partial least squares-discriminant analysis (OPLS-DA) and cluster analysis (CA) were performed based on texture, volatile flavor components, and differential volatile flavor components were screened using variable importance in the projection (VIP) values. The results showed that the optimal pre-treatment method for fresh mustard: soaked it in 4% saline for 2 h, then dried the surface moisture naturally (dried 8 h, moisture 83.3%). The total acid and amino acid nitrogen contents of the naturally fermented mustard product were 19.98 g/kg and 0.28 g/100 g, and the L* value, a* value, b* value, and color difference value were 36.07, -0.27, 4.70, 4.21, respectively. The comprehensive texture score was 1.71 points, and the sensory score was 92 points. The nitrite content was 0.014 3 mg/kg, which was much lower than the national limit standard (20 mg/kg). A total of 74 volatile flavor components in fermented mustard samples with different pretreatments were detected, including 15 alcohols, 1 phenol, 2 ketones, 12 aldehydes, 3 nitriles, 7 esters, 4 isothiocyanates, 29 hydrocarbons, and 1 other type. OPLS-DA could effectively distinguish fermented mustard samples with different pretreatments, and a total of 45 differentially volatile flavor components (VIP values>1) were screened.