Application Of Lactic Acid Bacteria In Mustard Pickling Process

The process of the traditional high-salted pickled mustard is easy to lead to higher nitrite, too long marinated time and other unfavorable factors. Besides excessive amount of salt is a waste of resources. Lactic acid is the main specie during the pickled process, whose safety has been widely recognized. The pickled vegetable inoculated lactobacillus technology has been matures. Now, the study of lactic acid bacteria inoculated pickled vegetables mainly focused on the production of Paocai, There are very few studies about pickled mustard for artificial inoculation process, especially mustard salt-dehydration in Zhejiang province. Based on this, the author makes an in-depth exploration on the lactic acid bacteria inoculation pickled mustard of Zhejiang region.In this paper, the high-density culture conditions were optimized for three strains of laboratory strains (D, M, Z). including lactic acid bacteria culture of environmental factors (temperature, pH, inoculum size) and medium composition (including carbon and nitrogen sources). The optimization made three strains of lactic acid bacteria reached1010cfu/mLThe three strains of lactic acid bacteria cultured in high-density (number of M, Z, D) were inoculated in the tuber mustard. The result showed that the pH value, the number of lactic acid bacteria and nitrite content were significantly better than the control groups. The sensory evaluation orthogonal analysis identified as the optimum technology:fresh vegetable with salt amount was8kg/100kg, inoculum5mL/Kg, and lactobacillus strains (Z) was chosed.The best strain (Z) was inoculated in the pickled process of Zhacai at the low salt condition. LAB (Z) was inoculated in the pre-pickle process, or both the pre-pickle process and the pre-pickle and re-pickle process. The pH value, the number of LAB, and the nitrite content in the pickle progress, as well as the amino nitrogen mustard content and the flavor components of the final products were determined separately. The results showed that:For Zhacai inoculated in the pre-pickle process and inoculated in both pickle process, the pH value quickly reduced to4or less, the number of lactic acid bacteria could reach10’cfu/mL, and nitrite peak value appeared4-6days earlier than the control, which was lower than1.0μg/mL. Besides, Zhacai inoculated with LAB (Z) had more amino nitrogen content, organic acids and flavor than the control group. The amount of amino nitrogen could reach0.48g/100mL. The optimum was:in pre-pickle process, the salt amount was50g/kg, inoculation3mL (strain concentration105cfu/mL), curing time16-18d; in the re-pickle process, the salt amount was30g/kg, inoculum2mL (strain concentration105cfu/mL), curing time14-16d.The strain lactobacillus (L) of high-yield GABA (γ-aminobutyric acid) was inoculated in pickled mustard according to the optimum technology. The result showed that the number of lactic acid, pH and nitrite content during the process were fit with national standards, and almost same to strain (Z), but the GABA content of lactobacillus (L) could reach143.6mg/kg, significantly higher than ordinary strains.