The invention provides a preparation method of a gamma-
polyglutamic acid containing
food additive. The preparation method comprises the following steps: preparing activated
bacillus natto, then inoculating a
solid culture medium with the activated
bacillus natto according to an inoculating amount of 5-10%, and fermenting to obtain a fermented product A; adding 5-10-fold of water by volume, dissolving, diluting to obtain a mixed
system, preserving heat, centrifuging, and filtering to obtain a gamma-
polyglutamic acid containing filtrate; adding saccharides into the gamma-
polyglutamic acid containing filtrate, inoculating with
lactobacillus according to an inoculating amount of 2-5%, and fermenting to obtain a fermented product B; centrifuging, decolorizing, concentrating, precipitating and
drying to obtain the gamma-polyglutamic acid containing
food additive. The preparation method of the gamma-polyglutamic acid containing
food additive, provided by the invention, is easy to operate, safe and reliable; by the preparation method, growth of pathogens and
spoilage bacteria can be inhibited, bad smell can be eliminated, the product
flavor can be improved, and the quality of the gamma-polyglutamic acid containing food additive can be improved, so that the preparation method has a wide application prospect.