Study On The Lactic Acid Bacteria Flora And Flavor Compounds During The Pickled Processing Of Potherb And It’s Fermentation Conditioning Technology

Allium mongolicum regel (AMR) and dandelion resources are very rich in Ningxia province, potherb’s nutrition maintain and resource conservation are very well after pickled. Suitable pickled conditions can improve potherb’s ferment flavor and product quality. With total acidity and sensory score for index, central composite design experiments and response surface methodology were adopted, the effect of dish-water ratio, salt concentrations and spices content were researched in the process. In order to understand naturally fermented AMR and dandelion and improve their ferment technics, identified the naturally fermented product’s main bacterial strains and free amino acids by using microbiological and analytical chemistry methods, the total acid, pH and salinity in the product were monitored too. Hydrolytic amino acid free amino acids were analyzed by amino acid analyzer, the nutritional value changes in the fermentation process of both dishes were based on the hydrolysis amino acid content, and the free amino acids that affected the senses were classified in accordance with the taste intensity. This research provides scientific basis for potherb’s exploitation and industrial development. The results are as follows.(1) The results show that the optimum process methods as follows:Pre-pickled AMR with Brine (3/4) for 8-12h, then re-pickled AMR into the cans with the remaining 1/4 salt, the optimal condition is salt concentrations of 6%, AMR of 50%, spice content of 2.5%. By the validation test the sensory evaluation is 90.3 and total acidity is 1.25g/100mL under the optimum condition, which is basically correspond to the model prediction value of 91.8 and 1.30g/100mL. Dandelion pickled with 3%o-4%o pepper water after blanching, the optimal condition is salt concentrations of 5%, dandelion of 70%, spice content of 4%. By the validation test the sensory evaluation is 93.1 and total acidity is 0.66g/100mL under the optimum condition, which is basically correspond to the model prediction value of 94.3 and 0.71g/100mL.(2) In AMR, umami amino acids’(Glu, Asp, Lys) content is particularly high before fermentation, Lactobacillus planetarium is dominant and the content of each amino acids decreases in the early fermentation process. Lactobacillus planetarium, Lactobacillus fermentum and Lactobacillus acidlophilus take an active part in the main fermentation stage. Meanwhile, the bitter amino acid (Leu, Val, Arg, Ile, Trp, Met), sweet amino acids (Ser, Thr, Gly, Ala, His, Pro) and umami amino acids have a similar content. In the late fermentation process, Lactobacillus casei is dominant, sweet amino acids’ content is higher than others. Throughout the fermentation process, the content of aromatic amino acids (Tyr, Cys, Phe) is low and changes a little, AMR enjoys a best taste from the seventh to fifteenth day after fermentation. In dandelion, Lactobacillus planetarium is dominant and the content of bitter amino acids is higher than the others in the early fermentation process. Lactobacillus planetarium and Lactobacillus brevis take an active part in the main fermentation stage. The bitter amino acids’content decreases, and the content of sweet amino acids and umami amino acids increases at the same time. In the late fermentation process, Lactobacillus fermentum is dominant, and the sweet and umami amino acids’content is higher than the bitter. Throughout the fermentation process, the content of aromatic amino acids changes a little. Dandelion enjoys a best taste from the seventh to twentieth day after fermentation.(3) Through the analysis of amino acid hydrolysis from AMR and dandelion, both of them contain 18 kinds of amino acids. In AMR, human essential amino acid content among the total amino acid content is up to 41%-45% in each period of fermentation. Compared with the amino acid pattern spectrum, AMR’s nutritional value of unfermented and primary fermentation period are the best, raw AMR’s SRC is as high as 87.64, SRC of fermentation 3d and 7d are close to 80 points, the contents of Mets and Cys are insufficient afterl4d, which respectively affect its nutritional value. In dandelion, human essential amino acid content among the total amino acid is up to 42% in each period of fermentation. Compared with the amino acid pattern spectrum, dandelion’s nutritional value of primary fermentation period is the best, SRC is close to 80 points. the contents of Mets and Cys are insufficient on Od and after14d, which respectively affect its nutritional value. Overall, AMR and dandelion are kinds of high nutrient plants.