Effect of Inoculating Lactic Acid Bacteria Starter on Physicochemical Properties and Safety Quality of Air-dried Sausage During Air Drying

In order to study the effects of lactic acid bacteria starter on the physical and chemical properties and safety quality of air-dried sausage during processing, SHI-59 (Staphylococcus xylose, Pediococcus pentosus, Lactobacillus plantarum), WBL-45 (Staphylococcus xylose, Staphylococcus botulinus, Lactobacillus sake), PRO-MIX5 (Staphylococcus xylose, Lactobacillus sake, Lactobacillus plantarum) compound commercial starter was inoculated into meat stuffing, the three groups were represented by SHI, WBL and PRO respectively, and fermented air-dried sausage was produced after 12 days of air drying process, no inoculation was used as control check (CK). The water content, water activity (a_w), color difference (L^* and a^*), pH and total volatile basic nitrogen (TVB-N) of the air-dried sausage of the four groups were measured on the 0, 3, 6, 9 and 12 days of air drying. The contents of biogenic amines, nitrite residues and 6 kinds of N-nitrosamines (NAs) were measured on the 6th and 12th day of air drying, respectively. The results showed that with the progress of air drying process, the moisture content and a_w of the four groups of air-dried sausage decreased gradually, the TVB-N value, L^* value and a^* value increased gradually, and the pH decreased first and then increased slowly. Inoculation of SHI-59 and WBL-45 could rapidly reduce the pH of meat filling system to 5.39 and 5.10 during the 0~3 days of air drying. When air dried for 12 days, the water content of WBL group was the highest (27.57%), which could improve the sensory properties of air-dried sausages. The pH of the air-dried sausage in the four groups was less than 5.4, and the nitrite residue was in the range of 1.91~2.95 mg/kg. The L^* and a^* values of the three groups were significantly higher than those of the CK group (P<0.05), the chromogenic effect of WBL-45 starter was the best. The content of total NAs in PRO Group and SHI group was significantly lower than that in CK group (P<0.05). The content of N-nitrosodimethylamine (NDMA) in the three inoculation groups was 1.24 ~1.82 µg/kg, which was much lower than the national limit standard and CK group, indicating that the three commercial compound bacteria had a significant inhibitory effect on NAs. The three fermentation agents had obvious inhibitory effects on tryptamine and spermidine, but had no inhibitory effect on the total amount of cadaverine, histamine, tyramine and biogenic amine, but their contents were safe and controllable. On the whole, inoculating three kinds of compound fermentation agents could keep the residues of NAs and nitrite at a low level, and could improve the safety and quality of air-dried sausage to varying degrees.