The adsorption of 2-amino-1-methyl-6-phenyl-imidazolium [4, 5-B] pyridine (PhIP) by lactic acid bacteria 37X-15 and its peptidoglycan.

The heterocyclic amine 2-amino-1-methyl-6-phenyl-imidazolium [4, 5-B] pyridine (PhIP), commonly found in roasted meat products, is considered a potential carcinogen. This study is to explore the underlying mechanisms involved in the adsorption of PhIP by lactic acid bacteria 37X-15 and its peptidoglycan. The scanning electron microscope results suggested that the strain's adsorption on PhIP occurs on the cell wall, primarily composed of peptidoglycan. The fourier-transformed infrared spectroscopy results indicated that PhIP adsorption by both lactic acid bacteria 37X-15 and its peptidoglycan primarily involved OH and NH binding groups. Different adsorption conditions affected the adsorption rate of PhIP by peptidoglycan. The optimal values for each adsorption condition were 2 h, 37 °C, and pH 6 when the maximum adsorption rate reached. This study provides a new direction for the application of lactic acid bacteria and its peptidoglycan in food safety.

The Effect of Lactiplantibacillus plantarum x3-2b Bacterial Powder on the Physicochemical Quality and Biogenic Amines of Fermented Lamb Jerky.

In this study, a protective agent was added to prepare a high-activity Lactiplantibacillus plantarum x3-2b bacterial powder as a fermentation agent and explore its effect on the physicochemical quality, biogenic amines, and flavor of fermented lamb jerky. A composite protective agent, composed of 15% skim milk powder and 10% trehalose, was used, and bacterial mud was mixed with the protective agent at a 1:1.2 mass ratio. The resulting freeze-dried bacterial powder achieved a viable count of 5.1 lg CFU/g with a lyophilization survival rate of 87.58%. Scanning electron microscopy revealed enhanced cell coverage by the composite protective agent, maintaining the cell membrane's integrity. Inoculation with x3-2b bacterial powder increased the pH and the reduction in aw, enhanced the appearance and texture of fermented lamb jerky, increased the variety and quantity of flavor compounds, and reduced the accumulation of biogenic amines (phenethylamine, histamine, and putrescine). This research provides a theoretical basis for improving and regulating the quality of lamb jerky and establishes a foundation for the development of bacterial powder for the commercial fermentation of meat products.

Effects of Microbial Communities on Volatile Profiles and Biogenic Amines in Beef Jerky from Inner Mongolian Districts.

Beef jerky is a traditional fermented meat product from Inner Mongolia, handcrafted by artisans. We investigated the bacteria of the microbial community, volatile flavor components, and biogenic amines of Inner Mongolia beef jerky via high-throughput sequencing, solid-phase microextraction with gas chromatography−mass spectrometry, and high-performance liquid chromatography, respectively. Thirty-three bacteria were identified, predominantly from the genera Pseudomonas (45.4%), Ralstonia (13.4%), and Acinetobacter (7.3%). Fifty-nine volatile flavor compounds and eight biogenic amines were detected. Based on Spearman's correlation coefficient, 20 bacterial genera were significantly associated with the dominant volatile compounds in the beef jerky samples (p < 0.05). The results demonstrated that beef jerky may be toxic due to cadaverine, putrescine, and histamine; moreover, the amounts of putrescine and cadaverine were positively correlated with the abundance of unclassified_f_Enterobacteriaceae (p < 0.05). These findings shed light on the formation of the microbial community, flavor components, and biogenic amines of beef jerky, thereby providing a basis for improving its quality.

Effect of Biogenic Amine-Degrading Lactobacillus on the Biogenic Amines and Quality in Fermented Lamb Jerky.

This study compares five types of lamb jerky, namely, CO (without starter culture), PL-4 (with producing putrescine, cadaverine, histamine, and tyramine), BL4-8 (degrading putrescine, cadaverine, histamine, and tyramine), CL4-3 (degrading putrescine and tyramine), and X3-2B (degrading histamine and tyramine). A study was performed to examine the effects of starter culture on the physical−chemical quality, flavor, and biogenic amines (BAs) during fermentation and ripening. At the end of fermentation, the pH value of the BL4-8 group (4.75) was significantly lower than that of other groups (p < 0.05). After high-temperature roasting, the water activity (0.55), water content (22.6%), nitrite residue (0.41 mg/kg), and TBARS value (0.27 mg/100 g) of the X3-2B group were significantly lower than those of other groups (p < 0.05). The findings show that adding starter BL4-8, CL4-3, and X3-2B can increase the variety and content of flavor in the product. The levels of histamine, putrescine, and tyramine were significantly lower in the BL4-8, CL4-3, and X3-2B groups than in CO and PL-4 groups. This study shows that BL4-8, CL4-3, and X3-2B are potential starters for fermented meat products.