Nitroso-hemoglobin Increased the Color Stability and Inhibited the Pathogenic Bacteria in a Minced Beef Model: A Combined Low-field NMR Study

This study mainly investigated the improvement effect of nitroso-hemoglobin (NO-Hb) and four lactic acid bacteria (LAB) (Streptococcus thermophiles, Lactobacillus bulgaricus, Lactobacillus casei, and Montessori enterococcus) on the color and microbiological qualities of raw beef. Three strains of Escherichia coli, Staphylococcus, Salmonella, and Pseudomonas were used as pathogenic bacteria. The results showed that both NO-Hb and LAB could enhance the color stability and scavenged the spoilage bacteria in a minced beef model. But the improvement effect of NO-Hb was more significant than LAB. This suggested that NO-Hb, as a novel ingredient, could be used as a promising substitute for nitrite in meat products to improve the color and safety of meat products. In addition, low field (LF)-NMR method has been established to be practicable to identify changes in the relaxation times of water and fat caused by different type of bacteria and the storage periods. The number of relaxation components in minced beef was affected by bacteria and increase of the storage period.