Effect of sodium lactate coating enriched with nisin on beef strip loins (M. Longissimus lumborum) quality during cold storage and electronic nose rapid evaluation

Effects of sodium lactate (SL) coating enriched with nisin on beef strip loins (M. Longissimus lumborum) quality were evaluated in this research. Samples were coated with different chemical preservatives (2% SL, 4% SL, 2 g/L nisin, 2% SL + 2 g/L nisin, and 4% SL + 2 g/L nisin). Deionised water was used as negative control. Sensory evaluation, microbial, total viable counts, weight loss, surface colour, pH, and total volatile basic nitrogen (TVB-N), were examined. In order to explore a new way for beef quality rapid evaluation, electronic nose (e-nose) was used to measure beef samples. E-nose stochasic resonance (SR) and double-layered cascaded series stochastic resonance responses were used to conduct multiple variable regression (MVR) with key physio-chemical indexes to investigate their correlation relationship. Results indicated that the most effective treatment was 4% SL + 2 g/L nisin. By the optimal preservative, beef showed lower microbial propagation, less moisture loss and TVB-N content. Also, this method maintained original colour and pH, and displayed higher sensory acceptability. Therefore, thus coating with 4% SL + 2 g/L nisin effectively prolonged the shelf life of beef samples. Electronic nose was used to evaluate the quality of different beef samples. MVR results indicated that SR based e-nose discriminated the beef in different quality, and also presented a closer correlation with beef quality indexes.