Abstract
The aim of this study was to investigate the effects of biopreservation using Lactobacillus plantarum and Lactobacillus sakei on wet aged venison. Twenty-one venison loins from one-year-old male deer were obtained at 24 hours post-mortem. Samples were assigned to three groups which included non-treated venison, L. plantarum treated venison, and L. sakei treated venison. All samples were vacuum packed and stored at 4°C for up to 7, 14, and 21 days, and assessed for pH, purge loss, cook loss, tenderness, microbiological count, thiobarbituric acid reactive substances (TBARs), total volatile basic nitrogen (TVB-N), and volatile analyses. The multivariate data analysis (MVDA) tools used included principal component analysis (PCA) as an exploratory technique, and partial least squares discriminant analysis (PLS-DA) for supervised classification. Variable identification (VID) was used to identify the most discriminating volatile compounds. Aging time was found to have the most significant influence on the results, with treatment and interaction effects being less significant influencers. Aging time was found to reduce the shear force (P < 0.05), while biopreservative bacteria treatment increased TBARs and TVB-N values (P < 0.05). The volatile profiles were changed over aging time. The aldehydes such as heptanal, pentanal, and hexanal decreased with time. The interaction between lipid oxidation and proteolysis resulted in the production of non-volatile compounds and reduced aldehyde concentrations. Among the two treatments, L. sakei seems to have a higher activity and enhanced the formation of Maillard reactions-related volatile compounds (e.g. pyrazines and Strecker aldehydes). The L. sakei treated group had lower pH (P < 0.05) and higher TVB-N (P < 0.05) values compared to the control group and the L. plantarum treated group. There were a few interaction effects in lactic acid bacteria counts (LAB) counts, total viable microbial counts, and TBARs (P < 0.05), but no general trends were observed. Furthermore, volatile profiles showed significant differences due to the cooking methods used (boiled and pan-fried), aging time, and biopreservative treatment (P < 0.05). The L. plantarum treated group was observed to have similar physical and chemical levels as the control group and produced significantly different volatile profiles (P < 0.05). As TVB-N is a crucial spoilage index in meat science, microbial inoculum should be expected to have the effect of maintaining or decreasing the TVB-N value.