Effect of fermented blueberry on the oxidative stability and volatile molecule profiles of emulsion-type sausage during refrigerated storage.

The aim of this work was to assess the effect of fermented blueberry (2%, 4% and 6%) on the oxidative stability and volatile molecule profiles of emulsion-type sausage stored at 4 °C for 28 days. The antioxidant activity of fermented blueberry (FB) was determined through radical-scavenging activity of 2, 2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH) and hydroxyl radicals. Four formulations of sausage treatments with different FB levels (0, 2, 4, 6%) were prepared, then peroxide value (POVs), thiobarbituric acid-reactive substances (TBARS) values, protein carbonyls and thiol groups were measured. The aroma profiles of sausages for each treatments were also determined. The IC50 value indicated that FB had greater scavenging ability than ascorbic acid against DPPH and hydroxyl radicals. Sausages with FB significantly retarded increases in POVs and TBARS, as well as in the content of protein carbonyls during all storage days (p < 0.05). Particularly, 4% and 6% FB-treated sausages had better oxidation inhibition effects. However, FB accelerated the reduction in thiol groupss (p < 0.05). Additionally, FB inhibits the excessive formation of aldehyde compounds; for example, hexanal decreased from 58.25% to 19.41%, which may cause rancid flavors. FB also created 6 alcohols (i.e., 2-methyl-1-propanol, 3-methyl-1-butanol and phenylethyl alcohol), 5 ester compounds (i.e., ethyl acetate, ethyl lactate and ethyl hexanoate) and 3-hydroxy-2-butanone in the sausages that contribute to sausage flavors. The principal component analysis (PCA) showed that the aroma profiles of sausages with and without FB are easily identified. The addition of FB could significantly recduce the lipid and protein oxidation and improve oxidative stability for storage. Also, adding FB could inhibit rancid flavors and contribute to sausage flavors.