Effects of red grape, wild grape and black raspberry wines on ground pork during refrigerated storage

The effects of red grape, wild grape and black raspberry wines on the quality of ground pork during a 15 days refrigerated storage period were investigated. The levels of phenolic compounds were the highest in black raspberry wine (P0.05). The addition of 5% and 10% wine influenced the quality of ground pork by decreasing pH, inhibiting the progression of lipid oxidation and the formation of total volatile basic nitrogen (TVB-N), and stabilizing the red colour of the ground pork compared to control samples to which no wine was added. In ground pork, addition of red grape wine led to lower concentrations of thiobarbituric acid reactive substances (TBARS, 0.19–0.39 mg kg−1) and TVB-N values (69.1–119.9 mg kg−1) than wild grape (0.16–0.43 mg kg−1 and 72.0–194.1 mg kg−1, respectively) or black raspberry wine (0.33–0.58 mg kg−1 and 81.7–225.4 mg kg−1, respectively) up to 10 days of storage. Results from the present study suggested that the quality of ground pork was affected by wine type and storage period. These effects could be due to phenolic compounds as well as other chemical components of the wines

Liberation of hydrogen sulfide from dicysteinyl polysulfanes in model wine

Diorganopolysulfanes can be generated when hydrogen sulfide (H₂S) and thiols are oxidized in the presence of Cu(II) under conditions usually aimed at removing H₂S from wine. This work sought to understand if polysulfanes could act as latent sources of H₂S during postbottling storage. The stability of the polysulfanes formed in situ in model wine containing cysteine, H₂S, and transition metals was dependent both on the number of sulfur linking atoms (Sn) and on the presence of a reducing agent, such as sulfur dioxide or ascorbic acid. A polysulfane containing three linking sulfur atoms was the most stable, with 84% of the relative initial amount remaining in solution after six months, compared to polysulfanes containing four or more linking sulfur atoms that decomposed rapidly, with 26% remaining after six months. Importantly, sulfur dioxide was associated with the rapid degradation of polysulfanes and subsequent liberation of H₂S. Three cysteine- S-sulfonates were also tentatively identified, which gives insight into the possible release mechanisms involved with H₂S reappearance.Marlize Z. Bekker, Gal Y. Kreitman, David W. Jeffery and John C. Danilewic