S-sulfonate determination and formation in meat products

A treatment with cyanide for the analysis of S-sulfonates in meat and meat derivatives, after a study of the effectiveness of this agent and that of d ithiothreitol (DTT), is proposed. Once the protein-bound sulfite has been r eleased, it is determined by HPLC ion exclusion with electrochemical detect ion. In the assay on the reproducibility of the method, standard deviations were 7.4, 9.2, and 11.4 for mean S-sulfonate values of 69, 107, and 130 mu g of SO2/g, respectively. Mean recovery was 91.2% for different amounts (56 , 111, and 223 mug of SO2/g) of S-sulfocysteine added. A study was made of the formation of S-sulfonates in model systems and in meat from different s pecies-chicken and beef-with different fat contents. In the assays with mea t, two different levels of sulfite addition were used: 600 and 1200 mug of SO2/g. From the assays carried out in model systems with sulfite and cystin e it may be concluded that one factor limiting the interaction is the acces sibility to disulfide groups. The proportion of S-sulfonates in sulfited me at remains relatively constant and does not seem to be governed by the meat component, the level of sulfite addition, or the fat content. However, the latter two factors are inversely correlated with the, retention of sulfite in the foods analyzed.