Ultraviolet spectrophotometric determination of sorbic acid in dry fermented sausage.

A rapid and reliable method is described for determining sorbic acid in dry fermented Italian salami (moisture < 50%, fat > 25%). Sorbic acid was extracted from the homogenized sample with metaphosphoric acid and partitioned into isooctane. The absorbance of the extract was read at 255 nm. Background UV-absorbing materials were determined by their absorbance at 255 nm after permanganate oxidation of sorbic acid. Unexpectedly, spice components contributed to the UV absorbance of permanganate-labile substances, and sorbic acid was at first overestimated. Interference caused by spice components was calculated by measuring the difference in absorbance before and after permanganate treatment of a sample extract from a salami which had not been treated with sorbic acid. Recovery of added sorbic acid (50--600 ppm) was between 92 and 98.7%.