Nutritional value of sausages as a factor of their connective tissue content

Investigations were carried out on experimental sausages, raw and steamed, with the following levels of connective tissue: 1.8, 10, 20, 30, 50 and 76% . Total protein content was determined by the Kjeldahl method, total collag en by the modified Stegemann method, biological value by the PER method and by the amino acid composition. The limiting amino acid (chemical score) wa s also determined. It was found that an increase in the level of connective tissue was followed by a significant decrease in PER and essential amino a cid content, both in raw and steamed products. The decrease in particular a mino acid contents was 42-89% (raw) and 38-92% (steamed). The smallest drop was in the leucine level (38-43%), and the greatest in the tryptophan leve l (89-92%). The limiting amino acid changed depending on the connective tis sue content: at a low connective tissue content (1.8%), there were methioni ne and cystine, at a medium content (10-20%) phenyloalanine and tyrozine, a t a higher content (30:76%) tryptophan. Characteristic of steamed products was a significantly higher biological value than in the raw products, which was likely due to thermohydrolysis of collagen. The results indicate that one of the criteria for quality meat products should be the quantitative le vel of connective tissue.