USE OF AGGLUTINATION-SENSITIVE BULK STARTERS IN THE MANUFACTURE OF STIRRED CURD CHEESE

The effect of agglutinated bulk cultures on the manufacture of experim ental stirred curd cheese was observed. To prepare three bulk starters , three aliquots of bulk medium were inoculated with cultures differin g in agglutination sensitivity. Each bulk starter was divided into two portions, one of which was homogenized at 17.2 MPa (13.8 MPa, first s tage; 3.4 MPa, second stage) pressure. Seventy grams (1%) of each star ter were inoculated into 7000 g of milk, and stirred curd cheese was m anufactured. The experiment was replicated three times. Cell chain len gth and clump size were markedly reduced in starters that were homogen ized. No differences were observed in culture activity (acid productio n) during cheese manufacture between homogenized and unhomogenized cul tures. Acid production was uniform throughout the vat of milk for both homogenized and unhomogenized cultures. The pH at the bottom of the v at was slightly lower when unhomogenized culture CH970 (a clump former ) was used as the bulk starter. Large agglutinated complexes of bacter ia and protein may have been physically buoyed up by the fat globules based upon photomicrographs of the cheese coagulum.