14A-46 |
Application of high hydrostatic pressure attenuated Lactobacillus helveticus in Cheddar cheese production |
S. I. Manurung, J. R. POWERS, S. Clark, L. O. Luedecke, and B. G. Swanson. Dept. of Food Science & Human Nutrition, Washington State Univ., PO Box 646376, Pullman, WA 99164-6376 Bacterial lysis is important in delivering aminopeptidase (AP) to cheese, facilitating the breakdown of peptides. Previously HHP (410 MPa treatment 20 min) was reported to retard acid production by 8 h and enhance AP specific activities in milk. The objective of our study was to evaluate Cheddar cheeses manufactured with addition of HHP treated Lb. helveticus. Full fat (FF) and low fat (LF) Cheddar cheeses were manufactured with or without (Lb. helveticus WSU19, W260R, or HHP attenuated W260R) adjuncts. HHP did not enhance lysis of W260R in cheese. Previously we found that HHP caused lysis of W260R in pseudocurd. At 18 weeks, cheeses contained ~104 CFU Lactobacilli/g regardless of adjunct. FF cheeses containing control W260R exhibited the greatest PepN and PepX activities (1131 and 822 nmoles/h/g cheese). HHP treatments reduced PepN and PepX activities in aged FF cheese (494 and 201 nmoles/h/g). Proteolysis in FF aged cheeses containing HHP treated W260R was less than FF cheeses containing control W260R (2454 and 2670 mM Glycine equivalent/g) at 28 weeks. A trained panel judged all adjunct cheeses to be less bitter than control cheeses at 22 and 28 weeks. However, there was no significant effect of adjunct strain on bitterness. Addition of untreated W260R increased sweetness and reduced weak body significantly in LF cheeses. In 22 week cheeses, Cheddar flavor was perceived as most intense in FF cheeses containing WSU19. However, at 28 weeks, no significant difference was found in Cheddar flavor in cheeses containing either adjunct. HHP did not enhance W260R cell lysis, AP specific activities or proteolysis in Cheddar cheeses. Strain W260R contributes to flavor development in Cheddar cheese without HHP. The addition of strain W260R may improve texture and flavor qualities of LF Cheddar cheese.
Session 14A, Dairy Foods: General developments in dairy technology I
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