The impact of lipase specificity on cheddar cheese flavor development during cheese ripening
General Material Designation
[Thesis]
First Statement of Responsibility
H.-S. Kwak
.PUBLICATION, DISTRIBUTION, ETC
Name of Publisher, Distributor, etc.
Kansas State University
Date of Publication, Distribution, etc.
1989
PHYSICAL DESCRIPTION
Specific Material Designation and Extent of Item
175
DISSERTATION (THESIS) NOTE
Dissertation or thesis details and type of degree
Ph.D.
Body granting the degree
Kansas State University
Text preceding or following the note
1989
SUMMARY OR ABSTRACT
Text of Note
Patterns of releasing short-chain free fatty acids (FFA) from milk fat were studied utilizing twenty-five commercial food grade and analytical grade lipases in cheese slurries. Principal Component Analysis showed that there were four distinctive groups indicated by the FFA ratios and five groups of lipases indicated by the FFA concentrations. Average Linkage Cluster Analysis also showed similar results, although the patterns of FFA released were a matter of distance defined statistically between groups of lipases. Based on the patterns of releasing short-chain FFA as well as their source, four lipases (from calf, porcine pancreas, Aspergillus niger, and Pseudomonas fluorescens) were selected and subjected to investigation for the implication of lipase specificities on the release of specific fatty acids as well as their impact on the formation of neutral volatile compounds in cheese slurries. Calf lipase-treated cheese slurries showed a good Cheddar flavor (mild) only at initial stage, and imparted lipolyzed flavor defect thereafter. A. niger lipase-treated cheese slurries also showed similar trends to the calf lipase-treated samples. However, porcine pancreatic lipase-treated cheese slurries developed a good Cheddar flavor (medium) at 1 wk and generated moderately lipolyzed flavor thereafter. P. fluorescens lipase-treated slurries showed similar trends to the pancreatic lipase-treated slurries. Statistical analysis indicated that ratios as well as concentrations of short-chain FFA, individually or in combinations, were related to Cheddar flavor as well as lipolyzed defect. Commercial porcine-pancreatic lipase was selected as one of the most probable enzyme from the four lipases tested previously. The lipase was incorporated into granular Cheddar cheese at two levels of concentration and ripened at 7, 13, and 21 for 20 wk. The main objective was to investigate the effects of the lipase on the production of short-chain FFA, neutral volatile compounds, and organoleptic flavors in the cheese at different ripening temperatures. They were roughly equivalent to medium and sharp cheeses when ripened at 7, 13, and 21C at 3 to 15 wk. (Abstract shortened with permission of author.)