15C-5 |
Influence of adjunct cultures on volatile free fatty acids of reduced fat edam cheese |
W. TUNGJAROENCHAI1, W. E. Holmes2, C. H. White, and M. A. Drake. (1) Dept. Food Science and Technology, Mississippi State University, Box 9805, Mississippi State, MS 39762, (2) Mississippi State Chemical Laboratory
Lipolysis is one of the biochemical processes in cheese and the main route for formation of free fatty acids. Volatile free fatty acids (VFFA) contribute to the final flavor characteristics of cheese and indirectly serve as precursors of aroma compounds. By incorporating adjunct bacterial cultures in reduced fat cheese, lipolytic activity in cheese could be characterized through VFFA profiling. Our objective was to determine the effect of adjunct cultures in reduced fat edam cheese on VFFA profiles during ripening. Duplicate batches of full fat and 33% reduced fat control cheeses (no adjunct) were made along with five treatments of reduced fat cheeses which included adjuncts: Brevibacterium linens BL2, Lactococcus lactis ssp. diacetylactis, Lactobacillus helveticus LH212, Lactobacillus reuteri ATCC 23272, and a combination of these cultures. VFFA analysis of 1, 3, and 6 mo cheeses was determined by static headspace analysis using 4-bromofluorobenzene gas as the internal standard. Changes in VFFA concentrations were found in cheeses after 3 and 6 mo ripening. Cheeses with L.reuteri produced the highest concentration (p<.01) of heptanoic, n-caproic, iso-caproic and acetic acid in 6mo cheese while 3mo cheese with L. diacetylactis contained the highest (p<.01) concentrations of n-caproic and iso-caproic acid. Cheeses with L. helveticus produced constant levels of acetic, isobutyric, butyric, isovaleric, n-valeric , n-caproic, and heptanoic acid during ripening. Cheeses with L.reuteri showed the highest rate (16.84 ug/g cheese/month) of total VFFA production during ripening. VFFA profiles indicated obvious lipolytic activity in cheeses after 3mo ripening, and differences existed in VFFA profiles of the cheeses with different adjuncts. Rate of total VFFA production was a better indication of lipolytic activity in cheeses than the concentration of individual free fatty acids. Results will aid future research on VFFA production in cheese.
Session 15C, Dairy Foods
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