14A-45 |
The role of glutathione in the ripening of Swiss cheese slurries |
M. D. RUHLMAN, K. D. Kent, and W. J. Harper. Dept. of Food Science & Technology, Ohio State Univ., 2015 Fyffe Ct., 110 Parker Food Science Bldg., Columbus, OH 43210-1007 The addition of glutathione (GSH), a tripeptide, to Swiss cheese slurry systems has been previously shown to enhance flavor development through protection of esterases and releasing of peptides that enhance cheese ripening. The mechanistic role of residual GSH in cheese slurries on ripening is not known. The objective of this study was to determine if the residual free GSH levels in the slurries with and without the addition of 100ppm (326然) GSH were related to differences in volatile aroma compounds formed during the ripening of the slurries. Swiss cheese slurries were prepared with 2% NaCl (w.b.), packed in plastic bags and vacuum sealed. The slurries were incubated at 30蚓 and sampled daily for 10 days. GSH was measured using a spectrophotometric assay and aroma profiles were evaluated by an electronic nose (EN) with a mass spectrometer sensor. Following the addition of GSH to the slurries, 96% was immediately oxidized to glutathione disulfide (GSSG), leaving only a small amount of residual GSH (14然). In comparison, the control slurries contained 8然 GSH. For both the control and the experimental slurries, the levels of GSH cycled between 8-16然 until day 5 where the levels continued to increase to 20然 at day 10. Using the EN, differences between the two slurries aroma patterns were apparent at day 5 and had distinct differences between different slurries at day 6. Differentiation in aroma was related primarily to diacetyl, 2-butanol, acetone, and butyric acid. Based on the results of this study, the addition of GSH may influence the flavor production. However, this does not appear to be related to residual reduced glutathione, since the levels of GSH in both cheese slurries are similar. The basis for the cyclic nature of the GSH may be related to GSH reductase activity in the slurry.
Session 14A, Dairy Foods: General developments in dairy technology I
|