15C-30 |
Modified atmosphere packaging gas type influences some indices of Cheddar cheese shred ripening |
S. L. OWENS1, S. A. Rankin1, V. Galindo-Cuspinera, and D. C. Westhoff1. (1) Dept. of Animal & Avian Sciences, Univ. of Maryland, College Park, MD 20742 In response to the demands for convenience and prepared foods, modified atmosphere packaging has become an increasingly important technology in the manufacturing process of Cheddar cheese shreds. However, little is known about the effects of shredding and modified atmosphere packaging (MAP) gas type on the ripening quality of Cheddar cheese. The objective of this research was to characterize proteolysis, lipolysis and the microbial profile of Cheddar cheese shreds packaged under typical MAP parameters. Blocks of young Cheddar cheese were mechanically shredded, then treated with antimycotic and anticaking agents. Shreds were randomly distributed into 15.2 x 15.2 x 2.54 cm pouches, using 60 to 70 g of cheese per pouch. Gas treatments were as follows: 100% CO2, 100% N2, 70:30 CO2/N2, 70:30 N2/CO2, vacuum and vacuum block controls. The pouches were stored at 4 ± 1°C for 1, 30, or 90 days. Proteolysis was determined using a ninhydrin assay . Lipolysis was measured using acid degree values. Enumeration of starter and nonstarter lactic acid bacteria (NSLAB) was achieved with M17 and Rogosa agars, respectively, using a standard protocol. Proteolysis and lipolysis were significantly influenced by MAP gas type and time. Proteolysis was inversely proportional to the %CO2 at 90 days and as expected, increased over time. Lipolysis was greatest at 30 days and correlated with the NSLAB populations. NSLAB populations increased with increasing CO2 concentrations. Starter bacteria populations decreased over time and were not dramatically influenced by MAP gas type. Gas type has a significant effect on ripening indices of Cheddar cheese. These results may be used to influence the rate of ripening in Cheddar and possibly other cheeses packaged using MAP technologies.
Session 15C, Dairy Foods
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