Abstract #28

# 28
Impact of stretching temperature in a waterless cooker on the functionality of Mozzarella cheese.
E. K. Aversa*1, S. Govindasamy-Lucey2, M. E. Johnson2, J. J. Jaeggi2, J. A. Lucey1,2, 1University of Wisconsin-Madison, Madison, WI, 2Wisconsin Center for Dairy Research, Madison, WI.

Use of high stretch temperatures during manufacture of low moisture part-skim (LMPS) Mozzarella cheese decreases residual rennet activity (RRA) and microbial counts. High stretch temperatures could help extend the shelf-life of LMPS destined for export. The aim of this study was to determine the impact of stretching temperatures (60, 74, and 88°C) in a waterless cooker on the composition, texture, flavor, and functional properties of LMPS Mozzarella. Four LMPS Mozzarella cheeses (n = 4) were manufactured using camel chymosin and an Airdus waterless cooker. Cheeses were stored at 4°C and analyzed at 2 wk, 3 and 6 mo. Cheeses were analyzed for RRA and primary proteolysis. Changes in flavor, shred properties, and pizza performance were evaluated using quantitative descriptive analysis (QDA). Cheeses stretched at ≤74°C had similar and typical composition. Cheese stretched at 88°C had reduced fat and moisture contents due to losses during the heating process. Cheese stretched at ≥74°C had higher pH values (P < 0.05) because of low acid development due to reduced microbial starter counts. Cheese stretched at ≥ 74°C had decreased RRA compared with cheese stretched at 60°C, resulting in lower proteolysis during storage. Stretching temperature affected the shred and pizza characteristics of the cheeses. Cheese stretched at ≥74°C had lower shred adhesiveness during storage compared with cheese stretched at 60°C, which had high adhesiveness (P < 0.05). Cheeses stretched at ≥74°C were characterized by higher blister quantity, hardness values, and more skinning when baked. During storage, the blister quantity increased for cheeses stretched at 60°C but not for cheeses stretched ≥74°C. Proteolysis in the cheeses stretched at 60°C caused a decrease in strand length and thickness. Cheese stretched at ≥74°C retained firmness and chewiness. This was consistent with TPA data where hardness values were maintained in cheese stretched at 88°C due to decreased proteolysis and higher protein content. Use of high stretch temperatures could be a useful method for helping to extend the performance shelf life of LMPS Mozzarella.

Key Words: low moisture part-skim (LMPS) Mozzarella, performance shelf life, high stretching temperature