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N. NORONHA, D. O'Riordan, and M. O'Sullivan. Dept. of Food Science, Univ. College Dublin, Agriculture Bldg., Belfield, Dublin, 4, Ireland Traditionally, imitation cheese is manufactured using a specialized helical twin-screw cooker rather than high shear single-blade cookers that are at hand in many food companies. The effect of ingredients on imitation cheese functionality has been the main focus of research to date, and the impact of processing parameters has not been extensively investigated. The objective of this study was to determine the impact of cooker design and/or blade/auger speed on the functional properties of imitation cheese. Imitation cheeses with similar compositions (48% moisture) were manufactured using water, rennet casein, rapeseed oil, hydrogenated palm oil, and emulsifying salts in a twin-screw or a single-blade cooker. The single-blade cooker was operated at an auger speed of 750, 1125, or 1500 rpm (maximum setting), and the twin-screw cooker was operated at speeds of 100 or 200 rpm (maximum setting). Increasing the blade speed of the single-blade cooker from 750 to 1500 rpm increased (P< 0.001) the hardness from 392 to 533N and decreased the meltability of imitation cheese from 112 to 66mm, respectively. Hardness and meltability values of cheeses made in the twin-screw cooker were only slightly affected by varying the blade speed from 100 to 200 rpm. Cheeses made in the single-blade cooker at 1500 rpm were significantly harder and lower melting than cheeses made in the twin-screw cooker. However, the hardness and meltability of the cheeses made at shear rates of 1125 and 750 rpm in the single-blade cooker were comparable to those made in the twin-screw cooker. The cheese made with the single-blade cooker at 1500 rpm had the highest G¢ and G² values at 22 °C, compared to all other cheeses. The melting temperature (G¢=G²) was not substantially affected by cooker type or agitation speed. This study shows that imitation cheese with acceptable functional properties can be successfully manufactured in a single-blade cooker.
Session 31, Dairy Foods: General I
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |