Abstract:

In order to improve the quality of imitation cheese, the effects of emulsifying salts, temperature and pH on sol
properties of rennet casein were explored, the minimum amount of emulsifying salt added before lactic acid fermentation was
determined, and the sensory quality and microstructure of the resulting cheese were analyzed. The results indicated that the
effect of five emulsifying salts on sol properties of rennet casein followed the decreasing order: sodium pentapolyphosphate >
sodium hexametaphosphate > JOHA PZ 7 > trisodium citrate dehydrate > tetrasodium pyrophosphate. In the range of
25–42 ℃, the solubility of rennet casein rapidly increased with an increase in temperature, whereas the increase was slower
as the temperature continued to increase to 85 ℃. As the pH increased from 5.5 to 11.5, the solubility significantly increased.
The minimum amount of emulsifying salt added to rennet casein was a rennet casein:sodium pentapolyphosphate:water ratio
of 1 g:25 mg:2.5 mL. The fermented imitation cheese scored much higher than the ordinary one (unfermented) in sensory
scores for both flavor and overall quality. Therefore, the imitation cheese obtained in this study not only had desirable
appearance and texture characteristics, but also overcame the intrinsic flavor defects of ordinary imitation cheese.

Key words: rennet casein, sol properties, lactic acid fermentation, imitation cheese, microstructure