Cheese production potential of milk of Dahlem Cashmere goats from a rheological point of view

Coagulation properties, along with the main components (protein, casein, fat), of goat milk during cheese processing were rheologically evaluated on milk of two breeds of goats (Dahlem Cashmere: DC and German Fawn: GF) using dynamic mechanical analyses. Coagulation time (CT) was estimated during gel formation at 1 Hz and 1% strain for 79 min after rennet addition. In the sol-gel transition range, aggregation rate (AR) was characterized by the linear increase of the storage modulus G′ monitored after CT over 8 min. Curd firmness (CF) was evaluated based on subsequent frequency spectra of the resulting gels. Applying contrast analysis, it was confirmed that DC milk resulted in higher (P < 0.01) CF than that of GF, and in (P < 0.01) increased AR irrespective of lactation stage and number of parturitions. CT within milk samples of DC (8-32 min) and GF goats (8-20 min) had no significant difference between the two breeds. Fat, protein and casein contents of DC milk were significantly higher (P < 0.05) than of GF milk. Cheese production efficiency was directly proportional to AR and CF. Higher CF of DC milk compared to that of GF milk reflected denser network formation which was related to casein composition and content.