Abstract:
The present study was carried out at Haramaya University dairy laboratory with the intention of investigating (1) the effect of camel chymosin on milk coagulation properties of camel milk and (2) the effect of camel chymosin and cooking on soft unripened cheese characteristics. Two experiments were conducted. The first experiment was on milk coagulation with completely randomized design (CRD) and different chymosin concentrations (40, 70 and 100 IMCU/L) were tested for gelation time (tg), maximum gel firmness (G’Max) and time for maximum gel firmness (tG’max). Whereas, the second experiment was on soft unripened cheesemaking with 3x2 factorial design with CRD arrangement and the effect of different camel chymosin concentrations (40, 70, and 100 IMCU/L) and cooking were tested for cheese quality, cheese yield, texture profile analysis (TPA) hardness and sensory attributes. Significantly Shortest gelation time (p<0.01) was observed by both 100 IMCU/L (348sec) and 70 IMCU/L (433sec) and highest maximum gel firmness (p<0.05) was observed for 40 IMCU/L (61.9 pa). With 100 IMCU/L significantly highest (p<0.05) yield, protein, and TPA hardness (11.93gm, 17.73%, and 5.85N respectively) are showed. Uncooked cheese samples showed significantly higher yield (11.48 gm) (p<0.05) than cooked cheese samples. But, cooked cheese samples showed significantly lower pH (p<0.001), lower fat (p<0.05), higher TS (p<0.05) (5.01, 19.25gm and 41.47% respectively) and higher TPA hardness (3.65 N) (p<0.05). Regarding interaction effect, higher yield was observed on 100 IMCU/L Uncooked cheese samples (12.60gm). Significantly higher protein (18.40gm), total solid (42.98gm), ash (2.20gm) content and TPA hardness (6.89 N) (p<0.001) are observed for100 IMCU/L Cooked. The color, texture and appearance of 40 IMCU/L cooked cheese scored higher value. Whereas the taste, aroma and overall acceptance of 70 IMCU/L cooked cheese is showed higher score. Considering better consumer acceptance and comparable yield and quality; using medium level camel chymosin concentration (70 IMCU/L) was found to be the best. Again considering higher TPA hardness, higher acceptance and better quality for cooked cheeses, it can be concluded that cooking the cheese curd is mandatory. So, using 70 IMCU/L with cooking results acceptable quality.
