Development of ricotta cheese from concentrated buffalo cheese whey by optimization of processing conditions using RSM

Yield and quality of ricotta cheese from concentrated whey is affected by various processing conditions. The present study aims to explore the optimal processing conditions regarding temperature, pH and calcium chloride (CaCl₂) concentration for maximum yield of ricotta cheese. Buffalo cheese whey was concentrated by vacuum concentrator at 50 °C resulting in total solids (TS) percentage of 48.62 ± 0.195 and total protein content of 5.64 ± 0.043 percent. Twenty experiments were performed to optimize the processing conditions like temperature (60–90 °C), pH (3–7) and CaCl₂ concentration (2.0–6.0 mM) for maximum yield/recovery of milk constituents from this concentrated whey. Consequently, three best combinations of processing conditions, RCW1 = 90 °C, pH 7, CaCl₂ 6 mM), RCW2 = (100 °C, pH 5, CaCl₂ 4 mM) and RCW3 = (75 °C, pH 8.4, CaCl₂ 4 mM) were selected for ricotta cheese preparation. These cheeses were compared for various physicochemical characteristics during storage of 60 days at 4 ± 2 °C. Yield increases (5.59–10.80%) with increased in temperature (60–90 °C) respectively at the same pH 7.0, however when temperature increased from 60 to 90 °C at the same pH 3.0 the yield increase from 4.19 to 4.90% respectively. It was observed that all three factors affect the yield (%) of ricotta cheese. Temperature and pH had strong effect as compared to CaCl₂. The results showed that the ricotta cheese prepared at 100 °C, pH 5 and CaCl₂ 4 mM resulted the maximum yield, proteins and TS. Significant increase in acidity and non-protein nitrogen was observed during storage. The pH, fat, and lactose contents of ricotta cheese was significantly decreased during storage. However; moisture, ash, protein and TS were non-significant effect during that period.