Variation in physico-chemical and biochemical parameters during the preparation of Raib from camel milk

Abstract

The raw milk is a highly nutritious product. The preparation of Raib by spontaneous fermentation of milk requires strict control to minimize health risks. The aim of this study is to assess the effect of spontaneous fermentation of camel milk on the physicochemical and biochemical quality of Raib. The analysis of camel milk samples collected in the region of Ghardaïa, south of Algeria, are analyzed during fermentation time (T0 hour until 120 hours). The monitoring during the time has shown that the pH value decreases from 6.53 to 3.85 at T120H. Conversely, the value of Dornic acidity increased from 18 °D to 105 °D. As for the total dry matter and the ashes, these experienced a significant reduction in the rates respectively from 123.2 ± 8.1 and 8.38 ± 0.5 g/l to the rates of 113.4 ± 7.3 and 7.87 ± 0.6 g/l at T120H. Biochemical analyzes have revealed that fermentation leads to a significant reduction in fat which is from 45.2 g/l to 37.5 g/l at T120H. However, the lactose, total protein and casein content have decreased significantly. The rates increased respectively from 42.2 ± 2.03, 34.1 ± 1.1 and 28.05 ± 0.65 g/l to 23.4 ± 1.13, 29.0 ± 1.4 and 23.48 ± 1.45 g/l before and after fermentation. The lactic acid bacteria have a considerable initial load (3.83 Log10 ufc/ml) and increase to a high value after T120H (8.06 Log10 ufc/ml). These results indicate that the fermentation process induced by the development of the lactic acid bacteria of camel milk promotes the degradation of certain biochemical parameters. These results seem to be an asset in promoting fermentation products.