Évalluattiion de lla qualliitté nuttriittiionnelllle ett miicrobiiollogiique du llaiitt de chèvre ett ses apttiittudes de ttransfformattiion « Beurre »

Abstract

The objective of this study was to evaluate the nutritional and microbiological quality of goat milk collected from two wilayas in western Algeria (Saida and Mostaganem), and to characterize their suitability for processing into fresh butter (zabda), and to establish the effect of shelf life on the nutritional and organoleptic quality of traditionally made butter. 6 samplings were made, 2 regions of the province of Saida and 4 regions of the wilaya of Mostaganem (each of which corresponds to 3 samples). Milks in the Saida region were significantly richer in EST and GM than those in the Mostaganem region. Fresh butter yields were higher for the Mostaganem region (4-6%) compared to the Saida region (3.2-3.7%). The butter was made from milk from two regions (Mostaganem and Saida). The search was done using two factors namely; Factor region and shelf life at a refrigeration temperature of 4 ° C (D0 to D21). The biochemical analyzes of butter concerned dry matter, water, acid number and saponification index, as well as the evolution of the peroxide index and the degree of lipid peroxidation (TBARS). The region factor is the shelf life exhibits a highly significant effect (P <0.01) on the evolution of the indices (peroxide, acids, saponification) and lipid oxidation (TBARS) of the butter during the storage period of the product. The results show a change in butter peroxidation of two regions from D0 to D21 with (10.06μg to 36.13μg) for the Saida region and an increase of (4.46μg 28.267μg) for the region of Mostaganem. Thus, there is an increase in the acid number (1.29 mg to 0.96 mg) in butter from Saida and (0.53 mg to 1.05 mg) for butter from Mostaganem, hence the a 5-fold increase in lipolysis (TBARS) for the Saida region and a 6-fold increase in the Mostaganem region. As regards the saponification index of butter, the results obtained have made it possible to deduce that the region factor (climate and farming system) influences saponification, the content of which is higher in butter of the Saida region and which is 51.89 mg / g and 82.67 mg / g, knowing that the content of the saponification index for butter in the Mostaganem region is 51.85 mg / g to 67.94 mg / g. Regarding the sensory analysis of butter we find that the butter of the region of Saida (Ouled Khaled) has a creamy white color, homogeneous, firm, easy to spread with a smell and Abstract a taste of the fresh cream knowing that the butter of the region of Mostaganem has a creamy white color and an odor and a taste of rancid little pronounced.