Mustapha Mbye’s research while affiliated with Emirates Aviation University and other places

The camel milk (CM) industry has witnessed a notable expansion in recent years. This expansion is primarily driven by the rising demand for CM and its fermented products. The perceived health and nutritional benefits of these products are mainly responsible for their increasing popularity. The composition of CM can vary significantly due to various factors, including the breed of the camel, its age, the stage of lactation, region, and season. CM contains several beneficial substances, including antimicrobial agents, such as lactoferrin, lysozyme, immunoglobulin G, lactoperoxidase, and N-acetyl-D-glucosaminidase, which protect it from contamination by spoilage and pathogenic bacteria, and contribute to its longer shelf life compared to bovine milk (BM). Nevertheless, certain harmful bacteria, such as Listeria monocytogenes, Yersinia enterocolitica, and Escherichia coli, have been detected in CM, which is a significant public health concern. Therefore, it is crucial to understand and monitor the microbial profile of CM and follow good manufacturing practices to guarantee its safety and quality. This review article explores various aspects of CM, including the types of beneficial and harmful bacteria present in it, the composition of the milk, its antimicrobial properties, its shelf life, and the production of fermented CM products.

The aim of this study was to assess the effects of ultrafiltration (UF) combined with high-pressure processing (HPP) or heat treatment on the quality of soft cheese produced from camel milk (CM) or bovine milk (BM). Milk was concentrated by UF (0, 1, and 2-fold) before treatment with HPP at 350 MPa or 550 MPa for 5 min at 4 °C or by pasteurization at 65 °C for 30 min or at 75 °C for 30 s. Cheeses were produced using starter cultures and camel chymosin and pH, yield, proximate composition, texture profile, rheological properties, and protein profiles were determined. The highest yield of BM cheese (26%) was observed under the treatment with 2-fold UF combined with HPP at 550 MPa. CM cheese had the highest storage and loss moduli as well as the total solid and protein content under this treatment. According to SDS-PAGE electrophoresis, CM cheeses were more susceptible to proteolysis and had a higher number of low-molecular-weight bands, indicating the involvement of some active enzymes compared with BM cheeses. In conclusion, UF combined with HPP can enhance the cheese total solid content and gel structure in CM cheese products compared with heat treatment.

The milk of mammals is a complex fluid mixture of various proteins, minerals, lipids, and other micronutrients that play a critical role in providing nutrition and immunity to newborns. Casein proteins together with calcium phosphate form large colloidal particles, called casein micelles. Caseins and their micelles have received great scientific interest, but their versatility and role in the functional and nutritional properties of milk from different animal species are not fully understood. Caseins belong to a class of proteins that exhibit open and flexible conformations. Here, we discuss the key features that maintain the structures of the protein sequences in four selected animal species: cow, camel, human, and African elephant. The primary sequences of these proteins and their posttranslational modifications (phosphorylation and glycosylation) that determine their secondary structures have distinctively evolved in these different animal species, leading to differences in their structural, functional, and nutritional properties. The variability in the structures of milk caseins influence the properties of their dairy products, such as cheese and yogurt, as well as their digestibility and allergic properties. Such differences are beneficial to the development of different functionally improved casein molecules with variable biological and industrial utilities.

The aim of this study was to assess the effects of ultrafiltration (UF) combined with high-pressure processing (HPP) or heat treatment on the quality of soft cheese produced from camel milk (CM) or bovine milk (BM). Milk was concentrated by UF (0, 1, and 2-fold) before treatment with HPP at 350 MPa or 550 MPa for 5 min at 4°C or by pasteurization at 65°C for 30 min or at 75°C for 30 s. Cheeses were produced using starter cultures and camel chymosin and pH, yield, proximate composition, texture profile, rheological properties, and protein profiles were determined. The highest yield of BM cheese (26%) was observed under the treatment with 2-fold UF combined with HPP at 550 MPa. CM cheese had the highest storage and loss moduli as well as the total solid and protein content under this treatment. According to SDS-PAGE electrophoresis, CM cheeses were more susceptible to proteolysis and had a higher number of low-molecular-weight bands, indicating the involvement of some active enzymes compared with BM cheeses. In conclusion, UF combined with HPP can enhance the cheese total solid content and gel structure in CM cheese products compared with heat treatment.

Numerous people in African, Middle Asian, Middle Eastern, and Gulf Cooperation Council (GCC) countries highly value camel milk (CM) as it plays a vital role in their diet. The protein composition of CM as well as the structure of its casein micelles differs significantly from bovine milk (BM). Cheeses made from CM have a weak curd and soft texture compared to those made from BM. This review article presents and discusses the effect of milk protein composition, processing conditions (pasteurization and high-pressure treatment), and coagulants (camel chymosin, organic acids, plant proteases) on the quality of CM cheeses. CM cheese's weak texture is due to compositional characteristics of the milk, including low κ-casein-to-β-casein ratio (≈0.05 in CM vs. ≈0.33 in BM), large micelle size, different whey protein components, and higher proteolytic activity than BM. CM cheese texture can be improved by preheating the milk at low temperatures or by high pressure. Supplementing CM with calcium has shown inconsistent results on cheese texture, which may be due to interactions with other processing conditions. Despite their structure, CM cheeses are generally well liked in sensory studies.

Withania coagulans ( W. coagulans ) extract and camel chymosin have aspartic protease capable of coagulating milk for cheese production. This study investigated the quality of camel and bovine milk cheeses coagulated using Withania extracts, came chymosin, and their mixture in two experiments. In Experiment (1), a factorial design with four factors ( W. coagulans , camel chymosin, incubation time, and incubation temperature) was performed. The effect of these factors on cheese’s yield and hardness were assessed. An enzyme concentration corresponding to a 36 µg/L of milk of W. coagulans , 50 IMCU/L of camel chymosin, holding time of 4 h, and incubation temperature of 60 °C provided the optimal textural hardness for both camel and bovine milk cheeses. Seven treatments were analyzed in experiment (2) were analyzed for physicochemical properties, yield, and sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGEitation). The results showed that pure Withania extract exhibited the lower coagulating effect resulting in cheeses with low yield, hardness, fat, protein, and total solids. The SDS-PAGE electropherograms of camel cheese showed several low molecular weight bands as compared to bovine cheese. This phenomenon is due to excessive proteolysis in camel cheese, which we believed is caused by the presence of endogenous enzymes.

The effects of high-pressure processing (HPP) compared to thermal treatments on the quality of camel vs. bovine cheeses were studied. The study showed that camel milk has a lower microbial load compared to bovine milk, which is maintained during 7 days' storage of the processed milk. The effect of three HPP treatments (350, 450, and 550 MPa for 5 min at 4°C) and two pasteurization treatments (65°C for 30 min and 75°C for 30 s) on the quality of soft unripened camel and bovine milk cheeses were accessed. The cheeses were evaluated for pH, yield, proximate composition, textural and rheological properties, microstructure, and protein profile by SDS-PAGE electrophoresis. The effects of the treatments on cheese's hardness were different between the camel and bovine cheeses; while heat treatment at 65°C for 30 min gave the hardest bovine milk cheese (1,253 ± 20), HPP treatment at 350 MPa for 5 min gave the highest value for camel milk cheese (519 ± 5) (p < 0.05). The hardness of the cheeses was associated with low yield and moisture content. SDS-PAGE electrophoresis revealed that extensive proteolysis might have contributed to the softness of camel cheeses compared to bovine and suggested the involvement of some residual enzyme activities.

This study evaluated the effects of added casein (CN), whey proteins (WPs), calcium chloride (CaCl2), and a hydrocolloid [gum arabic (GA), gelatin (GL), sodium alginate (ALG), or pectin (PC)] on the quality of camel milk yogurts. Maximum viscosity was achieved with 4% WP and 2% CN. Addition of CaCl2, GA, and GL negatively affected the viscosity/rheology of WP/CN-fortified yogurts while ALG and PC had positive effects. Syneresis was highest in yogurts containing WP/CN and was reduced with the addition of hydrocolloids in the order GA<GL<PC<ALG. Yogurts containing WP-CN, alone or together with PC and ALG received better consumer acceptability scores.