A Comprehensive Review of the Composition, Nutritional Value, and Functional Properties of Camel Milk Fat

Characterization of phospholipidome in milk, yogurt and cream, and phospholipid differences related to various dairy processing methods

Milk phospholipids have multiple health benefits, but the deficiency of detailed phospholipid profiles in dairy products brings obstacles to intake calculation and function evaluation of dairy phospholipids. In present study, 306 phospholipid molecular species were identified and quantified among 207 milk, yogurt and cream products using a HILIC-ESI-Q-TOF MS and a HILIC-ESI-QQQ MS. The phospholipid profiles of five mammals' milk show that camel milk contains the most abundant phosphatidylethanolamine, phosphatidylserine and sphingomyelin; cow, yak and goat milk have similar phospholipidomes, while buffalo milk contains abundant phosphatidylinositol. Fewer plasmalogens but more lyso-glycerolphospholipids were found in ultra-high-temperature (UHT) sterilized milk than in pasteurized milk, and higher proportions of lyso-glycerolphospholipid/total phospholipid were observed in both cream and skimmed/semi-skimmed milk than whole milk, indicating that UHT and skimming processes improve glycerolphospholipid degradation and phospholipid nutrition loss. Meanwhile, more diacyl-glycerolphospholipids and less of their degradation products make yogurt a better phospholipid resource than whole milk.

Human milk sphingomyelin: Function, metabolism, composition and mimicking

Human milk, which contains various nutrients, is the "gold standard" for infant nutrition. Healthy human milk meets all the nutritional needs of early infant development. Polar lipids mainly exist in the milk fat globule membrane, accounting for approximately 1-2% of human milk lipids; sphingomyelin (SM) accounts for approximately 21-24% of polar lipids. SM plays an important role in promoting the development of the brain and nervous system, regulating intestinal flora, and improving skin barriers. Though SM could be synthesized de novo, SM nutrition from dietary is also important for infants. The content and composition of SM in human milk has been reported, however, the molecular mechanisms of nutritional functions of SM for infants required further research. This review summarizes the functional mechanisms, metabolic pathways, and compositional, influencing factors, and mimicking of SM in human milk, and highlights the challenges of improving maternal and infant early/long-term nutrition.

Invited review: Camel milk and gut health-Understanding digestibility and the effect on gut microbiota

Camel milk (CM), known for its immune-regulatory, anti-inflammatory, antiapoptotic, and antidiabetic properties, is a natural healthy food. It is easily digestible due to the high levels of β-casein and diverse secreted antibodies, exhibiting superior antibacterial and antiviral activities compared with bovine milk. β-casein is less allergic and more digestible because it is more susceptible to digestive hydrolysis in the gut; therefore, higher levels of β-casein make CM advantageous for human health. Furthermore, antibodies help the digestive system by destroying the antigens, which are then overwhelmed and digested by macrophages. The connection between the gut microbiota and human health has gained substantial research attention, as it offers potential benefits and supports disease treatment. The gut microbiota has a vital role in regulating the host's health because it helps in several biological functions, such as protection against pathogens, immune function regulation, energy harvesting from digested foods, and reinforcement of digestive tract biochemical barriers. These functions could be affected by the changes in the gut microbiota profile, and gut microbiota differences are associated with several diseases, such as inflammatory bowel disease, colon cancer, irritable bowel disorder, mental illness, allergy, and obesity. This review focuses on the digestibility of CM components, particularly protein and fat, and their influence on gut microbiota modulation. Notably, the hypoallergenic properties and small fat globules of CM contribute to its enhanced digestibility. Considering the rapid digestion of its proteins under conditions simulating infant gastrointestinal digestion, CM exhibits promise as a potential alternative for infant formula preparation due to the high β-/αs-casein ratio and protective proteins, in addition to the absence of β-lactoglobulin.

A novel approach to insulin delivery via oral route: Milk fat globule membrane derived liposomes as a delivery vehicle

The current research endeavor seeks to unlock the potential of orally administered insulin formulations by utilizing liposomes derived from the fat globule membrane (MFGM) of camel milk as carriers for insulin. This pursuit emerges as a result of the recognized limitations of subcutaneous insulin therapy. The liposomes were meticulously created using the thin film hydration method, followed by comprehensive chemical and morphological analyses. Additionally, comprehensive safety assessments were carried out in vitro and in vivo, revealing significant findings. The Fourier-transform infrared (FTIR) spectrum confirmed the presence of insulin within the liposomes, demonstrating changes in their size and charge. The in vitro cytotoxicity analysis, performed on HEK-293 cell lines through the MTT assay, yielded results indicating a cell viability of over 90%. In the in vivo investigation, diabetic rats induced by STZ were utilized to evaluate the effects of the liposomes, revealing substantial reductions in blood glucose levels, bilirubin, alkaline phosphatase (ALP), albumin, and alanine aminotransferase (ALT) levels. Hepatic histopathological assessments showed signs of recovery across all treatment groups, with no observable microscopic changes in renal tissue. This investigation highlights the significant hypoglycemic effects observed in insulin-loaded liposomes derived from MFGM obtained from camel milk when administered orally.

Analysis for lipid nutrient differences in the milk of 13 species from a quantitative non-targeted lipidomics perspective

Lipids are essential organic components in milk and have been associated with various health benefits for newborns. However, a comprehensive analysis of lipid profiles across multiple species and levels has been lacking. In this study, we employed liquid chromatography-tandem mass spectrometry (LC-MS/MS) to accurately determine the absolute content of lipid molecules. It revealed that ruminants exhibit a higher concentration of short-chain fatty acids compared to non-ruminants. Additionally, we identified ALC (camel), MGH (horse), and DZD (donkey) as species that display similarities to components found in human milk fat. Remarkably, it reveals that porcine milk fat is characterized by long chain lengths, low saturation, and a high proportion of essential fatty acids. PS (22:5_18:2) could potentially serve as a biomarker in porcine milk. These unique characteristics present potential opportunities for the utilization of porcine milk. Overall, our findings provide valuable insights into the lipidomics profiles of milk from different species.

The Potential of Sheep or Camel Milk Constituents to Contribute to Novel Dressings for Diabetic Wounds

Impaired wound healing is a complication of diabetes, which constitutes a serious problem in clinical practice. Currently, there is a high demand on the market for local treatment options for difficult-to-heal wounds caused by diabetes. The development of dressings that accelerate wound healing has recently been the subject of much research. Sheep and camel milk is gaining importance due to the content of many bioactive substances with health-promoting effects, such as insulin, LF, proline, or CLA. Sheep and camel milk proteins are a promising source of insulin, antidiabetic, and antihypertensive peptides. Numerous studies show that local administration of insulin has a significant impact on the healing of diabetic wounds. Sheep and camel milk, due to the highest LF content among ruminants, reduces autoimmune inflammatory processes and protects against bacterial and viral infections in the wound environment. Sheep's milk has the highest content of proline and CLA, and their addition to a hydrogel dressing can help in the development of an effective dressing material. The production of hydrogel dressings containing sheep and camel milk, which are naturally rich in the bioactive substances presented in this review, may be a promising step in the market of specialized dressings for difficult-to-heal diabetic wounds.

Effect of camel milk on lipid profile among patients with diabetes: a systematic review, meta-analysis, and meta-regression of randomized controlled trials

The effects of camel milk (CM) intake on lipid profile among patients with diabetes remain controversial. This systematic review and meta-analysis of randomized controlled trials (RCTs) aimed to calculate the effect size of CM intake on blood lipids among patients with type 1 (T1D) and type 2 (T2D) diabetes. We searched nine databases from inception until December 31, 2022, to identify relevant RCTs. Effect sizes for total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), and high-density lipoprotein (HDL) were calculated and expressed using mean differences (MD) and confidence intervals (CI). Of 4,054 retrieved articles, 10 RCTs (a total of 347 participants aged 8-70 years, 60.5% male) were eligible for inclusion. The pooled results from a random-effects model showed statistically significant decreases in TC (MD - 21.69, 95% CI: 41.05, - 2.33; p = 0.03; I2=99%), TG (MD - 19.79, 95% CI: -36.16, - 3.42; p=0.02, I2=99%), and LDL (MD -11.92, CI: -20.57, -3.26; p = 0.007, I2=88%), and a significant increase in HDL (MD 10.37, 95% CI, 1.90, 18.84; p=0.02, I2=95%) in patients with diabetes supplemented with CM compared with usual care alone. Subgroup analysis revealed that only long-term interventions (> 6 months) elicited a significant reduction in TC levels and TG levels. Consumption of fresh CM by patients with diabetes resulted in significant reductions in TC, TG, and LDL levels, while showing a significant increase in HDL levels. Patients with T1D elicited a more beneficial effect in lowering TC, LDL, and TG levels and in increasing HDL levels than their corresponding partners with T2D. In conclusion, long-term consumption of CM for patients with diabetes, especially those with T1D, could be a useful adjuvant therapy to improve lipid profile alongside prescribed medications. However, the high heterogeneity in the included studies suggests that more RCTs with larger sample sizes and longer intervention durations are required to improve the robustness of the available evidence.

Facile Synthesis of Multifunctional Carbon Dots Derived from Camel Milk for Mn7+ Sensing and Antiamyloid and Anticancer Activities

Carbon dots (CDs) are promising biocompatible fluorescent nanoparticles mainly used in bioimaging, drug delivery, sensing, therapeutics, and various other applications. The utilization of natural sources and green synthetic approaches is resulting in highly biocompatible and nontoxic nanoparticles. Herein, we report an unprecedented facile and green synthesis of highly luminescent carbon dots derived from camel milk (CM) for sensing manganese (Mn7+) ions and for identifying the anticancer potential and antiamyloid activity against α-synuclein amyloids. α-Synuclein amyloid formation due to protein misfolding (genetic and environmental factors) has gained significant attention due to its association with Parkinson's disease and other synucleinopathies. The as-synthesized CM-CDs possess an average hydrodynamic diameter ranging from 3 to 15 nm and also exhibit strong photoluminescence (PL) emission in the blue region. The CM-CDs possess good water dispersibility, stable fluorescence under different physical states, and outstanding photostability. Moreover, the CM-CDs are validated as an efficient sensor for the detection of Mn7+ ions in DI water and in metal ion-polluted tap water. In addition, the CM-CDs have demonstrated a very good quantum yield (QY) of 24.6% and a limit of detection (LOD) of 0.58 μM for Mn7+ ions with no incubation time. Consequently, the exceptional properties of CM-CDs make them highly suitable for a diverse array of biomedical applications.

Camel milk products: innovations, limitations and opportunities

Camel milk is the mainstay for millions of people in arid and semi-arid environments. In these areas, it is mainly consumed raw or after it spontaneously turns sour. Although some attempts have been made to produce dairy products from camel milk, processing of camel milk is generally considered to be difficult and the quality of the final products made from camel milk do not correspond to their bovine milk counterparts. This paper reports a comprehensive analysis of the literature on camel milk products and presents synthesis of the latest developments, limitations pertaining processing and opportunities for development of new and improved camel milk products. The protein composition and colloidal structure of camel milk differs from cow milk. It is characterized by absence of β-lactoglobulin, low κ-casein content, high proportion of β-casein, larger casein micelles and smaller fat globules. These differences lead to the difficulty of making dairy products from camel milk using the same technologies as for bovine milk. Some of the challenges of camel milk processing include poor stability of the milk during UHT treatment, impaired rennetability, formation of weak and fragile curd during coagulation, longer fermentation time, and low thermal stability of the milk during drying. Despite these difficulties, it has now become possible to produce a range of commercial and traditional dairy products from camel milk. Some of the strategies that could be applied to improve the quality and characteristics of camel milk products are discussed.

Graphical Abstract

Yield and Composition Variations of the Milk from Different Camel Breeds in Saudi Arabia

With the increasing interest in the identification of differences between camel breeds over the last decade, this study was conducted to estimate the variability of milk production and composition of four Saudi camel breeds during different seasons. Milk records were taken two days per week from females of Majahem, Safra, Wadha, and Hamra breeds distributed over Saudi Arabia. The milk yield during winter indicated that the weekly average of the Wadha breed was significantly lower (27.13 kg/week) than Majahem and Hamra breeds. The Safra breed had the lowest milk yield (30.7 kg/week) during summer. During winter, the Hamra breed had a lower content of all analyzed milk components except proteins and was characterized by a lower pH than the milk of the other breeds. However, the Hamra breed had significantly higher contents of milk fat and lactose than the other breeds during summer, with the corresponding values of 3.87 and 4.86%, respectively. Milk collected during winter from Majahem, Safra, and Wadha breeds was characterized by a significant increase in all milk components and milk pH. Finally, the isoelectric focusing analysis revealed noticeable variability of casein purified from camel milk within the different Saudi breeds, with the highest significant value of 2.29 g per 100 mL recorded for the Wadha breed.

Non-Bovine Milk: Sources and Future Prospects

Milk is the first food that mammals are exposed to [...]

Camel Milk Targeting Insulin Receptor—Toward Understanding the Antidiabetic Effects of Camel Milk

Camel milk (CM) is known for its beneficial virtues in the human diet and health. This includes its antidiabetic properties demonstrated in many in vitro and in vivo studies. Nevertheless, the scientific rationale behind the molecular and cellular basis of such beneficial effects and the exact antidiabetic agent(s)/mechanism(s) are still elusive. In this review, we focused on the recent advances supporting the targeting of insulin receptor (IR) by CM components. Indeed, our recent work reported that CM proteins and derived peptides pharmacologically target IR in vitro leading to its activation and potentiation of insulin-mediated responses. The review describes the experimental approaches used to investigate the effects of CM on IR in vitro based on the fractionation of CM whey proteins to purify functional proteins and their hydrolysis by gastric proteases to generate bioactive peptides. In addition, we illustrated our cellular and molecular model consisting of studying the functional activity of CM fractions on IR and its downstream signaling pathways in the hepatocarcinoma (HepG2) and the human embryonic kidney (HEK293) cells using the bioluminescence resonance energy transfer (BRET), phosphorylation, and glucose uptake assays. Overall, our work demonstrated for the first time that CM lactoferrin and CM-derived bioactive peptides positively modulate IR and its related signaling pathways in HepG2 and HEK293 cells. As a conclusion, the pharmacological targeting of IR by CM sheds more light on the antidiabetic properties of CM by providing its molecular basis that may constitute a solid rationale for the development of new generation of antidiabetic tools from CM-derived proteins and peptides and the utilization of CM in the management of diabetes. The sequencing and the synthesis of the potent bioactive CM peptides may open promising perspectives for their application as antidiabetic agents.

Milk Fat Depression and Trans-11 to Trans-10 C18:1 Shift in Milk of Two Cattle Farming Systems

Milk fat depression (MFD) syndrome, a consistent decrease in milk fat content, is related to important changes in fatty acid composition due to feed imbalances and the consequent ruminal metabolism alteration. Milk produced in two different farming systems was compared: Holstein Friesian fed with unified in intensive production and Podolica raised on a pasture in an extensive system. Milk chemical characteristics and fatty acid composition were determined comparing milk with a normal fat level (>3.8%) to milk with a low fat level (<3.2%) in each breeding system. Holstein Friesian milk showed the decrease in trans-11 and increase in trans-10 C18:1 (shift from trans-11 to trans-10 C18:1) in low fat with respect to normal fat milk with a consequent decrease in the trans-11/trans-10 C18:1 ratio. Even conjugated linoleic acid (CLA), C18:2 cis-9, trans-11, was lower while CLA trans-10, cis-12 was higher in low fat milk than in normal fat milk from Holstein Friesian. These changes, that are indicators of MFD syndrome, were not found in Podolica milk between fat levels. Holstein Friesian milk showed less short-chain fatty acids (9.48 % vs. 11.05%, p < 0.001), trans vaccenic acid (C18:1 trans-11, 0.51% vs. 3.39%, p < 0.001), rumenic acid (CLA C18:2 cis-9, trans-11, 0.32% vs. 1.45%, p < 0.001) and total CLA (0.53% vs. 1.91%, p < 0.001) contents than Podolica milk. Further losses of these human healthy nutrients in low fat Friesian milk reduced the nutritional quality of the milk, while the milk from animals raised on the pasture was of better quality even when the level of fat was low.