Camel Milk Powder Research Articles

Surface fat and insolubility of whole camel milk powders as affected by spray drying operating parameters

Face centered central composite design was used to investigate the effect of spray drying process parameters (inlet temperature, atomization pressure and feed flow rate) on selected quality parameters of whole camel milk. During storage by freezing, the integrity of camel milk fat globules is maintained with observed aggregation. Whole camel milk contains 12.18% total solids, 3.5% protein and 3.99% [w/w] lactose whereas for the powders, the total solids content was in the range of 94–97%, protein 22–29% and lactose 27–31% [w/w]. By combining response surface methodology with desirability function, the spray drying process of whole camel milk was optimized with objectives of maximizing the yield and minimizing undesired quality degradation parameters. Consequently, it was possible to recover 62% of total solids without affecting the desired aspects of the final physico-chemical properties of powders (minimum insolubility index of 0.1 mL and surface fat content of 4.2% [w/w]) with targeted final moisture content of 4.5% [w/w]. These properties would make the powders safe during extended period of storage.

Determination of 18 amino acids in three different kinds of milk powder by ultra performance liquid chromatography coupled with pre-column derivatization

近年来羊奶粉和骆驼奶粉备受消费者青睐,它们具有潜在的低致敏性,因此成为牛乳不耐受人群尤其是婴幼儿的母乳替代品,其营养价值备受关注。牛奶粉、羊奶粉和骆驼奶粉中氨基酸含量的比较研究鲜有报道。利用酸水解得到游离氨基酸,选择6-氨基喹啉-N-羟基琥珀酰亚胺氨基甲酸酯(AQC)进行柱前衍生,超高效液相色谱分离并检测,外标法定量。18种氨基酸在各自线性范围内线性关系良好,相关系数(r 2)大于0.999;以3倍和10倍信噪比(S/N)确定方法的检出限(LOD)和定量限(LOQ),分别为1.3~2.5 (mg/100 g)和3.9~7.5 (mg/100 g)。方法验证采用奶粉标准参考物质SRM 1849a,测定值符合其含量范围,6次测定值的相对标准偏差(RSD)为2.04%~3.65%。采用建立的方法分别对市售和网购的牛奶粉、羊奶粉和骆驼奶粉进行18种氨基酸成分和含量分析,旨在从氨基酸角度对这3种不同来源乳品进行对比。该方法快速,灵敏度高,准确可靠,适用于不同基质乳粉中18种氨基酸成分和含量的确定。

Maillard reaction products formation and antioxidative power of spray dried camel milk powders increases with the inlet temperature of drying

Demand for camel milk (CM) is increasing worldwide, due to its high nutritious value and health benefits. In this study, whole CM powders were produced by spray drying (SD) at six inlet temperatures (190 °C–250 °C) and by freeze drying (FD). Physicochemical and functional properties of CM powder proteins were investigated. SD at higher inlet temperatures (230 °C–250 °C) resulted in higher extent of Maillard reaction (MR), in comparison to lower temperatures (190 °C–200 °C) and FD treatment. Both treatments had negative effect on casein solubility, while whey proteins remained soluble and slightly increased its solubility with the extent of MR. The CM powders obtained at higher inlet temperatures demonstrated improved antioxidant activity. Secondary structure of whey proteins did not differ among the samples, while surface hydrophobicity of whey proteins was higher in all SD than in FD samples, suggesting only limited denaturation of camel whey proteins at higher inlet temperatures of drying. Thus, the effects of SD under the conditions applied in our study did not decrease camel whey protein solubility, while drying procedure itself regardless of temperature decreased solubility of camel milk caseins. MR generated during CM processing could be an important means of compensating for the lack of antioxidant protection normally associated with β-lactoglobulin but happens to be absent from this milk.

Determination of amino acid balancing of proteins of sour-milk product for herodietic food

The article presents the results of a study to determine and calculate the amino acid balance of proteins of fermented milk products for herodietal nutrition based on camel milk. It was found that the introduction of camel milk powder from a plant component, a product from a herb, increases the composition of essential amino acids in the preparation of fermented milk products for heroic nutrition in the following order, leucine - 8.66 g ± 0.2 g. Isoleucine - 4.81 g ± 0.1 g, lysine - 6.72 g ± 0.2, methionine - 3.26 g ± 0.2, phenialanine + tyrosine - 5.72 g ± 0.2, threonine - 6.3 g ± 0.2 tryptophan 1.18 g ± 0.2, valine 6.21 g ± 0.2. In addition to the results, mismatch coefficients were calculated, which have the following numbers: formulation No. 1 - 2.4, formulation No. 2 - 2.5.

Electronic nose technology for rapid detection of adulterated camel milk powder

Electronic nose technology for rapid detection of adulterated camel milk powder

Insolubility and denaturation of whey proteins of skimmed camel milk as affected by spray drying operating parameters

ABSTRACT The effect of spray drying process parameters (i.e., inlet temperature, atomization pressure, and feed flow rate) on the denaturation of whey proteins of skimmed camel milk was studied using a face-centered central composite design. Spray drying of skimmed camel milk (i.e., total solids of 8.4% [w/w]) produced powders with a total solids content of 94–97% (w/w), protein 22–29% (w/w) and lactose 27–31% (w/w). The process was optimized using response surface methodology in combination with desirability function. A maximum recovery of 61% of the total solids was achieved while still maintaining denaturation of whey protein and insolubility index levels at their minimum possible value of 39% and 0.1 mL, respectively. The final moisture content of the powder at these conditions was 3.3% (w/w). This implies that, as denaturation was the primary mechanism by which camel milk lose its protective proteins, minimizing denaturation would make it possible to produce skimmed camel milk powders with good nutritional and therapeutic values. The morphology of spray-dried skimmed camel milk processed at 140°C showed greater spherical intact particles than their cow milk powder counterparts.

Physicochemical, techno-functional, and fat melting properties of spray-dried camel and bovine milk powders.

In this study, three skimmed and one whole-fat spray-dried camel milk powders were produced and their characteristics were compared to those of bovine milk powders. The physicochemical analysis of the produced powders indicated that camel milk powders (whether skimmed or not) presented higher ash and whey protein contents as compared to those of bovine milk powders. Our results indicated that the investigated camel and bovine milk powders exhibited a high solubility index (>99%) with poor dispersibility and wettability indexes due to their small particles size (d50 ≤ 12µm) and their narrow size distribution (span ≤ 2). In addition, although camel and bovine milk powders presented the same total fat content, lower free fat content was measured for camel milk powders. Besides, the whey protein nitrogen index and the SDS-PAGE electrophoresis underlined that camel and bovine milk proteins remained intact after drying with low denaturation extent. It is worth noticed that camel milk proteins were less denaturized due to the absence of the heat-sensitive β-lactoglobulin in camel milk. Moreover, the low denaturation extent participated in the enhancing of the foaming capacity and stability of camel and bovine milk powders. Finally, the calorimetric analysis showed that higher fat melting temperatures were recorded in whole-fat camel milk powder and in their anhydrous form as compared to those of bovine milk. PRACTICAL APPLICATION: Camel milk powder is an emerging non-bovine dairy product. Understanding its rehydration ability and evaluating the impact of spray drying on its protein quality are promising approaches to obtain high-quality camel milk powder with high reconstitution ability. Findings of this study indicated that spray drying is a suitable technique to produce highly soluble camel milk powders with low denaturation extent. These results will benefit the research and development department of food industry (especially those producing camel milk powder) as well as the direct consumers.

Protein profile of whole camel milk resulting from commercial thermal treatment

Camel milk is rich in proteins that are beneficial to diseases. While commercial heat treatment is conducive to the storage, transportation and distribution of camel milk, such treatment could devalue the nourishment and destroy certain properties of camel milk proteins. In our study, Tandem mass tag (TMT) labeled camel milk samples, including raw camel milk (RCM), high-temperature processed liquid camel milk (PLCM) and camel milk powder (CMP), were examined by Liquid Chromatography combined with Tandem Mass Spectrometry (LC-MS/MS) to identify and quantify proteins undergoing significant changes. A total of 807 proteins were identified, with 246 and 170 proteins undergoing significant changes in PLCM and CMP, respectively. Those proteins are mainly involved in biological processes like metabolic process and cellular process and were mostly related to signaling pathways including RNA transport, PPAR signaling pathway and ribosome. Our results provide new insights into the effects of thermal treatment on changes of protein profile.

Effect of spray and freeze drying on physico-chemical, functional, moisture sorption and morphological characteristics of camel milk powder

This study investigated the changes in camel milk powder on spray and freeze drying by preparing spray dried whole camel milk powder (SDW), spray dried skimmed camel milk powder (SDS) and freeze-dried whole camel milk powder (FDW). All the powder variants showed significant changes (P < 0.05) in their composition, water activity and color values. Freeze dried powder (FDW) showed higher retention of calcium (15.33 g/kg) and iron (0.012 g/kg) while SDS possessed highest L* (94.83 ± 0.74) values. FDW sample had highest interstitial air (80.84 ± 0.66 mL/100 g), occluded air (119.47 ± 1.08 mL/100 g) and porosity (50.59 ± 0.56%) followed by SDS which was further reinforced by their SEM images. The water binding capacity was highest for FDW (5.21 g/g protein) and lowest for SDW which is attributed to highest porosity and presence of surface fat, respectively. Freeze-dried camel powder had porous sheet like structure while the spray dried samples were agglomerates of individual spherical particles. FTIR peak differences between whole camel milk powder samples (FDW and SDW) and skimmed powder sample (SDS) in wavenumber range 2850–3000 cm−1 was due to milk fat. Fitted with BET and GAB model, the moisture sorption isotherm showed lowest monolayer moisture content for SDW, thereby highlighting its better storage stability.

Changes in physical and biochemical properties of spray dried camel and bovine milk powders.

This study aimed at investigating the changes in skim camel milk (SCMP) and skim bovine milk (SBMP) powders produced by spray-drying. The physical (sorption isotherms at 25 °C and the glass transition temperature Tg at 0.13, 0.23 and 0.33 of water activities (aw)) and the biochemical (LC-MS, before and after drying) properties were assessed. Compared to SBMP, the results for SCMP indicated lower protein denaturation extent, lower critical aw for lactose crystallization (aw = 0.60 instead of 0.70), and lower Tg at 0.13 of aw (54.6 ± 1.4 °C instead of 57.8 ± 0.4 °C). Fitted to Guggenheim, Anderson and De Boer (GAB) model, the water sorption isotherms showed that both powders exhibited the same monolayer moisture content (Xm = 2.0 g 100 g−1, p > 0.05). These findings were linked to the absence of β-lactoglobulin, the high surface lactose content, the high initial lactose crystallization and the low size distribution (d50 < 10 μm) of SCMP.

Effect of spray‐drying parameters on the solubility and the bulk density of camel milk powder: A response surface methodology approach

Response surface methodology coupled with a Box–Behnken experimental design was used to investigate the effect of the air inlet drying temperature, the feed rate, and the fat content on the solubility and the bulk density of spray‐dried camel and cow milk powders. The response surface methodology analysis highlighted that milk fat content and feed rate were the most effective parameters affecting the solubility and the bulk density of cow and camel milk powders. Importantly, there was no significant interaction between the studied drying parameters and camel milk powder solubility or bulk density. Overall, camel milk powder exhibited a comparable solubility to that of cow milk powder with a higher bulk density.

Current Status of Camel Dairy Processing and Technologies: A Review

Camel milk is unique because it is not easily processed into different dairy products that are common for cow milk. It lacks β-lactoglobulin and has low κ-casein that hinders processing of camel milk into different dairy products. Hence it needs different processing methods and technologies. To this effect attempts were made to manufacture dairy products such as feta cheese, soft brined cheese, and fermented milk from camel milk that had been produced at laboratory level. Camel milk powder has also been manufactures and marketed in Middle East and beyond. Currently there are remarkable progresses in camel dairy technologies that paved the way for production of different camel dairy products at small, medium and large scale. A number of experiments were conducted on camel milk processing technologies from preservation of camel milk using lactoperoxidase system activation using hydrogen peroxide (H2O2) and thiocyanate as well as by H2O2 producing lactic acid bacteria (LAB) to metagenomic characterization of LAB isolated from spontaneously fermented camel milk. Therefore, this review paper is going to present current status of camel dairy technologies in Ethiopia.

The effects of camel milk powder on the stability and quality properties of processed cheese sauce.

Camel milk contains all the essential nutrients as cow&rsquo;s milk, and has potential beneficial nutritive properties. The drying process has a little effect on the surface composition of milk powders. The use of camel milk powder in the manufacture of processed cheese could produce a product with special functional properties. The effects of adding different concentrations of camel milk powder (CMP; ranging from 5 to 15%) as a new functional source to replace the cheese base in the manufacture of processed cheese sauces with highly acceptable quality and sensory properties were investigated. All treatments varied significantly (p &le; 0.05) in their properties depending on the percentage of CMP added and the storage period (6 &plusmn;0.5&deg;C for 30 days). The pH, meltability, oil separation, viscosity and sensory properties of cheese sauce were measured during the storage period. Also, the chemical composition of the freshly prepared cheese sauces was examined. The moisture and total solids content decreased and increased significantly (p &le; 0.05), in line with an increase of CMP in the cheese base formula, while the fat separation decreased with an increase in the percentage of camel milk powder added to the blends. The oil separation and meltability values increased (p &le; 0.05) in all treatments, even in the control, throughout the storage period. Among treatments, the cheese sauce containing 15% CMP (T3) was characterized by higher viscosity values during the examined time of shearing and presented higher upward shifting of the flow curve, as compared with the other treatments, either fresh or during storage. All cheese treatments were more accepted by the panelists and rated above average, particularly with an increase in the ratio of CMP added of 10%. The addition of CMP improved (p &le; 0.05) the quality attributes of cheese sauces and could be considered as a new different source to substitute cheeses used in base blends of processed cheese.

The effects of camel milk powder on the stability and quality properties of processed cheese sauce [pdf

The effects of camel milk powder on the stability and quality properties of processed cheese sauce [pdf

The potential of computational fluid dynamics simulation to investigate the relation between quality parameters and outlet temperature during spray drying of camel milk

The lack of appropriate quality indicators for Computational fluid dynamics (CFD) prediction of spray drying of camel milk impeded the simulation of the process. This research is designed to correlate the temperature profile of powder particles with the solubility of camel milk proteins with the ultimate goal of identifying best quality indicators suitable for CFD simulation. Spray drying experiment was conducted by varying drying temperature from 140–200 °C while maintaining the drying air flow rate (7.5 m3/min), emulsion feed rate (0.0003 kg/s) and atomization pressure (0.52 MPa) constant. The moisture content of camel milk powder varied from 7.04% [w/w] at lower temperature (140 °C) to 2.7% [w/w] at higher temperature (200 °C). Yield of powder could be increased with inlet temperature only up to 160 °C. Similarly, moisture removal from camel milk could be increased with temperature only up to 160 °C. From this point onward, powder yield and moisture removal showed inverse relation with temperature. CFD predicted the outlet temperature with 0.43% and 0.73% errors at inlet temperature of 140 °C and 170 °C, respectively and with 8.69% error at 200 °C. The loss of solubility of αS1- and κ-caseins as determined by SDS-PAGE of spray dried camel milk powders correlated well with the CFD predicted temperature profiles of particles. The SEM images of the powders illustrated that more round type particles are produced at higher temperature for both cow and camel milks whereas shriveled type powders at lower temperature only for cow milk.

Microstructure and chemical composition of camel and cow milk powders’ surface

This study aimed at investigating the chemical composition and microstructure of spray dried camel and cow milk powders' surfaces with two different milk-fat contents (1 and 20g 100 g−1). The SEM (Scanning Electron Microscopy) micrographs showed that spherical particles with a ‘brain’-type surface for both milk powders were produced. The surface roughness (Ra) of whole (WDMP) and skimmed (SDMP) camel milk powders (Ra = 7.6 ± 0.4 nm and 5.6 ± 0.7 nm, respectively) were significantly lower as compared with the partially skimmed (PSCMP) and skimmed (SCMP) cow milk powders. The XPS (X-ray Photoelectron Spectroscopy) analysis highlighted that the surface of skimmed camel milk powders contained twice the lactose amount (17.7 ± 0.8%) as compared to cow milk powders (8.7 ± 0.4%). Furthermore, both milk powders showed the overexposure of proteins and fats at their surfaces regardless of the fat content. The CLSM (Confocal Laser Scattering Microscopy) micrographs highlighted that most of the camel milk fat globules were encapsulated by the proteins near the powder surface. Camel milk fat behavior during particle formation was attributed to their lower size distribution and their higher crystallization temperature.

Analysis of triacylglycerols molecular species composition, total fatty acids, and sn-2 fatty acids positional distribution in different types of milk powders

Triacylglycerols (TAGs) are considered the main component of milk fat; possess significant functional roles from the technological, nutritional and physiological points of view. In this study, an ultra-performance liquid chromatography coupled with quadruple time-of-flight mass spectrometry was applied to identify the molecular species composition of TAGs in buffalo, camel, and ewe milk powders. The separation of TAGs was achieved by using two mobile phases; acetonitrile/isopropanol (1:9, v/v) as mobile phase A, and 40% acetonitrile as mobile phase B, the binary gradient elution allowed the separation of milk TAGs in consistent with the increase in partition number. More than 180 TAGs in buffalo milk, 90 TAGs in camel milk, and 129 TAGs in ewe milk were unambiguously identified, and the most abundant molecular species in the three types of milk powders were detected at mass to charge (m/z) values of 682.53, 822.67, and 656.53, respectively. The total acyl carbon numbers of buffalo milk TAGs ranged between 26 and 54, with double bonds from 0 to 6. While, the total acyl carbon numbers of camel milk TAGs ranged between 42 and 54, with double bonds from 0 to 3. The total acyl carbon numbers of ewe milk TAGs ranged between 26 and 52, with double bonds from 0 to 2. The major fatty acids (FAs) in the different types of milk powders were myristic, palmitic, stearic, oleic, and linoleic. The positional distribution of saturated FAs at the sn-2 position was higher in buffalo milk powder as compared to camel and ewe milk powders. This study reports a comprehensive identification of TAGs molecular species in different types of milk powders.

Changes in physicochemical properties of spray-dried camel milk powder over accelerated storage

Changes in physiochemical properties of spray-dried camel milk powders during storage at 11–32% RH and 37 °C over 18 weeks were investigated. The results showed that fresh camel milk powders had amorphous structure, clumsy spherical shape particles and almost 100% solubility in water. During storage at controlled low RH levels (<32% RH), reduction in moisture content and aw of the powders caused glass transition signals of lactose to evolve, although the powders exhibited a slight development of crystallinity. True density, colour (L*, a* and whiteness), and morphology were almost unchanged during storage while b* values associated with non-enzymatic browning, and fat oxidation into volatile compounds increased steadily. Over storage period, solubility of the powder declined just slightly and secondary structure of proteins unfolded from α-helices to β-sheets, loops and β-turns. These changes were more profound for the powders stored at 32% RH than those kept at 11 and 22% RH.

Influence of Inlet Drying Air Temperature and Milk Flow Rate on the Physical, Optical and Thermal Properties of Spray-Dried Camel Milk Powders

The influence of milk flow rate and inlet drying air temperature on the physical, optical and thermal properties of laboratory spray-dried camel milk powders is investigated. The physical, thermal and optical properties of laboratory spray-dried camel milk powders at three inlet drying air temperatures (110, 120 and 130 °C) and two milk flow rates (166 and 248 cm3/h) were evaluated. These properties are fundamental to understanding the quality, stability, final application and portability of the milk powders. Following this, the results were compared to commercial milk powder (CMM). Specifically, we evaluated the influence of the inlet drying air temperatures and feed rates on the reconstitution properties, particle properties, bulk, colour and thermal properties. Using response surface methodology (RSM), the findings indicated that the inlet drying air temperatures significantly influenced moisture content, and the L* a* b* colour properties (p < 0.0001) of the powders. However, the bulk and reconstitution properties were significantly influenced by the milk flow rate (p < 0.0001). The thermograms of all the milk powders had three endothermic peaks and two shifts. The onset of the glass transition increased in temperature with decreasing moisture content of the powders varying from 37.49 to 44.21 °C. Scanning electron microscopy (SEM) images of the laboratory spray dried powders were hollow and collapsed compared with the commercial samples which were spherical and rough with small cracks, dents and pores. The results demonstrated that both the inlet drying air temperature and the milk flow rate influenced the thermal, optical and physical properties of laboratory spray-dried powders.

Effect of outlet drying temperature and milk fat content on the physicochemical characteristics of spray-dried camel milk powder

A composite face-centered experimental design was used to investigate the influence of spray drying conditions on the physicochemical characteristics of camel and cow milk powders. Response surface methodology (RSM) was deployed to appraise the effects of these processing parameters (the outlet drying temperature and the milk fat content) on water activity (aw), glass transition temperature (Tg), bulk density, and free fat quantity. According to RSM analysis, it was noticed that the aw and the Tg were primarily influenced by the outlet drying temperature instead of by milk fat content. Our results highlighted the negative effects of milk fat content and of the outlet drying temperature on the bulk density as well as on the free fat quantity of camel milk powder. Likewise, our findings underlined the negative effect of the outlet drying temperature on the bulk density of cow milk powder. However, the increase of fat content has led to the overexposure of fat at the free surface of the cow milk powder. Our results suggested a marked similarity of the overall thermodynamic behavior of both milks, during drying. Nevertheless, some differences were highlighted regarding the structuring of the particles of camel milk powder.