Chemical Composition and Nutritional Quality of Camel Milk

Sawaya, W. N.; Khalil, Jehangir K.; Al-Shalhat, A.; Al-Mohammad, H. M.

doi:10.1111/j.1365-2621.1984.tb13200.x

Cited by 121 publications

(117 citation statements)

References 11 publications

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“…A distance equal to 84.5 Å should be attributed to crystalline forms with a four-chain length stacking (4L). Indeed, considering the fatty acid composition of the ADMF whose longest chain is C20:0 [1,7,8,24,26] and calculating the total chain length of a TG trisaturated in C20:0 in a 3L stacking, then one would have a value of about 76.2 Å. This value is by far lower than 84.5 Å, bringing us to conclude that the 84.5 Å period corresponds to a 4 L variety and not 3L.…”

Section: Crystalline Structures Formed Upon Cooling At 5 °C·min -1mentioning

confidence: 83%

“…Although data on the general composition of camel's milk is reported by several sources [3,11,12,26], data on the chemical and physical properties of anhydrous Dromedary milk fat polymorphism 435 dromedary milk fat (ADMF), which is the fat isolated from butter, are still scarce. ADMF is an essential nutriment in desert areas with a complex fatty acid composition [2,5,8], which has already been discussed in the first article of this series [9].…”

Section: Introductionmentioning

confidence: 99%

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Dromedary milk fat: thermal and structural properties 2. Influence of cooling rate

Karray¹,

Lopez

Lesieur

et al. 2005

Lait

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-The crystallization behavior of anhydrous dromedary milk fat (ADMF) was examined using Microcalix (Centre National de la Recherche Scientifique, Châtenay-Malabry, France), an instrument coupling time-resolved synchrotron X-ray diffraction as a function of temperature (XRDT) at both small and wide angles and high-sensitivity differential scanning calorimetry (DSC) at an intermediate (1 °C·min -1 ) and at a fast (5 °C·min -1 ) cooling rate from 60 to -20 °C, together with their subsequent melting at 1 °C·min -1 . Upon cooling at 1 °C·min -1 , the crystallization of ADMF started at about 24 °C with the formation of a lamellar structure with a 46.9 Å period corresponding to a double-chain length molecular stacking and hexagonal chain packing (2L 1 α). From 20 °C, a major crystalline species also with double-chain lengths of 42.5 Å and orthorhombic chain packing (2L 2 β') was observed. The successive crystallizations of varieties 2L 1 and 2L 2 were correlated with the apparition of two large exothermal events recorded simultaneously by thermal analysis (DSC). However, comparison of XRDT and DSC recordings revealed the presence of a third exothermal peak probably related to a transition α → β'. At fast cooling (5 °C·min -1 ) of ADMF, three crystalline varieties were formed: the 2L 1 α (47.6 Å), 2L 2 β' (42.15 Å) and a new crystalline structure with 4 chain lengths: 4L β' of period 84.5 Å, while three endotherms were recorded by DSC. This last crystalline form which had never been characterized until now, likely corresponds to the accumulation of defects in the stable 2L β' form (42.15 Å) resulting from fast cooling and then to a local lack of symmetry in the 4L cell along the c axis of the crystals. This lack of symmetry was released during a transition 4L → 2L observed upon heating. A polymorphic transition α →β' was always observed upon ADMF heating following cooling at either 5 or 1 ° C·min -1 . Compared with the slow cooling at 0.1 °C·min -1 which was studied in the previous paper of this series, ADMF presented different structural and thermal properties. Indeed, the cooling at 1 °C·min -1 and 5 °C·min -1 generated an unstable crystalline form (α) that was not found at slow cooling at 0.1 °C·min -1 . However, the major stable form 2L β' was always observed in the three types of cooling.polymorphism / X-ray diffraction / differential scanning calorimetry / camel's milk * Corresponding author ( ): michel.ollivon@cep.u-psud.frArticle published by EDP Sciences and available at http://www.edpsciences.org/lait or http://dx

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Section: Crystalline Structures Formed Upon Cooling At 5 °C·min -1mentioning

confidence: 83%

Section: Introductionmentioning

confidence: 99%

Dromedary milk fat: thermal and structural properties 2. Influence of cooling rate

Karray¹,

Lopez

Lesieur

et al. 2005

Lait

View full text Add to dashboard Cite

show abstract

“…FA composition of camel milk fat varies as a function of the countries where camels live [1,6,30,33]. FA composition is influenced by environmental and physiological factors such as diet, stage of lactation and genetic differences within the species [6] (Tab.…”

Section: Introductionmentioning

confidence: 99%

“…In camel milk, fat, that represents about 3.6% of the composition [33], is dispersed in the form of globules, enveloped in a membrane [3], derived from the secreting cell and constituted by phospholipid-protein complexes. Milk fat is mainly composed by triacylglycerols (TG) with a broad variety of FA composition.…”

Section: Introductionmentioning

confidence: 99%

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Dromedary milk fat: thermal and structural properties 1. Crystalline forms obtained by slow cooling

Karray¹,

Lopez²,

Lesieur

et al. 2004

Lait

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-The thermal and structural behavior of anhydrous dromedary milk fat (ADMF) was studied by a technique that allowed simultaneous time-resolved synchrotron X-ray diffraction as a function of temperature (XRDT) and high sensitivity differential scanning calorimetry (DSC). As the camel probably represents the mammalian species best adapted to the hottest temperatures on earth as well as to harsh climatic conditions, the fatty acid composition of ADMF and its thermal properties are of special interest. In this paper, the first of a series, the crystalline organizations made by the triacylglycerols (TG) of ADMF during a slow cooling rate at |dT/dt| = 0.1 °C·min -1 are addressed. The crystalline form obtained from about 29.5 °C corresponds to a lamellar structure with a double-chain length longitudinal organization of the TG molecules (2L = 42.3 Å) associated with a β' lateral packing of the chains. The crystallization range which spreads over about 75-80°C, is similar to that observed for bovine milk fat, although the final melting temperature is higher by about 5-8 °C. DSC scans revealed the existence of up to 6 exotherms on slow cooling. A similar complex behavior was also observed on heating. PEAKFIT analysis of the XRDT individual patterns and their evolutions observed at small angles also showed the existence of additional molecular packings. However, XRDT analysis was unable to resolve individual structures. A possible epitaxy phenomenon during crystallization is discussed. Polymorphism / X-ray diffraction / differential scanning calorimetry / solid fat content / epitaxyRésumé -Propriétés thermiques et structurales de la matière grasse de lait de dromadaire. 1. Formes cristallines obtenues lors d'un refroidissement lent. Les propriétés thermiques et structurales de la matière grasse anhydre extraite du lait de dromadaire (ADMF) ont été étudiées par une nouvelle technique qui permet des mesures simultanées, sur un même échantillon, des signaux de microcalorimétrie différentielle à balayage (DSC) et de diffraction des rayons X en fonction du temps et de la température. L'étude des propriétés thermiques de la matière grasse du lait de chamelle, en relation avec sa composition, revêt un intérêt particulier si l'on considère les conditions

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North African Brined Cheeses

El-Salam¹,

Benkerroum²

2006

Brined Cheeses

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Chemical Composition and Nutritional Quality of Camel Milk

Cited by 121 publications

References 11 publications

Dromedary milk fat: thermal and structural properties 2. Influence of cooling rate

Dromedary milk fat: thermal and structural properties 2. Influence of cooling rate

Dromedary milk fat: thermal and structural properties 1. Crystalline forms obtained by slow cooling

North African Brined Cheeses

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