Comparative study of fatty acid and sterol profiles for the investigation of potential milk fat adulteration.

Milk fat adulteration is a common issue in Central Asia. To assess the current situation in the commercial milk market, 17 milk samples were checked for fatty acid (FA) and sterol profiles to detect potential adulteration using multivariate analysis. Analysis of FA and sterols was performed using gas chromatography with flame ionization detection and gas chromatography with mass-spectrometric detection, respectively. Cluster analysis of FA profiles revealed 3 types of milk samples: (1) samples containing a higher proportion of short-chain FA, (2) samples containing a higher proportion of long-chain FA, and (3) samples with significant amounts of C18 FA. Analysis of sterols showed that samples included (1) milk fat containing 100% cholesterol, sometimes with traces of phytosterols, (2) milk fat with high proportions of ß-sitosterol and campesterol, and (3) milk fat containing high proportions of brassicasterol. We found significant relationships between FA profiles and sterol profiles. The profiles were compared with vegetable oil patterns reported in the literature. More than 50% of the samples appeared to be counterfeited. We conclude that identification of adulteration in milk can be based solely on determination of sterol patterns.

Comparative fatty acids composition and cholesterol content in Bactrian (Camelus bactrianus) and dromedary camel (Camelus dromedarius) meat.

The present study is aimed at comparing the fatty acid profiles, cholesterol, and atherogenicity index of Bactrian and dromedary camel meat by using discriminant analysis to identify the more discriminating fatty acids. Six muscles were sampled from nine Bactrian and nine dromedary camels and analyzed for fatty acid parameters and cholesterol content. The mean fatty acid profiles differed in higher proportion between species than between muscles. The main discriminating fatty acids between species (100% well-classed samples) were C15:0, C17:1, C14:1, C20:0, and C18:0. A significant difference was also observed in cholesterol content, with more cholesterol in Bactrian meat (53.6 ± 12.5 mg/100 g) compared to dromedary meat (49.4 ± 11.2 mg/100 g). However, the atherogenicity index was lower in Bactrian meat (1.196 ± 0.148) than in dromedary meat (1.379 ± 0.109). Despite the dietetic interest in camel meat due to its low cholesterol and low-fat content, the high atherogenicity index compared to other red meat appeared as an unfavorable argument.

Physiological change in camel milk composition (Camelus dromedarius) 2: physico-chemical composition of colostrum.

Eleven samples of dromedary camel colostrum in Kazakhstan, which originated from one farm only, were collected to study the changes in the physico-chemical composition (total fat, total protein, iodine index, lactose, calcium, phosphorus, iron, vitamin C, urea, ammonia, density, Dornic acidity, pH, and skimmed dry matter) all along the first postpartum week. At that time, the fat matter decreased from 25.9% to 3.1% and protein from 17.2% to 4.2%, in contrast to vitamin C which increased. Minerals showed high variations with lower values the first day after parturition and variable changes up to the end of the week where the values were stabilized. The iron concentration decreased from the second day postpartum. No clear changes of the other parameters were observed, notably for the non-protein nitrogen (urea and ammonia).

Lactoferrin and immunoglobulin contents in camel's milk (Camelus bactrianus, Camelus dromedarius, and Hybrids) from Kazakhstan.

Lactoferrin (Lf) and IgG were estimated in camel's milk from Kazakhstan, where 2 species of camels (Camelus bactrianus, Camelus dromedarius) and their hybrids cohabit. The concentrations of Lf and IgG were determined according to 3 variation factors: region (n = 4), season (n = 4), and species (n = 5; sample 4 was mixed milk and sample 5 was of unknown origin). The mean values in raw camel's milk were 0.229 +/- 0.135 mg/mL for Lf concentration and 0.718 +/- 0.330 mg/mL for IgG concentration. The seasonal effect was the only significant variation factor observed, with the highest values in the spring for Lf and in the winter for IgG. The Lf concentration varied in 1-wk postpartum milk from 1.422 to 0.586 mg/mL. The range in IgG concentration was wide and decreased from 132 to 4.75 mg/mL throughout the 7 d postpartum, with an important drop after parturition. In fermented milk, the lactoproteins are generally hydrolyzed. For milk samples from undefined species, discriminant analyses did not allow the origin of the species to be determined. A slight correlation between Lf and IgG concentrations was observed in raw milk. The values were slightly higher than those reported in cow's milk, but this difference was insufficient to attribute medicinal virtues to camel's milk.