Variation of vitamin C content in camel milk from Kazakhstan

Camel milk is well known for its richness in vitamin C but the variability of the vitamin C content is rarely studied. In a survey, achieved in Kazakhstan, 42 milk samples from Bactrian (double-humped camel), 73 from dromedary, 19 from hybrids, 22 from mixed farms and 24 undetermined species were collected for vitamin C determination. The samples were collected in four regions of the country and at four season of the year. In the whole sample, the mean value was 150.4+ 105 mg/L with a range of 15 to 435 mg/L, i.e. variability from 1 to 29. The vitamin C in camel milk varied significantly according to the place of sampling: the content was higher in Atyrau (175 ± 118 mg/L) in the western part of the country, compared to Almaty (161 ± 96 mg/L) and Shymkent (157 * 109 mg/L) and quite lower at Aralsk (80 + 61 mg/L). Milk from Bactrian was richer (169 ± 110 mg/L) than dromedary milk (146 ± 93 mg/L) or hybrid (133 + 129 mg/L). Within region, the variability could be higher: for example, in Almaty region, 201 mg/L on average in Bactrian vs 149 mg/L in dromedary. The seasonal variation was similar for all the species. In winter, dromedary milk was richer than Bactrian milk reverse to other seasons. The values for hybrid milk were intermediate between dromedary and Bactrian all over the year. As the whole, the summer milk was richer (227 + 110 mg/L) than in autumn (180 + 62 mg/L) and winter (157 + 58 mg/L). The spring milk contained lower vitamin C concentration (75 + 59 mg/L). All over the lactation period, vitamin C concentration in dromedary camel varied from 48 to 256 mg/L (mean = 184) and tended to increase all along the lactation period with an abrupt rise between week 5 and 7. A slight decrease was observed at week 14 (lactation peak) and the maximum was observed at week 31, i.e., according to calving season, in summer time. The colostrum contained less vitamin C than milk. (Texte intégral)