The use of donkey milk for human consumption has been recently revalued as an alternative dietary ingredient for sensitive consumers, for example infants with cow milk protein allergy, adults with inflammatory and allergic ailments, or aged healthy persons. In depth information on nitrogen and fat components and on major minerals are now available in literature but less attention has been devoted to minor trace elements in donkey milk. The aim of this trial was to study the concentration of Li, B, Ti, Cr, Rb, Sr and Cs in donkey milk and their distribution among fat, casein, whey proteins and aqueous phase. Mechanical milking was used to provide individual milk samples from 16 lactating donkeys (6 Amiata and 10 Ragusana breed). Subsequent centrifugation, ultracentrifugation, and ultrafiltration (cut-off 3kDa) were carried out to remove fat, casein and whey proteins, to obtain skimmed milk, a supernatant whey fraction and the aqueous phase of milk, respectively. An inductively coupled plasma-mass spectrometer was used to measure the concentration of the aforementioned elements in whole milk and fractions, and the concentration of elements associated with fat, casein and whey proteins was then calculated. The effect of removal of fat, casein, and whey proteins was determined by analysis of variance for repeated measures. The milk concentration of Li, B, Ti, Cr, Rb, Sr and Cs was 5.88 l, 209.3, 79.7, 2.17, 1,434, 370.4 and 2.50 μg/l, respectively. Li and B were entirely present in the aqueous phase of donkey milk, together with the large majority of Cs (96.3%) and Rb (87.2%). The effect of fat removal was significant for Ti, Cr, and Sr, of which the fat fraction carried 7.3, 10.4 and 4.5% of total milk concentration. Half of milk Ti (50.0%) and the majority of Sr (69.8%) were associated with the casein fraction, as well as 20.2% of Cr and 7.9% of Rb. A significant but low amount of milk Rb (4.0%), Sr (3.04%) and Cs (3.9%) was associated with the whey proteins fraction.
Distribution of minor trace elements in different fractions of donkey milk
F. FantuzPrimo
;S. FerraroSecondo
;L. Todini;R. Spurio;F. Marcantoni;
2021-01-01
Abstract
The use of donkey milk for human consumption has been recently revalued as an alternative dietary ingredient for sensitive consumers, for example infants with cow milk protein allergy, adults with inflammatory and allergic ailments, or aged healthy persons. In depth information on nitrogen and fat components and on major minerals are now available in literature but less attention has been devoted to minor trace elements in donkey milk. The aim of this trial was to study the concentration of Li, B, Ti, Cr, Rb, Sr and Cs in donkey milk and their distribution among fat, casein, whey proteins and aqueous phase. Mechanical milking was used to provide individual milk samples from 16 lactating donkeys (6 Amiata and 10 Ragusana breed). Subsequent centrifugation, ultracentrifugation, and ultrafiltration (cut-off 3kDa) were carried out to remove fat, casein and whey proteins, to obtain skimmed milk, a supernatant whey fraction and the aqueous phase of milk, respectively. An inductively coupled plasma-mass spectrometer was used to measure the concentration of the aforementioned elements in whole milk and fractions, and the concentration of elements associated with fat, casein and whey proteins was then calculated. The effect of removal of fat, casein, and whey proteins was determined by analysis of variance for repeated measures. The milk concentration of Li, B, Ti, Cr, Rb, Sr and Cs was 5.88 l, 209.3, 79.7, 2.17, 1,434, 370.4 and 2.50 μg/l, respectively. Li and B were entirely present in the aqueous phase of donkey milk, together with the large majority of Cs (96.3%) and Rb (87.2%). The effect of fat removal was significant for Ti, Cr, and Sr, of which the fat fraction carried 7.3, 10.4 and 4.5% of total milk concentration. Half of milk Ti (50.0%) and the majority of Sr (69.8%) were associated with the casein fraction, as well as 20.2% of Cr and 7.9% of Rb. A significant but low amount of milk Rb (4.0%), Sr (3.04%) and Cs (3.9%) was associated with the whey proteins fraction.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
