A Preliminary Assessment of HTST Processing on Donkey Milk

Abstract

Due to increasing attention from consumers on non-bovine milk types, and to the increase in the number of small dairy donkey farms in Italy, farmers require more advanced and reliable processing devices, in order to guarantee a safe product of high quality. To this aim, a new small-scale High-Temperature Short-Time (HTST) pasteurizer (72 • C for 15 s), prototyped by the authors, was tested on donkey milk. The efficacy of the HTST device was tested on raw donkey milk microflora by enumeration of total aerobic bacteria, Enterobacteriaceae and Bacillus cereus. The biochemical quality was assessed by determining the protein profile by monodimensional electrophoresis and by measuring lysozyme activity. The HTST apparatus was able to reduce the total bacteria count, and to completely eradicate Enterobacteriaceae. Bacillus cereus, when present, was decreased with low efficiency. Changes in the protein profile were observed in milk pasteurized in accordance with both processes, although HTST seemed to limit casein degradation. Lysozyme activity was not substantially affected in comparison to raw donkey milk. In conclusion, a tailored small-volume HTST device could be safely applied to pasteurize donkey milk in on-farm pasteurization processes on small dairy donkey farms.

Microbial Populations of Fresh and Cold Stored Donkey Milk by High-Throughput Sequencing Provide Indication for A Correct Management of This High-Value Product

“…Moreover, the authors solicited competent authorities to carry out more stringent official controls, with particular attention given to the level of primary production, as well as improving the traceability system in the donkey milk chain. This is in agreement with other recent studies, which revealed that the microbiological quality of raw donkey milk was not optimal, highlighting the importance of raw milk management, particularly with the need for animal hygiene management, and good dairy farming practices on donkey farms to improve handling procedures [4,54].…”

Potential Hazards Associated with Raw Donkey Milk Consumption: A Review

“…A total of 8 Bacillus cereus sensu strictu strains were analyzed for diarrhoic toxin, and 6 strains were enterotoxins producing [25]. In further donkey milk samples in Italy, B. cereus was isolated by other researchers [26].…”

Improving Pasteurization to Preserve the Biological Components of Donated Human Milk

“…The most evaluated method is high-temperature short-time (HTST) treatment, which involves the heating of milk at 72°C for 15 s. Several reports confirm that this procedure induces a drastic reduction in bacterial count and CMV infectivity. However, although a better preservation of several components like IgA and lactoferrin has been described, bile salt-stimulated lipase (BSSL) activity is almost completely eliminated ( 19 – 21 ). Two alternative prototypes suitable for use in an HMB have been recently described ( 22 , 23 ).…”