A Preliminary Assessment of HTST Processing on Donkey Milk.

Marzia Giribaldi,Sara Antoniazzi,Gian Gariglio,Alessandra Coscia,Laura Cavallarin,Enrico Bertino

doi:10.3390/vetsci4040050

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.

Highlights

In recent years, attention towards donkey milk production and commercialization has been rising, mainly driven by its claimed difference in chemical and biochemical composition with respect to bovine milk, making it potentially suitable for consumption by specific consumers
Donkey milk was traditionally used in the past for its antibacterial and cosmetic properties [1,2], and its use as a bovine milk substitute has only been reported in the scientific literature recently
From the remaining milk pool, four 250-mL aliquots were subjected to the tested pasteurization processes: two (HoDM—holder donkey milk) underwent holder pasteurization (63 ◦ C for 30 min) in sterile

Summary

Introduction

Attention towards donkey milk production and commercialization has been rising, mainly driven by its claimed difference in chemical and biochemical composition with respect to bovine milk, making it potentially suitable for consumption by specific consumers. Donkey milk was traditionally used in the past for its antibacterial and cosmetic properties [1,2], and its use as a bovine milk substitute has only been reported in the scientific literature recently. It’s only since the beginning of the century that the number of studies focusing on the protein fraction of donkey milk, and on its suitability for feeding children suffering from allergy to cow’s milk proteins (CMPA), has increased [3,4,5,6]. A review paper on donkey milk was published, focusing on its past and future technological applications [12].

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Conclusion