Physicochemical, Microbiological and Technological Properties of Red Deer (Cervus elaphus) Milk during Lactation

Abstract

This study describes chemical, physical, microbiological and technological characteristics of red deer milk and the effect of lactation on these parameters in order to know their potential aptitude to elaborate dairy products. During 18 weeks, milk from five hinds was monitored for composition, bacteriology, somatic cell count (SCC), physical properties and rennet coagulation. Mean values (g/100 g) for fat, protein, lactose and dry matter were 10.4, 7.1, 4.3 and 24.2, respectively, and for urea, 265 mg/100 mL. Except for lactose, a significant increase in these components was observed (p < 0.01) as lactation progressed. The average values for bacteriology and SCC were 5.3 log cfu/mL and 4.7 log cells/mL, respectively. Regarding physical properties, conductivity (mean: 2.8 ms/cm), viscosity (3.1 Cp), coordinates L* (89.9) and a* (−3.1) and milk fat globule diameter (D4,3: 6.1 µm) increased along with lactation while density (1.038 g/mL) decreased (p < 0.01). The pH (6.7), acidity (22.9° Dornic), coordinate b* (8.4) and ethanol stability (66.6% v/v) were stable during the study period. The stage of lactation also has a significant impact on milk coagulation properties and mean curd yield was 3.29 g/10 mL. These results suggest that red deer milk could be a potential innovative source of milk for the dairy industry.

Characteristics of Red Deer (Cervus elaphus) Milk: Lactational Changes in Composition and Processing Impacts on Structural and Gelation Properties

“…The proximate compositions of the deer milk and their lactational trends were mostly consistent with those reported previously [ 1 , 2 , 5 , 6 , 8 ], although the lactose content of the deer milk in the present study was at the higher end of the reported range. Increases in protein and fat contents and decreases in lactose content towards the end of lactation have also been reported for the milks of other ruminants (cow, sheep, and goat) [ 14 , 19 , 23 , 24 ].…”

“…Red deer ( Cervus elaphus ) are domesticated primarily for meat, velvet, leather, and hunting purposes [ 1 , 2 ]. New Zealand is one of the leading countries in deer farming.…”

“…New Zealand is one of the leading countries in deer farming. In addition to the main exports of venison and velvet, the New Zealand deer industry has been exploring red deer milk for its value as a novel ingredient in food, nutritional, and cosmetic products [ 1 , 2 ]. Unlike other common dairy ruminant species such as cattle, goats, and sheep, which belong to the family Bovidae, deer belong to the family Cervidae.…”

“…Possibly arising from this genetic difference, red deer milk has some unique characteristics, such as being naturally nutrient dense with markedly higher contents of protein, fat, and calcium compared with other ruminants’ milk [ 3 ]. Moreover, the lactation cycle of red deer is shorter than those of other common ruminant species and typically lasts for 16–20 weeks [ 2 , 4 , 5 ]. Great potential lies in utilizing the unique characteristics of red deer milk in novel products, and a better understanding of its production, natural variation, and functionalities will lay the foundation for future applications.…”

“…To date, research on deer milk has focused mainly on its compositional features [ 1 , 5 , 6 , 7 , 8 ]. A few studies have investigated some of the physicochemical properties such as ethanol stability [ 9 ], gelation properties [ 2 , 10 ], and protein characteristics [ 11 , 12 ] of deer milk. It is well known that the compositional and physicochemical properties of milk vary over the lactation cycle; these properties could not only determine the nutritional quality of the milk, but also influence its techno-functional properties [ 13 , 14 , 15 ].…”