A microbiological, biochemical and sensory characterisation of bovine milk treated by heat and ultraviolet (UV) light for manufacturing Cheddar cheese.

Cilliers, F.P., Gouws, P.A., Koutchma, T., Engelbrecht, Y., Adriaanse, C., and Swart, P. (2014). "A microbiological, biochemical and sensory characterisation of bovine milk treated by heat and ultraviolet (UV) light for manufacturing Cheddar cheese.", Innovative Food Science and Emerging Technologies, 23, pp. 94-106. doi : 10.1016/j.ifset.2014.03.005  Access to full text

Abstract

The aim of the study was to quantify microbiological, biochemical and sensory changes in full cream raw milk (RM) processed with high temperature short time (HTST) pasteurisation (P), ultraviolet light treatment (UV) and a combination of UV light treatment and HTST pasteurisation (UVP) in commercial scale production of Cheddar cheese. The three treatments have been compared at a similar level of microbial efficacy. No significant differences were reported on the macro-nutrient composition, however a 35% and 18% reduction in cholesterol in the UV and UVP treatments were observed. HTST treatment (UVP and P) reduced riboflavin and Vitamin B12 in milk by ~ 31% and ~ 18% respectively, with no reduction in riboflavin and Vitamin B12 observed after the UV treatment alone. Lipid oxidation and lipolysis results indicated a significant difference between raw and UVP treated milk (p < 0.05). Protein oxidation results indicated no significant differences except for methionine sulfone, which increased by 67.24% and 87.93% respectively for UV and UVP treatments. Some differences were noted with sensory results, most noticeably on the ‘tallowy’ flavour descriptor for the UV treated milk, however customer acceptance of UV treated milk will ultimately determine the acceptability of UV technology as an alternative or adjunct to commercial thermal treatment of milk in cheese production.

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