Properties of cream obtained from cow feeding with low level β-carotene feeds

Abstract

　The aim of this study was to clarify the effects of low level β-carotene feeding on properties of the cream obtained from the cow's milk. In the test farm where the breeding condition was controlled, lactating cows (Holstein) were fed with two types of feed with low level β-carotene contents for two weeks (Farm trial). Estimated β-carotene contents per Dry matter (DM) in feed were 12.8, 10.0 and 9.8 mg/kg-DM, respectively. The cream was prepared from each milk with the conventional method and their β-carotene contents, color, and flavor were evaluated. Then we collected milk from two farms in Hokkaido and prepared cream (Field trial). Estimated β-carotene contents in their feed were 13.4 and 10.6 mg/kg-DM. The relation between β-carotene contents and color or flavor of the prepared cream was examined, and liquid cream stability of each cream was also evaluated. In both trial, low level β-carotene feeding reduced the β-carotene contents and b* value in L*a*b* color system as an indicator of whiteness of the cream. The result of a sensory analysis showed the cream with lower b* value was whiter. The cream obtained from cows with low level β-carotene feeding had more fresh flavor. The freshness was possibly due to an increase in hexanal and decrease in hexanoic acid as flavor compounds. In field trial, the cream obtained from low level β-carotene feeding had higher liquid cream stability than another.