IMAI Tetsuya Kyoudo Milk Co., Research Institute Researcher, 応用研究所, 研究員
ANDO Takeshi Kyoudo Milk Co., Research Instiute Senior researcher, 応用研究所, 主任研究員
AMETANI Mitiko Utsunomiya University, Applied Biochemistry Research associate, 農学部, 助手 (80240688)
|Budget Amount *help
¥2,800,000 (Direct Cost : ¥2,800,000)
Fiscal Year 1994 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1993 : ¥2,100,000 (Direct Cost : ¥2,100,000)
1.Milk fat globule membrane (MFGM) was prepared from bovine milk in the following procedure, 1) washed cream was churned and buttermilk was recovered, 2) membrane materials were concentrated by ultrafiltration through membrane and pasteurized by high temperature-short time method, 3) finally MFGM was freeze-dried.
2.Phospholipid and protein composition as a representative component of MFGM were measured by HPLC and SDS-PAGE,respectively. Phospholipid was composed of mainly phosphatidyl choline, phosphatidyl ethanolamine, and sphingomylin. Protein consisted of PAS-1, -4, -5, -6 and -7 and CB-1. These components were found in every MFGM preparations.
3.For keeping the quality of MFGM preparation, MFGM was pasteurized by high temperature-short time method. For examinating the degree of pasteurization, the activity of FAD-pyrophosphatase which is stable for high temperature-short time pasteurization and of alkaline phosphatase which is denatured by high temperature-short time pasteurization were assayd. Alkaline phosphatase in the MFGM preparation was inactivated, whereas most of FAD-pyrophosphatase activity was kept, suggesting these markers are useful.
4.Emulsifying ability of MFGM preparation was evaluated. Emulsion was prepared by homogenizing (2min) on Polytron homogenizer (19,000rpm) a mixture of 1% MFGM and 25% milk fat in phosphate buffer (pH7.0). It was found that emulsion made by MFGM preparation had a higher emulsifying activity and emulsion stability and the median diameter of fat globule was about 3-5 mum.
5.It was recommended that MFGM preparation might be evaluated from three points of composition of MFGM constituents such as phospholipid and membrane protein, pasteurization by high temperature-short time method in order to avoid the denaturation, and function of MFGM such as emusification.