论文信息 - OPTIMIZING CONDITIONS FOR HEAT PUMP DEHYDRATION OF LACTIC ACID BACTERIA

OPTIMIZING CONDITIONS FOR HEAT PUMP DEHYDRATION OF LACTIC ACID BACTERIA

ABSTRACT Heat pump dryers were studied as an alternative to freeze drying for dehydration of lactic acid bacteria for starter cultures. Factors investigated were bacterial growth phase, addition of dehydro-protectants, drying conditions, drying media and storage life of the dried bacteria. The main criterion for evaluation was the activity of the dried product. Results indicated that single dehydro-protectants were not able to give high activities, but suitable combinations were found giving results at least equal to freeze-drying. Nitrogen purging was found to give a significant improvement in activity.

[1] A. I. Liapis,et al. Research and Development Needs and Opportunities in Freeze Drying , 1996 .

[2] G. Orndorff,et al. The function of the suspending medium during the freeze-drying preservation of Escherichia coli. , 1973, Cryobiology.

[3] Shahab Sokhansanj,et al. Drying Characteristics of Wheat, Barley and Canola Subjected to Repetitive Wetting and Drying Cycles , 1984 .

[4] A. Rapoport,et al. Conservation of Yeasts by Dehydration , 1987, Biotechnology Methods.

[5] J. R. Pemberton. Critical factors of the vacuum-oven technique which influence the estimation of moisture in veterinary biologics. , 1976, Developments in biological standardization.

[6] M. Potts. Desiccation tolerance of prokaryotes , 1994, Microbiological reviews.

[7] F. Rombouts,et al. Modeling of the Bacterial Growth Curve , 1990, Applied and environmental microbiology.

[8] T. Labuza. Prediction of moisture protection requirements for foods , 1981 .

[9] W. Sandine,et al. Improved Medium for Lactic Streptococci and Their Bacteriophages , 1975, Applied microbiology.

[10] ing. Ingvald Str⊘mmen,et al. NEW APPLICATIONS OF HEAT PUMPS IN DRYING PROCESSES , 1994 .

[11] John F. Carpenter,et al. The basis for toxicity of certain cryoprotectants: A hypothesis , 1990 .