• Food Science of Animal Resources
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• v.30 no.1
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• pp.28-35
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• 2010

This study was designed to compare the physicochemical and nutritional properties between reconstituted milk samples made from freeze-dried milk powder (FDMP) and spray-dried milk powder (SDMP). Reconstituted milk (87%, wb) was made by combining FDMP or SDMP with water. In the color analysis, the $L^*$, $a^*$ and $b^*$ values of the reconstituted milk samples made from both powders were not significantly different from the control. The thiobarbituric acid values and short-chain free fatty acid concentrations were considerably greater in the reconstituted milk made from SDMP than in the milk made from FDMP. The quantities of water-soluble and fat-soluble vitamins in the reconstituted milk samples made from SDMP were significantly lower than those made from FDMP. Based on the findings obtained in the present study, the reconstituted milk made from FDMP appeared to be more resistant to lipid oxidation and exhibited little changes in the nutrients levels when compared with reconstituted milk made from SDMP.

• Korean Journal of Food Science and Technology
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• v.16 no.3
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• pp.279-284
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• 1984

Microstructure of milk powder and cheese made from milk powder were observed by electron microscope. Freeze dried milk powder showed apple-like appearance. The cheese made from freeze dried milk powder had relatively flat surface and homogenous deposit in compare with classical processed cheese. Imported milk powder also indicated similar surface as well as freeze dried milk powder, however, the cheese made from imported milk powder had somewhat coarse surface structures with the spaces between casein matrix and deposit. Commericial milk powder showed irregular shape in size and coagulum which were possibly denatured in the course of drying. The cheese made from commercial powder indicted irregular and small deposit and porous structure. The porousity of the cheese seemed to be influenced by the degree of heat treatment. Denatured protein would be less dispersive than native in presence of polyphosphates. Fat globule and protein micelle of cheese made from skim milk powder get very adjacent to each other and showed compactness of micelles. It is thought that melting mechanism of skim milk powder was different from the melting of typical processed cheese.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.416-423
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• 1993

Milk powders were made by several drying methods and raw materials, and rheological properties of milk powders were investigated by an Instron Universial Testing Machine. The results obtained are summarised as follows. Bulk density of the drum dried whole milk powder was $0.382\;g/cm^3$ and was higher than that of other milk powders. The Hausner ratio, angle of repose and compressibility of the spray dried skim milk powder were 1.127, $32.5^{\circ}$ and 0.029 respectively. This result indicated that skim milk powder showed free flowing characterristics. The compressibility of the drum dried whole milk powder was decreased by the decrease of moisture content. Compressibility of the milk granule was 0.056 and was lower than that of milk powder. The spray dried milk powder of a grobular shape had higher solidity than the freeze or drum dried milk powder. The drum dried milk powder particles consist of irregular shape.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.881-888
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• 2000

Lactic acid bacteria(LAB) fermented food was prepared with milk or egg white powder(EWP) and added with freeze drying protectant(FDP). 0.2% of Tween 80 or 1% of ascorbate was added to milk sample and 3% of raffinose or 1% of ascorbate was added to EWP sample. Effects of FDP on sensory property, volatile aroma compounds and physical property of LAB fermented food were investigated. In case of non-freeze dried samples, sensory properties of milk sample with ascorbate were slightly better than those of reference sample(milk), while sensory properties of EWP sample or EWP sample with FDP were slightly inferior to reference sample. Sensory properties of all of the freeze dried/reconstituted samples were not different. Sensory properties of milk sample with ascorbate were reduced by freeze drying/reconstitution, while those of sample with ascorbate were not changed. Although all of the volatile aroma compounds were reduced by freeze drying, the residual ratio was slightly different between milk samples and EWP samples. Difference in volatile aroma compounds between milk samples and EWP samples before freeze drying was relatively large, while difference between two sample groups after freeze drying/reconstitution was relatively small. Rheological properties of milk samples were markedly changed by freeze drying/reconstitution, while those of EWP samples were changed slightly.

• Journal of Applied Biological Chemistry
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• v.55 no.2
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• pp.123-127
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• 2012

In order to develop eco-friendly biopesticide, an entomopathogenic bacterium Photorhabdus temperata M1021 has been lyophilized via freeze-drying along with protective agents such as skim milk, starch, sodium alginate, glucose and sodium glutamate to protect cells from lysis. Freeze-drying powder of P. temperata M1021 containing 7% skim milk (w/v) showed highest survival rate of 63% among all the protective agents used in trials. Furthermore, the freeze-dried microbial powder showed 75% of survival rate after stored at $4^{\circ}C$ for 4 weeks at air contact conditions. Injection toxicity of the freeze-dried sample was tested against larvae of Galleria mellonella. A dose of $2.0{\times}10^1$ cells of P. temperata M1021 killed 100% of the G. mellonella larvae within 4 days after injection. Moreover, $2.0{\times}10^0$ cells caused 50% mortality within the 4 days after injection. Freeze-dried P. temperata M1021 strains exhibited effective insecticidal activity and could be a better candidate for being used as a biopesticide.

• Journal of the Korean Society of Food Culture
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• v.30 no.1
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• pp.86-96
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• 2015

Onions contain antioxidant flavonoids and bioactive sulfur compounds. These substances are more abundant in the peel than in onion flesh. For this reason, whole onions including peels were added to soy milk to produce soy milk with whole onions (SWO), whereas peeled onions were added to soy milk to produce soy milk with peeled onions (SPO). The functional and antioxidant properties of these two kinds of soy milk were then analyzed and compared. Compared to control soy milk (CS) without onion powder, treated samples (to which freeze dried onion powder was added at 1.4, 1.6, 1.8, and 2.0%, respectively) showed significantly increased amounts of quercetin, isoflavone, and total phenol (p=0.05). The magnitude of the increase rose as the amount of added onion powder increased and when onion powder contained onion peels. With regards to antioxidant activity (DPPH and ABTS), SWO showed a greater value than SPO. The sensory evaluation scores of SWO and SPO were lower than CS for roughness and swallowing, as adding onion powder increased solid contents and viscosities. However, higher overall acceptability were obtained 1.8SPO and 1.8SWO.

• Journal of Dairy Science and Biotechnology
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• v.37 no.3
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• pp.206-212
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• 2019

This study was conducted to investigate the effect of cryoprotectants on the storage stability of Lactobacillus fermentum SK152, which was isolated as a probiotic candidate. Solutions of 10% glucose, trehalose, dextrin, and skim milk powder were used as cryoprotectants. The survival rates of L. fermentum SK152 after freeze-drying were 5.6% (dextrin), 2.2% (skim milk powder), 1.7% (glucose), and 1.5% (trehalose), suggesting that dextrin was most effective at minimizing the cell death of L. fermentum SK152 by lyophilization. The survival rates of L. fermentum SK152 stored at 4℃ ranged from 37% (dextrin)-90% (skim milk powder) after 8 weeks, while those at 20℃ ranged from 4% (dextrin)-12% (skim milk powder) after 7 weeks, indicating that skim milk powder was the best at minimizing the cell death of L. fermentum SK152 during storage, irrespective of storage temperature, among the cryoprotectants used.

• Microbiology and Biotechnology Letters
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• v.43 no.4
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• pp.385-390
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• 2015

In order to develop an eco-friendly biofertilizer, a plant growth promoting rhizobacterium (PGPR), Bacillus sp., SH1RP8 was investigated. SH1RP8 was lyophilized via freeze-drying along with other protective agents that protect cells from lysis. The freezedried powder of Bacillus sp. SH1RP8, containing 5% skim milk (w/v), exhibited the highest survival rate of 30.6% among all the protective agents (skim milk, glucose, and peptone). The lyoprotective effect of the skim milk, mixture including 5% skim milk, and substrates on the survival of the test strain was examined. Control group was added only skim milk and test groups were added skim milk and other substrates. As a result, the group supplemented with both glycerol and 5% skim milk showed the protective effect much higher by 214.29% than the control group. Freeze-dried Bacillus sp. SH1RP8 could be a good candidate as a potential biofertilizer due to its effective PGPR activity.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1349-1356
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• 1999

Freeze dried products of lactic acid bacteria fermented food prepared from milk or egg white powder(EWP) were stored at $28^{\circ}C.\;5^{\circ}C$ and $-18^{\circ}C$ for 20 weeks. Properties of stored, freeze dried product and viable cell count. pH and organoleptic properties of stored, reconstituted product were investigated. (1) The viable cell count of reconstituted milk or EWP product stored at $5^{\circ}C\;or\;-18^{\circ}C$ was not changed markedly. However, the viable cell count of milk or EWP product stored at $28^{\circ}C$ was reduced during storage and it was changed substantially between 4 weeks and 5 weeks. However, pH of all samples stored at three different temperature was not changed. (2) Color of freeze dried product prepared from EWP became clearly brown at 16 weeks. (3) Appearance of reconstituted milk product stored at $5^{\circ}C\;or\;-18^{\circ}C$ for 20 weeks was not changed. However, homogeneity and solubility of reconstituted milk product stored at $28^{\circ}C$ for 20 weeks were reduced. Taste, odor and texture of reconstituted milk product stored at $28^{\circ}C$ for 20 weeks were markedly changed. (4) Viscosity of reconstituted EWP product stored for 20 weeks was slightly reduced. Solubility of reconstituted EWP product stored at $28^{\circ}C$ for 20 weeks was reduced and its taste and odor were markedly changed. Texture of reconstituted EWP product stored at $28^{\circ}C$ became rough.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.655-659
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• 2014

Food-grade protective agents, namely, skim milk, yeast extract, soy powder, and trehalose, were studied for their ability to improve the viability of freeze-dried lactic acid bacteria (LAB), including Weissella cibaria SW1-1, Lactobacillus plantarum A-1, Lactobacillus sakei 2-12 24, and Leuconostoc citreum 3526. The best results were obtained with 10% soy powder; approximately 90% cell viability was observed during the freeze-drying process. Increase in the concentration of soy powder did not cause a proportional increase in the survival rate of LAB. Further, no significant difference was observed when two agents were combined in a 1:1 ratio (p<0.05).