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

• Food Science of Animal Resources
• /
• v.32 no.5
• /
• pp.540-544
• /
• 2012

During heat treatment and storage of milk, deteriorative reaction takes place, which consequently influence on the milk quality. In this study, formation of lactulose and furosine under different thermal conditions and storage conditions, and the ratio of lactulose and furosine (LU/FU) in presence of reconstituted milk powder were determined to establish chemical indicators for heat damages of milk and the adulteration of fresh milk in dairy field. The lactulose and furosine contents linearly increased with increased heating temperature and heating time. It showed high correlation between the formation of lactulose and furosine, and the treatment temperature and time (p<0.05). The lactulose and furosine concentration of HTST milk and UHT milk noticeably increased during storage at $30^{\circ}C$, but there was no noticeable increase of lactulose and furosine concentration at lower storage temperature. In the raw milk, the lactulose and furosine contents greatly increased with the addition of reconstituted milk. The increase level of furosine was much higher than that of lactulose, which consequently resulted in the lower LU/FU ratio in milk as increase of added reconstituted milk amounts. As comparing with raw milk, there was more than twice reduction in LU/FU ratios after the addition of reconstituted milk (p<0.05). It can be concluded that lactulose and furosine are suitable milk quality indicators of heat damage and for demonstrating improper addition of reconstituted milk powder.

• Journal of Food Hygiene and Safety
• /
• v.5 no.1
• /
• pp.35-40
• /
• 1990

As a link in the studies on the extracellular polysaccharide by lactic acid bacteria, the experiment was conducted to investigate the viscosity variations and rheological properties of 10% reconstituted skim milk and 12% reconstituted whole milk, respectively. 1. 10% reconstituted skim milk cultured by Str. thrennophilus 510 showed strong flow property of pseudoplastic fluid depending upon the production of exopolysaccharide. And the viscosity reached the highest value within 14% concentration. 2. 12% reconstituted whole milk cultured by lactic acid bacteria indicated flow property of pseudoplastic fluid. But there was a big difference in the viscosity as compared with 10% skim milk. 3. The maximum consistency index (k) and the minimum flow behavior index (n) of the fermented milk by Str. thermophilus 510 were 43 and 0.09, respectively. They were 35 and 0.09, in case of Lb. bulgaricus.

• Journal of Dairy Science and Biotechnology
• /
• v.19 no.1
• /
• pp.13-21
• /
• 2001

Milk can be regarded as a complete food, containing protein, fat, lactose, vitamins and minerals. Milk is heated for a variety of reasons. The main reasons are: to remove pathogenic organisms; to increase shelf-life. But, when milk is heated, many changes take place: denaturation of whey proteins and interaction with casein, Maillard browning, losses of vitamin and minerals. The addition of a additive and milk powder to flavor and taste may cause undesirable change of quality during heating milk. The reconstituted milk is the milk product resulting from the addition of water to the dried or condensed form in the amount necessary to re-establish the specified water solids ratio. Therefore, according to the increasement of consumption of processed milk, the necessity for study about the quality of processed milk mixed with reconstituted milk arose.

• Food Science of Animal Resources
• /
• v.22 no.1
• /
• pp.50-54
• /
• 2002

The aim of this work to determine the formation of lactulose during heat treatment process as a contribution to the estabilishment of limits of chemical indicators for different types of heat processed milk and analyze of lactulose for the reconstituted milk added samples. The HTST(75$\^{C}$/15s) and UHT(130$\^{C}$/2∼3s) treatment realized with a pilot plant and heat-treated samples were stroed at 4, 10, 30$\^{C}$ for 4 weeks. Changes in lactulose was evaluated at 7 days intervals. The other heat treatment was sealed in glass tube and heated at 75$\^{C}$ for 10 to 120s and heated at 130$\^{C}$ for 2 to 60s in a thermostatically controlled constant temperature bath of glycerol. The reconstituted milk was made with full fat dry milk that reconstituted with deionized water to 10% total solid, and was added to milk at 10, 20, 30% respectively. The samples processed with a HTST pilot plant showed that lactulose was contained at 1.47∼1.52mg/10()ml and 8.19 ∼8.32mg/100ml for UHT-treated samples. Changes in the lactulose content of heat-treated samples during storage at 4 and 10$\^{C}$ for 4 weeks caused a slight increase, however a noticeable increase was observed at 30$\^{C}$ for 4 week. The glass tube samples showed that high correlations between relative increase in content of lactulose and increasing processing times(75$\^{C}$ : r = 0.986, 130$\^{C}$ : r = 0.987, respectively). Added with reconstituted milk would cause a increase of the lactulose content linear with increasing addition amount(r = 0.982). This results observed for lactulose in commercial milk samples would applied to the detection of chemical changes during heat treatment and illegal use of reconstituted milk.

• Korean Journal of Food Science and Technology
• /
• v.30 no.6
• /
• pp.1448-1455
• /
• 1998

Fermented milk was prepared from milk or mixture of milk and apple juice/grape juice, and it was freeze dried. pH change and growth of Lactobacillus acidophilus (KCTC 2182) during freeze drying were studied. The effects of freeze drying on sensory evaluation and volatile aroma compounds in freeze dried sample or reconstituted sample were also studied. Freezing and freeze drying did not affect pH of fermented milk. Number of viable cells of L. acidophilus was markedly reduced during freezing or freeze drying. When number of viable cells in original fermented milk was considered as 100%, survival ratio of viable cells after freezing was $64.5{\sim}85.2%$ and that after freeze drying was $10.0{\sim}21.1%$. When sensory properties of original fermented milk prepared from juice-milk (ratio 15:35) were compared with those of freeze dried/reconstituted sample, sensory properties of original sample were better than those of freeze dried/reconstituted sample. Ethanol, diacetyl, butanol and acetoin were detected in all of original samples and freeze dried/reconstituted samples while acetone was detected in samples containing high amount of grape juice. Volatile aroma compounds in original fermented milk were reduced during freeze drying. L. acidophilus produced ethanol, diacetyl and acetoin during fermentation.

• Journal of Dairy Science and Biotechnology
• /
• v.14 no.2
• /
• pp.185-193
• /
• 1996

This study was to investigate principle of freeze concentration such as nucleation, crystal growth and procedure of freeze concentration, essential factor and application of freeze concentration. Especially, quality of milk was emphasized. For exemple, in sensory evaluation of freeze concentrated and reconstituted skim milk and whole milk, taste, color, mouth feel and texture were superior to control. Recently developed technique of freeze concentration for quality milk and dairy products may be expected for advanced quality of various milk and dairy products in near future.

• Korean Journal of Food Science and Technology
• /
• v.31 no.5
• /
• pp.1349-1356
• /
• 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 and cookery science
• /
• v.23 no.6
• /
• pp.968-976
• /
• 2007

This experiment was carried out to investigate the effects of spirulina powder on the growth properties of lactic acid bacteria in reconstituted skim milk. The spirulina powder supplemented to S. thermophilus and L acidophilus slightly stimulated lactic acid production. In addition, the growth and acid production of L. bulgaricus were enhanced by the addition of spirulina powder. When the spirulina powder was added to reconstituted skim milk at the level of 1%, the mixed cultures of S. thermophilus and L. bulgaricus showed higher numbers of viable cells and higher acid production than the other cultures. The effects of the addition amounts of spirulina powder (1%, 2% and 3%) to the reconstituted skim milk on the growth properties of the mixed cultures of S. thermophilus and L. bulgaricus were evaluated. The pH of the skim milk with added spirulina powder was lower than that of the control, but the amount of spirulina did not have a significant affect. The titratable acidity increased with the incubation time until 12 hr. The number of viable cells in the skim milk with added spirulina increased according to the amount of spirulina. Thus, the spirulina was effective for the increasing lactic acid bacteria in yoghurt.

• Korean Journal of Agricultural Science
• /
• v.11 no.1
• /
• pp.34-44
• /
• 1984

This experiment was carried out to obtain the fundamental data for development of digestibility and quality enhanced product of soy yogurt. Soy yogurt was processed from raw materials of soybean, defatted soybean and sprouted soybean which inoculated with Lactobacillus acidophilus and Bifidobacterium bifidum as a starter. Changes of chemical compositions, viable cell count and saccharides during processing were investigated including acceptibility of manufactured products. The results were summarized as follows; 1. Defatted soy milk ferment ed with Lactobacillus acidophilus was showed the greatest initial acid productivity and sprouted soy milk was showed the greatest growth of Loctobacillus acidophilus. 2. Acid production was accelerated when 2% glucose was used in soy milk. 3. Addition of reconstituted skim milk in soy milk and defatted roy milk increased acid production but was not showed the effect in the sprouted soy milk. 4. Sprouting soybean, the contents of raffinose and stachyose were decreased but those of glucose was increased. 5. When soy milk was fermented with Lactobacillus acidophilus. the contents of raffinose and stachyose were decreased. 6. As a result of panel test, sprouted soy yogurt which was produced by addition of reconstituted skim milk of 10% showed the greatest flavor and tastes.