• Journal of the East Asian Society of Dietary Life
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• v.18 no.1
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• pp.95-103
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• 2008

The aim of this study was to evaluate the physicochemical, microbial, and sensory characteristics, as well as antioxidative activities of yoghurts containing spirulina powder, during storage at 4$^{\circ}C$. The pH of the yoghurts decreased until the 9th day of storage, but significantly increased by the 12th day. Total acidity also increased until the 9th day of storage, and then significantly decreased by the 12th day. Sugar content did not change significantly (approximately 18 $^{\circ}Brix$). Viscosity(cP) increased until the 6th day of storage, but had decreased at the 12th day. The viable bacterial cell counts of the control group decreased during storage. In contrast, the viable cell counts of the spirulina containing samples increased until the 9th day, and then decreased by the 12th day of storage. Antioxidant activity decreased in all groups, but the changes in antioxidant activity were lower in the spirulina groups than in the control group. According to sensory evaluations, the samples presented no significant differences during storage. Based on the above results, the optimum concentration of spirulina was determined as 0.25%. Also, the period of circulation of yoghurt containing spirulina was estimated to be 9 days at 4$^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• v.18 no.4
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• pp.325-333
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• 2005

This experiment was carried out to investigate the effect of green tea powder on the growth and acid production of lactic culture in reconstituted skim milk. The supplementation level of green tea powder to reconstituted skim milk was $0.5\%,\;1.0\%,\;1.5\%,\;2.0\%\;and\;2.5\%$. Reconstituted skim milk containing green tea powder was fermented by single or mixed culture of Streptococcus thermophilus, Lactobacillus acidophilus and Lactobacillus casei. Supplementation of green tea powder did not significantly stimulate growth and acid production of Streptococcus thermophilus and Lactobacillus casei. But the growth and acid production of Lactobacillus acidophilus were slightly enhanced by the addition of green tea powder. When green tea powder was added to reconstituted skim milk at the level of $0.5\%\;or\;1.0\%$, all mixed cultures oi lactic acid bacteria showed high number of viable cell count and the acid production than 3 kinds of single cultures. Therefore, it was suggested to manufacture the yoghurt with the addition of $0.5\~1.0\%$ green tea powder and the inoculation of mixed cultures of lactic acid bacteria for on the stimulation of growth of the lactic culture.

• Journal of Dairy Science and Biotechnology
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• v.30 no.2
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• pp.83-92
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• 2012

This study was performed for analyzing the general composition and the change in the quality of soymilk-derived yogurts manufactured by adding skim milk and whey powder to soymilk heat-treated at $95^{\circ}C$/5 min and $120^{\circ}C$/10 min, respectively. 1. During the storage of soymilk yogurt, the concentrations of total solids, protein, fat, and lactose slightly decreased, whereas viscosity, content of ash and NPN, and the number of lactic acid bacteria remained unchanged. 2. The pH and titratable acidity changed rapidly in all soymilk yogurts after 3 h of incubation. 3. We found $7.8{\times}10^8$ lactic acid bacteria in the control sample, $4.7{\times}10^8$ and $5.02{\times}10^8$ in soymilk yogurt with skim milk, respectively, and $5.9{\times}10^8$ and $5.5{\times}10^8$, respectively in soymilk yogurt with whey powder according to degree of heat treatment with $95^{\circ}C$/5 min and $120^{\circ}C$/10 min. 4. The viscosity of yogurt samples became lower as the heat treatment increased in temperature and in the length of time. 5. The value of sensory evaluation was relatively high in soymilk yogurt with the added skim milk, which was heat-treated $95^{\circ}C$/5 min; however, the value was significantly lower than that of the control sample. 6. Lactose, glucose, and galactose were detected in all samples because lactose is degraded into glucose and galactose within 3 h of inoculation.

• Food Science of Animal Resources
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• v.29 no.4
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• pp.437-444
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• 2009

${\gamma}-Aminobutyric$ acid (GABA) producing lactic acid bacteria, Lactobacillus acidophilus RMK567 was cultivated in 50 L of sterilized MRS broth using a fermenter at $40^{\circ}C$ for 24 h. The cell number was increased to $10.04{\pm}0.13$ Log CFU/mL with a growth rate constant (k) of 0.454 generation/h and a generation time (g) of 2.303 h after a lapse of a lag phase (L) of 5.16 h. A total of 487 g of cell paste with 40.5% moisture was harvested with viable cell number of 12.48 Log CFU/g cell paste. The cell pastes after preparation with glycerol, glucose, and polydextrose as cryo-protectants were lyophilized under a vacuum of 84 m torr. A total of 408 g of freeze dried (FD) cell powders were mixed with a commercial strain of Streptococcus thermophilus to prepare of three types FD starter cultures with the viable cell numbers of 12.42 (FDA-GY), 12.60 (FDBGG) and 12.91 (FDC-GP) Log CFU/g. During preservation the FD cultures at -$18^{\circ}C$, the cell viability of the FD starter cultures were rapidly dropped to below 3.24% of the day of storage. No significant difference was found in the cell viabilities among three types of FD starters cultures, but significant difference (p<0.01) was found in storage periods. Yoghurts fermented through FD starter culture of L. acidophilus RMK567 were determined to contain $155.16{\pm}8.53$ ppm, $243.82{\pm}4.27$ ppm, and $198.64{\pm}23.46$ ppm of GABA, respectively. This study shows that GABA production activity of L. acidophilus RMK567 is not affected during the freeze drying process and would be available for commercial production of yoghurt containing high GABA content.

• Food Science of Animal Resources
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• v.29 no.5
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• pp.647-652
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• 2009

A duplex PCR technique was applied for specific identification of cow and goat milk in milk products by using primers targeting the mitochondrial 12S rRNA gene. Duplex PCR using primers specific for cow and goat generated specific fragments of 223bp and 326bp from cow and goat milk DNA, respectively. Duplex PCR was applied to 15 milk products purchased from the market to verify label statements. The labeling statements of four market milk products, three yoghurt products, and one whole milk powder product were confirmed in the duplex PCR. The labeling statements of five of seven infant milk powder products were also confirmed by duplex PCR but the other two products were shown to be contaminated with either cow or goat milk. The proposed duplex PCR provides a rapid and sensitive approach to detection of as little as 0.1% cow milk in goat milk and one-step detection of cow or goat milk in milk products.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.507-514
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• 2010

This study was performed to reduce unpleasant taste and flavor of $Gastrodia$ $elata$ Blume as well as to improve utilization as functional food materials using fermentation. The component, antioxidant activity, and taste test were compared between fresh and fermented $Gastrodia$ $elata$ Blume powder (FGP). FGP contained higher level of total fat, protein, mineral, and fiber than raw material. The pH of FGP was higher compared to raw $Gastrodia$ $elata$ Blume powder (RGP), and antioxidant activity was as high as vitamin C regardless material status (raw vs. fermented). This result indicated that its activity was not decreased by fermentation. Dispersiveness and solubility of $Gastrodia$ $elata$ Blume powder was the best in 60-70 mesh. For sensory evaluation, FGP or RGP was mixed with either orange juice or yoghurt. The results showed that overall preference, taste, flavor, texture, and color were better in fermented $Gastrodia$ $elata$ Blume drinks than in raw ones. It is plausible that unpleasant taste and flavor of $Gastrodia$ $elata$ Blume was declined by fermentation. Thus, fermentation can be easily applied to eliminate unpleasant smell in $Gastrodia$ $elata$ Blume, and FGP can be mixed with other beverages to produce healthy food and drinks.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.583-593
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• 2022

Cacao is recognized not only as a raw material for making chocolate but also as an excellent functional food with a high antioxidant effect. The consumption of raw cacao and its processed form of cacao has a beneficial effect on health. The aim of this study was to reveal the possible biological functions of yoghurt that was prepared with added cacao nibs (Theobroma cacao L.). The 2,2-anziobis (3-ehtylbenzothiazoline-6-sulfonic aicd (ABTS) radical scavenging ability of yogurt containing Cacao nibs from 1 to 5% was higher than that of the control group, and the ABTS radical scavenging ability was similar in all the test groups after 12 hours of fermentation. The antibacterial activity of the control and yogurt with the cacao nibs was shown to be very strong against Escherichia coli, Staphylococcus aureus 1631, Pseudomonas aeruginosa, and Salmonella Typhimurium M-15 in fermented milk for 16, 24, and 48 hours, but the fermentation times at 0, 4, and 8 hours showed no activity. The Cacao nibs powder inhibited IκBα-phosphorylation in a concentration-dependent manner. The yogurt containing the cacao nibs significantly inhibited the expression of the anti-inflammatory cytokines IL-1ß and IL-6 in a concentration-dependent manner. Our development of yogurt that combines milk as a complete food and cacao nibs, which has several physiological functions, is expected to greatly contribute to research on new functional fermented milk.

• Journal of Dairy Science and Biotechnology
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• v.34 no.2
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• pp.69-74
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• 2016

The main constituent of tea catechins, EGCG [(-)-Epigallocatechin-3-gallate], could inhibit the growth of various microorganisms and differently affect gram-positive and gram-negative bacteria. Antimicrobial activity of EGCG, a compound from green tea (Camellia sinensis) extract, against Cronobacter spp. and Salmonella spp. was studied to evaluate the possibility of using EGCG as a natural food additive in various dairy products. In pure TSB culture, the growth of Cronobacter spp. was suppressed below the detection limit (1 log CFU/mL) depending on EGCG concentration ($600{\sim}800{\mu}g/mL$), after 5~16 days at $4^{\circ}C$. Similarly, the growth of Salmonella spp. was suppressed below the detection limit (1 log CFU/mL) depending on EGCG concentration ($400{\sim}800{\mu}g/mL$), after 5~16 days at $4^{\circ}C$. Therefore, these results suggest that EGCG could be used as an effective additive to inhibit the growth of Cronobacter spp. and Salmonella spp. in various dairy products, such as yoghurt, cheese, dried infant powder, and so on.

• Food Science of Animal Resources
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• v.26 no.2
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• pp.257-262
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• 2006

This experiment was carried out to investigate the effect of hypoglycemic yogurt as a clinical test with person both who have diabetes and who don't have diabetes. Diabetes is a disease caused by unused and accumulated glucoses produced via the foods digestion due to the lack of insulin or lower tissue reaction to insulin. Patients with diabetes or complications of diabetes are on the rise annually. For the therapy and prevention of diabetes, a yogurt made from functional materials such as insulin-resistant FK-23 lactic acid bacteria, Pinitol, edible fiber which delays glucose-absorption, extract powder of glucose-absorption-inhibitory white bean and low-caloric Erythritol and banaba extract is effective for reduce or restrain the blood glucose levels. The blood glucose levels after a meal of non-diabetic persons were lower after drinking a hypoglycemic yogurt than they after drinking general yogurt. The blood glucose levels after a meal of 10 diabetic patients were checked after drinking the yoghurt. As a result, 19 mg/dL, 30 mg/dL, 31 mg/dL of blood glucose levels decreased in 30 min, 60 min and 120 min respectively after drinking the yogurt. Blood glucose inhibition rates of 80 % of the tested patients also decreased. The blood glucose level of the diabetic patients having drunk the yogurt for 30 days consistently decreased into 59 mg/dL in 120 min after a meal.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.564-569
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• 2000

An enzyme-linked immunosorbent assay(ELISA) was developed for the detection of milk proteins in processed foods. The ${\alpha}_{s1}-casein({\alpha}_{s1}-CN)$, a heat stable major milk protein, was immunized into rabbits to produce specific antibodies. When competitive indirect ELISA(ciELISA) using $anti-{\alpha}_{s1}-CN$ antibodies was established, its detection limit was $0.1\;{\mu}g/mL$. The reactivities of the specific antibodies toward ${\alpha}_{s1}-CN$, skim milk, ${\beta}-CN$ and whey protein isolate(WPI) were 100, 37, 0.14 and 0.04%, respectively, as determined by ciELISA. However $anti-{\alpha}_{s1}-CN$ antibodies did not have any reactivity to other milk proteins such as ${\beta}-lactoglobulin,\;{\alpha}-lactalbumin$, bovine serum albumin, and isolated soy protein. When sandwich ELISA was established, its detection limit was $0.01\;{\mu}g/mL$ which was 10 times more sensitive than that of ciELISA. In the spike test which was performed by adding 1-10% of whole CN to market milk, mean assay recovery as determined by sandwich ELISA was 94.8%(CV, 8.2%). Food stuffs and dairy products were assayed by sandwich ELISA to show 29, 0.13, 0.25, and 6.9% of whole CN in skim milk powder, WPI, semi-solid yoghurt, and processed cheese, respectively.