• Microbiology and Biotechnology Letters
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• v.43 no.2
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• pp.120-125
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• 2015

In this study, the probiotification of mango juice was carried out by lactic acid bacteria fermentation. Mango juice fermentation was performed at 30℃ for 72 h under micro-aerophilic conditions. The microbial population, pH, titrable acidity, sugar, and organic acid metabolism were measured during the fermentation period and the viability of the strains was determined under the storage conditions at 4℃ for 4 weeks. The lactic acid bacteria reduced the pH to as low as 3.2 from 4.5 within 72 h of fermentation. The substrate concentration was reduced to 5.8% (w/v) from 12% (w/v). Lactobacillus plantarum exhibited the fastest utilization of sugar and reduction of pH in the mango juice when compared to the other strains used. The viability of the cells was maintained at 1.0 × 10⁷ CFU/ml throughout the storage period. From this investigation, it can be concluded that mango juice is suitable for the production of probiotic beverage.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.768-772
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• 1995

The physico-chemical properties of hot-water extracts of dried and roasted Boxthorn(Lycii fructus) were investigated. The proximate composition of dried Boxthorn was 17.5% moisture, 5.4% ash, 14.7% lipid, 18.9% protein, 11.8% fiber and 31.7% carbohydrate. As the roasting temperature and time increased, water soluble solids, turbidity, titrable acidity and redness of the hot water extracts were increased, while the free sugar content was reduced. The linoleic acid of roasted Boxthorn decreased and palmitic acid increased at higher roasting temperature. The sensory properties of sweet odor, burnt odor, sour taste, burnt taste and tannic taste of the hot water extract were scored higher and sweet and roasted taste were lower as the roasting temperature and time increased.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.447-450
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• 1992

An attempt was made to investigate the some constituents and separation of flesh by drying of Corni Fructus for utilization as processing foods of Cornus officianalis S. et Z. Moisture and reducing sugar contents of Corni Fructus flesh were 40.4% and 18.6%, respectively. The content of anthocyanin was 183.0 mg/100g(dry base). The free sugars of Corni Fructus were consisted of glucose and fructose and their contents were 7.9% and 9.0%, respectively. The compositions of organic acids were malic and succinic acids which contained 1.9% and 0.5%, respectively. The titrable acidity as malic acid and pH were 3.6% and 3.19. The decrease ratio of weight and the drying temperature as the optimum conditions for the separation of flesh and seed of Corni Fructus were $30{\sim}35%$ and $60^{\circ}C$.

• Journal of the Korean Society of Food Culture
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• v.22 no.1
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• pp.97-103
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• 2007

In this study, physicochemical properties and the antioxidative activity of whey protein isolate(WPI) for com germ oil were measured. The pH of WPI was 6.26, and the titrable acidity was 0.18%. The WPI’s moisture content was 5.2% and each of the other element content such as lactose, crude protein, crude ash and crude fat was found to be 0.8%, 90.7%, 2.7% and 0.6%, respectively. The amounts of active SH group in WPI 9 ${\mu}$ M-g and total colony counts of bacteria was 5.9 ${\times}$ 10$^3$ CFU-g. ${\alpha}$-Lactalbumin, ${\beta}$-lactoglobulin and bovine serum albumin(BSA) were shown in WPI as major protein by electrophoresis. The antioxidative effect of WPI and other antioxidants on com germ oil used as substrate was determined by peroxide value(POV) and conjuqated dienoic acid value(CDV). By these results, the order of antioxidative effects could be defined as BHT 0.02%>ascorbic acid 0.1%>WPI 0.1%>WPI 0.02%>ascorbic acid 0.02%>control>tocopherol 0.02%>tocopherol 0.1%, respectively. Also the induction period of com germ oil added with WPI was longer by 1.6 times than that of control(none added any antioxidant). Therefore the fact suggested that WPI could be utilized as a good antioxidative agents.

• Korean journal of food and cookery science
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• v.17 no.1
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• pp.65-79
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• 2001

The effects of ${\alpha}$-chymotrypsin and trypsin treatments on the functional properties (degree of hydrolysis, solubility, and emulsifying capacity) of the soy protein isolate prepared from Jinpum soybean milk(JS milk) which has been developed as low lipoxidase-active soybean variety in Korea and extracted from commercially defatted soybean meal milk(DSM milk). The mixing ratios of JS milk to DSM milk were adjusted to 10:0, 7:3, and 5:5, respectively. The general quality attributes(yield, pH, titrable acidity, moisture contents, crude protein contents, color, textural properties, and sensory characteristics) of soybean cheese which has been prepared with the resulting soy protein hydrolysates were evaluated. Jinpum SPI was better subjected to trypsin than ${\alpha}$-chymotrypsin hydrolyses as indicated by better solubility and emulsifying capacity of the hydrolysates. The degree of hydrolysis and solubility of Jinpum SPI were higher than the soybean isolates from DSM milk. The increased ratios of DSM milk in the mixture resulted in the reduced yields and crude protein content along with the lowered titratable acidity while the pH values and moisture contents showed the opposite trends. In color characteristics, the increased amount of DSM milk brought about the significantly lower Hunter color reflectance values of lightness of the cheese products, along with the higher redness and total color difference value(ΔE). However, the enzyme treatment alone was not enough to cause any color differences. The increased ratios of DSM milk also caused the significantly lowered textural parameters such as hardness, adhesiveness and cohesiveness of the soybean cheese. Between the enzyme treatments, the ${\alpha}$-chymotrypsin treated samples resulted in the higher hardness and cohesiveness values of the products than those from the trypsin-treated ones. In organoleptic properties of the product, the better mouthfeel and overall quality scores were obtained from the trypsin treatments as compared with those from the ${\alpha}$-chymotrypsin ones. The mixing ratios of 10:0 and 7:3 were more favored than that of 5:5 as far as mouth-feel, yellowness and overall quality of the products were concerned. On the overall, the mixing ratio of 7:3(JS milk: DSM milk) and the trypsin treatment of the mixture was recommended for better manufacturing of high-quality soybean cheese.

• The Korean Journal of Mycology
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• v.16 no.4
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• pp.193-203
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• 1988

The changes of pH, titrable acidity, nitrite and dimethylamine(DAM) content in the various different kinds of the rice wine staters during the fermentation were studied, and the changes of nitrosodimethymaine(NDMA) contents were also determined by High Pressure Liquid Chromatography. After 24hrs, fermentation rice wine starter, pH was generally decreased to below 5 and after full fermentation the acidities were from 0.51 to 0.89 as succinic acid. After 12hrs, fermentation nitrate contents were rapidly decreased. The large amount of nitrite was formed in the beginning of the fermentation. But by the increase in the acidity due to the further fermentation nitrite contents were gradually disappeared. Generally the DMA contents of each rice wine starter were kept unchanged. On completion of fermentation, NDMA contents of starter added with nitrite and DMA were 472.1 ppb. The starter added with DMA was 329.0 ppb, whereas the other added with nitrite was 229.0 ppb, and control without addition of nitrite and DMA was 24.4 ppb. But the rice wine sold in market was not detected any NDMA at all.

• Korean journal of food and cookery science
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• v.26 no.3
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• pp.307-313
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• 2010

Yogurt base was prepared from skim milk added with 0.5, 1.0 and 1.5% (w/v) black garlic extracts(BGE, 60 brix), fellowed by fermentation with Lactic acid bacteria (the mixed strain of Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus) at $42^{\circ}C$ for 24 hr. The yogurt products were evaluated for acid production (pH, titrable acidity), number of viable cells, viscosity, color value, and sensory properties. The pH of yogurt with BGE was below 6.0 at 6 hr fermentation, after which it was rapidly acidifies. Aftert 24 hr, the titratable acidity of yogurt with 1.5% BGE was 0.74%, which was 5.7 times higher than that before fermentation. There was no significant difference in viable cell count between the samples after 3 hr fermentation. The viscosity of yogurt was decreased by the addition of BGE. As the percentage of BGE increased, the L value (lightness) decreased while the a value (redness) and b value (yellowness) increased. The overall sensory score of yogurt with BGE was lower than that of yogurt with only skim milk. Therefore, moderate addition of BGE was below 1% for the preparation of yogurt.

• Korean Journal of Food Science and Technology
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• v.47 no.6
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• pp.765-771
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• 2015

This study was performed to examine the quality characteristics and antioxidant activity of the curd yogurt with different contents (0.5-2%, w/w) of acanthopanax powder (AP). The pH decreased with increasing AP content until 16 h, whereas the treated groups showed higher pH levels than the control group after 20 h. The viscosity and the viable cell counts of the yogurt with 2% AP were lower than those of the control group during fermentation, significantly. Color values of AP yogurt were lower in terms of brightness, whereas redness and yellowness values were higher compared to the control group. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and soluble content significantly increased with increasing AP content. Consumer acceptability score of yogurt with 0.5% AP was ranked higher than other yogurts. Yogurt added with 0.5% AP showed no differences in pH, titrable acidity, and viable cell counts compared to the control group after storage at $4^{\circ}C$ for 14 days.

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.150-155
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• 1997

The twenty strains of Lactobacillus genus were tested for the optimal sponge fermentation of soda cracker. The six strains such as L. brevis, L. delbrueckii, L. fermentum, L. leichmanii, L. plantarum and L. sanfrancisco were selected because these strains did not smell off-flavor and showed the high value of TTA (total titrable acidity) after the fermentation. The selected strains consisted of the five strains of L. brevis, L. delbrueckii, L. fermentum, L. leichmanii and L. plantarum that mainly inhabited soda clacker and L. sanfrancisco that existed in San Francisco bread. The lactic acid bacteria were inoculated to the medium containing 10% wheat flour and then pH, TTA, acetic acid and lactic acid were measured during the sponge fermentation. The four strains of L. brevis, L. delbrueckii, L. fermentum and L. plantarum were used for the mixed lactic acid bacteria of sponge fermentation because the TTAs of L. brevis, L. fermentum and L. plantarum were higher than those of other lactic acid bacteria and L. delbrueckii rapidly produced organic acids and a large amount of acetic acid. Among the combination of L. brevis, L. fermentum, L. delbrueckii and L. plantarum, the mixed lactic acid bacteria of L. brevis, L. fermentum and L. plantarum showed the highest TTA, the lowest pH and the largest amount of acetic acid. Therefore, the mixed lactic acid bacteria of L. brevis, L. fermentum and L. plantarum were used for optimal sponge fermentation of soda cracker.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.343-347
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• 1997

Effect of culture conditions on the fermentation of wheat flour solution by mixed lactic acid bacteria of Lactobacillus brevis, L. fermentum and L. plantarum was investigated. The optimum temperature for the fermentation of wheat flour solution was $35^{\circ}C$ because pH decreased the lowest value and TTA (total titrable acidity) increased the highest value at this temperature. In aerobic condition, fermentor was purged with air at 1.0 vvm and was purged with nitrogen gas at 1.0 vvm in anaerobic condition. The decrease of pH and the increase of TTA in aerobic condition were higher than those in anaerobic condition. In aerobic condition, the optimum condition of oxygen supply was found to be oxygen transfer rate coefficient of $60\;hr^{-1}$ which corresponded to agitation speed of 250 rpm in a 5 L fermentor. Repeated fed-batch cultures were performed using pH-stat in order to increase the productivity of fermented wheat flour. With increasing the repeated fraction of culture volume, mean cycle time increased but maximum operation time decreased. However, the volume of produced broth per culture volume per time and total volume of produced broth per culture volume were maximum at the repeated fraction of culture volume of 20%. In a repeated fed-batch fermentation of wheat flour solution using mixed lactic acid bacteria, the culture condition was optimum at temerature of $35^{\circ}C$, aeration rate of 1.0 vvm, oxygen transfer rate coefficient of $60\;hr^{-1}$, and repeated fraction of culture volume of 20%.