• Journal of the Korean Professional Engineers Association
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• v.18 no.4
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• pp.12-22
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• 1985

This investigation was attempted to determine changes in chlorophyll. Pheophytin content PH and titratable acidity during young redish Kim chi fermentation. Young redishes divied in to leaf and vein and fermented in dark room for 35 days at 10$^{\circ}C$ after pickling each group. Samples were collected at 5 days interval for the chemical analysis. The following results were obtained. 1. Chlorophyll content in young redish was decreased by decreasing PH during fermentation periods. Chlorophyll content decreased from 11.60mg/g to 7.62mg/g in leaf, from 0.48mg/g to 0.33mg/g in vein respectively during 35 days fermentation periods. In contrast to chlorophyll. pheophytin content increased as chlorophyll content decreased during the period. The ratio of chlorophyll a and b content in young redish about 3 : 1 in leaf and vein and decreased nearly the same ratio during fermentation periods. In case of pheophytin a and b it was increased without any relation with the ratio chlorophyll a and b. In generally, the optimum PH for eating was known 4.3 to 5.0. Young redish Kim chi was reached the optimun PH at 15 to 25 days of fermentation at 10$^{\circ}C$. At this periods. Chlorophyll content varied from 11.32mg/g to 9.30mg/g for leaf and from 0.43mg/g to 3.37mg/g for vein, respectively. 2. Titratable acidity(as lactic acid) was increased to 0.54% in leaf at 20 days fermentation period during Kim chi fermentation. and nearly unchanged until 30days. At the end of fermentation period the titratable acidity was about 0.30％. Titratable acidity was increased as decreasing pH. and the correlation coefficients was -0.92 in leaf and -0.77 in Vien. 3. Correlation between titratable acidity and chlorophll, pheophytin content was not significant statistically.

• The Korean Journal of Food And Nutrition
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• v.26 no.3
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• pp.358-365
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• 2013

The study was conducted to investigate the condition for mixed fermentation of Rhodilola sachalinensis with red ginseng using Lactobacillus acidophillus 128 and the changes of physicochemical properties and antioxidant activities before and after the lactic acid fermentation was examined. In the single fermentation of Rhodiola sachalinensis extract, the pH and titratable acidity rarely changed, and the number of lactic acid bacteria decreased greatly. On the other hand, in the lactic acid fermentation of Rhodiola sachalinensis-red ginseng mixed extract of 50% red ginseng content, the pH decreased, whereas the titratable acidity and the number of lactic acid bacteria increased. The solid content of optimal mixed extract for lactic acid fermentation was 0.5%. Sugar content decreased during fermentation, but total phenolic compounds tended to increase during fermentation. The salidroside and p-tyrosol content of the initial Rhodiola sachalinensis-red ginseng mixed extract was 419.5 mg% and 60.1 mg%, respectively; after fermentation, the salidroside content after lactic acid fermentation decreased greatly to 81.8 mg%, and the amount of p-tyrosol increased greatly to 324.9 mg%. The DPPH scavenging activity of Rhodiola sachalinensis-red ginseng mixed fermentate was 78.1% at 0.1% concentration, showing a tendency to increase as compared to 50.3% of Rhodiola sachalinensis-red ginseng mixed extract before the fermentation (p<0.05); it was a higher antioxidant activity as compared to the single fermentation of Rhodiola sachalinensis or red ginseng.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.365-367
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• 2004

Electrolyzed-acid water was used to prolong shelf life of salted Chinese cabbage during storage, Chinese cabbage was salted, washed twice with electrolyzed-acid water, packaged in high-density polyethylene film, and stored at $10^{\circ}C$. Titratable acidity, pH, color, and microbial loads of salted Chinese cabbage were measured. Treated sample showed lower pH, total microbial count, and lactic acid bacteria than those of control, whereas almost equal titratable acidity and color, Acidity of treated sample maintained lower pH value until 6 days, and remained constant thereafter, Sharp decrease in L value occured after 2 days for control, and was delayed 4-6 days for treated sample. Salted Chinese cabbage treated with electrolyzed-acid water showed lower total microbial load ($10^3\;CFU/mL$) and lactic acid bacteria ($10^1\;CFU/mL$) after washing, whereas similar loads, compared to control after 6 days. Treatment with electrolyzed-acid water maintained higher quality for salted Chinese cabbage, with limited shelf life extension.

• Journal of Applied Biological Chemistry
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• v.53 no.1
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• pp.51-55
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• 2010

A lactic acid bacterial strain showing fast growth and high acid production in Korean pear puree was isolated from Kimchi. This strain was analyzed by API 50 CHL kit and 16S rRNA sequencing analysis and identified as Leuconostoc (Ln.) mesenteroides KACC 91495P. Korean pear puree was fermented using Ln. mesenteroides KACC 91495P strain at $30^{\circ}C$ for 18 h. The changes of pH, titratable acidity and viable cell number during fermentation were investigated. The pH and titratable acidity were reached to pH 3.86 and 1.09% after 18 h fermentation, respectively. The viable cell population of Ln. mesenteroides KACC 91495P was rapidly increased to $2.0{\times}10^9\;CFU/g$ during the 9 h of cultivation. The contents of lactic acid, acetic acid and malic acid were determined to be 0.213, 0.259, and 0.217% after 18 h fermentation, respectively. The content of polyphenolic compounds, known as antioxidants, in pear puree were enhanced by Ln. mesenteroides KACC 91495P cultivation. The level of total polyphenolic compounds was increased to around 140% of initial concentration. When the fermented pear puree was kept at $4^{\circ}C$, pH, titratable acidity and number of viable cells population were nearly maintained for 13 days.

• Journal of Microbiology
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• v.42 no.2
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• pp.133-138
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• 2004

This study was aimed to determine the accumulation of free fatty acid by mesophilic lactic acid bac-teria (Lactococcus lactis subsp. lactis 1471, Lactococcus lactis subsp. cremoris 1000 and Lactobacillus casei 111) in cold-stored milk. According to the results, all cold-stored milks had higher acid degree val-ues than those of fresh milk. This phenomenon showed that a slight increase occurred in the accumulation of free fatty acids as a result of spontaneous lipolysis during cold storage. All lactic acid bacteria showed good performance in production of titratable acidity, which increased during fermentation of the milk (fresh and stored milks). Moreover, as the storage time was prolonged, more free fatty acid accumulation was obtained from the fermentation of the cold-stored milk by the investigated lactic acid bacteria. The control milk, which was without lactic acid bacteria, showed no change in the accumulation of free fatty acid during fermentation. From this result, it can be suggested that longer cold-storage time can induce higher free fatty acid accumulation in milk by lactic acid bacteria.

• Journal of the East Asian Society of Dietary Life
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• v.4 no.2
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• pp.39-44
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• 1994

To prepare the basic information for the fermentation of high quality persimmon vinegar in the farm. the quality of the complex fermented persimmon vinegar(CFPV) was compared to that of naturally fermented persimmon vinegar (NFPV). The titratable acidity of the CFPV was 3% which was the half concentration of the NFPV. The content of total free sugar by HPLC was 6% in CFPV and NFPV was 5%. Organic acid compositions in persimmon vinegar were oxalic acid, malic acid, lactic acid, citric acid, succinic acid and glutaric acid in addition to acetic acid. Total content of the organic acids in NFPV was higer than in CFPV. Especially, the content of latic acid in NFPV was very higher than that of CFPV. the flavour, color and taste of persimmon fruit itself in CFPV were stronger than those in NFPV.

• Food Science and Preservation
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• v.19 no.6
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• pp.933-938
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• 2012

The quality characteristics of rice wine seed mash and rice wine made with different lactic acid concentrations were investigated. The pH decreased along with the lactic acid concentration. The total titratable acid content of the rice wine seed mash was lowest when 0.5% lactic acid was added, and the ethanol contents of the mash samples were not significant. The results of the measurement of the microorganism number, C (cell numbers of the total bacteria and the lactic acid bacteria), decreased along with the lactic acid concentrations of the mash samples. The yeast cell numbers of the rice wine seed mash samples according to the lactic acid concentrations were high (0.5, 0.3, 1.0, control, and 0.7%, respectively). The pH and total titratable acid levels of rice wine according to the lactic acid concentration were stable during fermentation, according to the increase in the amount of lactic acid. The organic acids in the rice wines were highest in the lactic acid. The rice wines to which lactic acid had been added had lower acetic acid contents than the control. Also, the acetic acid contents decreased along with the lactic acid concentrations, except in the rice wine treated with 1.0% lactic acid. The ethanol contents of the tested rice wines were not significant. All in all, in the sensory evaluation, the rice wines treated with 0.5 and 0.7% lactic acid scored higher than the other treatments.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.210-218
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• 2000

Since the SSC(soluble solid contents) and titratable acidity of fruit are highly concerned to the taste, the need for measuring them by non-destructive technology such as NIR(Visual and Near-infrared) spectroscopy is increasing. Specially, in order to grade the quality of each fruit with a sorter at sorting and packing facilities, technologies for online measurement satisfying the tolerance in terms of accuracy and speed should be developed. Many researches have been done to develop devices to measure the internal qualities of fruit such as SSC, titratable acidity, firmness, etc. with the VIS(Visual)/NIR(Near Infrared) reflectance spectra. The distributions of the SSC, titratable acidity, firmness, etc. are different with respect to the position and depth of fruit, and generally the VIS/NIR light can interact with fruit in a few millimeters of pathlength, and it is very difficult to measure the qualities of inner flesh of fruit. Therefore, to measure the average concentrations of each quality factor such as SSC and titratable acidity with the reflectance-type NIR devices, the spectra of fruit at several positions should be measured. Recently, the interest about the transmittance-type VIS/NIR devices is increasing. NIR light can penetrate through the fruit about 1/10-1/1,000,000 %. Therefore, very intensive light source and very sensitive sensor should be adopted to measure the transmitted light spectra of intact fruit. The ultimate purpose of this study was to develop a device to measure the transmitted light spectra of intact fruit such as apple, pear, peach, etc. With the transmittance-type VIS/NIR device, the feasibility of measurement of the SSC and titratable acidity in intact fruit cultivated in Korea was tested. The results are summarized as follows; A simple measurement device which can measure the transmitted light spectra of intact fruit was constructed with sample holder, two 500W-tungsten halogen lamps, a real-time spectrometer having a very sensitive CCD array sensor and optical fiber probe. With the device, it was possible to measure the transmitted light spectra of intact fruit such as apple, pear and peach. Main factors affecting the intensity of transmitted light spectra were the size of sample, the radiation intensity of light source and the integration time of the detector. Sample holder should be designed so that direct light leakage to the probe could be protected. Preprocessing method to the raw spectrum data significantly influenced the performance of the nondestructive measurement of SSC and titratable acidity of intact fruit. Representative results of PLS models in predicting the SSC of peach were SEP of 0.558 Brix% and R2 of 0.819, and those in predicting titratable acidity were SEP of 0.056% and R2 of 0.655.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.76-84
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• 2013

A polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique followed by sequencing of the 16S rDNA fragments eluted from the bands of interest on denaturing gradient gels was used to monitor changes in the bacterial microflora of two commercial kimchi, salted cabbage, and ingredient mix samples during 30 days of fermentation at $4^{\circ}C$ and $10^{\circ}C$. Leuconostoc (Lc.) was the dominant lactic acid bacteria (LAB) over Lactobacillus (Lb.) species at $4^{\circ}C$. Weissella confusa was detected in the ingredient mix and also in kimchi samples throughout fermentation in both samples at $4^{\circ}C$ and $10^{\circ}C$. Lc. gelidum was detected as the dominant LAB at $4^{\circ}C$ in both samples. The temperature affected the LAB profile of kimchi by varing the pH, which was primarily caused by the temperature-dependent competition among different LAB species in kimchi. At $4^{\circ}C$, the sample variations in pH and titratable acidity were more conspicuous owing to the delayed growth of LAB. Temperature affected only initial decreases in pH and initial increases in viable cell counts, but affected both the initial increases and final values of titratable acidity. The initial microflora in the kimchi sample was probably determined by the microflora of the ingredient mix, not by that of the salted cabbage. The microbial distributions in the samples used in this study resembled across the different kimchi samples and the different fermentation temperatures as the numbers of LAB increased and titratable acidity decreased.

• Journal of Dairy Science and Biotechnology
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• v.35 no.4
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• pp.249-254
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• 2017

The purpose of this study was to investigate the acid tolerance, bile acid tolerance, and fermentation activity of lactic acid bacteria isolated from Kimchi in the presence of hydrolysates of whey protein concentrate. Kimchi isolates DK109, DK119, DK121, DK128, DK211, DK212, and DK215, which were identified as Lactobacillus sp., and L. casei DK128 showed the highest acid and bile acid tolerance. To produce whey hydrolysates, enzymes were added to a 10% (w/v) whey protein concentrate (WPC) solution at 1:50 (w/v, protein). The viabilities of the DK strains were determined in the presence of low pH and bile salts. Then, yogurt was produced via fermentation with L. casei DK128, an isolate from Kimchi, in the presence of the following additives: CPP, WPC, and WPC hydrolysates (WPCH) generated by alcalase (A) or neutrase (N). The produced yogurts were subjected to various analyses, including viable cell counts (CFU/mL), pH, titratable activity, and sensory testing. After 8 h of fermentation, the pH and titratable activity values of all test samples were 4.2 and 0.9, respectively. The viable counts of LAB were $3.49{\times}10^8$, $5.72{\times}10^8$, $7.01{\times}10^8$, and $6.97{\times}10^8$, for the Control, CPP, A, and N samples, respectively. These results suggest that whey proteins have potential as dietary supplements in functional foods and that WPCH could be used in yogurt as a low-cost alternative to CPP.