• 제목/요약/키워드: potential acidity

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Storage Response of 'Kamchun' and 'Chuhwang' Pears by Harvest Dates (신품종 배 '감천'과 '추황'의 수확시기에 따른 저장반응)

  • Hwang, Yong Soo;Chun, Jong Pil;Lee, Jae Chang;Seo, Jung Hak
    • Horticultural Science & Technology
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    • 제19권1호
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    • pp.48-53
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    • 2001
  • The study was conducted to examine the storage potential of recently developed oriental pears, 'Kamchun' and 'Chuhwang'. The content of soluble solids of 'Kamchun' pears was above 13.2% but the acidity was below 0.082% at three harvest dates. Although skin browning disorder did not occur in 'Kamchun', about 40% of fruits were affected by core breakdown especially when harvested after middle of October. In contrast, flesh browning was also observed in early harvested fruit. Flesh firmness of 'Chuhwang' was higher than that of 'Kamchun' at harvest as well as after storage. The acidity of 'Chuhwang' was constantly higher than that of 'Kamchun'. Severe skin browning (approximately 80%) occurred in 'Chuhwang' pears regardless of harvest dates. Also, more flesh browning disorder was found in fruit harvested early in the season. Further research is required to determine the optimum harvest date of both cultivars and postharvest managements to inhibit the physiological disorders.

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Quality Characteristics and Antioxidant Activity of the Traditional Korean Rice Wine Makgeolli Containing Lotus Leaf Nelumbo nucifera Powder During Fermentation (연잎(Nelumbo nucifera) 분말을 첨가하여 제조한 막걸리의 발효 중 품질 특성 및 항산화 활성)

  • Kim, So Hee;Jeon, Eun Bi;Song, Min Gyu;Park, Shin Young
    • Korean Journal of Fisheries and Aquatic Sciences
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    • 제55권6호
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    • pp.769-776
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    • 2022
  • As an aquatic plant, the lotus leaf Nelumbo nucifera is rich in polyphenols, carotenoids, and flavonoids. We analyzed the chemical (pH, acidity, sugar, alcohol), microbiological (lactic acid bacteria, yeast), and antioxidant activity of Makgeolli supplemented with 5% and 10% lotus leaf (ll) during fermentation for 7 days. The pH of the non-additive group (control) was 3.10-6.03, that of the 5% added group was 3.17-5.77, and that of the 10% added group was 3.27-5.70, which decreased significantly (P<0.05) as the fermentation time elapsed. The acidity and sugar content were 1.89-2.12% and 9.10-12.90 Brix, respectively, which were significantly higher (P<0.05) as the amount of added ll increased. The alcohol content was 5.90-7.20% and was the highest on the seventh day of fermentation. The lactic acid bacteria was 6.07-7.17 log CFU/mL, which was higher in ll Makgeolli. Yeast increased until day 3 and then decreased to 3.27-5.86 log CFU/mL. DPPH (1,1-diphenyl-2-picrylhdrazyl) and ABTS [2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)] radical scavenging activities were higher in ll Makgeolli (DPPH 68.72-81.48%, ABTS 90.71-91.67%). In this study, the commercialization potential of ll Makgeolli was expanded by enhancing the quality and antioxidant function of Makgeolli added with ll.

Angiotensin-I-Converting Enzyme Inhibitory Peptides in Goat Milk Fermented by Lactic Acid Bacteria Isolated from Fermented Food and Breast Milk

  • Rubak, Yuliana Tandi;Nuraida, Lilis;Iswantini, Dyah;Prangdimurti, Endang
    • Food Science of Animal Resources
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    • 제42권1호
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    • pp.46-60
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    • 2022
  • In this study, angiotensin-I-converting enzyme inhibitory (ACEI) activity was evaluated in fermented goat milk fermented by lactic acid bacteria (LAB) from fermented foods and breast milk. Furthermore, the potential for ACEI peptides was identified in fermented goat milk with the highest ACEI activity. The proteolytic specificity of LAB was also evaluated. The 2% isolate was inoculated into reconstituted goat milk (11%, w/v), then incubated at 37℃ until pH 4.6 was reached. The supernatant produced by centrifugation was analyzed for ACEI activity and total peptide. Viable cell counts of LAB and titratable acidity were also evaluated after fermentation. Peptide identification was carried out using nano liquid chromatography mass spectrometry (LC-MS/MS), and potential as an ACEI peptide was carried out based on a literature review. The result revealed that ACEI activity was produced in all samples (20.44%-60.33%). Fermented goat milk of Lc. lactis ssp. lactis BD17 produced the highest ACEI activity (60.33%; IC50 0.297±0.10 mg/mL) after 48 h incubation, viable cell counts >8 Log CFU/mL, and peptide content of 4.037±0.27/mL. A total of 261 peptides were released, predominantly derived from casein (93%). The proteolytic specificity of Lc. lactis ssp. lactis BD17 through cleavage on the amino acid tyrosine, leucine, glutamic acid, and proline. A total of 21 peptides were identified as ACEI peptides. This study showed that one of the isolates from fermented food, namely Lc. lactis ssp. lactis BD17, has the potential as a starter culture for the production of fermented goat milk which has functional properties as a source of antihypertensive peptides.

Assessment of the erosive potential of elder-friendly foods (액상형 고령친화식품의 치아부식능 평가)

  • Jung, Eun-Ha;Kang, Jung-Yun;Han, Sun-Young
    • Journal of Korean society of Dental Hygiene
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    • 제22권5호
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    • pp.461-468
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    • 2022
  • Objectives: To investigate the effect of several elder-friendly foods on oral health and suggest guidelines for proper food intake. Methods: Six elderly-friendly foods (liquid type) and two control groups (mineral water and mixed coffee) were selected for this study. The pH of the food was measured using a calibrated pH meter, and the titratable acidity was determined using 1 M NaOH until 7.0 (TA 7.0). The screening method suggested by the International Organization for Standards was performed using an undersaturated hydroxyapatite solution to determine the difference between the initial and final pH of the screening solution (△pH). In addition, the sugar content was measured and expressed as Brix (%). Results: All the elder-friendly foods tested in this study showed a neutral pH (6.68-7.35), similar to mineral water (pH 7.84). The range of TA 7.0 values was 0.00-0.54 ㎖. The changes in pH determined using the screening solution confirmed that the largest change in pH was found in Careon (△pH 1.14±0.02), which has no erosive potential. Nevertheless, all elder-friendly foods had higher sugar content than the negative control group. Conclusions: Low tooth erosive potential was found in elder-friendly foods, but these foods showed high sugar content.

Effects of paper ash on the neutralization of nursery soil acidity (종이 소각재의 육묘상토(育苗床土)에 대한 산도교정(酸度矯正) 효과(效果) 연구(硏究))

  • Kim, Chang-Yong;Lee, Dong-Hoon;Park, No-Kwuon;Kim, Jong-Soo;Seo, Young-Jin
    • Korean Journal of Environmental Agriculture
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    • 제20권4호
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    • pp.258-261
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    • 2001
  • The paper industry produces about 6,000 ton of paper ashes yearly with by-products in Yuhan-Kimberly Ltd. The paper ashes was analyzed and evaluated for their potential as the soil acidity amendment materials. This study was conducted to investigate a reasonable amount of paper ashes for soil acidity amendment effect to be applied onto raising seedling of Calendula officinalis L. The mixed proportion of applied ashes, which was compared with agricultural lime, was treated to 0, 5, 10 and 15% (v/v) in mixed soil (pH 6.0) and the peat moss (pH 3.8) respectively. Consequently paper ashe was found to be more effective than agricultural lime at germination percentage, growth condition and in sharp initial increase of soil pH. The appropriate proportion of applied paper ash was 10% (v/v) at the soil-mix, and 15% (v/v) at the peat-moss. Soil application of paper ashes may provide supplemental quantities of K, Ca, Mg and other plant nutrients. But heavy metal concentrations in paper ash was low and should not limit application rates.

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Changes in quality characteristics of salted Kimchi cabbage and kimchi paste during storage (절임배추 및 김치 양념의 저장기간 중 품질 특성 변화)

  • Song, Hye-Yeon;Cheon, Seon-Hwa;Yoo, SeungRan;Chung, Young Bae;Seo, Hye-Young
    • Food Science and Preservation
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    • 제23권4호
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    • pp.459-470
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    • 2016
  • This study was conducted to determine the potential use for salted Kimchi cabbage and kimchi paste by analyzing the quality characteristic of kimchi prepared with stored them. Salted Kimchi cabbages were packed with the 2% brine and kimchi paste were stored at $4^{\circ}C$ for 8 weeks, respectively. Kimchi prepared at 0 day and kimchi prepared with stored salted Kimchi cabbage and kimchi paste every week were stored at $4^{\circ}C$ for 8 weeks. The salinity and titratable acidity of salted Kimchi cabbage packed with the brine was lower than control. The results of salinity, pH and moisture contents of kimchi paste did not show any significant differences during storage, however, the titratable acidity was increased. In sensory evaluation, salted Kimchi cabbage packed with the brine showed higher score in overall preference than control. Kimchi paste showed 4.9~6.1 score in overall preference during storage. The titratable acidity of kimchi prepared with stored salted Kimchi cabbage and kimchi paste was lower than control. But, the results of sensory evaluation did not show significant difference among treatments. The study suggested that the use of 2% brine is an effective way for extending shelf-life of salted Kimchi cabbage and Kimchi prepared with stored salted Kimchi cabbage and kimchi paste every week is effective to delay the fermentation but no difference in sensory evaluation.

Performance Evaluation of Hydrogen Separation and Generator for Hydrogen Water (수소수를 위한 수소분리 및 생성기 성능 평가)

  • Kim, Gui-Jung;Han, Jung-Soo
    • Journal of Digital Convergence
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    • 제14권9호
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    • pp.281-286
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    • 2016
  • In this paper, we optimized the structure of hydrogen water generator and assessed by developing a generator with dissolved hydrogen amount(1,000~1,200 ppb) of world-class level. Evaluation is divided into four types, such as dissolved hydrogen amount, pH, maximum pressure, redox potential, and it was evaluated for each of the targets. It was performed through the experiment of four in all five times and all of them show superiority results appearing in the target range. In addition, the assessment got 25/30 functionality, 17/20 maintainability, 26/30 usability, and 19/20 efficiency. In particular, we proved the validity of this study in high efficiency. We developed this hydrogen water generator system as possible to be substitution of water purifier.

Evaluation of the Potential of Commercial Vitamin Drinks to Induce Tooth Erosion

  • Kim, Han-Na;Yoon, Tae-Lim;Min, Ji-Hyun
    • Journal of dental hygiene science
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    • 제19권3호
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    • pp.154-161
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    • 2019
  • Background: The market for vitamin drinks is expanding both in Korea and worldwide. However, it was difficult to find studies regarding the possibility of tooth erosion induction due to vitamin drinks. The purpose of the present in vitro study was to evaluate the effect of tooth erosion caused by a few commercial vitamin beverages on bovine teeth enamel in terms of erosion depth and fluorescence loss. Methods: Three experimental groups (vitamin drinks), a positive control group (Coca-Cola), and a negative control group (mineral water) were established. Each group consisted of 5 specimens obtained from sound bovine teeth. The pH and titratable acidity of beverages were measured. Specimens were immersed in the beverages and artificial saliva for 6 and 18 hours, respectively. This cycle was repeated for 5 days. The depth of the tooth loss caused by tooth erosion (erosion depth) and maximum loss of fluorescence (Max ${\Delta}F$) were measured using the microscope and quantified light-induced fluorescence-digital, respectively. For the statistical analysis, the Kruskal-Wallis test and ANOVA were used to compare the erosion depth and Max ${\Delta}F$ of the enamel surfaces. In addition, Spearman correlations were estimated. Results: The pH of the three vitamin beverages ranged from 2.65 to 3.01, which is similar to that of the positive control group. All beverages, except mineral water, had sugar and acidic ingredients. Vitamin drinks and the positive control, Coca-Cola, caused tooth erosion lesions, and showed significant differences in erosion depth compared to mineral water (p<0.05). The vitamin beverages with low pH were associated with high erosion depth and Max ${\Delta}F$. Conclusion: Vitamin drinks have the potential to cause tooth erosion.

Isolation and Characterization of Potential Starter Yeasts from Traditional Moroccan Sourdoughs

  • Aouine, Mouna;Misbah, Asmae;Elabed, Soumya;Haggoud, Abdelatif;Mohammed, Iraqui Houssaini;Koraichi, Saad Ibnsouda
    • Microbiology and Biotechnology Letters
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    • 제49권4호
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    • pp.501-509
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    • 2021
  • The increasing demand for baked products has given a boost to research on isolation and selection of novel yeast strains with improved leavening activity. Twelve sourdough samples were collected from several localities of the Fez region in Morocco. The pH and total titratable acidity (TTA) values of these samples varied from 3.03-4.63 and 14-17.5 ml of 0.1 N NaOH/10 g of sourdough, respectively, while yeast counts ranged from 5.3 6.77 Log CFU/g. Thirty-two yeast isolates were obtained and evaluated for their leavening ability. Out of all isolates, four yeasts molecularly identified as Saccharomyces cerevisiae (three strains) and Kluyveromyces marxianus (one strain) showed highest specific volumes of 4.69, 4.55, 4.35 and 4.1 cm3/g, respectively. These strains were further assessed for their tolerance to high concentrations of salt, sugar, elevated temperatures, and low pH conditions. K. marxianus showed higher resistance than the S. cerevisiae. Thus, Moroccan sourdoughs harbor technologically relevant yeasts that could be used as potential starters for bread preparation.

Physicochemical and Microbiological Properties of Skate (Raja kenojei) Kimchi on the Market (시판 홍어 김치의 이화학적 및 미생물학적 특성)

  • Kim, Kyung-Hee;Cho, Hee-Sook
    • Journal of the Korean Society of Food Culture
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    • 제23권2호
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    • pp.235-242
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    • 2008
  • In this study, the physicochemical and microbiological properties of market-available skate (Raja kenojei) kimchi were evaluated in comparison to long-term fermented Baechu kimchi. The comparative results for the skate (Raja kenojei) and Baechu kimchi products are as follows: salt concentrations = 3.40% and 3.95%, respectively; pH and acidity values = 4.01 and 3.90, and 0.65% and 0.82%, respectively; redox potential Eh values = 119.82 mV and 123.08 mV respectively; reducing sugars levels = 15.51 mg% and 13.23mg%, respectively; ascorbic acid levels = 24.21mg% and 22.18mg%, respectively; color L-values = 46.86 and 44.54, a-values = 15.46 and 12.28, and b-values = 29.94 and 28.36, respectively; hardness properties = 11.36 kgf and 10.23 kgf, respectively; hot water soluble pectin (HWSP) contents and sodium hexametaphosphate soluble pectin (NaSP) contents = 15.23% and 17.35%, and 32.51% and 29.64%, respectively; hydrochloric acid soluble pectin (HClSP) contents = 55.1% and 53.2%, respectively; total viable cell counts = $4.78{\times}10^8$ and $1.35{\times}10^8$, respectively; lactic acid bacteria counts = $5.18{\times}10^5$ and $1.32{\times}10^5$, respectively; and yeast levels = $8.52{\times}10^5$ and $5.23{\times}10^5$, respectively.