• Title/Summary/Keyword: titratable acid

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Effect of Quality Change of 'Fuji' Apple by Pressure Cooling (차압예냉 처리가 '후지' 사과의 품질 변화에 미치는 영향)

  • Park Hyung-Woo;Kim Sang-Hee;Cha Hwan-Soo;Kim Yoon-Ho;Choi Jee-Young
    • Food Science and Preservation
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    • v.13 no.4
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    • pp.427-431
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    • 2006
  • The research was conducted to measure the effect of pressure cooling of 'Fuji' apple during of 24 weeks. Weight loss in pressure cooling was lower than control at 24th week, and firmness in pressure cooling was higher than control. Titratable acidity in control and pressure cooling was 0.0823% 0.1103% in 24 weeks, respectively. Soluble solid content (SSC) in pressure cooling were higher than control. Decayed rate in control and pressure cooling was 46.4% 34.5% in 24 weeks, respectively. Total ascorbic acid contents were decreased in control and pressure cooling during 24 weeks. Therefore, it could be suggested that pressure cooling is more effective than control in storage of 'Fuji' apple.

Physicochemical Properties of Kefir Manufactured by a Two-Step Fermentation

  • Yoo, Sung-Ho;Seong, Ki-Seung;Yoon, Sung-Sik
    • Food Science of Animal Resources
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    • v.33 no.6
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    • pp.744-751
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    • 2013
  • The objective of this study was to assess the physicochemical and sensory changes of a kefir manufactured by a two-step fermentation (MTY, $1^{st}$ step: $37^{\circ}C$ for 9 h; $2^{nd}$ step: $24^{\circ}C$ for 15 h) and compare it with kefirs produced by two conventional methods (GTY, fermentation at $37^{\circ}C$ for 24 h; KEY, $22^{\circ}C$ for 24 h). Rapid changes in pH and titratable acidity (TA) were observed in samples from all three manufacturing methods during fermentation process and storage period. Lactic acid bacteria (LAB) counts of MTY increased gradually up to 12 h of fermentation, reaching 9.28 Log CFU/mL, with maximum value observed in this experiment of 9.48 Log CFU/mL. The LAB counts of all samples decreased significantly during storage. The highest viscosity was observed for MTY (1750-1771 cPs), compared with the lowest viscosity observed for KEY (1250-1277 cPs). The viscosity of all samples increased slightly during storage (1250-1805 cPs, p<0.05), as well as carbon dioxide content (0.01-1.36%, p<0.05), except for GTY. The most significant increase in alcohol concentration during storage period was seen in MTY from 0.01% to 1.36% (p<0.05). MTY scored significantly higher in most items of the sensory analysis, indicating that the product manufactured by the two-step fermentation method is more acceptable compared with conventionally produced kefirs.

Antioxidant Activity and Quality Characteristics of Yogurt Added Green Olive Powder during Storage

  • Cho, Won-Young;Yeon, Su-Jung;Hong, Go-Eun;Kim, Ji-Han;Tsend-Ayush, Chuluunbat;Lee, Chi-Ho
    • Food Science of Animal Resources
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    • v.37 no.6
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    • pp.865-872
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    • 2017
  • The objective of this study was to determine the antioxidant and quality characteristics of yogurt added green olive powder stored at $4^{\circ}C$ for 15 d. The following four groups were used in this study: Control group (GY0), Yogurt added with 1% green olive (GY1), with 3% green olive (GY3), and with 5% green olive (GY5). The more time of titratable acidity went by, the more it increased. Except GY0, viscosity tended to decrease in other groups (p>0.05), and the more time of syneresis went by, the more it increased, but GY3 of them showed the lowest syneresis. Lactic acid bacteria showed no significant with GY0 until 5 d, but after that, GY1, GY3 and GY5 showed lower than GY0. Yogurt added green olive showed darker color than GY0 (low $L^*$ and high $a^*$). The antioxidant activity of GY5 was found to be the highest among the four groups at day 1 of storage. Total phenolic content, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and reducing power of GY5 was found to be the highest among the four groups at day 1 of storage which were 6.96 mg GAE/kg, 47.53%, and 0.57, respectively. In the sensory evaluation sweet and overall of GY3 indicated the highest score among the four groups. Results of this study demonstrated that green olive powder might be used to improve the antioxidant capacity and sensory characteristics of yogurt.

Biochemical, Microbiological, and Sensory Characteristics of Stirred Yogurt Containing Red or Green Pepper (Capsicum annuum cv. Chungyang) Juice

  • Kang, Su-Hyun;Yu, Mi-Sang;Kim, Jeong-Mee;Park, Sung-Kwon;Lee, Chi-Ho;Lee, Hong-Gu;Kim, Soo-Ki
    • Food Science of Animal Resources
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    • v.38 no.3
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    • pp.451-467
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    • 2018
  • Hot pepper has anti-obesity effects by controlling appetite and reducing blood fat level. To reduce the pungency of capsaicin, red or green hot pepper juice was fermented with Bacillus licheniformis SK1230. Fermented hot pepper juice was then added into yogurt at different ratios. The pH of yogurt added with hot pepper juice was decreased from 4.61 to 4.48. Titratable acidity and counts of lactic acid bacteria were increased with increasing amount of pepper juice added. However, the viscosity was decreased significantly compared to the control. On chromaticity test, when more pepper juice was added, $L^*-value$ was decreased whereas $a^*$- and $b^*$- values were increased significantly (p<0.05). The spectrum of antimicrobial activity of yogurt was slightly changed compared to using pepper juice. Total polyphenol contents and antioxidant activity were increased with increasing amount of pepper juice added. Stirred yogurt added with fermented red pepper juice at 3% or green pepper juice at 1% showed high scores in flavor, appearance, texture, and overall acceptance in sensory test. Yogurt added with fermented pepper juice with reduced pungency showed also good palatability during storage at $4^{\circ}C$. Yogurt with added hot pepper juice can be play an important role in functional food relative to anti-obesity.

Change of Physicochemical Properties and Hesperidin Contents of Jeju Processing Citrus Fruits with the Harvest Date (수확시기별 제주산 가공용 감귤의 이화학적 특성과 hesperidin함량)

  • Yang, Jiwon;Choi, Il Sook;Lee, Jeong Hee;Cho, Chang-Won;Kim, Sung Soo
    • Food Science and Preservation
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    • v.19 no.5
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    • pp.652-658
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    • 2012
  • This study, the changes in physicochemical properties and hesperidin content of Jeju-processed citrus fruits according to the harvest date were evaluate. The soluble-solid content, pH, and soluble solid-acid ratios gradually increased, but titratable acidity slightly decreased with a delay in the harvest date. The color index, lightness, yellowness, and turbidity slightly decreased whereas the redness slightly increased with a delay in the harvest date. The hesperidin content slightly decreased with a delay in the harvest date. Hesperidin, which is the major cause of juice cloudiness, decreased with a delay in the harvest date. These results suggest that later-harvested fruit juice is bound to be less cloudy.

A Study on Quality Characteristics of Kimchi with added Mulberry Leaves Extracts (뽕잎 추출액 첨가 김치의 품질 특성에 관한 연구)

  • Lee, Young-Sook;Rho, Jeong-Ok
    • Journal of the East Asian Society of Dietary Life
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    • v.24 no.6
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    • pp.827-836
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    • 2014
  • In this study, the effects of Mulberry leaves extract (ME) addition on the quality of Kimchi was investigated during 30 days of fermentation at $5^{\circ}C$. ME was added to salted cabbage at concentrations of 0% (C), 0.4% (ME1), 0.8% (ME2) and 1.2% (ME3) (w/w). The pH of Kimchi added above 0.8% ME was higher than that of Kimchi without ME after 12 days of fermentation. During overall fermentation, the titratable acidity of Kimchi with 1.2% ME remained at the lowest level. The degree of salinity decreased with increasing amount of added ME, whereas control groups showed the highest salinity. In L, a and b values of samples, the highest Figures of L and b were observed in control groups, and ME3 showed the highest value of a. In addition, the cutting force during the fermentation period was higher in all treated groups compared with control groups, and ME3 showed the highest hardness value. Moreover, growth of lactic acid bacteria and total bacteria were inhibited by addition of ME. In the sensory assessment, 0.4% ME improved the quality of Kimchi, showing the highest taste score and overall preference. Therefore, addition of 0.4% ME appears to be an acceptable approach to enhance the quality of Kimchi without reduction of acceptability.

Efface of Liquid Calcium Addition on the Quality of Kimchi during Fermentation (액상칼슘 첨가 김치의 숙성 중 품질에 미치는 영향)

  • Jang Se-Young;Kim Ok-Mi;Jeong Yong-Jin
    • Food Science and Preservation
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    • v.11 no.4
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    • pp.472-477
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    • 2004
  • This study was carried out to investigate the effect of liquid calcium(LC) on the quality of kimchi during fermentation. LC retarded the decreasing rate of pH and the increasing rate of titratable acidity during fermentation at $10^{\circ}C$, and the effect was more conspicuous at $7.0\%(v/w)$ than at $3.5\%(v/w)$ in each LC type. Microbial counts of total and lactic acid bacteria were lower in LC added kimchi than control before 8 days but higher in LC added kimhi after 8 days. Changes in color of a value were gradually increased, but L and b value were decreased. Calcium content of added LC on kimchi; A concentration $3.5\%(v/w),\;7.0\%(v/w)$ were $103{\sim}110\;mg\%,\;145{\sim}163\;mg\%$ and B concentration $3.5\%,\;7.0\%$ were $140{\sim}151\;mg\%,\;210{\sim}220\;mg\%$.

Changes in the Food Components during Storage of Oyster Mushroom Kimchi (느타리버섯 김치의 숙성중 식품학적 성분 변화)

  • 서권일;한서영
    • Food Science and Preservation
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    • v.9 no.1
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    • pp.51-55
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    • 2002
  • Changes in food components of oyster mushroom Kimchi were investigated during storage at 20$^{\circ}C$. The pH of raw oyster mushroom Kimchi (ROMK) was higher than that of Chinese cabbage Kimchi (control) at initial stage, but it was lower than that of control after 1 day of storage. pH of blanched oyster mushroom Kimchi (BOMK) was slightly higher than that of controls The titratable acidity of oyster mushroom Kimchi was in inverse state to the pH. Amino acid nitrogen content of Kimchi tended to increase during storage, the content of ROMK was higher than that of control, the content of BOMK was not different from that of control. The reducing sugar content of Kimchi decreased significantly during storage, the content of ROMK was higher than that of controls the content of BOMK was slightly lower. The bacterial number of control increased rapidly at 2 days fermantation and reached plateau afterward. The number of ROMK tended to he alike that of control during storages the number of BOMK was fewer than that of control. On the taste panel of Kimchi after 1 day of storages ROMK obtained higher score than BOMK but the score was lower than control.

Quality Characteristics of Commercial Kimchi Paste (시판 김치 양념의 품질특성)

  • Cheon, Seon-Hwa;Lee, Sang-Il;Hwnag, In-Min;Seo, Hye-Young
    • Korean journal of food and cookery science
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    • v.33 no.1
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    • pp.9-19
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    • 2017
  • Purpose: This study was conducted to obtain basic data for the quality characteristics of commercial kimchi pastes. Methods: The physicochemical, microbial, and sensory quality characteristics of kimchi paste purchased from 12 companies (KP 1-12) were investigated. Results: Commercial kimchi pastes contained a moisture content of 61.60-82.99%. The pH and titratable acidity of samples were 4.88-5.92 and 0.56-1.58%, respectively, and salinity was on average, 3%. The reducing sugar content was approximately 67.35 mg/mL, and those of KP 8 was higher by approximately 100 mg/mL. American Spice Trade Association (ASTA) value of kimchi pastes varied based on the samples. The commercial kimchi pastes contained capsaicin and dihydrocapsaicin at 1.51-7.84 and, 0.54-2.26 mg/100 g, respectively; sodium and potassium contents were 383.32-1,563.45 mg/100 g and 264.49-571.95 mg/100 g, respectively; and the Na/K ratio was 1.21-5.48. The number of aerobic bacteria and lactic acid bacteria detected from 5.00 to 8.00 log CFU/g. The number of yeast and mold detected from 0.50 to 2.66 log CFU/g. Coliform was detected at approximately 3-4 log CFU/g, whereas Escherichia coli was detected only in KP 3 and KP 7. Overall acceptability of kimchi paste showed a higher score in KP 1. The commercial kimchi pastes showed higher salinity and Na/K ratio and E. coli was detectedin some kimchi paste samples. Conclusion: Therefore, further studies are required to lower the Na/K ratio, for recipe developments, and the standardization of quality and hygiene safety of kimchi paste.

Biochemical Changes in Muscle Protein of Squid Sikhae during Fermentation -Effects of Temperature and Moisture Content- (오징어 식해 숙성중 단백질 화학적 변화 -온도 및 수분함량의 영향-)

  • Lee, Nam-Hyouck;Oh, Se-Wook;Kim, Young-Myoung
    • Korean Journal of Food Science and Technology
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    • v.28 no.2
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    • pp.292-297
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    • 1996
  • In this study, biochemical changes of muscle protein in squid Sikhae prepared at various temperatures and moisture content were investigated. The pH values in squid Sikhae decreased rapidly with increase in titratable acidity during fermentation at high temperature and moisture content. Growth rate of lactic acid bacteria increased rapidly during fermentation at high temperature and moisture content. Changes in muscle protein subunit were analyzed by SDS-PAGE; myosin heavy chain component disappeared completely during preparation of squid Sikhae and actin component decreased slowly during fermentation. Therefore, it was suggested that myosin heavy chain component in squid muscle protein was autolyzed at the incipient for-mentation time and actin component was degraded by acidic protease in muscle and protease produced from microorganisms during fermentation.

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