• Title/Summary/Keyword: Quality properties

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Changes in Allergenicity and Quality of Nuruk during Fermentation (전통 누룩 발효과정 중 품질 및 항원성 변화)

  • Lee, Hyo-Hyung;Lee, Jin-Hyeong;Ko, Yu-Jin;Park, Mi-Hwa;Lee, Jeong-Ok;Ryu, Chung-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.1
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    • pp.76-82
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    • 2009
  • Wheat is the most widely cultivated cereal and an important source of dietary protein worldwide. Wheat allergy, defined as an adverse immunologic reaction to wheat, encompasses a broad spectrum of disorders with different pathomechanisms and clinical manifestation. The Nuruk, a traditional Korean Koji for brewing, was made with wheat flour and fermenting microbes such as bacteria, yeast and mold. The strains grown on Nuruk secrete various enzymes as amylase and protease. By the activation of such enzymes, starch and proteins in Nuruk are hydrolyzed to sugar and amino acid. Therefore, it is supposed to reduce allergic proteins in wheat. To study quality properties and degradation degree of allergenicity in Nuruk by fermentation, we investigated the changes of general ingredients and allergenicity in Nuruk during fermentation. Moisture contents was decreased from 24.2% to 13.6% during fermentation. Crude lipid and protein contents were gradually increased during fermentation. After 15 days of fermentation, reducing sugar and total sugar contents were reached its maximum level, and they were 27.45% and 39.00%, respectively. Acid and neutral protease activity were significantly increased during fermentation, but alkaline protease activity was not detected. ${\alpha}$-amylase activity was gradually increased and showed maximum level about 2,833.00 U/g after 15 days of fermentation. Glucoamylase activity was the highest level about 497.9 U/g after 10 days of fermentation. The increase of these proteolytic and saccharogenic enzyme activities will provide efficient condition for production of rice wine. Also, protein fractions were isolated from Nuruk, and degradation of these proteins during fermentation were confirmed by SDS-PAGE. IgE immunoblotting using patient's sera with wheat allergy was performed to confirm allergenic protein in Nuruk. These results as fermentation of Nuruk will provide a useful tool for developing safer wheat products to prevent wheat allergy.

Studies on the Quality Characteristics and Shelf-life of Maejackwa Containing Nuts and Seeds Prepared by Baking Method (굽는 방법으로 제조한 견과종실류 첨가 매작과의 품질특성 및 저장성에 관한 연구)

  • Chung, Hai-Jung;Kim, Sung-Joon;Baek, Jung-Eun;Sung, Dae-Kyung;Song, Hwa-Youn;Lee, Jin-Young;Kim, Gyu-Heun
    • Korean journal of food and cookery science
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    • v.24 no.6
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    • pp.811-817
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    • 2008
  • The principal objective of this study was to evaluate the effects of baking method on the quality and shelf-life of Maejakgwa containing nuts and seeds. Four different types of nuts and seeds (almond, cashewnut, coconut, and sunflower seed) were added to flour, and baking method was applied to prepare the Maejakgwa, physicochemical properties of which were then evaluated. The proximate composition analysis demonstrated that crude protein, crude fat, and ash contents were higher in the Maejakgwa containing nuts and seeds than in the control group. The lightness (L) value of the control Maejakgwa was lower than that observed in the groups containing nuts and seeds. Maejakgwa made with cashewnut, coconut, and sunflower seed evidenced higher yellowness (b) values than were recorded in the control and coconut groups. The incorporation of cashewnut, coconut and sunflower seed into the Maejakgwa lowered the hardness values (p<0.05). Our consumer test demonstrated that Maejakgwa prepared with almond was the most highly preferred, and the control group was the least favored. After 30 days of storage at $60^{\circ}C$, the peroxide value of the Maejakgwa containing sunflower seed was substantially higher than in any other groups, thereby suggesting that the addition of sunflower seeds resulted in accelerated lipid oxidation. No noticeable changes in peroxide values were observed in the groups prepared with coconut and cashewnut during storage time. The acid value increased with increasing storage time, and the addition of sunflower seed evidenced the highest values as compared to other groups.

Effect of Packaging Methods on the Quality Properties of Stick Type Restructured Jerky (재구성 스틱형 육포의 포장방법이 저장중 품질특성에 미치는 영향)

  • Choi, Yun-Sang;Jeong, Jong-Youn;Choi, Ji-Hun;Han, Doo-Jeong;Kim, Hack-Youn;Lee, Mi-Ai;Paik, Hyun-Dong;Kim, Cheon-Jei
    • Food Science of Animal Resources
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    • v.27 no.3
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    • pp.290-298
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    • 2007
  • The effect of packaging methods on the quality of stick type restructured jerky was investigated in terms of pH, water activity $(A_w)$, TBA (thiobarbituric acid) value, total bacterial counts, and sensory evaluation during storage at room temperature $(25^{\circ}C)$ for 90 days. The jerky was subjected to plastic or vacuum packaging at $(25^{\circ}C)$. The pH decreased slightly as storage time increased (p<0.05), but there were no significant differences between the packaging methods. The water activity of jerky in plastic packaging decreased as storage time increased (p<0.05), however jerky in vacuum packaging showed no significant change. Vacuum packaging resulted in a higher water activity value than plastic packaging. The TBA and hardness values decreased as storage time increased (p<0.05), and there were significant differences between packaging methods during the storage period (p<0.05). The total bacterial counts in vacuum packaged jerky were lower than jerky in plastic packaging. The sensory evaluation of each treatment decreased slightly as storage time increased (p<0.05), however there was no significant difference between packaging methods. Based on our findings, we conclude that vacuum packaging provides more effective storage than common packaging of jerky.

Changes in Various Quality Characteristics of Short-ripened Salami During Storage at Chilled or Room Temperatures (단기숙성 살라미의 냉장 및 실온저장 중 품질 특성 변화)

  • Lee, Keun-Taik;Lee, Youn-Kyu;Son, Se-Kwang;Choi, Suk-Ho;Lee, Seung-Bae
    • Food Science of Animal Resources
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    • v.29 no.1
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    • pp.24-33
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    • 2009
  • This study investigated the microbial contamination levels of raw meats used for short-ripened salami and changes in the microbial and physico-chemical properties of the product during storage at 10 and $25^{\circ}C$ for up to 120 days. The microbial counts of raw meats ranged between 2 and 4 Log CFU/g. Frozen-thawed sow meat showed higher total aerobe and Enterobacteriaceae counts than fresh chilled pork and pork back fat. Staphylococcus aureus was found in all raw materials except fresh chilled pork samples, and Clostridium perfringens was detected in a sample stored for 21 days at $25^{\circ}C$. The counts of total aerobes, lactic acid bacteria and Staphylococcus spp. decreased more rapidly at $25^{\circ}C$ than at $10^{\circ}C$ when the storage time was extended. The growth of Enterobacteriaceae, Pseudomonas spp., Clostridium spp., yeast, and mold were restricted to levels below 2 Log CFU/g during storage. The contents of salt, water, crude protein, crude fat, and ash of salami samples were 3.4, 33.4, 30.8, 32.7, and 4.3%, respectively, which were not affected by storage time or temperature. The pH value of the salami was initially 4.79 and increased to 5.02 and 5.26 after 120 days of storage at 10 and $25^{\circ}C$, respectively, whereas the water activity values decreased from an initial value of 0.91 to 0.90 and 0.88 after 120 days at 10 and $25^{\circ}C$, respectively. The TBA and VBN values increased slowly during storage. The redness value of the salami samples stored at $25^{\circ}C$ decreased more significantly than the samples stored at $10^{\circ}C$. With increased storage time, the values for the rheological characteristics of the salami in terms of hardness, brittleness, elasticity, cohesiveness, gumminess, and adhesiveness tended to decrease more remarkably at $25^{\circ}C$ than at $10^{\circ}C$. Based on sensory evaluation scores, it appears that short-ripened salami is no longer acceptable after 90 days at $10^{\circ}C$ and 30 days at $25^{\circ}C$.

Comparing the Properties and Functionality of Kimchi Made with Korean or Japanese Baechu Cabbage and Recipes (한국산 및 일본산 배추를 이용하여 제조한 한국식 김치와 일본식 김치의 품질 특성과 기능성 비교)

  • Kim, Hee-Young;Kil, Jeung-Ha;Park, Kun-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.4
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    • pp.520-526
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    • 2013
  • To determine the kimchi with the best quality and functional characteristics, we manufactured and compared recipes for Korean and Japanese kimchi made either Korean or Japanese baechu cabbages. All batches were fermented for 4 weeks at $5^{\circ}C$, and tested for pH, texture, microbial count, sensory evaluation, DPPH radical-scavenging activity, and cell proliferation (using the MTT assay on AGS human gastric cancer cells). By the third week of fermentation, Korean kimchi made with Korean baechu (KK) and Japanese kimchi made with Korean baechu (KJ) showed a higher acidity than Korean or Japanese kimchi made with Japanese baechu (JK and JJ, respectively). KK ranked highest in springiness, followed by KJ, JK, and JJ. Therefore, the texture of kimchi produced with Korean baechu was appears better than kimchi produced with Japanese baechu. This was confirmed in masticatory tests. Kimchi produced with Korean baechu (KK and KJ) showed lower total aerobic bacterial counts, while the total lactic acid bacterial counts were higher (p<0.05). In sensory evaluation test, KK received the highest overall acceptability score, while JJ earned the lowest score. In the DPPH assay for anti-oxidative activity, KK showed a 94% anti-oxidative effect, followed by KJ (92%), JK (91%), and JJ (88%) (p<0.05). In the MTT assay for analyzing the cell proliferation of AGS human gastric cancer cells, KK showed a 64% anticancer effect in vitro, followed by KJ (57%), JK (38%), and JJ (26%). Therefore, the anti-oxidative and anti-cancer functionalities of kimchi made with Korean baechu were higher than those made with Japanese baechu, regardless of the kimchi recipe applied. Overall, Korean baechu had important and superior effects on the quality and functionality of kimchi.

Investigating the Influence of Perceived Usefulness and Self-Efficacy on Online WOM Adoption Based on Cognitive Dissonance Theory: Stick to Your Own Preference VS. Follow What Others Said (온라인 구전정보 수용자의 지각된 정보유용성과 자기효능감이 구전정보 수용의도에 미치는 영향에 관한 연구: 의견고수와 구전수용의 비교)

  • Lee, Jung Hyun;Park, Joo Seok;Kim, Hyun Mo;Park, Jae Hong
    • Asia pacific journal of information systems
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    • v.23 no.3
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    • pp.131-154
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    • 2013
  • New internet technologies have created a revolutionary new platform which allows consumers to make decision about product price and quality quickly and provides information about themselves through the transcript of online reviews. By expressing their feelings toward products or services on virtual opinion platforms, users extend their influence into cyberspace as electronic word-of-mouth (e-WOM). Existing research indicates that an impact of eWOM on the consumer decision process is influential. For both academic researchers and practitioners, investigating this phenomenon of information sharing in online website is essential given the increasing number of consumers using them as sources of purchase decisions. It is worthwhile to examine the extent to which opinion seekers are willing to accept and adopt online reviews and which factors encourage adoption. Discerning the most motivating aspects of information adoption in particular, could help electronic marketers better promote their brand and presence on the internet. The objectives of this study are to investigate how online WOM influences a persons' purchase decision by discovering which factors encourage information adoption. Especially focused on the self-efficacy, this research investigates how self-efficacy affects on information usefulness and adoption of online information. Although people are exposed to same review or comment about product or service, some accept the reviews while others do not. We notice that accepting online reviews mainly depends on the person's preference or personal characteristics. This study empirically examines this issue by using cognitive dissonance theory. Specifically, in the movie industry, we address few questions-is always positive WOM generating positive effect? What if the movie isn't the person's favorite genre? What if the person who is very self-assertive so doesn't take other's opinion easily? In these cases of cognitive dissonance, is always WOM generating same result? While many studies have focused on one direct of WOM which indicates positive (or negative) informative reviews or comments generate positive (or negative) results and more (or less) profits, this study investigates not only directional properties of WOM but also how people change their opinion towards product or service positive to negative, negative to positive through the online WOM. An experiment was conducted quantitatively by using a sample of 168 users who have experience within the online movie review site, 'Naver Movie'. Users were required to complete a survey regarding reviews and comments taken from the real movie page. The data reflected user's perceptions of online WOM information that determined users' adoption level. Analysis results provide empirical support for the proposed theoretical perspective. When user can't agree with the opinion of online WOM information, in other words, when cognitive dissonance between online WOM information and users' preference occurs, perceived self-efficacy significantly decreases customers' perception of usefulness. And this perception of usefulness plays an important role in determining users' intention to adopt online WOM information. Most of researches have been concentrated on characteristics of online WOM itself such as quality or vividness of information, credibility of source and direction of online WOM, etc. for describing effect of online WOM, but our results suggest that users' personal character (e.g., self-efficacy) plays decisive role for acceptance of online WOM information. Higher self-efficacy means lower possibility to accept the information that represents counter opinion because of cognitive dissonance, whereas the people that have lower self-efficacy are willing to accept the online WOM information as true and refer to purchase decision. This study suggests a model for understanding role of direction of online WOM information. Also, our result implicates the importance of online review supervision and personalized information service by confirming switching opinion negative to positive is more difficult than positive to negative through the online WOM information. This implication would help marketers to manage online reviews of their products or services.

Physicochemical Characteristics of Sikhye (Korean Traditional Rice Beverage) with Specialty Rice Varieties (특수미 품종에 따른 식혜의 이화학적 특성)

  • Kim, Kee-Jong;Woo, Koan-Sik;Lee, Jin-Seok;Chun, A-Reum;Choi, Yoon-Hee;Song, Jin;Suh, Sae-Jung;Kim, Sun-Lim;Jeong, Heon-Sang
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.11
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    • pp.1523-1528
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    • 2008
  • This study was carried out to compare the physicochemical characteristics and sensory quality of Sikhye (a Korean traditional rice beverage) prepared with specialty rice varieties. The results showed that Ilpum had higher hulling recovery, milled/brown rice ratio, and milling recovery than Sulgaeng, Baegjinju, Baegjinju 1, and Dongjinchal. The alkali digestive value, protein content, and amylose contents of Sulgaeng were 6.3, 7.3% and 19.3%, respectively. The highest brix degree was $10.00^{\circ}Bx$ in Baegjinju Sikhye. The turbidity appeared at 0.4440, 0.4100, 0.3828, 0.3372, 0.1414 in Ilpum, Baegjinju, Baegjinju 1, Sulgaeng, and Dongjinchal Sikhye, respectively. There were no significant differences in pH and maltose contents among the groups. The highest L-value was 44.62 in Ilpum Sikhye. The a-value and b-value were $-1.66{\sim}-0.70$ and $-9.18{\sim}-5.19$, respectively. Finally, the sensory evaluation results indicated that there were no significant differences in appearance, aroma, and taste between the groups, and the Sulgaeng Sikhye showed higher overall quality than the Dongjinchal Sikhye as the control.

Quality Properties of the Refrigerated or Frozen Irradiated Beef Patty (방사선조사된 패티용 분쇄우육의 가열전 품질특성)

  • Jeon, Ki-Hong;Oh, Se-Wook;Lee, Nam-Hyouck;Kim, Yun-Ji;Park, Ki-Jae;Kim, Young-Ho
    • the MEAT Journal
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    • s.36 summer
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    • pp.72-86
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    • 2009
  • Microbial reduction, physicochemical property, and sensory evaluation of irradiated beef patty were investigated. The microbial counts of refrigerated beef patty were reduced to below the number of 3 logs after irradiation at 3 kGy. But no viable microorganism was detected in frozen beef patty irradiated at 3 kGy. Food additives such as nitrite, salt, phosphate and ascorbic acid did not affect on the inactivation of microorganism by irradiation. The irradiation effect on the water holding capacity was not significant, but frozen irradiated beef patty showed higher water holding capacity than refrigerated beef patty. The drip loss of irradiated beef patty did not show significant differences according to irradiation doses. Considering the influence of food additives, the irradiated beef patty mixed with salt and phosphate showed lower drip loss than that without food additives. In refrigerated beef patty, TBARS values were increased with increase of irradiation doses and showed lower values in the beef patty mixed with food additives than that without food additives. The redness of refrigerated beef patty showed highest values at 3 kGy of irradiation and then decreased with increasing irradiation doses, while in the frozen beef patty did not show distinct tendency according to the irradiation doses or food additives. In sensory evaluation. the irradiated beef patty showed unpleasant smell as compared with the non irradiated beef patty, but showed somewhat higher score in smell at the sample contained ascorbic acid regardless of irradiation doses.

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Effects of Membrane-filtered Powder of Sunmul on the Quality Characteristics of Noodles (막분리한 순물의 농축분말 첨가가 국수의 품질에 미치는 영향)

  • Chung, Hai-Jung;Choi, Min-Hee;Kim, Woo-Jung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.2
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    • pp.199-204
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    • 2006
  • This study was conducted to investigate the quality characteristics of noodles prepared with the addition of nanofiltered (NF) powder of sunmul. Noodles were prepared with different levels $(0\%,\;1.5\%,\;3\%\;and\;5\%,\;w/w)$ of NF powder and physico-chemical properties were examined. Results of rapid visco analyzer showed that peak, trough, final viscosity and set back decreased as the NF powder level increased. The weight and volume of cooked noodles increased with the addition of NF powder. Turbidity of soup also increased as the amount of NF powder increased, indicating higher cooking loss. The color of wet and cooked noodles became greenish yellow as the NF powder level increased. Hardness, springiness, gumminess and brittleness of cooked noodles decreased with the increasing amount of NF powder. Results of sensory evaluation showed that noodles prepared with up to $3\%$ addition of NF powder was considered to be as acceptable as noodles prepared without NF powder.

Quality Characteristics of Kochujang Prepared with Korean Single-Harvested Pepper (Capsicum annuum L.) (한국산 일시 수확형 고추를 이용한 고추장의 품질 및 저장 특성)

  • Kim, Kyung-Seon;Park, Jae-Bok;Kim, Sun-A
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.6
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    • pp.759-765
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    • 2007
  • This study was conducted to analyze the chemical properties of single.harvested pepper (YW211, YW213), and to investigate the change of kochujang quality by the addition of single-harvested peppers. Capsaicinoids content of YW211 was $271.65{\pm}25.10mg/100g$ and ASTA color value of YW213 was $212.71{\pm}2.38$, which were comparatively higher values than commercial red peppers. Mixed red pepper powder used for kochujang production were prepared with various mixing ratios of commercial red peppers (YY & GR) and single-harvested pepper (YW211 & YW213). Capsaicinoids content of YY, $3.98{\pm}0.24mg/100g$, was increased to $52.61{\pm}8.62mg/100g$ by mixing 30% YW211. ASTA color value of GR was $110.63{\pm}1.89$ and was increased to $130.01{\pm}1.31$ by mixing 30% YW213. The pH values of kochujang added YW211 or YW213 were slowly reduced and acidities were increased during fermentation; however, both values weren't statistically different. The contents of amino nitrogen increased until 60 days, and then decreased thereafter. Reducing sugars were increased considerably until 30 days, and reduced slowly after fermentation for 90 days.