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1.
Foods ; 10(3)2021 Mar 12.
Article in English | MEDLINE | ID: mdl-33809083

ABSTRACT

The relationship between food-related individual characteristics and performance in sensory evaluation was investigated. The study focused on differences in discriminative ability and perceptual sensitivity according to levels of product involvement or food neophobia during the intensity rating of sensory attributes in consumer profiling. Consumers (N = 247) rated the intensity of attributes for seven flavored black tea drinks and completed the Food Neophobia Scale and the Personal Involvement Inventory measuring product involvement with the flavored black tea drink. In the higher product involvement (IH) group and the lower food neophobia (NL) group, the number of sensory attributes representing the sample effect and of subsets discriminating the samples were greater, and more total variance of the samples was explained. The higher the product involvement or the lower the food neophobia, the greater the differentiation in characterizing samples with more attributes in the intensity ratings. Interestingly, the high food neophobia (NH) group showed less active performance compared to the NL group during the sensory evaluation overall, but the NH group was more concerned about unfamiliar attributes and samples. The results implied that the positive attitude resulting from high product involvement and low food neophobia may induce more active behavior and better performance during the sensory evaluation.

2.
Food Sci Biotechnol ; 29(3): 359-369, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32257519

ABSTRACT

Food involvement is one of the personality traits that influences the food cognition and behavior of consumers. Given the irrelevance of previous food involvement scales such as measuring lifestyle diligence and a food culture, this study aimed to develop the food involvement inventory (FII) designed specifically for foods and current consumers. This study focused on identifying the factors/constructs of the FII that would best represent and explain food involvement through item generation, administration, and validation. The collected items from involvement-related scales and expert discussions were administrated based on the evidence of construct and content. Validation of the FII based on the exploratory factor analysis identified four attitudinal components as constructs (affective, cognitive, behavioral-purchase, and behavioral-cooking) within the final 25 items. These four constructs constituted structural models for the FII, and the models were shown to be acceptable in the confirmatory factor analysis.

3.
Food Sci Biotechnol ; 29(1): 45-53, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31976126

ABSTRACT

Hydrolyzed vegetable protein (HVP) has received wide attention as a flavor enhancer that can replace monosodium glutamate (MSG). The objective of this study was to investigate the effect of added acid-hydrolyzed vegetable protein (aHVP) and enzyme-hydrolyzed vegetable protein (eHVP) on consumers' responses of Korean Doenjang soup. One hundred and twenty female consumers who consume Doenjang soup on a regular basis were participated in consumer test of 8 Doenjang soup samples containing a flavor enhancer such as aHVP, eHVP, or MSG. The results indicated that the HVPs showed flavor-enhancing effects similar to those of MSG, respectively. It was also found that consumers preferred specific aHVP- or eHVP-added samples to MSG-added samples. These findings suggest that HVP could be used as a flavor enhancer in Doenjang products such as Doenjang soup.

4.
J Food Sci ; 84(10): 2961-2972, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31612540

ABSTRACT

The high sodium content of kimchi is a contradicting factor from its fame as a healthy food. With the aim of reducing the sodium content of kimchi, the objective of this study was to understand the effect of providing "sodium-reduced" information on the acceptance of kimchi according to the age of consumption. Six sodium-reduced kimchi samples, prepared with different percentages of sodium reduction (25% and 50%) and potassium chloride concentration (none, 0.47%, and 0.93%), were compared to control kimchi (2.0% w/v NaCl). Sensory characterization of the samples was obtained using descriptive analysis. A total of 167 kimchi consumers with balanced proportion of the young (below 40) and the old (above 40) evaluated seven kimchi samples in either of the two conditions: blind testing condition or informed testing condition where each of the samples was provided with a label that informed about "sodium reduction percentage" and "whether a salt replacer was used or not." The results showed that in terms of healthiness perception, Korean female consumers believed that kimchi with a high sodium reduction rate would contribute to health in general, though an unfavorable notion of using a salt replacer was also observed. Also, the results suggested that promoting information about sodium reduction in kimchi would generally increase consumer acceptance. However, this phenomenon was influenced not only by the sample for which the information was provided, but also by the age of consumers with different health interests and kimchi experience. PRACTICAL APPLICATION: The findings of this study showed simply reducing sodium and promoting it with a health claim showed limitation in achieving a high level of sodium reduction, such as a 50% reduction rate, which implied the importance of using supplementary material such as potassium chloride that can fulfill the missing saltiness and flavors of the original product. Promotion of "sodium-reduced" claims in kimchi generally results in increased consumer acceptance. However, the effectiveness of the information was dependent on which sample was provided and the age of the consumers, among whom health interests and kimchi experience differ.


Subject(s)
Consumer Behavior , Diet, Sodium-Restricted/psychology , Fermented Foods/analysis , Potassium Chloride/analysis , Sodium Chloride/analysis , Vegetables/chemistry , Adult , Aged , Aged, 80 and over , Behavior , Female , Flavoring Agents/analysis , Food Additives/analysis , Humans , Male , Middle Aged , Taste , Young Adult
5.
Appetite ; 123: 306-316, 2018 04 01.
Article in English | MEDLINE | ID: mdl-29325771

ABSTRACT

This study was conducted to understand the acceptance levels of hot sauces among consumers from different culinary cultures. Two newly developed hot sauces [fermented red chili pepper with soybean-paste-based sauce(GS) and fermented red chili-pepper-based sauce(KS)] were compared with Tabasco sauce(TB) and Sriracha sauce(SR). Two separate cross-cultural home-use tests(HUTs) were conducted: pizza and cream soup were provided as food items in HUT 1, whereas grilled chicken wings and rice noodle soup were provided in HUT 2. Consumers residing in Denmark, South Korea, and US participated in each HUT (n≅100 per country). Acceptance levels and the reasons for (dis)liking particular hot sauces applied to food systems were assessed. The food items that paired well with different hot sauces when the sauces were applied freely to regular meals were also analyzed among the US and Korean subjects. When the hot-sauce samples were applied to pizza and cream soup, the preferred order of the samples exhibited a cross-cultural agreement (GS = KS > TB). In the case of grilled chicken and rice noodle soup, the acceptance rating was similar for the three types of hot sauces among Koreans, whereas the acceptance was higher for SR among the US subjects for both foodstuffs, while Danish subjects preferred GS and KS over SR. The US subjects did not like hot-sauce samples with sweet and weak spiciness, whereas the Korean and Danish subjects disliked the hot-sauce sample when it was too spicy and not sufficiently sweet. These findings indicate that the matching of particular sauces with specific food items is culture-dependent, and this needs to be considered when trying to export food products such as hot sauce to other countries.


Subject(s)
Capsicum , Consumer Behavior , Cross-Cultural Comparison , Food Handling , Food Preferences , Adult , Animals , Chickens , Denmark , Female , Fermentation , Humans , Male , Middle Aged , Poultry , Republic of Korea , Spices , Taste , Young Adult
6.
J Food Sci ; 83(2): 464-474, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29350752

ABSTRACT

Doenjang, a Korean traditional fermented soybean paste, is one of the most essential condiments in Korean cuisine. Condiments are rarely consumed as it is, and are generally applied to other foods. The objective of this study was to understand how sensory drivers of liking of Doenjang would be affected according to food forms in which it is evaluated: the original paste form compared with a normally consumed soup form, and to understand the association of familiarity of evaluated food form. Descriptive analysis and consumer acceptability test was performed in 2 consumption forms: the original paste form and the Doenjang soup from. For consumer liking test, elderly consumers who have more experience to traditional Deonjang were compared to the young in their response to Doenjang paste and soup. The descriptive analysis results showed that the characteristic sensory features of the Deonjang samples were little affected based on the food system in which it was evaluated. However, when the paste was applied in soup, the intensities of the characteristic sensory features were reduced. Acceptability and familiarity of traditional type Doenjang samples for the young and for the elderly consumers were very similar in paste, but it differed when the samples were evaluated in soup. Thus, expectation difference between the young and the elderly was better revealed in soup, a more common food form consumed in practice. The results of this study indicate the importance of understanding sensory drivers of liking for a condiment such as Doenjang in their commonly consumed forms. PRACTICAL APPLICATION: Compared to the original condiment form, expectation difference between the young and the elderly were better revealed in Deonjang soup, a food form normally consumed in practice. Thus, the results of this study reinforced the importance of investigating sensory drivers of liking for a condiment in a food form that is normally consumed in practice for accurate understanding on consumer preference.


Subject(s)
Condiments/analysis , Consumer Behavior , Food Additives/analysis , Soy Foods/analysis , Adolescent , Adult , Female , Fermentation , Humans , Middle Aged , Recognition, Psychology , Residence Characteristics/statistics & numerical data , Glycine max/chemistry , Taste , Young Adult
7.
Food Res Int ; 91: 148-160, 2017 01.
Article in English | MEDLINE | ID: mdl-28290319

ABSTRACT

Understanding cross-cultural differences in food perception is a key issue of food research in order to understand consumer behaviour in different countries. The objective of this study was to explore potential cultural differences of balsamic vinegar perception between Korean and Italian consumers using the sorted napping method. Nine balsamic vinegars different in terms of ingredients, aging time, and origin were evaluated by Korean (n=50) and Italian (n=49) consumers using sorted napping. Familiarity and food matching were also examined. Descriptive analysis was performed to verify the attitude of the consumers in product description. The results obtained from two groups of consumers in Korea and Italy revealed a higher description attitude of the Italians (higher number of total elicited attributes, of attributes in common with the trained panel, of attributes shared with the vocabulary reported in literature, of significant specific positive product-attribute associations). Italian subjects generated various descriptors associated with the European gastronomic culture (aromatic herbs, fortified wine, dried figs, Indian fig, Parmigiano-Reggiano cheese), whereas Korean consumers used more terms related to the Asian food culture (red ginseng, Chinese medicine, Japanese apricot, teriyaki sauce, persimmon vinegar, balloon flower roots). Moreover, cultural differences of food matching were also observed: the Italians would pair the balsamic vinegars mainly with vegetables, fruits and cheese, while Koreans would combine the balsamic vinegars preferably with bread, vegetables and meat. In conclusion, familiarity resulted the main factors for cross-cultural differentiation.


Subject(s)
Acetic Acid , Asian People/psychology , Consumer Behavior , Feeding Behavior/ethnology , Taste Perception , Taste , White People/psychology , Adolescent , Adult , Cross-Cultural Comparison , Female , Fermentation , Humans , Italy , Recognition, Psychology , Seoul , Young Adult
8.
J Sci Food Agric ; 96(4): 1362-72, 2016 Mar 15.
Article in English | MEDLINE | ID: mdl-25906998

ABSTRACT

BACKGROUND: The introduction of ready-to-drink (RTD) green tea beverage has allowed diverse consumers to consume green teas and related products. Green tea that has been traditionally consumed for its delicate flavor characteristics is also widely consumed for its recognition as a healthy product. Because it is reported that age difference exists in consideration of health-related information, the objective of the study was to investigate how sensory and non-sensory factors, in particular health-related information, price and packaging, would affect the flavor acceptability of green tea beverages, depending on consumers' age and gender. RESULTS: Regardless of the product information, old consumers preferred products that provided an indication of health beneficial effect. On the other hand, young consumers tended to be influenced by extrinsic product information such as packaging, brand/manufacturer and/or price, though these consumers were not so much influenced by health beneficial information as were the old consumers. CONCLUSION: The findings of the study implied that the influence of non-sensory information such as health beneficial information in flavor liking differed depending mostly on consumers' age, and little on gender, for RTD green tea beverages.


Subject(s)
Age Factors , Beverages , Consumer Behavior/statistics & numerical data , Food Labeling , Sex Factors , Tea , Adolescent , Adult , Beverages/economics , Camellia sinensis , Child , Costs and Cost Analysis , Female , Food Packaging , Humans , Male , Middle Aged , Nutritive Value , Sensation , Taste , Tea/economics , Young Adult
9.
Food Sci Biotechnol ; 25(3): 745-756, 2016.
Article in English | MEDLINE | ID: mdl-30263332

ABSTRACT

The present work explored how consumers' product perceptions differ when flavor familiarity with the product set varied. Half of the samples used in this study contained fermented ingredients (fermented red pepper or gochujang, a traditional Korean fermented soybean/red pepper paste), and the others were top selling hot sauce products in the US market. Free-choice profiling was performed by Korean and US consumers and was analyzed using GPA. Descriptive analysis was conducted and analyzed using PCA. While Korean and US consumers perceived product similarly along the first principal dimension which described distinctive sensory differences among the products, in the next principal dimension, it was found that these consumers perceived the products differently. Observations indicated that this discrepancy seemed to be originated from differences in flavor familiarity. This study showed flavor familiarity not only influences one's preference but also may influence perception of foods such as hot sauces.

10.
Food Sci Biotechnol ; 25(5): 1353-1360, 2016.
Article in English | MEDLINE | ID: mdl-30263416

ABSTRACT

Long steeping process of waxy rice involved in Gangjung production is essential for obtaining good quality Gangjung, but it causes many related problems. The objective was to examine physiochemical properties of waxy rice flour and expansion properties of Gangjung manufactured using waxy rice flour treated with protease (P-flour), α-amylase (A-flour), or in combination of the two (PA-flour) over different durations. While crude protein and reducing sugar contents of P-flour and Aflour differed depending on enzyme treatment time, it was not observed for PA-flour. Gangjung made with P-flour or A-flour could show similar expansion rate to that of Gangjung made with waxy rice flour steeped under the optimal condition, however, Gangjung made with PA-flour showed lower expansion rate than of the optimal one. These findings indicate that treatment of waxy rice flour with either protease or α-amylase, but not both, could reduce the steeping time involved in Gangjung production.

11.
J Food Sci ; 80(11): S2570-7, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26447813

ABSTRACT

UNLABELLED: In this study, consumer acceptability was considered as a tool of reducing sodium rather than just using it as a final examination of the successfulness of the substitution. This study consisted of 4 experimental steps. First, by gradually reducing the concentrations of NaCl, consumer rejection threshold (CRT) of NaCl in beef soup was examined. Then, the amount of KCl that can increase preference was examined in 2 low sodium beef soups, with sodium concentrations slightly above or below the CRT. Relative saltiness of various KCl and NaCl/KCl mixtures were also measured. Finally, consumers evaluated acceptability and intensities of sensory characteristics for 9 beef soup samples that differed with respect to NaCl content and/or KCl content with/without addition of salty-congruent odor (soy-sauce odor). The results showed that in the "above CRT" system, consumer acceptability as well as sensory profile of low sodium beef soup substituted using KCl had similar profile to the control although saltiness was not fully recovered, whereas in the "below CRT" system, consumer acceptability was not recovered using KCl solely as a substitute. Potential of using salty-congruent odor as a final touch to induce salty taste was observed; however, the results inferred the importance of having almost no artificialness in the odor and having harmony with the final product when using it as a strategy to substitute sodium. Overall, the results of the study implied the importance of considering consumer acceptability when approaching sodium reduction to better understand the potentials of the sodium substitutes and salty-congruent odor. PRACTICAL APPLICATION: Strategies attempting to reduce sodium contents in food have mainly substituted sodium to the level that provides equivalent salty taste and then examined consumer liking. However, these approaches may result in failure for consumer appeal. This study attempted to consider consumer acceptability as a tool of reducing sodium in beef soup substituted using potassium chloride and salty-congruent odor. The result showed that considering consumer acceptability during sodium reduction enabled to better understand the potentials of the sodium substitutes and salty-congruent odor.


Subject(s)
Consumer Behavior , Odorants , Potassium Chloride , Red Meat , Sodium Chloride, Dietary/administration & dosage , Sodium/administration & dosage , Taste , Animals , Cattle , Diet, Sodium-Restricted , Food Preferences , Humans , Soy Foods
12.
J Sci Food Agric ; 95(8): 1613-25, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25092220

ABSTRACT

BACKGROUND: The present study cross-culturally investigated the drivers of liking for traditional and ethnic chicken marinades using descriptive analysis and consumer taste tests incorporating the check-all-that-apply (CATA) method. Seventy-three Koreans and 86 US consumers participated. The tested sauces comprised three tomato-based sauces, a teriyaki-based sauce and a Korean spicy seasoning-based sauce. Chicken breasts were marinated with each of the five barbecue sauces, grilled and served for evaluation. Descriptive analysis and consumer taste tests were conducted. Consumers rated the acceptance on a hedonic scale and checked the reasons for (dis)liking by the CATA method for each sauce. A general linear model, multiple factor analysis and chi-square analysis were conducted using the data. RESULTS: The results showed that the preference orders of the samples between Koreans and US consumers were strikingly similar to each other. However, the reasons for (dis)liking the samples differed cross-culturally. The drivers of liking of two sauces sharing relatively similar sensory profiles but differing significantly in hedonic ratings were effectively delineated by reasons of (dis)liking CATA results. CONCLUSION: Reasons for (dis)liking CATA proved to be a powerful supporting method to understand the internal drivers of liking which can be overlooked by generic descriptive analysis.


Subject(s)
Condiments , Consumer Behavior , Spices , Taste , Adult , Animals , Chickens , Cooking , Cross-Cultural Comparison , Culture , Female , Food Preferences , Humans , Meat , Republic of Korea , Smell , United States
13.
Food Chem ; 145: 950-5, 2014 Feb 15.
Article in English | MEDLINE | ID: mdl-24128568

ABSTRACT

Six low-methoxy pectins with different degrees of methylesterification and amidation, and molecular weights were used to prepare gels with similar moduli of elasticity by varying the concentrations of pectin and calcium phosphate. Five aroma compounds were added to the gels and their sensory textural properties, release and perception of aromas were investigated. Sensory firmness, springiness, adhesiveness, chewiness and cohesiveness differed according to the gel type, even though the moduli of elasticity were not significantly different (p<0.05). Release and perception of aromas also displayed significant difference according to the gel type (p<0.05). Low-methoxy amidated pectin exhibited the lowest release and perception for all the aroma compounds, while pectin-methylesterase-treated pectin gels exhibited relatively higher aroma release and perception. These results showed that the structural properties of pectins and gelling factors that increase the non-polar character of the gel matrices could decrease the release and perception of aromas in pectin gel systems.


Subject(s)
Carboxylic Ester Hydrolases/metabolism , Dietary Proteins/chemistry , Food, Formulated/analysis , Pectins/chemistry , Plant Proteins/metabolism , Volatile Organic Compounds/analysis , Amides/chemistry , Chemical Phenomena , Citrus sinensis/enzymology , Dietary Proteins/metabolism , Elastic Modulus , Female , Food Handling , Fruit/enzymology , Gels , Humans , Mechanical Phenomena , Methylation , Molecular Weight , Odorants , Pectins/metabolism , Principal Component Analysis , Protein Conformation , Volatile Organic Compounds/metabolism , Volatilization
14.
J Food Sci ; 77(6): S233-9, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22591448

ABSTRACT

UNLABELLED: This study was conducted to investigate the sensory characteristics and consumer acceptability of beef stock samples containing GSH-xylose Maillard reaction product (GX) and/or monosodium glutamate (MSG) with varying levels of salt (NaCl). The sensory characteristics of the beef stock samples were examined using a descriptive analysis. Total of 50 consumers evaluated overall acceptability and flavor intensities of beef odor, salty taste, beef flavor, and seasoning flavor in the samples. Samples containing both GX and MSG (GX-MSG), GX only (GX), and GX with higher salt level (GX-NaCl) had stronger "beef odor/flavor,""sulfur odor/flavor," and "chestnut odor/flavor" than those of the other samples, whereas beef stocks containing MSG, salt only (CON), and CON with higher salt level (CON-NaCl) had stronger "potato odor/flavor" and "soy sauce odor/flavor" than those of the other samples. The consumers liked GX-MSG and MSG the most. Overall liking scores of GX-NaCl and CON-NaCl were significantly higher than that of CON. GX was not significantly preferred to CON. Partial least square regression results showed that salty, MSG, and sweet tastes had more significant impact on consumer perception of the beef and spice flavors and the liking score than strong beef odor/flavor of GX. However, high hedonic ratings of GX-MSG, which contained half the doses of GX and MSG used for the GX and MSG samples, suggest that the combination of GX and MSG had a synergistic effect on flavor enhancement of beef stock. PRACTICAL APPLICATION: Due to increasing needs for food products that provide more health benefits but maintain palatability, the food industry is looking for a new type of flavor enhancer. The Maillard reaction product of xylose and glutathione (GX), a tripeptide known to increase complexity and mouthfulness, was examined for its potential as a flavor enhancer. GX enhanced beef flavor significantly and salty taste somewhat at a weak suprathreshold level. With adjusting salty taste intensity by adding MSG at a weak suprathreshold level and/or increasing NaCl by 0.05% to 0.1%, GX significantly increased consumer acceptability.


Subject(s)
Consumer Behavior , Flavoring Agents/metabolism , Food Preferences , Glutathione/analogs & derivatives , Meat Products/analysis , Sodium Glutamate/metabolism , Xylose/analogs & derivatives , Animals , Cattle , Female , Flavoring Agents/analysis , Food Preferences/ethnology , Glutathione/analysis , Glutathione/metabolism , Humans , Least-Squares Analysis , Maillard Reaction , Odorants , Osmolar Concentration , Principal Component Analysis , Republic of Korea , Sensation , Sodium Chloride, Dietary/analysis , Sodium Chloride, Dietary/metabolism , Sodium Glutamate/analysis , Taste , Xylose/analysis , Xylose/metabolism
15.
Anal Chim Acta ; 703(2): 204-11, 2011 Oct 10.
Article in English | MEDLINE | ID: mdl-21889635

ABSTRACT

The non-targeted analysis, combining gas chromatography coupled with time-of-flight mass spectrometry (GC-TOF/MS) and sensory evaluation, was applied to investigate the relationship between volatile compounds and the sensory attributes of glutathione-Maillard reaction products (GSH-MRPs) prepared under different reaction conditions. Volatile compounds in GSH-MRPs correlating to the sensory attributes were determined using partial least-squares (PLS) regression. Volatile compounds such as 2-methylfuran-3-thiol, 3-sulfanylpentan-2-one, furan-2-ylmethanethiol, 2-propylpyrazine, 1-furan-2-ylpropan-2-one, 1H-pyrrole, 2-methylthiophene, and 2-(furan-2-ylmethyldisulfanylmethyl)furan could be identified as possible key contributors to the beef-related attributes of GSH-MRPs. In this study, we demonstrated that the unbiased non-targeted analysis based on metabolomic approach allows the identification of key volatile compounds related to beef flavor in GSH-MRPs.


Subject(s)
Flavoring Agents/analysis , Gas Chromatography-Mass Spectrometry/methods , Glutathione/metabolism , Meat/analysis , Metabolomics/methods , Volatile Organic Compounds/analysis , Animals , Cattle , Glutathione/chemistry , Least-Squares Analysis , Maillard Reaction
16.
Anal Chim Acta ; 693(1-2): 106-13, 2011 May 05.
Article in English | MEDLINE | ID: mdl-21504817

ABSTRACT

An immunochromatographic assay (ICA) based on competitive antigen-coated format using colloidal gold as the label was developed for the detection of the organophosphorus insecticide chlorpyrifos. The ICA test strip consisted of a membrane with a detection zone, a sample pad and an absorbent pad. The membrane was separately coated with chlorpyrifos Hapten-OVA conjugate (test line) and anti-mouse IgG (control line). Based on the fact that the competition is between the migrating analyte in the sample and the analyte hapten immobilized on the test strip for the binding sites of the antibody-colloidal gold (Ab-CG) conjugate migrating on the test strip, this study suggests that the relative migration speed between the two migrating substances is a critically important factor for the sensitive detection by competitive ICA. This criterion was utilized for the confirmation of appropriateness of a nitrocellulose (NC) membrane for chlorpyrifos ICA. The detection limit of the ICA for chlorpyrifos standard and chlorpyrifos spiked into agricultural samples were 10 and 50 ng mL(-1), respectively. The assay time for the ICA test was less than 10 min, suitable for rapid on-site testing of chlorpyrifos.


Subject(s)
Chlorpyrifos/analysis , Immunoassay/methods , Insecticides/analysis , Animals , Antibodies, Monoclonal/immunology , Binding Sites , Binding, Competitive , Chlorpyrifos/isolation & purification , Collodion/chemistry , Cross Reactions , Gold/chemistry , Haptens/chemistry , Insecticides/isolation & purification , Mice , Ovalbumin/chemistry
17.
Opt Express ; 19(26): B515-21, 2011 Dec 12.
Article in English | MEDLINE | ID: mdl-22274064

ABSTRACT

We proposed a simple and cost-effective burst mode bit discrimination circuit for dual rate reach extender based on 10 gigabit Ethernet passive optical network. To distinguish the dual rate burst mode packets, periodic idle patterns which have specific frequency components in the frequency domain and radio frequency power detection technique were used. The burst mode dual rate upstream transmission was demonstrated to confirm the feasibility of our suggested method in a coexisted gigabit Ethernet passive optical network and 10 gigabit Ethernet passive optical network. We achieved the dual rate burst mode receiver sensitivity of - 32 dBm for 1.25 Gbit/s signal and -27 dBm for 10.3 Gbit/s signal, respectively.

18.
Opt Express ; 19(26): B522-30, 2011 Dec 12.
Article in English | MEDLINE | ID: mdl-22274065

ABSTRACT

We propose a self-wavelength initialization method for the waveguide Bragg-grating based tunable external cavity laser. Reflection characteristics of the Bragg-grating, and the wavelength routing property in the wavelength division multiplexing-passive optical network (WDM-PON) were used in our proposed method. By adding a cost-effective and low- power broadband light source in the central office, the tunable laser can align its output wavelength with the wavelength at the center of the pass band of the WDM multiplexer. This method can be applicable for the Bragg-grating based tunable laser, which is placed either in the central office or in the subscriber region. The operating principle and the feasibility of the proposed method were described by evaluating the transmission performance. By using our initialization method, a tunable laser with a Bragg-grating can be used as a true colorless light source for the WDM-PON.

19.
Int J Biol Macromol ; 45(3): 226-30, 2009 Oct 01.
Article in English | MEDLINE | ID: mdl-19467257

ABSTRACT

High- and low-methoxyl pectins were treated with pectin methylesterase (PME) and the functional properties of the resulting pectin gels were characterized. The degree of esterification of high- and low-methoxyl pectins decreased from 74.5% to 6.3% and 40.0% to 6.5%, respectively while not changing their molecular weight. Also, the addition of glucono-delta-lactone (GDL) dramatically affected the gel strength and the pH reduction by the GDL led to the increased syneresis of the pectin gels, which was also observed in the PME-treated samples. When flavor compounds were incorporated into the pectin gels, the flavor release from the gels increased with decreasing the degree of esterification due to increased hydrophilic properties.


Subject(s)
Carboxylic Ester Hydrolases/metabolism , Gels/metabolism , Pectins/metabolism , Esterification/drug effects , Flavoring Agents/metabolism , Gluconates/pharmacology , Hardness/drug effects , Hydrogen-Ion Concentration/drug effects , Lactones , Molecular Weight , Solutions
20.
J Agric Food Chem ; 55(6): 2323-8, 2007 Mar 21.
Article in English | MEDLINE | ID: mdl-17323969

ABSTRACT

Two independent approaches, gas chromatography-olfactometry and sensory analysis, were used to evaluate and compare the aroma characteristics of pine-mushrooms (Tricholoma matsutake Sing.) of four different grades. The aroma-active compounds responsible for the sensory attributes of pine- mushrooms were investigated based on the correlation between instrumental and sensory analyses through partial least-square regression. Piny, meaty, and floral attributes were strongly correlated with each other and were the most important descriptors for defining the pine-mushrooms of the highest grade, and they decreased as the grade decreased. Among 23 aroma-active compounds, (E)-2-decenal, alpha-terpineol, phenylethyl alcohol, and 2-methylbutanoic acid ethyl ester contributed most to these attributes. On the other hand, the major aroma characteristics of the pine-mushrooms of the lowest grade were wet soil-like, alcohol, metallic, moldy, and fermented, and they decreased as the grade increased. These aroma characteristics were strongly associated with 1-octen-3-one, 1-octen-3-ol, 3-octanol, 3-octanone, (E)-2-octen-1-ol, and methional.


Subject(s)
Agaricales/chemistry , Chromatography, Gas/methods , Odorants/analysis , Smell , Taste , Adult , Female , Humans
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