Jae-Hee Hong

Interaction of copper and human salivary proteins.

Interaction of taste molecules with saliva is the first step in the flavor perception process. Saliva is assumed to influence copper-induced sensation by controlling the copper solubility or causing astringency via binding of proteins with copper. This study was performed to identify the nature of copper-protein interactions in relation to the sensory perception of copper. Saliva was treated with CuSO4 x 5H2O at levels of 0, 2.5, 5, 10, 20, or 40 mg/L, and changes in salivary proteins were analyzed using high performance liquid chromatography (HPLC) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Protein peaks that showed changes in HPLC were characterized with SDS-PAGE. HPLC analysis revealed that copper treatment up to 40 mg/L decreased several proteins, including the dominant peak, by 70%. This peak was composed of alpha-amylase, a secretory component, and basic proline-rich proteins. SDS-PAGE results showed that salivary proteins of molecular weight 29 kDa and 33 kDa precipitated when copper was added at concentrations > or =10 mg/L. This study provides biochemical information for understanding perception mechanisms of copper sensation.

Sensory characteristics and cross-cultural comparisons of consumer acceptability for Gochujang dressing

This study was conducted to identify the sensory profiles of gochujang dressing prepared with different formulations, and to compare hedonic responses crossculturally. Gochujang dressing samples were prepared by varying levels of gochujang and sugar. The sensory attributes of the samples were examined by 8 descriptive analysis panelists. Consumers from Korea (n=50), China (n=34), and the US (n=26) participated in the consumer test. Sourness and pungency of the samples were decreased by adding more gochujang. A significant gochujang× sugar interaction was observed for the sweetness and burning sensation. Korean consumers liked the dressing whose sugar level was increased from that of the control. There was no significant difference in Chinese and the US consumers’ liking score between the samples, but multiple factor analysis result suggested that the sample with the decreased sugar level was particularly liked by the US consumers whereas the sample with lower gochujang level was disliked by Chinese consumers.

Acceptance of Vegetable Menus of a School Lunch Program by High School Students in Seoul and its Association with Health and Dietary Behavioral Factors

This study was conducted to investigate the acceptance of vegetable menus by high school students and the factors that influence the acceptability. Second-grade high school students (n=389) in Seoul were asked to assess their acceptability of vegetable menus and plate waste, and answered survey questions concerning their demographic characteristics, health-related attitudes, dietary attitudes, dietary habits, and nutritional knowledge. Overall, the menus containing items that were sweet or familiar to the subjects were preferred. Acceptability was significantly associated with the amount of consumption. The acceptability was correlated with dietary habits, dietary attitudes, nutritional knowledge, and several health-related variables. The vegetable-liking groups showed significantly higher scores concerning dietary habits, dietary attitudes, and nutritional knowledge, but did not exhibit a specific pattern of association with the health-related variables. This result implies that intervention strategies focusing on changes in cognitive and/or hedonic factors, such as nutritional education or flavor-flavor learning, would be beneficial for increasing students’ acceptance of vegetable menus.

Sensory characteristics and consumer acceptability of red ginseng extracts produced with different processing methods.

UNLABELLED The aims of this study were: to develop objective and effective sample preparation and presentation procedures for the sensory analysis of red ginseng extracts (RGE); to identify their sensory attributes in relation with the consumer acceptability of RGEs produced with different processing techniques. The samples included 7 different types of RGE, among which 2 samples were of commercial products and the other samples were specially prepared for the study. The samples differed in processing methods (traditional method, high-hydrostatic pressure [HHP], and fermentation) and extraction solvents (ethanol, water). For the descriptive analysis, 7 trained panelists developed and evaluated 30 attributes. Principal component analysis was conducted to summarize the relationships between the sensory attributes and to get a representation of the samples according to those attributes. Consumers evaluated the appearance and flavor acceptability of the extracts. Hierarchical cluster analysis was conducted on consumer acceptability of flavor. The results showed that the clear differences among the RGEs in terms of sensory perceptions were explained by the processing methods. Consumers were segmented into 3 distinct groups in terms of preference: a consumer cluster that likes the RGEs produced with HHP or fermentation, a cluster that likes a product with strong ginseng flavor, and a cluster that likes a RGE with sweet taste and jujube flavor. These 3 clusters differed somewhat in their consumption frequency and purchase factors, also. PRACTICAL APPLICATION The red ginseng extract (RGE) market is rapidly growing due to the consumer awareness of its superior health-promoting effects. However, little attention has been given to sensory properties that are a critical factor in determining quality and consumer preference. The results of this study will be helpful for researchers and manufacturers to understand the sensory characteristics of RGEs and to detect the driving factors of consumer acceptability. Also, the sample preparation and presentation procedures developed in this experiment will be used effectively in academia and industries to examine sensory characteristics of RGE products.

Consumer Acceptability and Purchase Intent of Traditional Korean Soup in the United States and Japan

Samgyetang and yukgaejang are relatively unknown to US and Japanese consumers. This study was conducted 1) to identify how flavor modification and previous consumption affect foreign consumer liking of these foods, and 2) to examine the effect of information on purchase intent. Traditional and modified types were prepared based on focus group interviews that included 13 US and 16 Japanese consumers residing in Korea. A consumer test was then conducted with 104 participants for samgyetang and 106 participants for yukgaejang in the US, and 100 participants for both foods in Japan. Liking scores for these new foods were mainly influenced by flavor modification, with a strong preference for the modified types over the traditional types. Liking of foods that were more familiar to consumers was influenced more by previous consumption experience. The purchase intent was increased after information about the foods was provided.

Relative sweetness, sweetness quality, and temporal profile of xylooligosaccharides and luo han guo (Siraitia grosvenorii) extract

This study was conducted to elucidate comprehensive sensory profiles of potential natural alternative sweeteners, xylooligosaccharides (XOS), and luo han guo extract (LHGE). Relative sweetness to 5% sucrose was obtained using the two-alternative forced-choice method. Sensory and temporal profiles were identified using descriptive analysis and time-intensity analysis, respectively. XOS and LHGE were 0.25- and 75.76-fold sweeter than 5% sucrose solution, respectively. At equi-sweetness concentrations to 5% sucrose, XOS was characterized by sourish and corn silk flavor. LHGE was distinguished from other sweeteners by its yellowness, honey-like flavor, and licorice flavor. Bitterness and acridness of these sweeteners were not significantly different from those of sucrose. Both sweeteners exhibited a delayed time to peak intensity and persistent sweet aftertaste. Further studies are required to enhance the sweetness profile of XOS and LHGE toward achieving more sucrose-like sweetness impression.

Effect of vinegar on the perceived saltiness of naengmyeon and onmyeon soup systems

This study was conducted to investigate whether the saltiness of naengmyeon (NMS) and onmyeon soups (OMS) could be influenced by the addition of vinegar. The NMS samples were prepared by adding NaCl (at 0.25-1.0%) and v inegar (at 0, 0.5, or 1.0%) to cold beef s tock (10°C). Perceived saltiness was assessed by 41 panelists using a generalized labeled magnitude scale. The OMS samples were prepared by adding NaCl (at 0.5 or 1.0%) and vinegar (at 0.03-0.15%) to hot beef stock (60°C). Perceived saltiness was assessed using a two-alternative forced choice test with 56 panelists. Vinegar significantly increased the saltiness of NMS with 0.25 and 0.5% NaCl, but suppressed the saltiness of those with 0.75 and 1.0% NaCl. In the OMS samples, vinegar significantly enhanced the saltiness of soups with 0.5% NaCl, but the saltiness of those with 1.0% NaCl was enhanced only by 0.15% vinegar.

Comparison of perceptual representations of soymilk products between consumers with different nuttiness rating tendencies

Internal perceptual representations of soymilk between 2 groups with different nuttiness rating tendencies were compared. A total of 30 consumers who emphasized a cooked soybean flavor (SOY group) and 30 consumers who emphasized sweetness and nut flavors (SWTNUT group) for rating nuttiness flavor participated. A sorted napping procedure was applied to 10 commercial soymilk samples. Data were analyzed using hierarchical multiple factor analysis. Both groups differentiated samples similarly, primarily on the basis of sweetness and textual properties. Noticeable differences between the 2 groups were found in the use of verbal descriptors. Sensory terms were more frequently elicited from the SOY group, whereas affective terms were more frequently elicited from the SWTNUT group. There was no difference in sensory perceptions between the 2 groups of consumers, but each group used different strategies to verbalize sensory perceptions.

Relative sweetness and sweetness quality of Xylobiose

Xylobiose (XB), a xylose dimer, is a low-calorie sweetener with prebiotic activity. Unlike its well-defined biosynthesis and production methods, its sensory characteristics have not been well investigated. This study aims to identify the relative sweetness and sensory profile of XB. XB was prepared as an aqueous solution, and its relative sweetness (RS) compared to 5% sucrose was determined using the 2-alternative forced choice method. The sensory profile was identified by 10 trained panelists using descriptive analysis. The RS of XB was determined to be 0.34. XB was characterized by its yellowness, corn aroma and flavor, and its nurungji (scorched rice) candy flavor. The persistence of sweetness of XB was similar to that of sucrose, but its onset of sweetness was slower. When XB was mixed with sucrose at a ratio of 7:93, the mixture exhibited a similar sensory quality to that of sucrose, thereby making it a useful sucrose complement.

Comparison of consumer perception and liking of bulgogi marinade sauces between Korea and Japan using flash profiling

This study compared the perception of and preference for seven bulgogi marinade sauces between Korean and Japanese consumers. Flash profiling (10 panelists each) and consumer test (97 Japanese and 102 Koreans) were conducted. Results showed that both Korean and Japanese panelists perceived the samples similarly but described using different terms. There were significant crosscultural differences in most liking and just-about-right attributes, except texture liking and sweetness. Both consumer panelists preferred sweeter samples, but Japanese consumers rated liking for less sweet samples higher than Korean consumers. Japanese consumers considered strong saltiness, umami, and soy sauce flavor as “just-about-right,” whereas Korean consumers considered the same levels as “much too strong”. Familiarity showed a significantly positive correlation with both Korean and Japanese consumers’ liking, but authenticity was only significantly correlated with Korean consumers’ liking. This indicates that perception of authenticity might not have a strong impact on Japanese consumers’ liking.