Seo-Jin Chung

Application of GPA and PLSR in correlating sensory and chemical data sets

Abstract This paper discusses the application of various multivariate statistical procedures to understand the relationship between sensory and instrumental flavor profiles. Ice cream with varying fat levels was used as the vehicle for the flavor compounds in the experiment. Chemical and sensory flavor profiles were obtained by modified dynamic headspace analysis and descriptive analysis, respectively. Chromatographic peak areas of flavor-volatiles were used as the variables for the chemical data set. Initially, principal component analysis and canonical variate analysis were performed separately on the chemical and sensory data sets to explore the structure of each set. Flavor volatiles were then further studied to investigate their impact on the sensory profile of ice cream using general procrustes analysis and partial least squares regression analysis. The results from the two statistical analysis methods are compared and discussed. Additionally, the effect of log-transformation of chemical data on the overall chemical–sensory relationship was evaluated within each statistical method.

Relative Sweetness and Sensory Characteristics of Bulk and Intense Sweeteners

The objectives of this study were to measure and validate the relative sweetness of various sweeteners and to identify the sweeteners having similar sensory quality to that of sucrose. Twelve types of bulk and intense sweeteners were investigated. The relative sweetness was measured by 2-alternative forced choice method with 5% sucrose solution and the results were validated using descriptive analysis. The relative sweetness of the novel sweeteners such as tagatose, erythritol, stevia, and rebaudioside A 97 were shown to be 0.85, 0.63, 64.1, and 227, respectively. Maltitol and tagatose were shown to elicit very similar sensory characteristics to that of sucrose.

Identifying the drivers of liking by investigating the reasons for (dis)liking using CATA in cross‐cultural context: a case study on barbecue sauce

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.

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.

Comparative Analysis on Preference for Korean Traditional Foods in Foreigners and Koreans

This study was conducted to compare the preference and satisfaction for Korean traditional foods (Jeonju Bibimbap, Daetongbap, Jeonbokjuk, Jorangiddockguk, Hobakbumbuk, Darkgalbee, Eonyang Bulgogi, Moyackgwa, Insam Jeonggwa, Maejackgwa) in foreigners and Koreans. In this study, 27 foreign and 31 Korean university students were surveyed. Statistical analysis and Mann-Whitney U test were performed using the SPSS statistical package (17.0). The major findings were as follows: 1) Foreigners had higher experience of eating Darkgalbee (84.6%), Jeonju Bibimbap (80.8%), Daetongbap (53.8%), and Jeonbokjuk (53.8%) among Korean traditional foods, whereas their eating experience of Insam Jeonggwa (3.8%), Maejackgwa (11.5%), Moyackgwa (15.4%) and Jorangiddockguk (23.1%) was lower. 2) Foreigners and Koreans both liked sweet taste, but disliked sour taste, bitter taste, garlic flavor, sesame flavor, and soy sauce flavor among the sensory characteristics of Korean traditional foods. 3) Foreigners scored their overall satisfaction of Korean traditional foods in the order of Jeonju Bibimbap (), Eonyang Bulgogi (), Daetongbap (), Darkgalbee (), and Jeonbokjuk (), whereas Koreans rated higher scores for Eonyang Bulgogi (), Darkgalbee (), Jeonju Bibimbap (), Jeonbokjuk (), and Moyackgwa ().

Sweetness potency and sweetness synergism of sweeteners in milk and coffee systems

This study investigated the presence of sweetness synergism in milk and instant coffee systems. It consists of three parts: 1) modeling concentration-sweetness intensity curves of sweeteners (stevia, sucralose, xylose, tagatose and erythritol); 2) measuring the sweetness potencies of sweeteners compared to sucrose at wide concentration range; and 3) investigating the presence of sweetness synergisms in binary sweetener mixtures. The panelists evaluated sweetness and other sensory characteristics of sweeteners using descriptive analysis. Based on the modeled curve derived from step 1, the concentration of each sweetener with sweetness intensity equal to 2.5% or 2.8% sucrose was calculated for milk and coffee systems, respectively. For the sweetness synergism study, one type of intense sweetener was mixed with one type of bulk sweetener, each eliciting 2.5% or 2.8% equi-sweetness to sucrose, and compared with 5% sucrose added to a milk system or 5.6% sucrose added to a coffee system. The sweetness potencies of bulk sweeteners generally increased whereas the sweetness potencies of intense sweeteners decreased as the concentration increased. The binary sweetener mixtures mostly showed additivity in milk and suppression in coffee system rather than synergism when the concentration dependent nature of sweetness potency for each sweetener was taken into account.

Sensory Drivers of Liking for Adlay (Coix lacryma-jobi) Tea

This study investigated the sensory characteristics of adlay tea favorably consumed by Korean consumers and analyzed the drivers behind for liking or disliking adlay tea. Six adlay tea products showing the highest market share in South Korea were selected. Sensory properties of the six products were analyzed using generic descriptive analysis. Among these, four products were further selected for consumer taste acceptance test. Sensory lexicons of adlay tea were developed by trained panelists, and the sensory characteristics of each adlay tea product were measured based on the perceived intensities of these attributes elicited from the samples. In the consumer taste acceptance test, frequent tea and coffee drinkers participated. Consumers rated the acceptance of each tea product on a 9-point hedonic scale and evaluated the reasons for liking or disliking each product based on the check-all-that-apply method. Analysis of Variance, principal component analysis, frequency analysis, and correspondence analysis were utilized for statistical analysis. Twenty sensory attributes were developed in order to characterize the six adlay tea products. The results of the descriptive analysis showed that attributes such as viscosity, black soybean flavor, goso flavor, peanut flavor, seaweed flavor, green, and presence of chunks were key factors differentiating the adlay tea products. In the consumer taste test, roasted flavor, goso flavor, peanut flavor, and presence of chunks were positive drivers for liking the adlay tea products, whereas seaweed and green flavors were negative attributes that drove consumers away.

Sensory Characteristics of Different Types of Commercial Soy Sauce

Abstract Soy sauce, a basic ingredient in Asian cuisine, is made of fermented soybeans, salt, water, and barley or wheat flour. Thesensory characteristics of soy sauce are not only determined through its main ingredients but also by various flavorcompounds produced during the fermentation process. This study was conducted to identify the sensory attributes of fivedifferent commercial soy sauce samples that differ in Meju types (traditional Meju or modified Meju) and usage types. Thirtythree sensory attributes, including appearance (1), odor (16), flavor (14), and mouthfeel (2) attributes, were generated andevaluated by eight trained panelists. The collected data were analyzed by analysis of variance and principal componentanalysis. There were significant differences in the intensities of all sensory attributes among the soy sauce samples. Soy sauc emade with traditional Meju had high intensity of fermented fish, beany, musty odors and salt, Cheonggukjang, fermentedfish flavors. Whereas two soy sauces made with modified Meju were strong in alcohol, sweet, Doenjang, roasted soybeanflavors. Two soy sauces for soup made with modified Meju had medium levels of briny, sulfury, fermented odors and bitter,chemical flavors and biting mouthfeel characteristic.Key Words: Soy sauce, descriptive analysis, sensory characteristic

Understanding the sensory characteristics and drivers of liking for gochujang (Korean fermented chili pepper paste)

The present study investigated the sensory characteristics of 31 types of gochujang, a Korean fermented chili paste, produced in various regions of Korea. Generic descriptive analysis was conducted to analyze the sensory properties of the samples. Among these, four samples were selected for consumer taste test based on their distinct sensory profiles. The drivers of liking for gochujang were identified when the samples were applied to four different food systems. Consumers (age range: 20’s–60’s) rated the acceptance of the samples. ANOVA and multivariate analyses were conducted on the data. The types of carbohydrate sources or usage of additional seasoning showed stronger influence on the sensory characteristics of gochujang than the production location. Samples with strong fermented soy and fish sauce characteristics were fairly unacceptable to the consumers. The positive drivers of gochujang were appropriate levels of spiciness and sweet odors/flavors, whereas the negative drivers were off-note and fermentation-related flavors.

The Use of the Pathogen-specific Bacteriophage BCP8-2 to Develop a Rice Straw-derived Bacillus cereus-free Starter Culture

The purpose of this study was to develop a rice straw-derived Bacillus cereus (B. cereus)-free starter culture for traditional soybean fermented products using a B. cereus-specific bacteriophage, BCP8-2. To determine the optimal medium that supports the growth of rice straw-derived microorganisms and BCP8-2 activity, 5 different culture media were tested. The 5% ground bean (GB) medium was selected for further study. No B. cereus was detected in the BCP8-2-treated rice straw in GB medium, whereas B. cereus at a level of 107 CFU/mL was recovered in the no-phage control. The total bacterial count reached approximately 109 CFU/mL regardless of phage addition. When the 16S rRNA sequence-based microbial community was monitored using denaturing gradient gel electrophoresis (DGGE) and pyrosequencing, a similar microbial community was observed in the phage-treated and control samples. In conclusion, we demonstrate that phage can be used to prepare a rice straw-derived B. cereus-free starter culture with minimal effect on natural microflora.