Progress 09/15/06 to 08/31/11
Outputs
OUTPUTS: Watermelons have been processed to make juice. Sensory attributes have been tested and microbiological data collected. Juice extracted from red seedless watermelons was pasteurized and prepared for consumer tests. Freshly extracted juice was used as a control. Consumers evaluated acceptability of appearance, colloidal-particles, color, odor, taste, mouth feel, and overall liking using a 9-point hedonic scale. Overall acceptance and purchase intent were evaluated using a binomial scale. Data were analyzed using ANOVA, MANOVA, discriminant (DDA) and logistic (LRA) regression analysis, and the McNemar test. Juice pasteurized for 30 seconds was more acceptable than that pasteurized for 45 seconds. DDA indicated that appearance, colloidal-particles, color, and odor were attributes contributing to overall differences among products. LRA showed that overall liking, taste, and odor determined acceptance and purchase intent. This study revealed that taste and odor along with product health benefits influenced acceptance and purchase intent of watermelon juice. Fresh pressed watermelon juice samples had high total plate count (larger than 10 million per ml) and total coliform counts ranging from 0 to several hundred per ml. Heated juice samples did not have any positives for coliforms. Salmonella were not found in any juice samples. PARTICIPANTS: Co-PI's were Dr. K. R Cadwallader from the University of Illinois Urbana-Champagne and Dr. W. Prinyawiwatkul from Louisiana State University. Two graduate students at UMES participated in this project. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Fresh juice was more accepted in all attributes when compared to the pasteurized juices. The juices pasteurized at 30 and 45 s were different from each other only in the attributes of odor, taste, and overall liking. The pasteurized juices were rated higher in flavor than the fresh juice due to the absence of a grassy flavor after pasteurization. The sensory attributes of particles, appearance, and color have the three highest canonical correlation values in the first dimension. In the second dimension, the odor was the attribute contributing to overall differences among the three treatments. Overall liking, taste, odor, and appearance were the four most critical sensory attributes for product acceptance. Overall liking and taste were found to be the two most influential sensory attributes for purchase intent with the additional information of its health benefits. Odor and particles are strongly correlated, and these two attributes were found to be responsible for the underlying differences among samples from DDA. Raw juice had higher acceptance scores on these attributes. The pasteurized juices had lower acceptance scores in all attributes. However, microbiological data indicate that heat treatment is necessary to ensure product safety. Overall liking and taste are the two most critical sensory attributes in determining consumer acceptance and purchase intent before and after additional information regarding health benefits were informed. The presence of a health claim significantly increased positive purchase intent of the juices.
Publications
- No publications reported this period
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Progress 09/15/09 to 09/14/10
Outputs
OUTPUTS: We evaluated sensory attributes driving acceptance and purchase intent of pasteurized watermelon juice containing no added sugar. Juice was extracted from red seedless watermelons, pasteurized (HTST), and stored at 4 ⁰C. All juices had no added sugar and were prepared one day before consumer tests. Freshly extracted juice was used as a control. Consumers evaluated acceptability of appearance, colloidal-particles, color, odor, taste, mouth feel, and overall liking using a nine-point hedonic scale. Overall acceptance and purchase intent were evaluated using a binomial scale. Data were analyzed using ANOVA, MANOVA, discriminant (DDA) and logistic (LRA) regression analysis, and the McNemar test. Juice pasteurized for 30 seconds was more acceptable than that pasteurized for 45 seconds. DDA indicated that appearance, colloidal-particles, color, and odor were attributes contributing to overall differences among products. LRA showed that overall liking, taste, and odor determined acceptance and purchase intent. This study revealed that taste and odor along with product health benefits influenced acceptance and purchase intent of watermelon juice. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Fresh juice was more accepted in all attributes when compared to the pasteurized juices. The juices pasteurized at 30 and 45 s were different to each other only in the attributes of odor, taste, and overall liking. The pasteurized juices were rated higher in flavor than the fresh juice due to the absence of grassy flavor after pasteurization. The sensory attributes of particles, appearance, and color have the three highest canonical correlation values in the first dimension. In the second dimension, the odor was the attribute contributing to overall differences among the three treatments. Overall liking, taste, odor, and appearance were the four most critical sensory attributes for product acceptance. Overall liking and taste were found to be the two most influential sensory attributes for purchase intent with the additional information of its health benefits. Odor and particles are strongly correlated, and these two attributes were found to be responsible for the underlying differences among samples from DDA. Raw juice had higher acceptance scores on these attributes. The pasteurized juices had lower acceptance scores in all attributes. Overall liking and taste are the two most critical sensory attributes in determining consumer acceptance and purchase intent before and after additional information regarding health benefits were informed. The presence of a health claim significantly increased positive purchase intent of the juices.
Publications
- No publications reported this period
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Progress 09/15/08 to 09/14/09
Outputs
OUTPUTS: We evaluated sensory attributes driving acceptance and purchase intent of pasteurized watermelon juice containing no added sugar. Juice was extracted from red seedless watermelons, pasteurized (HTST) and stored at 4 C. All juices had no added sugar and were prepared one day before consumer tests. Freshly extracted juice was used as a control. Consumers evaluated acceptability of appearance, colloidal-particles, color, odor, taste, mouth feel, and overall-liking using a 9-point hedonic scale. Overall acceptance and purchase intent were evaluated using a binomial scale. Data were analyzed using ANOVA, MANOVA, discriminant (DDA) and logistic (LRA) regression analysis, and McNemar test. Juice pasteurized for 30 seconds was more acceptable than that pasteurized for 45 seconds. DDA indicated that appearance, colloidal-particles, color and odor were attributes contributing to overall differences among products. LRA showed that overall-liking, taste, and odor determined acceptance and purchase intent. This study revealed that taste and odor along with product health benefits influenced acceptance and purchase intent of watermelon juice. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Dr. Jurgen Schwarz assumed responsibility as PI after departure of the previous PI.
Impacts
Fresh juice was more accepted in all attributes when compared to the pasteurized juices. The juices pasteurized at 30 and 45 s were different to each other only in the attributes of odor, taste, and overall liking. The pasteurized juices were rated higher in flavor than the fresh juice due to the absence of grassy flavor after pasteurization. The sensory attributes of particles, appearance, and color have the three highest canonical correlation values in the first dimension. In the second dimension, the odor was the attribute contributing to overall differences among the three treatments. Overall liking, taste, odor, and appearance were the four most critical sensory attributes for product acceptance. Overall liking and taste were found to be the two most influential sensory attributes for purchase intent with the additional information of its health benefits. Odor and particles are strongly correlated and these two attributes were found to be responsible for the underlying differences among samples from DDA. Raw juice had higher acceptance scores on these attributes. The pasteurized juices had lower acceptance scores in all attributes. Overall liking and taste are the two most critical sensory attributes in determining consumer acceptance, purchase intent before and after additional information regarding health benefits were informed. The presence of a health claim significantly increased positive purchase intent of the juices.
Publications
- No publications reported this period
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Progress 09/15/07 to 09/14/08
Outputs
OUTPUTS: Juice obtained from red seedless watermelon was pasteurized using the HTST pasteurizer at 76.7 degree C for 30 and 45 s. Acceptability of appearance, particles, color, odor, taste, mouthfeel, and overall liking were sensory evaluated by untrained 150 panelists using the 9-point hedonic scale in the central location test. The just-about-right scale was used to rate the intensity of red color, sweetness, and watermelon odor. Overall product acceptance, initial purchase intent, and purchase intent after being provided with additional health benefits of the natural antioxidant in watermelon juice were evaluated. Juice yield after filtering was about 50.92 %. The multivariate analysis of variance (MANOVA) was done to determine the overall product difference. With the Wilks' Lambda p-value of <0.0001, an overall difference existed among all three treatments when all seven attributes were considered at the same time. Descriptive discriminant analysis (DDA) used to determine attributes underlying differences among the three treatments since the MANOVA result showed a significant difference. An effective method was developed to isolate aroma components responsible for "fresh" watermelon aroma. The predominant aroma components of fresh watermelon juices were determined by instrumental-sensory techniques. Ripe watermelons were cut and immediately subjected to juice extraction by pressing pulp through cheese cloth. Calcium chloride was added to retard deleterious enzyme activities. The juice was subjected to direct solvent extraction followed by high vacuum distillation to recover the watermelon aroma extract. Gas chromatography-mass spectrometry and GC-olfactometry analysis of the aroma extract revealed the importance of (Z,Z)-3,6-nonadienal (fresh watermelon like odor) and (Z)-3-nonenal (fresh green odor) in the typical aroma of freshly pressed watermelon juice. Fresh watermelon juice was obtained from washed watermelon skin with water before slicing and from unwashed watermelon. Then, watermelon juice was treated with high hydrostatic pressure (HHP) at 45,000 and 55,000 psi at 150 seconds. Standard plate counts (SPC), total coliform counts (TCC), and total yeast and mold count (TYM) were conducted for watermelon juice prepared from washed and unwashed watermelon skin before slicing and for the juice treated with high hydrostatic pressure to achieve 5-log reduction of microbial counts according to the 21CR120 requirement for 100% juice. The objective is to confirm the hypothesis that pre-washing watermelon before slicing will reduce the microbial loads in the juice and to determine the minimum pressure used to treat watermelon juice before starting the fermentation process of watermelon. PARTICIPANTS: Elizabeth Genthner, UIUC graduate student under Dr. Keith R Cadwallader (started in May 2008); Pamarin Waimaleongora-ek, LSU graduate student under Dr. Witoon Prinyawiwatkul; and Taha Bourgo, UMES graduate student under Dr. Voranuch Suvanich(Started Fall semester 2008) TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The raw juice averaged 9.6% Brix with pH of 5.65. The pasteurized juices had higher pH with lower Brix. The fresh juice was darker reddish than the pasteurized juices. The color intensity of fresh raw juice was higher than those of pasteurized juices. Fresh juice was more accepted in all attributes when compared to the pasteurized juices. The juices pasteurized at 30 and 45 s were different to each other only in the attributes of odor, taste, and overall liking. The pasteurized juices were rated higher in flavor than the fresh juice due to the absence of grassy flavor after pasteurization. The sensory attributes of particles, appearance, and color have the three highest canonical correlation values in the first dimension. In the second dimension, the odor was the attribute contributing to overall differences among the three treatments. Overall liking, taste, odor, and appearance were the four most critical sensory attributes for product acceptance. Overall liking and taste were found to be the two most influential sensory attributes for purchase intent with the additional information of its health benefits. Odor and particles are strongly correlated and these two attributes were found to be responsible for the underlying differences among samples from DDA. Raw juice had higher acceptance scores on these attributes. The pasteurized juices had lower acceptance scores in all attributes. Overall liking and taste are the two most critical sensory attributes in determining consumer acceptance, purchase intent before and after additional information regarding health benefits were informed. The presence of a health claim significantly increased positive purchase intent of the juices. The two main aroma components identified, (Z,Z)-3,6-nonadienal and (Z)-3-nonenal, are known to be unstable to both heat (e.g. pasteurization) and can be readily degraded by endogenous watermelon enzymes, e.g., cis/trans (Z/E) isomerases catalyze the isomerization of the (Z)-3- bond to the (E)-2- bond and alcohol dehydrogenase catalyzes the reduction of the aldehydes to alcohols. Both thermal and enzymatic reactions lead to loss of typical fresh watermelon flavor. We are currently evaluating the use nonthermal pasteurization methods to reduce the enzyme activities (and microbial loads), while maintaining the typical fresh aroma of watermelon juice. In addition, we are also synthesizing and evaluating alternative flavoring agents based on the (Z,Z)-3,6-nonadienyl and (Z)-3-nonenyl moieties to provide an alternative flavoring strategy for watermelon-flavored products. Juice obtained from unwashed watermelon had SPC 6-log CFU/g; TCC 117 CFU/g; and TYM too many to count. Juice obtained from washed watermelon had SPC 5-log CFU/g; TCC 36 CFU/g; and TYM 4-log CFU/g. Washing watermelon before processing juice reduced 1-log of SPC and TCC in juice. Juice treated with HHP at 45K psi had TCC 2 CFU/g and SPC 10 CFU/g, whereas no SPC and TCC found in juice treated at 55K psi. Juice treated with HHP had no TYM. Treating watermelon juice with HHP at 45K or at 55K psi for 150 s provided 5-log reduction of microbial loads.
Publications
- No publications reported this period
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Progress 09/15/06 to 09/14/07
Outputs
(N/A)
Impacts
Successful outcomes will enhance uses of watermelon as value-added health and wellness products. High lycopene single strength watermelon juice and overripe watermelon will be processed into agricultural wines, and these products will enhance and strengthen MD agriculture and rural communities and the UMES-FDST program. This project will motivate minority graduates to undertake higher education in food and agriculture science and pursue research-oriented careers. The successful outcomes will build up students' confidence and is expected to improve their potential to be come a multidiscipline researchers and to be able to work in academia, government, and/or private industry. Project funds will reinforce research capacities of the UMES-FDST program, which subsequently will train minority students and will create workforce diversity at the regional and state levels.
Publications
- No publications reported this period
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