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Kim Y.,Sensus LLC | Welt B.A.,University of Florida | Talcott S.T.,Texas A&M University
Journal of Agricultural and Food Chemistry | Year: 2011

Ready to drink (RTD) teas are a growing segment in the beverage category, brought about by improvements in the flavor of these products and healthy market trends driven by consumers. The presented results evaluated the antioxidant phytochemical stability of RTD teas from aqueous infusions of traditional green tea (Camellia sinensis) and a botanical tea from yaupon holly (Ilex vomitoria) as influenced by packaging materials during cold storage. Two common packaging materials for RTD products are glass and polyethylene terephthalate (PET) and have been compared to a retortable pouch (RP), an emerging packaging material for various types of food since it is durable, inexpensive, lightweight, and easy to sterilize. Storage stability was then evaluated for each aqueous infusion prepared at 10 g/L at 90 °C for 10 min and evaluated at 3 °C in the absence of light over 12 weeks. Analyses included quantification and characterization of individual polyphenolics by high-performance liquid chromatography - photodiode array and liquid chromatography-electrospray ionization - mass spectrometry as well as changes in total antioxidant capacity. For green tea, concentrations of the three major flavan-3-ols, epigallocatechin gallate, epigallocatechin, and epicatechin gallate were better retained in glass bottles as compared to other packages over 12 weeks. In yaupon holly, chlorogenic acid and its isomers that were the predominant compounds were generally stable in each packaging material, and a 20.6-fold higher amount of saponin was found as compared to green tea, which caused higher stability of flavonol glycosides present in yaupon holly during storage. The antioxidant capacity of green tea was better retained in glass and PET versus RP, whereas no differences were again observed for yaupon holly. Results highlight the superiority of oxygen-impervious glass packaging, but viable alternatives may be utilizable for RTD teas with variable phytochemical compositions. © 2011 American Chemical Society. Source

Miyazaki T.,University of Florida | Plotto A.,U.S. Department of Agriculture | Goodner K.,Sensus LLC | Gmitter F.G.,University of Florida
Journal of the Science of Food and Agriculture | Year: 2011

BACKGROUND: With the desirable combination of sugars and acids, volatile compounds contribute to the essential organoleptic attributes of citrus. This study evaluated the aroma volatiles of 20 tangerine hybrids of the University of Florida breeding program. Volatiles were sampled from hand-squeezed juice by headspace solid-phase microextraction (SPME), and analyzed by gas chromatography-mass spectrometry. Principal component analysis (PCA) and cluster analysis (CA) were used to find similarities among samples due to volatile composition with effect of genetic background. RESULTS: In total, 203 volatiles were detected in all samples. Volatiles in lower amounts were widely distributed among samples and were classified mainly as terpene hydrocarbons and oxygenated compounds, such as aldehydes, esters, alcohols and ketones. PCA, based on relative peak areas (content) clearly separated the samples higher in volatile content, mainly those with sweet orange genetic contributions in their background. CA, based on volatile presence/absence, grouped samples into five clusters, each showing distinctive volatile profiles. CONCLUSION: The genetic background of tangerine hybrids affected volatile composition and content of samples. In general, tangerines were characterized by fewer volatiles (in both quality and quantity) and more aldehydes, and hybrids with sweet orange in their background had more sesquiterpenes and esters, which would likely affect their aroma. © 2010. Source

Giusti M.M.,Ohio State University | Atnip A.,Ohio State University | Sweeney C.,Ohio State University | Sweeney C.,Sensus LLC | Rodriguez-Saona L.E.,Ohio State University
ACS Symposium Series | Year: 2011

Authentication of fruit juices is a major challenge for an industry that is fast growing and expanding. Traditional methods to monitor authenticity such as HPLC, GC or sensory methods are time consuming and require well-trained personnel. There is a need for a rapid, easy to use, inexpensive method to monitor the authenticity of fruit juices. Infrared technology has gained acceptance as a rapid and reliable technique. It can be used to evaluate the overall sample composition, providing a fingerprint that is characteristic of the product. This eliminates the need to test for several individual components. Multivariate statistical analyses are used to evaluate the infrared spectral information. This technique could be used to determine addition of foreignmaterials, differentiate different juice commodities, or even to evaluate geographical origin of a juice. © 2011 American Chemical Society. Source

Kim Y.,Sensus LLC | Goodner K.L.,Sensus LLC | Park J.-D.,Tea Research Institute of JARES | Choi J.,Tea Research Institute of JARES | Talcott S.T.,Texas A&M University
Food Chemistry | Year: 2011

Monomeric flavonoids (flavan 3-ols or tea catechins) present in Camellia sinensis leaf are transformed to polymeric theaflavin and thearubigin by oxidation occurring during tea fermentation. The distinctive colour, decreased bitterness and astringency, and characteristic flavour are derived from the fermentation process giving fermented teas a marked distinction from non-fermented green tea. Even though teas are available in many different fermentation levels from green to black, the difference in phytochemicals and volatile compounds in teas with different degrees of fermentation has not been fully investigated yet within the same tea leaf. The objective of this study was to observe non-volatile phytochemicals including polyphenolic and volatile compounds changes by oxidation under strict processing control and to evaluate the degree of fermentation for the maximum antioxidant capacity with the same tea material. Harvested tea leaf was immediately processed to different degrees of oxidative fermentation (0%, 20%, 40%, 60%, and 80%). Tea infusions brewed with each processed tea leaf were analysed for polyphenolic profile, total soluble phenolics, antioxidant capacity, and volatile profile using LC-MS, HPLC, Folin-Ciocalteu assay, Oxygen Radical Absorbance Capacity (ORAC), and GC-MS analyses. The flavonoids in non-fermented green tea were significantly lessened during the oxidative fermentation process and the decreased monomeric flavonoids were transformed to polymeric theaflavin and thearubigin as the leaves were more processed. Total soluble phenolics and antioxidant capacity were significantly higher as tea leaves were less processed with a high correlation with individual polyphenolic changes. Volatile compounds present in tea leaf were analysed by GC-MS to observe changes due to processing and were utilised to create a model to differentiate fermentation based on volatile composition. Twenty-four compounds were used to build an initial model which was optimised to 16 compounds with complete separation of the groups using discriminant function analysis. The data suggested that fermentation diminished antioxidant capacity of tea and could result in lowering potential health benefits from flavonoids. This result should be considered for tea manufacturing and the development of functional foods desiring maximum potential health benefits from antioxidant flavonoids in tea. © 2011 Elsevier Ltd. All rights reserved. Source

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