Produced by bees, propolis has attracted substantial scientific interest and consumer demand as a “superfood”. Long used in folk medicine, propolis is known for its purported health promoting properties and pleasant aroma. Propolis is consumed as a dietary supplement; it is also a raw material in chewing gums, confections, and honey, and a preservative added directly to food or integrated into packaging. Although propolis volatiles have been studied for many years, little is yet known about the key aroma-active compounds responsible for its pleasant characteristic aroma. Research has shown that propolis volatiles vary with geographic location, time of collection, and plant source. However, no research has documented variability in the aroma active compounds of propolis from the same bee hive over consecutive years or investigated which compounds are key odorants with greatest influence on the unique aroma of propolis. This research, therefore, aimed to identify key aroma active compounds in propolis and to gain insight into its seasonal variability. Aromas were isolated gently by solvent assisted flavor evaporation (SAFE) and volatile components were separated by on-column gas chromatography mass spectrometry (GC-MS) in addition to purge and trap thermal desorption (P&T-TD-GC-MS). Although hundreds of volatiles were present and identified in the samples, gas chromatography olfactometry (GC-O) demonstrated that only 47 were aroma active. Application of comparative aroma extract dilution analysis (cAEDA) identified α-pinene (pine-like), 1,8-cineole (eucalyptus-like), (E)-2-nonenal (green), (E,Z)-2,6-nonadienal (cucumber-like), (E)-β-damascenone (cooked apple), 2-methoxyphenol (smoky), phenylethyl alcohol (floral, rose), β-ionone (floral, berry), eugenol (clove-like), (E)-ethyl cinnamate (cinnamon-like), 2-methoxy-4-vinylphenol (clove-like), and 3-phenylpropanoic acid (floral) as the most aroma-active compounds. Concentrations of individual components varied with season, but overall distribution of odorants was remarkably consistent over three years. These results provide considerable insight into aroma compounds that contribute to propolis aroma and into seasonal changes in composition of those compounds. This knowledge should contribute significantly to applications of propolis to dietary, pharmaceutical, flavor and fragrance industries, and also set the stage for future research on the key aroma active compounds of propolis collected from different geographical locations as well as the development of aroma standardization and quality control methods.
Subject (authority = RUETD)
Topic
Food Science
Subject (authority = ETD-LCSH)
Topic
Propolis
Subject (authority = ETD-LCSH)
Topic
Bees--United States--New Jersey
RelatedItem (type = host)
TitleInfo
Title
Rutgers University Electronic Theses and Dissertations
Identifier (type = RULIB)
ETD
Identifier
ETD_7240
PhysicalDescription
Form (authority = gmd)
electronic resource
InternetMediaType
application/pdf
InternetMediaType
text/xml
Extent
1 online resource (xiv, 94 p. : ill.)
Note (type = degree)
M.S.
Note (type = bibliography)
Includes bibliographical references
Note (type = special display note)
by Monika Jozefa Tomaszewski
RelatedItem (type = host)
TitleInfo
Title
Graduate School - New Brunswick Electronic Theses and Dissertations
Identifier (type = local)
rucore19991600001
Location
PhysicalLocation (authority = marcorg); (displayLabel = Rutgers, The State University of New Jersey)
Rutgers University. Graduate School - New Brunswick
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Type
License
Name
Author Agreement License
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