Abstract
| - Aqueous extracts were prepared from five barley crystal malts (color range 15−440 °EBC, EuropeanBrewing Convention units). Antioxidant activity was determined by using the 2,2‘-azinobis(3-ethylbenothiazoline-6-sulfonic acid) (ABTS•+) radical cation scavenging method. Antioxidant activityincreased with increasing color value although the rate of increase decreased with increasing colorvalue. Color was measured in CIELAB space. Extracts of the 15, 23, and 72 °EBC malts followedthe same dilution pathway as did the 148 °EBC sample at higher dilution levels, indicating thatthey could each be used to give the same color by appropriate dilution. The 440 °EBC sample followeda different dilution pathway, indicating that different compounds were responsible for color in thisextract. Fifteen selected volatile compounds were monitored using gas chromatography/massspectrometry (GC/MS). Levels of methylpropanal, 2-methylbutanal, and 3-methylbutanal werehighest for the 72 °EBC sample. When odor threshold values of the selected compounds were takeninto account, 3-methylbutanal was the most important contributor to flavor. Relationships betweenlevels of the lipid oxidation products, hexanal and (E)-2-nonenal, and antioxidant activity werecomplex, and increasing antioxidant activity for samples in the range of 15−148 °EBC did not resultin reduced levels of these lipid-derived compounds. When different colored malt extracts were dilutedto give the same a* and b* values, calculated antioxidant activity and amounts of 3-methylbutanal,hexanal, and (E)-2-nonenal decreased with increasing °EBC value. Keywords: Malt; crystal malt; antioxidants; antioxidant activity; color; flavor
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