No abstract

Six commercial Korean rice wines were described their sensory profiles by trained American panelists, and assessed acceptances by American subjects to identify the drivers of liking and disliking factors. Thirteen statistically different descriptive attributes were defined for Korean rice wines: aromas (apple, pear, earthy, peach, nutty, yeasty, honey), flavor (yeasty, nutty), taste (sweet, sour, bitter), and aftertaste (apricot). Samples A and F were characterized as sweet taste and fruity attributes, and sample C was characterized as being pear flavor and bitter taste. Sample B exhibited a strong earthy aroma, determined as the aroma of ginseng. The American subjects could not identify ginseng aroma due to their lack of experience in ginseng. Samples D and E were described as nutty and yeasty. In consumer test, consumer preference was skewed to sample A, for which the consumer preference revolved around the sweet, sour, and fruity characteristics of the sample by the principal component analysis. Few consumers expressed preference toward samples D and E, as evidenced by the lowest consumer acceptance ratings. Partial least squares regression revealed that the key liking factors of Korean rice wines were sweet, sour, and apricot flavors. Fruity characteristics (peach, apple, and pear) were also positively correlated with overall acceptance. The key disliking factors were yeasty and nutty characteristics. American subjects regarded Korean rice wine as belonging to the wine category, prompting them to grant the highest rank to sample A, which has similar characteristics to semisweet white wine.

Mononuclear nonheme iron(III) complexes of tetradentate ligands containing two deprotonated amide moieties, [Fe(Me(2)bpb)Cl(H(2)O)] (3 a) and [Fe(bpc)Cl(H(2)O)] (4 a), were prepared by substitution reactions involving the previously synthesized iron(III) complexes [Et(3)NH][Fe(Me(2)bpb)Cl(2)] (3) and [Et(3)NH][Fe(bpc)Cl(2)] (4). Complexes 3 a and 4 a were characterized by IR and elemental analysis, and complex 3 a also by X-ray crystallography. Nonheme iron(III) complexes 3, 3 a, 4, and 4 a catalyze olefin epoxidation and alcohol oxidation on treatment with m-chloroperbenzoic acid. Pairwise comparisons of the reactivity of these complexes revealed that the nature of the axial ligand (Cl(-) versus H(2)O) influences the yield of oxidation products, whereas an electronic change in the supporting chelate ligand has little effect. Hydrocarbon oxidation by these catalysts was proposed to involve an iron(V) oxo species which is formed on heterolytic O-O bond cleavage of an iron acylperoxo intermediate (FeOOC(O)R). Evidence for this iron(V) oxo species was derived from KIE (k(H)/k(D)) values, H(2) (18)O exchange experiments, and the use of peroxyphenylacetic acid (PPAA) as the peracid. Our results suggest that an Fe(V)=O moiety can form in a system wherein the supporting chelate ligand comprises a mixture of neutral and anionic nitrogen donors. This work is relevant to the chemistry of mononuclear nonheme iron enzymes that are proposed to oxidize organic substrates via reaction pathways involving high-valent iron oxo species.

This study assessed the functionality and consumer acceptance of yeast fermented coffee beans. Green coffee beans were fermented for 24 h with three different yeast strains to increase functionality. The yeast fermentation was effective in fortifying the functionality of coffee by significantly increasing antioxidant activity according to the results of ORAC and SOD-like assay ( < 0.05). The TPC and TFC contents in the fermented coffee beans were significantly higher than those in the controls ( < 0.05). The consumer acceptance for the fermented coffee beans was slightly lower than that of the controls. Fermentation seemed to influence the aroma and flavor of coffee. However, agglomerative hierarchical clustering analysis revealed that approximately 39% of consumers significantly liked one of the fermented coffees (F3) more than the controls ( < 0.05). These consumers indicated that the yeast fermentation of green coffee beans did not generate a negative aroma or flavor and can be attractive with high antioxidant activity.