Volatiles from Delicious Apple Essence—Extraction Methods

Abstract

SUMMARY— The organic volatiles in commercial Delicious apple essence were extracted and reduced to an oil by five different extractants: isopentane, diethyl ether, charcoal (with elution by ether), liquid carbon dioxide, and 1,2‐dichloro‐1,1,2,2‐tetrafluoroethane. Identification and quantitative estimation of the maior constituents were made by gas‐liquid chromatography and mass spectrometry. Isopentane and the fluorocarbon were similar in action. Compared with ether they gave lower recoveries, especially for the low‐molecular‐weight alcohols, but they gave extracts with higher concentrations of esters and aldehydes and thus are useful for further composition studies. Liquid carbon dioxide gave an extract similar to that given by ether. Adsorption on charcoal gave generally good recoveries and was outstanding for alcohols. Panel tests indicated that the low‐molecular‐weight alcohols have only minor importance, if any, to apple aroma. A major proportion of the principal aroma‐bearing constituents was extracted by the methods used.

Whiskey Composition: Identification of Additional Components by Gas Chromatography‐Mass Spectrometry

“…The Freon extract, however, was found to contain a higher concentration of aldehydes and esters, in-cIuding a few esters not detected in the ether-pentane extract of the same sample of whiskey. This agrees with the findings of Schultz et al (1967).…”

Fractionation technologies for liquid mixtures using dense carbon dioxide

“…Early researchers of the Western Regional Research Laboratory of the USDA (California) applied the semi-batch mode of operation. In the work developed by Schultz et al [83] and Schultz & Randall [81], aqueous apple juice essence was dispersed into liquid CO 2 . After ~3.3 cycles of aqueous essence passing through the column, the concentration went from 150-fold to 10,000-fold although steady-state was not achieved.…”

Amino acid sequence of elongation factor Tu. Sequence of a region containing the thiol group essential for GTP binding

“…Since they occur only once in a peptide, these residues are indicated by the integral value (in parentheses). The initial appearance of only aspartic acid and homoserine on limited acid hydrolysis can be explained by first cleavage at aspartic acid bonds [8] and subsequent hydrolysis of the cyclic cysteine derivate (II) to succinyl cysteine at longer times.…”

“…T-IB and T-IC were sequenced directly by solid-phase Edman degradation; T-IA, however, was blocked, indicating that it was the N-terminal peptide of T-I. Limited acid hydrolysis [8] of T-IA for 4 hr gave one residue each of homoserine and aspartic acid upon amino acid analysis. After 20 hr, approx.…”