Graduate Thesis Or Dissertation
 

Dealcoholization and concentration of fermented fruit juices

Pubblico Deposited

Contenuto scaricabile

Scarica il pdf
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/kk91fp11q

Descriptions

Attribute NameValues
Creator
Abstract
  • It has long been recognized that fermented food products possess a characteristic but pleasant flavor. The use of such foods, however, has been limited by the presence of ethanol. Thus the objective of this research was to investigate the possibility of producing non-alcoholic fermented juice concentrates. Three varieties of juices, Concord grape, apple, and blackberry, were ameliorated as needed and fermented to five to seven percent alcohol by volume. The fermented flavor was extracted with ethyl chloride and concentrated by distillation. These extracts were analyzed by gas chromatography using two different column temperatures. Low column temperature was 100°C while high column temperature was 170°C. Four peaks were found to contribute from 93 to 97 percent of the flavor compounds chromatographically separated from the three juices at low temperature. By use of the enrichment technique, these peaks appeared to be propyl alcohol, isobutyl alcohol, butyl alcohol, and a mixture of isoamyl and active amyl alcohol. At high temperature separation, four peaks were observed to comprise 56 to 64 percent of the flavor components fractionated. These four peaks appeared to be a mixture of acetic acid and ethyl octanoate, caproic acid, phenethyl alcohol and caprylic acid. Other components were tentatively identified to be acetone, ethyl acetate, ethanol, n-amyl alcohol, ethyl hexanoate, n-hexanol, propionic acid, 2, 3-butylene glycole, butyric acid, isovaleric acid, diethyl succinate, 4-butyrolactone, valeric acid and capric acid. Freeze drying and a combined method of distillation and freeze centrifugation were the two methods employed to remove ethanol and water from the fermented juices. A fivefold concentration of the original juices was obtained. From 91 to 95 percent of the alcohol and 80 percent of the water were removed from the juices by freeze drying while the combined technique removed only 79 percent of the ethanol and 80 percent of the water. Total acids, color and total soluble solids were not affected by the freeze drying procedure whereas the combined technique for removal of the alcohol resulted in some loss of these constituents. The fermented dealcoholized juices were analyzed by gas chromatography using only high temperature columns. These data indicate that dealcoholization resulted in a decrease in the peak heights of the first ten peaks to be separated. The remainder of the peaks generally showed an increase although a few exceptions were noted. The dealcoholized fermented juice concentrates were reconstituted and evaluated by a flavor panel. The panel data indicated that the rank order of preference for the three juices was blackberry, apple and Concord grape. The flavor panel also preferred the juices served at the higher levels of sweetness. The total average panel score for these three juices was observed to be about a neutral rating of "neither like nor dislike".
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Dichiarazione dei diritti
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome, 256 Grayscale) using Scamax Scan+ V.1.0.32.10766 on a Scanmax 412CD by InoTec in PDF format. LuraDocument PDF Compressor V.5.8.71.50 used for pdf compression and textual OCR.
Replaces

Le relazioni

Parents:

This work has no parents.

In Collection:

Elementi

Thumbnail Titolo Data caricata Visibilità Azioni
file details ELMILADISAMIR1966.pdf 2017-08-08 Pubblico Scaricare