Extraction of expander-pretreated cottonseed with aqueous isopropyl alcohol /

Isopropyl alcohol (IPA) has been considered as an alternative

Bibliographic Details
Main Author: Zhang, Fan, 1960-
Format: Thesis Book
Language:English
Published: [Place of publication not identified] : [publisher not identified] ; 1995.
Subjects:
Online Access:Link to OAKTrust copy
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Description
Summary:Isopropyl alcohol (IPA) has been considered as an alternative
to hexane for vegetable oil extraction. This study evaluated
aqueous IPA (88, 93, 95 and 97%, w/w) extraction of
cottonseeds in combination with an expansion pretreatment.
The cottonseeds were flaked and cooked before the expansion.
Both fhvex and Solvex expanders were used to produce
cottonseed collets, and the couets were dried using a belt
dryer. Oil was extracted from the collets and flakes by a
simulated 7-stage countercurrent extraction using a
laboratory extraction unit. The Hivex expander removed about
35% of the original oil in the cottonseeds. Expansion
reduced considerably the level of free gossypol in the meals.
The collets and flakes were extracted with 95% IPA and the
solvent holdup of the collets was much lower than that of the
flakes. The oils produced from the collets were lower in
free fatty acid, gossypol, and sugar than the oils from the
flakes. But the phosphorus content of the oil from the
collets was 45% higher than that of the oil from the flakes.
The lower calcium and magnesiinn contents as well as the data
from HPLC analysis indicated that the expander process
produced oil with more hydratable phospholipids. Hexane
extraction was used as a control to compare with aqueous IPA
extractions. The aqueous IPA sufficiently extracted oils
from cottonseed, but not as efficiently as hexane. The
extraction efficiency of IPA increased with the increase in
IPA concentration. The miscelia formation proceeded more
slowly in the IPA extraction than in the hexane extraction.
Also, solvent holdup was higher for aqueous IPA than hexane,
and this decreased when the IPA concentration increased.
Aqueous IPA extracted a large amount of non-glyceride
substances with the crude cottonseed oil. The aqueous IPA-
extracted oils contained more free fatty acid, phosphorus,
gossypol, and sugar than the hexane-extracted oil. In
addition, the aqueous IPA extracted more hydratable
phospholipids with the oil. The defatted meals resulting from
the aqueous IPA and hexane extraction contained similar
amount of protein. But hexane-extracted meals had higher
protein dispersibility than aqueous IPA-extracted meals. All
the aqueous IPAextracted collets, from either the Hivex or
Solvex expander, contained less than 450 ppm free gossypol,
making them suitable for poultry and most non-ruminant feeds.
Item Description:Vita.
"Major Subject: Food Science and Technology".
Physical Description:xiii, 109 leaves : illustrations ; 28 cm.
Issued also on microfiche from University Microfilms Inc.
Bibliography:Includes bibliographical references.