Group Title: Citrus Station mimeo report - Florida Citrus Experiment Station ; CES 67-6
Title: Rich sources of pectin from citrus raw materials in Florida
Full Citation
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 Material Information
Title: Rich sources of pectin from citrus raw materials in Florida
Series Title: Citrus Station mimeo report
Physical Description: 2 leaves : ; 28 cm.
Language: English
Creator: Rouse, A. H
Citrus Experiment Station (Lake Alfred, Fla.)
Florida Citrus Commission
Publisher: Citrus Experiment Station :
Florida Citrus Commission
Place of Publication: Lake Alfred FL
Publication Date: 1966
Subject: Citrus -- By-products -- Florida   ( lcsh )
Pectin -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Statement of Responsibility: A.H. Rouse.
General Note: Caption title.
General Note: "400-10/4/66-AHR."
 Record Information
Bibliographic ID: UF00072444
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 76752344

Full Text

Citrus Experiment Station CES 67-6
and Florida Citrus Commission,
Lake Alfred, Florida. 400-10/4/66 AHR

Rich Sources of Pectin from Citrus Raw Materials in Florida

A. H. Rouse
University of Florida
Citrus Experiment Station
Lake Alfred, Florida

The citrus processor holds the key to several excellent sources of raw
materials for the manufacture of pectin. The present type juice extractor
supplies a peel free from excess juice, rag, and seeds. Peel amounts to
approximately 20% of the whole orange and 28% of the whole grapefruit and it
contains the white spongy albedo rich in protopectin. Citrus peel ranges from
12 to 20% pectin, as anhydrogalacturonic acid (AGA), on a dry weight basis.
This amount is approximately doubled when peel is properly leached to remove
the water-soluble solids. As juice production from lemons and limes increases
in Florida, more of these kinds of peel becomes available. Such peel is a
better source of raw material for high quality pectin than that from orange or

Another excellent source of raw material containing pectin is usually re-
ferred to as grapefruit "cores", a waste product from the sectionizing operation.
The FMC mechanical sectionizer supplies the center core and attached segment
membrane which are much richer in quality and quantity of pectin than orange or
grapefruit peel (Table 1). Segment membrane amounts to approximately 10% of the
grapefruit and 12% of the orange. The yield, jelly grade, jelly units, and
purity are similar for pectins extracted from either Valencia orange or grape-
fruit membranes (Table 1). These average values are based on a two-year maturity
study of prepared dried alcohol-insoluble solids (AIS). Jelly grade values for
pectins in both Tables 1 and 2 were measured by the Delaware Jelly-Strength
Tester, which gives slightly higher values in the upper range than those obtained
when the Exchange Ridgilimeter was used. The Ridgilimeter is now used in common
practice for determining jelly grade.

Table 1. Comparative values of pectins from peel and membrane
of Valencia oranges and Silver Cluster grapefruit
Orange Grapefruit
Peel Membrane Peel Membrane
Yield-% 25.0 33.5 21.7 33.6
Jelly grade 205.6 313.9 228.6 323.2
Jelly units 51.4 105.0 49.7 108.6
Purity as AGA-% 91.4 93.3 86.5 90.8

During the past citrus season two companies have begun to dry citrus peel
on a semi-commercial basis for the purpose of manufacturing pectin. The dryer
operating at Goulds was producing dried lime pomace and the one located at Lake
Wales was producing both grapefruit and orange pomace. In the latter instance
the peel was supplied by the sectionizing line during the early part of the

season and by the juice line during the latter part of the season. Also, the
dryer at Lake Wiaes has been used for trial runs on drying lime and lemon peel.
Generally, the processing of dried peel consists of grinding, cold water
leaching, pressing, and drying in a direct-fired dryer, Because the peel can
be supplied continuously, no enzyme inactivation is necessary with steam or
hot water.

Data on pectins extracted from dried orange, grapefruit, lemon, and lime
peels, as well as AIS from dried grapefruit "cores" are presented in Table 2.

Table 2. Comparative values of pectins from commercially dried citrus
peels and dried alcohol-insoluble solids from grapefruit "cores"
Source of Yield Jelly Jelly
raw material % grade units
Orange peel 30.4 227 69
Grapefruit peel 28.6 241 69
Lemon peel 26.3 304 80
Lime peel 31.0 338 105
Grapefruit "cores" (AIS) 31.3 366 115

The outlook for producing a high quality pectin from richer and better
sources of raw material, such as grapefruit "cores" and citrus peel, should
encourage Florida citrus processors to venture into this field, which is new
to Florida.

Florida Citrus Experiment Station
and Florida Citrus Commission,
Lake Alfred, Florida.
400-10/4/66 AHR

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