Group Title: Citrus Station mimeo report - Florida Citrus Experiment Station ; 57-4
Title: Spectrophotometric data on citrus oils in the ultraviolet and infrared
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Permanent Link: http://ufdc.ufl.edu/UF00072381/00001
 Material Information
Title: Spectrophotometric data on citrus oils in the ultraviolet and infrared
Series Title: Citrus Station mimeo report
Physical Description: 4 leaves : ; 28 cm.
Language: English
Creator: Kesterson, J. W
Hendrickson, Rudolph
Edwards, G. J
Citrus Experiment Station (Lake Alfred, Fla.)
Publisher: Florida Citrus Experiment Station
Place of Publication: Lake Alfred FL
Publication Date: 1956
 Subjects
Subject: Orange oil -- Processing -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (leaf 4).
Statement of Responsibility: J.W. Kesterson, R. Hendrickson and G.J. Edwards.
General Note: Caption title.
General Note: "October 11, 1956."
 Record Information
Bibliographic ID: UF00072381
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 74906977

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Citrus Station Mimeo Report 57-4
October 11, 1956

Spectrophotometric Data on Citrus Oils in the Ultraviolet and Infrared

J. W. Kesterson, R. Hendrickson and G. J. Edwards


Various chemical and physical procedures have been used to arrive at stand-
ards of identity for citrus oils. However, for the most part organoleptic methods
have been the final judge of quality. Since this procedure is strictly a matter
of opinion, it leaves much to be desired as a method of analysis. It would be
most desirable to have objective methods capable of giving both qualitative and
quantitative results. While the examination of essential oils by ultraviolet and
infrared (1, 2, 4, 5, 6) is not new, it does offer a new criterion by which quali-
ty and purity may be measured. In anticipation that ultraviolet and infrared
absorption data may eventually be used to supplement the present standards of
purity for citrus oils, information is presented relative to coldpressed Florida
orange, Temple orange, grapefruit, tangerine, Italian mandarin, Persian lime and
lemon oil.


METHODS

In this investigation representative samples from large lots of oil were
secured from plants utilizing the two methods previously described by Kesterson
and Hendrickson (3) for the production of essential oils in Florida. The com-
mercial samples used in this study were considered to be of excellent quality, as
well as conforming to the standards of purity for each particular type oil.

UltraViolet absorption data were secured in accordance with the procedure
of Sale et al (5). A Beckman Model DU quartz spectrophotometer with hydrogen
lamp attachment and dilutions of 0.25 gram oil in 100 ml. of 95 percent ethanol
were used. In evaluating the orange, mandarin, tangerine and lemon oil samples,
a 10 mm. silica-absorption cell was used. However, for grapefruit and Persian
lime oil the concentration was so great that it became necessary to use a 1 mm.
silica-absorption cell to obtain a curve.

Infrared absorption data were obtained using the Perkin-Elmer, Model 21,
double beam recording infrared spectrophotometer. Each particular oil as such
was run in a sodium chloride cell of either 0.0226 or 0.0270 mm. thickness.


EXPERIMENTAL PROCEDURE AND DISCUSSION OF RESULTS
ULTRAVIOLET

Coldpressed Orange Oil. Twenty-two samples of coldpressed orange oil were
collected from 28,000 lb. lots of commercial orange oil. These samples were
examined by ultraviolet. It can be seen from the ultraviolet data in Table 1
that the CD values ranged from 0.28 to 0.39. The peak absorptions occurred at
330 mu. with values from 0.42 to 0.68. These samples of oil collected in

Florida Citrus Experiment Station
Lake Alfred, Florida.
708 10/11/56 3WK






Table 1. Spectrophotometer Analysis of Coldpressed Orange Oil
in Ultraviolet.



Date quantity
Sample CD Peak mu. Cone. Light Path Oil
Collected____ Absorption gm./ml. am. lb.

12/29/55 0.30 0.52 330 0.0025 10 28,000
12/29/55 0.29 0.49 330 0.0025 10 28,000

1/9/56 0.26 0.43 330 0.0025 10 28,000
1/16/56 0.25 0.42 330 0.0025 10 28,000

1/16/56 0.27 0.44 330 0.0025 10 28,000
1/31/56 0.32 0.52 330 0.0025 10 28,000
2/2/56 0.27 0.46 330 0.0025 10 28,000

2/2/56 0.33 0.57 330 0.0025 10 28,000
2/2/56 0.39 0.68 330 0.0025 10 28,000
2/2/56 0.30 0.50 330 0.0025 10 28,000
3/13/56 0.3028 0.47 330 0.0025 10 28,000
4/6/56 0.31 0.51 330 0.0025 10 28,000
4/6/56 0.33 0.55 330 0.0025 10 28,000
5/18/56 0.30 0.50 330 0.0025 10 28,000
5/18/56 0.30 0.50 330 0.0025 10 28,000
5/18/56 0.30 0.50 330 0.0025 10 28,000
5/18/56 0.29 0.49 330 0.0025 10 28,000

6/16/56 0.29 0.49 329 0.0025 10 28,000

6/16/56 0.29 0.48 330 0.0025 10 28,000
6/16/56 0.29 0.48 330 0.0025 10 28,000
6/16/56 0.29 0.49 329 0.0025 10 28,000
6/16/56 0.29 0.49 329 0.0025 10 28,000

Maximum 0.39 0.68 330 -
Minimum 0.28 0.42 329 -

Florida Citrus Experiment Station,
Lake Alfred, Florida. 708d -10/11/56 JWK








-2-


December and January were produced from mixtures of Hamlin and Parson Brown fruit,
whereas the February samples were produced from Pineapple oranges. The March and
April samples were produced from mixtures of Pineapple and Valencia oranges,
whereas the May and June samples were produced from Valencia oranges. It is
interesting to note that the variety of fruit had no influence on the CD values
or peak absorptions obtained. However, during June three samples gave peak
absorptions at 329 mu. instead of 330 mu. This difference is not great enough
to appear significant.

In the course of this study the opportunity presented itself to secure three
samples of coldpressed orange oil made by the same process where the only variable
was the different yield of oil obtained. Data relative to these oils are pre-
sented in Table 2 and show that as the yield increased, the values for specific
gravity, evaporation residue, and refractive index also increased, but the values
for optical rotation decreased. This is in accordance with previous findings.
However, it is most interesting to note that as the yield increased, the values
for peak absorption and CD also increased. Evidently, as the yield of oil is
increased, more high boiling, high-molecular-weight constituents are extracted;
the presence of a higher percentage of these compounds in the oil causes a re-
duction in the percentage of d-limonene, resulting in higher CD and peak absorp-
tion values.

The origin of the Temple orange, according to Webber and Batchelor (7), is
unknown, but a very similar fruit has been reported as occurring in Jamaica. Its
characteristics suggest that it is a hybrid of the tangerine with sweet orange.
One sample of Temple orange oil was investigated and a peak absorption occurred
at 327 mu. which is intermediate between orange (330Gnu.) and tangerine (325 mu.)
oil. A second peak absorption occurred at 270 mu. which is characteristic only
for tangerine oil. This would indicate as presupposed that the Temple orange is
a hybrid of the tangerine and sweet orange. This observation could have signifi-
cant importance in that it offers a possible method by which many unknown citrus
hybrids could be identified.

Coldpressed Grapefruit Oil. Three lots of commercial coldpressed Duncan
grapefruit oil were analyzed by ultraviolet as shown in Table 3. The peak
absorptions occurred at 319.5 to 321 mu. with values from 0.317 to 0.365; whereas,
the CD values ranged from 0.252 to 0.290. These particular values are considered
to represent the normal range in variation since they were collected during two
different seasons.

Coldpressed Tangerine Oil. Three lots of coldpressed Dancy tangerine oil
were collected and analyzed over a period of three years, as shown in Table 4.
Peak absorptions occurred at 325 mu. and 270 mu. Peak absorption values at 325
mu. ranged from 1.05 to 1.28; whereas, at 270 mu., they ranged from 1.27 to 1.43.
At 325 mu., CD values ranged from 0.53 to 0.68 and at 270 mu. from 0.21 to 0.24.
Since these values were collected over a period of three years, they are con-
sidered to be approximately the normal range for tangerine oil.


Florida Citrus Experiment Station
Lake Alfred, Florida.
708a 10/11/56 JWK








Table 2.- Relation of Yield to the Ultraviolet Characteristics of Coldpressed
Orange Oil.



Yield Specific Refractive Optical Evaporation Peak
lb. oil/ton peel Gravity Index Rotation Residue CD Absorption
2yC/2yC N22 V25 % (330 mu.)


2.16 0.8430 1.4730 +97.23 2.03 0.27 0.46

3.22 0.8435 1.4732 +97.21 2.39 0.33 0.57

3.50 0.8438 1.4733 +96.50 2.55 0.39 0.68


Spectrophotometer Analysis
Ultraviolet.


of Coldpressed Duncan Grapefruit Oil in


Date Light Quantity
Sample CD Peak mu. Cone. Path Oil
Collected Absorption gm./ml. mm. lb.

1/7/55 0.253 0.322 321.0 0.0025 1 28,000

4/7/55 0.252 0.317 320.0 0.0025 1 28,000

4/18/56 0.290 0.365 319.5 0.0025 1 4,000

Maximum 0.290 0.365 321.0 -
Minimum 0.252 0.317 319.5 -

Florida Citrus Experiment Station
Lake Alfred, Florida. 708e -.- 10/11/56 JWK


Table 3.-








Table 4.- Spectrophotometer Analysis of Coldpressed Tangerine Oil in Ultraviolet.


Date 325 mu. 270 mu. Light Quantity
Sample CD Peak CD Peak Cone. Path Oil
Collected Absorption Absorption gm./ml. am. lb.

12/16/54 0.59 1.17 0.21 1.33 0.0025 10 1,000

6/10/55 0.53 1.05 0.20 1.27 0.0025 10 500

1/19/56 0.68 1.28 0.24 1.43 0.0025 10 3,000


Maximum 0.68 1.28 0.24 1.43 -
Minimum 0.53 1.05 0.21 1.27 -
-- _- '_ ...


Table 5.-


Spectrophotometer
Ultraviolet.


Analysis of Coldpressed Persian Lime Oil in


Florida Citrus Experirent Station,
Lake Alfred, Florida. 708f 10/11/56 JWK


Date Light Quantity
Sample CD Peak mu. Cone. Path Oil
Collected Absorption gm./ml. Mn. lb.

11/15/54 1.09 1.37 320 0.0025 1 2500

1/23/56 1.23 1.59 320 0.0025 1 2500








-3-


One sample of coldpressed Italian mandarin oil was studied for comparison
purposes with tangerine oil. While tangerine and Italian mandarin oil give curves
of the same general nature, they are different in that the mandarin oil has peak
absorptions at 345 mu, and 237 mu.

Coldpressed Persian Lime Oil. Two lots of coldpressed Persian lime oil were
analyzed by ultraviolet as shown in Table 5. Peak absorptions occurred at 320 mu.
with values of 1.37 and 1.59 with CD values of 1.09 and 1.23, respectively.

Coldpressed Lemon Oil. Seven lots of coldpressed Florida lemon oil have
been analyzed by ultraviolet as shown in Table 6. Peak absorptions occurred at
315 mu. except for one sample which was 325 mu. This particular sample was pre-
pared from Meyer lemon. The Meyer lemon is a hybrid of unknown origin; therefore,
it would not be expected to give the same result as true lemon oil. Peak absorp-
tions ranged from 0.61 to 1.19 while CD values ranged from 0.26 to 0.67.


INFRARED

Infrared spectrophotometry is finding greater use by the Essential Oil
Industry as a method for evaluating perfumery materials. However, to date this
method has not been used for the evaluation of citrus oils. Since all organic
compounds absorb in the 2.0 to 16.0 micron range, a finger-print picture of the
various components in the oil can be obtained. For this particular reason the
infrared method is especially well suited for the evaluation of citrus oils since
each particular oil will have its own unique spectrum by which it may be identi-
fied.

The maximum absorption areas for Florida coldpressed orange, Temple orange,
grapefruit, tangerine, Italian mandarin, Persian lime and lemon oil, as well as,
double distilled d-limonene are as follows:

Coldpressed Valencia Orange Oil. 2.31, 3.22, 3.43, 3.64, 5.56, 5.73, 5.92,
6.04, 6.23, 6.93, 7.23, 7.50, 7.61, 7.75, 8.05, 8., 813 8.33, 8.64, 8.69, 8.95,
9.27, 9.50, 9.82, 10.12, 10.44, 10.92, 11.28, 12.53, 12.66, and 13.15 u. Sodium
chloride cell 0.0270 mm. thickness.

Coldpressed Temple Orange Oil. 2.30, 3.22, 3.43, 3.64, 5.57, 5.72, 5.92,
6.03, 6.22, 6.92, 7.23, 7.50, 7.61, 7.75, 8.05, 8.33, 8.63, 8.69, 8.95, 9.25,
9.49, 9.83, 10.11, 10.44, 10.92, 11.27, 12.52, 12.66 and 13.18 u. Sodium
chloride cell 0.0270 mm. thickness.

Coldpressed Grapefruit Oil. 2.32, 3.23, 3.44, 3.64, 5.58, 5.68, 5.93, 6.04,
6.16, 6.93, 7.24, 7.51, 7.62, 7.76, 7.83, 8.13, 8.34, 8.64, 8.70, 8.9, 9.30, 9.51,
9.85, 10.12, 10.45, 10.94, 11.34, 12.02, 12.53, 12.68, and 13.21 u. Sodium
chloride cell 0.0226 mm. thickness.

Coldnressed Tangerine Oil. 2.30, 3.22, 3.45, 3.64, 5.57, 5.72, 5.92, 6.04,
6.23, 6.58, 6.92, 7.24, 7.50, 7.62, 7.75, 8.05, 8.33, 8.64, 8.70, 8.96, 9.27, 9.50,
9.83, 10.12, 10.45, 10.93, 11.27, 12.53, 12.66, and 13,18 u. Sodium chloride
cell 0.0226mm. thickness.
Florida Citrus Experiment Station
Lake Alfred, Florida.
708b 10/11/56 JWK











Table 6.- Spectrophotometer Analysis of Coldpressed Lemon Oil in
Ultraviolet.


Date Light Quantity
Sample CD Peak mu. Cone. Path Oil
Collected Absorption gm./ml. m. lb.


1/8/54 0.38 0.86 315 0.0025 10 1000

10/26/54 0.43 0.92 315 0.0025 10 1000

11/15/54 0.67 1.19 315 0.0025 10 1000

10/30/55 0.30 0.62 315 0.0025 10 50

12/5/55 0.26 0.61 315 0.0025 10 190

12/ 55 0.40 0.92 315 0.0025 10 2000

1/20/56 0.50 0.96 325 0.0025 10 3 oz.


Maximum 0,67 1.19 -
finimum 0.26 0.61 -
.. .'IL-


Florida Citrus Experiment Station,
Lake Alfred, Florida. 708g 10/11/56 JWK






Coldpressed Italian Mandarin Oil. 2.32, 3.45, 5.58, 5.88, 6.05, 6.28, 6.58,
6.94, 7.25, 7.50, 7.63, 7.76, 7.93, 8.03, 8.34, 8.64, 8.71, 8.98, 9.17, 9.30, 9.51,
9.84, 10.14, 10.55, 10.93, 11.28, 12.54, 12.69, 12.74, 13.20, 13.37, and 14.27 u.
Sodium chloride cell 0.0226 mm. thickness.

Coldpressed Persian Lime Oil. 2.32, 3.45, 5.68, 5.91, 6.04, 6.15, 6.92,
7.24, 7.50, 7.62, 7.78, 8.08, 8.32, 8.64, 8.99, 9.17, 9.30, 9.51, 9.82, 10.14,
10.54, 10.92, 11.27, 11.71, 12.14, 12.52, 12.68, 13.20 and 13.97 u. Sodium chlor-
ide cell 0.0270 mm. thickness.

Coldpressed Lemon Oil. 2.33, 3.42, 5.63, 5.69, 5.92, 6.04, 6.94, 7.24, 7.50,
7.62, 7.76, 8.12, 8.34, 8.64, 8.70, 8.96, 9.51, 9.84, 10.13, 10.46, 10.54, 10.93,
11.34, 11.72, 12.54, 12.68 and 13.21 u. Sodium chloride cell 0.0270 mm. thickness.

Double Distilled D-Limonene. 2.31, 3.23, 3.48, 3.64, 5.57, 5.80, 5.92, 6.04,
6.24, 6.95, 7.24, 7.50, 7.61, 7.75, 8.05, 8.33, 8.64, 8.70, 8.95, 9.26,9.50,,9.84,
10.12, 10.39, 10.93, 11.33, 12.53, 12.66, and 13.18 u. Sodium chloride cell 0.0542
mm. thickness.

SUMMARY
Ultraviolet and infrared absorption data are presented for Florida coldpressed
orange, Temple orange, tangerine, Italian mandarin, grapefruit, Persian lime and
lemon oil.

The yield of oil obtained from the fruit was shown to have an influence on
the ultraviolet absorption characteristics of coldpressed orange oil.

Temple orange oil was used to illustrate how ultraviolet absorption tech-
niques could possibly be used as a method to identify unknown citrus hybrids.

The data presented indicate that each particular oil has typical ultraviolet
and infrared absorption characteristics which possibly could be used as a criteri-
on to supplement the present standards of purity.

LITERATURE CITED
1. Carrol, M. F. and W. D. Fordham. Aspects of the Analysis of Pure Perfumery
Chemicals. Soap, Perfumery and Cosmetics, February, 1955.

2, Dijkstra, K. Onderzock von Fenige Altherische Olien Door Absorptiening in
Het Ultraviolet. Pharmac. Wubl. 73: 502-516. 1936.

3. Kesterson, J. W. and R. Hendrickson. Two Commercial Methods for the Product-
ion of Citrus Oils in Florida. Amer. Perf. and Aromatics 67: 2: 35-38.
1956.
4. Presnell, A. K. Infrared Spectroscopy of Essential Oils. Jour. Soc.
Cosmetic Chem. 4: 2: 101-109. 1953.
5. Sale, J. W. et al. Analysis of Lemon Oil. Jour. Assoc. Offic. Agr. Chemists
36: 1: 112-119. 1953.
6. Van Os, D. and K. Dijkstra. L'Examen des hiles essentielles par la measure
de l'absorption dans l'ultra-violet. J. Pharmac. Chimie 25: 437-454.
1937.
7. Webber, J. H. and L. D. Batchelor. The Citrus Industry. Vol. I. Univ. of
Calif. Press. 1948..
Florida Citrus Experiment Station, Lake Alfred, Fla. 708c 10/11/56 JWK




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