ORGANIZATION OF THE SECTION FOR SPECIFICATIONS OF FLAVOURING AGENTS
At its 44th meeting JECFA considered a new approach to the safety evaluation of flavouring agents. This approach incorporates a series of criteria whose use enables the evaluation of a large number of these agents in a consistent and timely manner. At the 46th meeting the Committee applied these procedures to the evaluation of 52 flavouring agents. At the current session of the Committee, the procedure was applied to additional 217 flavouring agents. Specifications of identity and purity were prepared for 164 of these 217 flavouring agents and are documented on the following pages.
The specifications are presented in a tabular format because with the number of flavouring agents now being evaluated, the method of presentation becomes a matter of efficiency. Some of the substances have uses additional to that of being a flavouring agent, for example also serving as a carrier solvent. For these substances the specifications are presented both in the traditional format in Section A and in the tabular format in Section B. Section B, in some cases, contains a reference back to Section A so as to avoid repeating some tests which apply to all uses.
Information on specifications is given under the following headings, most of which are self-explanatory: Name; Chemical name; Synonyms; Flavour and Extract Manufacturer's Association of the United States (FEMA) No; Council of Europe (COE) No; Chemical Abstract Service Registry (CAS) No; Molecular weight; Chemical formula; Physical form/odour; Solubility; Solubility in ethanol*, Boiling point (information only); Identification test (ID), IR infrared spectrum; Assay min%**; Acid value max; Refractive index (at 20°, if not otherwise stated); Specific gravity (at 25°, if not otherwise stated); Other requirements, e.g. additional tests; and last the JECFA column that indicates the Session at which the specifications were prepared, E means "extraction solvent, C means "also used as carrier solvent" (See Section A), P means "preservative, R means "specifications revised", S means "existing specifications maintained, S, T means "existing tentative specifications maintained, N means "new specifications", and N, T means "new tentative specifications - further information required).
* See General Methods (Guide to JECFA Specifications), FAO Food and Nutrition Paper (FNP) 5/Rev. 2 (1991).** See Gas chromatographic (GC) Assay of Flavour Chemicals.
Previous specifications of flavouring agents having no other functional uses have been converted to the new tabular format. The tables were generated using Microsoft Excel 5.0.
The infrared spectra, used for identification and comparison purposes, are provided from page 239 onwards, except for those 52 flavouring agents, evaluated at the 46th session of the Committee. For the IR spectra of these substances, see FNP 52 Addendum 4 (1996).
NOTE: Many of the above IR spectra are of unsatisfactory editorial quality. The FAO JECFA Secretariat is exploring ways and means to produce satisfactory and consistent IR spectra when these specifications are printed again.
The following IR-spectra are reprinted from Merck FT-IR Atlas through courtesy of Dr. K.G.R. Pachler, Mr. F. Matlock, and Dr. H-U. Gremlich, and VCH Verlagsgesellschaft, Weinheim, Germany: 79, 80, 81, 82, 83, 84, 85, 86, 87, 91, 92, 93, 95, 96, 97, 98, 99, 101, 102, 103, 104, 105, 108, 110, 111, 113, 114, 116, 117, 118, 119, 125, 126, 127, 128, 137, 141, 142, 143, 148, 149, 179, 183, 184, 185, 186, 206, 217, and 218.
The following IR-spectra are reprinted with the permission from the Food Chemicals Codex, 4th Edition. Copyright 1996 by the National Academy of Sciences. Courtesy of the National Academy Press, Washington, D.C.: 53,54,56, 57, 58, 59,60, 61, 62,66, 65, 71,89,94,100,106,107,109,122,130,131, 134,151,158,174,188,196, and 198.
GAS CHROMATOGRAPHIC (GC) ASSAY OF FLAVOUR CHEMICALS
This procedure applies both to the assay of flavour chemicals and to the quantitation of minor components in flavour chemicals. Analysts following this procedure and performing the test should obtain sufficient resolution of major and even trace components of a mixture to calculate accurately the concentration of the desired component; should be familiar with the general principles, usual techniques, and instrumental variables normally met in gas chromatographic analysis; and should pay particular attention to the following:
1. Stability of baseline, return to baseline before and after each peak of interest, and minimum use of recorder attenuation.2. Any incompatibility between a sensitive sample component and column support, liquid substrate, or construction material.
3. The response to different components of the same or different detectors. Since sizable errors may be encountered in correlating area percent directly to weight percent, the methods for calculating response factors should be known.
4. Where limits for minor components are specified in the column entitled Other Requirements in the above tabular specifications for flavour chemicals, analysts should use authentic materials to confirm the retention times of minor components. Determine the quantity of components following the instructions below under Calculations and Methods.
GC CONDITIONS FOR ANALYSIS
Column: open tubular capillary column of fused silica or deactivated glass 30 m long x 0.25 to 0.53 mm id
Stationary phase:
1. For a nonpolar column: methyl silicone gum, or equivalent (preferable a bonded and cross-linked dimethyl polysiloxane)2. For a polar column: polyethylene glycol, or equivalent (preferable a bonded and cross-linked polyethylene glycol)
3. The stationary phase coating should have a thickness of 1 to 3 m m
Carrier gas: helium flowing at a linear velocity of 20 to 40 ml/s
Sample size: 0.1 to 1.0 m l
Split ratio: (for 0.25 mm to 0.35 mm id columns only) 50:1 to 200:1, typically, making sure that no one component exceeds the capacity of the column
Inlet temperature: 225 to 275°
Detector temperature: 250 to 300°
Detectors: use either a thermal conductivity or flame ionization detector operating both as recommended by the manufacturer
Oven program: 50 to 240°, increasing the temperature by 5 °/min, hold at 240° for 5 min
Analysts can also use any GC conditions providing separations equal to (or better than) those obtained with the above method, but in the case of a dispute, the above method must stand.
CALCULATIONS AND METHODS
A. Peak area integration with total area detected normalized to 100%, using electronic integrators: Use an electronic peak integrator in accordance with the manufacture's recommendations, ensuring that the integration parameters permit proper integration of the peaks of a variety of shapes and magnitudes and do not interpret baseline shifts and noise spikes as area contributed by the sample. Use internal or external standards as needed to confirm that the total GC peak area corresponds to 100% of the components present in the sample.
B. Results obtained as described above are based on the assumption that the entire sample has eluted and the peaks of all of the components have been included in the calculation. They will be incorrect if any part of the sample does not elute or if all the peaks are not measured. In such cases, and in all methods described above, the internal standard method may be used to determine percentages based on the total sample. For this method, measurements are required of the peaks of the component(s) being assayed and of the internal standard.
An accurately weighed mixture of the internal standard and the sample is prepared and chromatographed, the area ratio(s) of the component(s) to the standard is computed, and the percentage(s) of the component(s) is calculated.
If this calculation is to be applied, the substance used as the standard should be one that meets the following criteria:
a. Its detector response is similar to that of the component(s) to be determined. In general, the more nearly the chemical structure of the component resembles that of the standard, the closer the response will be.b. Its retention time is close to, but not identical with, that of the component(s).
c. Its elution time is different from that of any other component in the sample so that its peak does not superimpose on any other.
The weight ratio of the internal standard to the sample should be such that the internal standard and the component sought produce approximately equal peaks. This is, of course, not possible if several components of interest are at different levels of concentration.
If the internal standard method is applied properly, it may be assumed that the ratio of the weight of component to the weight of internal standard is exactly proportional to the peak area ratio, and under these conditions no correction factor is needed. The sample is first run by itself to determine whether the internal standard would mask any component by peak superposition. If there is no interference, a mixture is prepared of the sample and of the internal standard in the specified weight ratio, and the percentages of the internal standard and of the sample in the mixture are calculated. The mixture is chromatogrphed, and the areas of the component peak and the internal standard peak are calculated by one of the methods described above.
The calculations are as follows:
1a. % Component in Mixture/%Internal Standard in Mixture = Component Area/Internal Standard Area, or1b. % Component in Mixture = % Int. Std. in Mixture x (Component Area/Internal Standard Area)
2. % Component in Sample = (%Component in Mixture x 100)/%Sample in Mixture
Should calibration be necessary, mixtures should be prepared of internal standard and component, of either 100% or of known purity. The number of mixtures and the weight ratios to be used depend on the component being analyzed. Usually, three mixtures will be required. The weight ratio of one is chosen so that the heights of component and standard are equal. The ratios of the other two may be two-thirds and four-thirds of their value. Each mixture should be chromatographed at least three times, and areas calculated. The factor for each chromatograph should be calculated as specified below, and the averages taken for each mixture. An overall average factor is calculated from them. The calibration should be performed periodically.
1. Factor = [(Wt. Component x % Purity)/(Wt. Int. Std. x % Purity)] x [(Int. Std. Area)/Component Area]2. % Component in Sample Mixture = (Component Area x Factor x % Int. Std. in Sample Mixture)/Int. Std. Area
3. % Component in Sample = (% Component in Sample Mixture x 100)/% Sample in Sample Mixture
GC SYSTEM SUITABILITY TEST SAMPLE
The GC system suitability test sample consists of an equal-weight mixture of food-quality acetophenone, benzyl alcohol, benzyl acetate, linalool, and hydroxycitronellal.
Using the test sample described below, periodically test the performance of and resolution provided by the gas chromatograph employed. The test sample must display results comparable in quantitative composition, peak shape, and elution order to those specified herein. The quantitative composition should not deviate from the results listed below by more than 10%. Analyze the GC test sample using the GC Conditions for Analysis given above.
|
Component in Test Sample |
Order of Elution |
Normalized % |
Area (FID) | |
|
|
Non-polar |
Polar |
Non-polar |
Polar |
|
Benzyl alcohol |
1 |
4 |
22.0 |
21.3 |
|
Acetophenone |
2 |
2 |
21.1 |
21.4 |
|
Linalool |
3 |
1 |
20.8 |
21.0 |
|
Benzyl acetate |
4 |
3 |
18.6 |
19.1 |
|
Hydroxycitronellal |
5 |
5 |
16.7 |
16.7 |
SPECIFICATIONS OF FLAVOURING AGENTS LISTED AS "TENTATIVE" AT THE 49TH MEETING OF JECFA
|
No |
Substance |
Information required |
|
21 |
Allyl 2-furoate |
Assay; Acid value |
|
64 |
Rhodinyl propionate |
Assay; Acid value |
|
69 |
Citronellyl valerate |
Assay; Acid value |
|
70 |
Geranyl hexanoate |
Assay; Acid value |
|
72 |
Geranyl isobutyrate |
Boiling point; Acid value |
|
74 |
Rhodinyl isobutyrate |
ID test; Acid value |
|
75 |
Geranyl isovalerate |
Boiling point; Acid value |
|
77 |
Rhodinyl isovalerate |
Assay; Acid value |
|
78 |
Geranyl 2-ethylbutanoate |
Boiling point; Assay; Acid value; Refractive index; Specific gravity |
|
121 |
Heptyl formate |
Assay; Acid value |
|
140 |
2-Ethylbutyl acetate |
Assay; Acid value |
|
154 |
Heptyl butyrate |
Assay; Acid value |
|
155 |
Octyl butyrate |
Assay; Acid value |
|
156 |
Decyl butyrate |
Assay; Acid value |
|
165 |
cis-3-Hexenyl hexanoate |
Boiling point; Acid value |
|
168 |
Propyl heptanoate |
Assay; Acid value |
|
169 |
Butyl heptanoate |
Assay; Acid value |
|
171 |
Octyl heptanoate |
Assay; Acid value |
|
172 |
Isobutyl heptanoate |
Assay; Acid value; Refractive index |
|
176 |
Heptyl octanoate |
Assay; Acid value |
|
177 |
Octyl octanoate |
Assay; Acid value |
|
178 |
Nonyl octanoate |
Assay; Acid value; Refractive index |
|
182 |
Isoamyl laurate |
Boiling point; ID test; Assay; Acid value; Refractive index; Specific gravity |
|
184 |
Butyl stearate |
Assay; Acid value; Refractive index |
|
204 |
2-Methylbutyl 2-methylbutyrate |
Assay; Acid value; Specific gravity |
|
210 |
Isopropyl 2-methylbutyrate |
Boiling point; ID test; Acid value; Specific gravity |
|
211 |
3-Hexenyl 2-methylbutanoate |
Boiling point; Acid value; Specific gravity |
|
213 |
Methyl 2-methylpentanoate |
Boiling point; Assay; Acid value; Refractive index; Specific gravity |
|
215 |
Ethyl 3-methylpentanoate |
Boiling point; Assay; Acid value; Refractive index; Specific gravity |
INFRARED (IR) SPECTRA OF CERTAIN FLAVOURING AGENTS
53 Citronellyl formate
54 Geranyl formate
56 Rhodinyl formate
57 Citronellyl acetate
58 Geranyl acetate
59 Neryl acetate
61 Citronellyl propionate
62 Geranyl propionate
66 Geranyl butyrate
69 Citronellyl valerate
71 Citronellyl isobutyrate
75 Geranyl isovalerate
76 Neryl isovalerate
78 Geranyl 2-ethylbutanoate
94 Heptyl alcohol
100 Nonyl alcohol
134 cis-3-Hexenyl acetate
151 Butyl butyrate
158 Isobutyl butyrate
171 Octyl heptanoate
174 n-Amyl octanoate
191 trans-3-Heptenyl 2-methylpropanoate
200 Octyl isovalerate
202 3-Hexenyl 3-methylbutanoate
203 2-Methylpropyl 3-methylbutyrate
204 2-Methylbutyl 3-methylbutanoate
208 Hexyl 2-methylbutanoate
211 3-Hexenyl 2-methylbutanoate
212 2-Methylbutyl 2-methylbutyrate
