GB/T 14454.2-2008 English PDF (GBT14454.2-2008)
GB/T 14454.2-2008 English PDF (GBT14454.2-2008)
GB/T 14454.2-2008: Fragrance/Flavor substances -- Method for valuation of odour
NATIONAL STANDARD OF THE
PEOPLE REPUBLIC OF CHINA
Replacing GB/T 14454.2-1993
Fragrance/Flavor substances - Method for valuation of odour
ISSUED ON. JULY 15, 2008
IMPLEMENTED ON. DECEMBER 1, 2008
Issued by. General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China;
Standardization Administration of the People's Republic of
Table of Contents
Foreword ... 3
1 Scope ... 5
Method I -- The triangle valuation method ... 5
2 Terms and definitions ... 5
3 Principle ... 6
4 Preparation prior to valuation ... 6
5 Operating procedures ... 8
6 Expression of results ... 9
Method II -- Paired comparison test method ... 10
7 Principle ... 10
8 Standard sample, solvent and fragrance blotter ... 10
9 Operating procedures ... 11
10 Expression of results ... 12
GB/T 14454, Fragrance/Flavor substances - General test methods, comprises the following parts.
-- Part 1. Fragrance/Flavor substances - Preparation of test samples;
-- Part 2. Fragrance/Flavor substances - Method for valuation of odour; -- Part 4. Fragrance/Flavor substances - Determination of refractive index; -- Part 5. Fragrance/Flavor substances - Determination of optical rotation; -- Part 6. Fragrance/Flavor substances - Quantitative evaluation of residue on evaporation;
-- Part 7. Fragrance/Flavor substances - Determination of freezing point; -- Part 11. Fragrance/Flavor substances - Determination of content of phenols; -- Part 12. Fragrance/Flavor substances - Method for determination of trace chlorinated compounds;
-- Part 13. Fragrance/Flavor substances - Determination of carbonyl value and carbonyl compounds content;
-- Part 14. Fragrance/Flavor substances - Preparation of standard solution test solution and indicator solution;
-- Part 15. Oil of sassafras - Determination of safrole and isosafrole content - Gas chromatographic method on packed columns.
This Part is Part 2 of GB/T 14454.
This Part is a revision of GB/T 14454.2-1993, Fragrance/Flavor substances - Method for valuation of odour. Compared with GB/T 14454.2-1993, the major change of this Part is the addition of the method of triangle valuation.
GB/T 14454.2-1993 adopts the paired comparison test method. It is finally determined by the valuators giving valuation scores whether the sample is good, fair, qualified and unqualified. The advantage of the method is that it is simple and will not cause sensory fatigue easily, but the disadvantage is that the vulnerable valuators are easily mislead by the experts and unable to make their own choices, when the know samples are compared.
In this Part, in addition to the paired comparison test method, we also refer to the triangle valuation method and the three-point test method in related sensory analysis method which are implemented by many enterprises at present. The odour of Fragrance/Flavor substances - Method for valuation of odour
The first method of this Part of GB/T 14454 specifies the triangle valuation method to valuate and determine the differences between the odours of sample to be tested and standard sample, which applies to the routine control of the odours of fragrance/flavor substances.
The second method of this Part specifies the paired comparison test method to valuate and determine the differences between the odours of sample to be tested and standard sample, which applies to the routine control of the odours of fragrance/flavor substances.
Method I -- The triangle valuation method
2 Terms and definitions
For the purposes of this Part of GB/T 14454, the following terms and definitions apply. 2.1
method of triangle valuation
Mark 4 fragrance blotters respectively; use 2 fragrance blotters to dip in sample to be tested; use another 2 fragrance blotters to dip in standard sample; and then mix the 4 fragrance blotters together. Take one and reserve 3 randomly and let the valuators to find the fragrance blotter whose odour is different.
The valuation of fragrance blotters which are prepared just a short moment ago (within 10 min after being dipped in sample), is called wet method.
The valuation of fragrance blotters which are prepared a relatively long time ago (after 30 min, within 48 h), is called dry method.
5 Operating procedures
5.1 Liquid fragrance/flavor substances
5.1.1 The presider shall first ensure the valuation environment is as specified and then notify the members of the valuation team. The time is preferably the middle period of the morning or afternoon.
5.1.2 Prepare standard sample and sample to be tested (samples may be poured into a clean container without a peculiar odour). Fragrance blotters for the dry method may be prepared in advance.
5.1.3 The presider uses particular codes/symbols to mark at the ends of 4 fragrance blotters which are not dipped in samples.
5.1.4 Take 2 marked fragrance blotters to immerse into standard sample about 1 cm to take some liquid; try to scrape away excessive sample liquid at the mouth of standard sample; and do not place the ends dipped into sample liquid vertically upward after taking the fragrance blotters out, to avoid excessive sample liquid flowing downwards. The presider records their codes/symbols.
5.1.5 Take 2 marked fragrance blotters to dip into sample to be tested with the height of dipping into sample liquid identical to that into standard sample. The presider records their codes/symbols.
If the same height of dipping can not be obtained, it is preferable to dip the 4 fragrance blotters independently and avoid the valuators from identifying at the height of dipping sample liquid. If visible chromatic aberration occurs on the fragrance blotters of the two samples, turn the light down in the valuation room.
5.1.6 The presider mixes the four fragrance blotters dipped into samples crossly; and during the process, avoid mutual contact and cross contamination of the ends dipped into samples.
5.1.7 During valuation, attention is drawn to that the distance from the fragrance blotters to the nose is maintained at 1 cm ~ 2 cm; do not let the fragrance blotters contact the nose; and inhale slowly. When the valuators feel olfactory fatigue, they may smell their own sleeve.
5.1.8 The sample liquid of one of the remaining three fragrance blotters is certainly from the different sample. The valuators shall find the fragrance blotter having the different odour in accordance with their own olfactory sense.
5.1.9 If the valuation team carry out valuation together, the valuators shall not discuss with each other during the valuation process; and it needs to carry out 3 rounds of dipping and valuation for the same group of standard sample and sample to be tested. Each valuator needs to find the fragrance blotter having the different odour once within made from different materials or the synthetic which is made through different process routes; and those of different specifications.
Standard sample shall be jointly determined by the technical and quality inspection departments of the enterprise and/or the customer.
Standard sample shall be stored in a clean, dry, closed inert container, which is fully filled (or filled with nitrogen), kept from sunlight and prevented from odour contamination; and it shall comply with the requirements of relevant departments. 8.2 Solvents
If necessary, select ethyl alcohol, benzyl alcohol, benzyl benzoate, diethyl phthalate, isopropyl myristate or water as the solvents in accordance with different fragrance/flavor types.
8.3 Fragrance blotter
Use clean, contamination-free fragrance blotters. Use good quality odourless, absorbent paper (of thickness about 0.5 mm); an...