Commission Regulation (EEC) No 2568/91Show full title

Commission Regulation (EEC) No 2568/91 of 11 July 1991 on the characteristics of olive oil and olive-residue oil and on the relevant methods of analysis

[F1ANNEX XII U.K. ORGANOLEPTIC ASSESSMENT OF VIRGIN OLIVE OILS

Textual Amendments

1. PURPOSE AND SCOPE U.K.

This Annex sets the criteria required for organoleptic assessment of the virgin oils defined at 1 in the Annex to Regulation No 136/66/EEC and describes the method of grading them with reference to characteristics.

This method can be used only for grading virgin oils on the basis of fruitiness and intensity of defects by a group of selected trained tasters operating as a panel in line with section 4.

2. GENERAL U.K.

For the general basic vocabulary, the tasting room, the general methodology and the tasting glass compliance with the stipulations of the International Olive Oil Council is recommended.

3. SPECIFIC VOCABULARY U.K.

3.1. Positive attributes U.K.

Fruity : range of smells (dependent on variety) characteristic of oil from healthy fresh fruit, green or white, perceived directly or retronasally.

Bitter : characteristic taste of oil from green olives or olives turning colour.

Pungent : tingling sensation characteristic of oil made at the beginning of the season mainly from olives that are still green.

3.2. Negative attributes U.K.

‘Atrojado’ (fusty ): characteristic flavour of oil from piled olives in advanced anaerobic fermentation.

Mustiness/humidity : characteristic flavour of oil from olives in which large numbers of fungi and yeasts had developed as a result of storage for several days in humid conditions.

Muddy sediment : characteristic flavour of oil that has remained in contact with sediment in vats and tanks.

Winey/vinegary : characteristic flavour of certain oils reminiscent of wine or vinegar, due basically to formation of acetic acid, ethyl acetate and ethanol by fermentation of the olives.

Metallic : flavour reminiscent of metal, characteristic of oil that has been in prolonged contact with metal surfaces during crushing, mixing, pressing or storage.

Rancid : flavour of oil that has become oxidised.

Heated or burnt : characteristic flavour caused by excessive and/or prolonged heating during production, particularly by thermo-mixing of the paste in unsuitable conditions.

Hay/wood : characteristic flavour of certain oils from dry olives.

Rough : thick and pasty mouthfeel produced by some oils.

Greasy : flavour reminiscent of diesel, grease or mineral oil.

Vegetable water : flavour acquired by oil through prolonged contact with the vegetable water.

Brine : flavour of oil from olives preserved in salt solution.

Esparto : characteristic flavour of oil from olives pressed in new esparto mats. It can vary according to whether the mats are of green or dried esparto.

Earthy : flavour of oil from olives collected with earth or mud on them and not washed.

Grubby : flavour of oil from olives heavily attacked by grubs of the olive fly (Bactrocera oleae).

Cucumber : characteristic flavour of oil kept too long in hermetically sealed containers, notably in tins, attributed to formation of 2,6-nonadienal.

4. PANEL U.K.

The panel is appointed by the Member State and consists of a panel head and from eight to twelve tasters. However, for the 2001/02 marketing year, the panel may consist of fewer than eight tasters.

The panel head must be a soundly trained expert in the various types of oil. He or she is responsible for the panel and its organisation and operation, including preparation, coding and presentation of the samples to the tasters and collection and processing of the data.

He or she selects the testers, sees to their training and checks that their performance remains of adequate standard.

The testers must be selected and trained on account of their skill in distinguishing between similar samples. The International Olive Oil Council's manual on the selection, training and monitoring of qualified virgin oil tasters must be followed.

Panels must undertake to participate in national, Community and international organoleptic assessments organised for the purposes of periodic monitoring and harmonisation of perception criteria. They must also provide the Member State concerned with full information each year on the composition of the panel and the number of assessments made in their capacity as an approved panel.

5. PROCEDURE FOR ORGANOLEPTIC ASSESSMENT AND GRADING U.K.

5.1. Use of profile sheet by taster U.K.

The profile sheet to be used by the taster is reproduced as Appendix A.

Tasters must each smell and then taste (1) the oil submitted for examination contained in the tasting glass, analysing their olfactory, gustatory, tactile and kinaesthetic perceptions and mark on the sheet the intensity of their perception of each negative and positive attribute.

If negative attributes not listed on the profile sheet are perceived these must be noted under ‘ Other ’ using those of the terms defined in 3.2 above that best describe them.

5.2. Processing of data by panel head U.K.

The panel head collects the profile sheets completed by the tasters and scrutinises the intensities assigned. In the event of an anomaly he or she will ask tasters to re-examine their sheet and if necessary repeat the test.

The panel head may feed each tester's data into a computer programme for calculating the median (Appendix B). Input of each sample shall be made with the help of a grid of 10 vertical columns for the 10 sensory attributes and one line for each panel member.

If a negative attribute is mentioned under ‘ Other ’ by 50 % of the panel the head must calculate the median for this attribute and grade accordingly.

In cases of assessment in connection with monitoring of conformity to standards and of counter-assessment the panel head shall arrange for the assessment to be repeated twice at intervals of at least one day. The attribute medians shall be calculated using the data from the profile sheets of the three assessments.

5.3. Grading of oils U.K.

The oil is graded as follows in line with the median of the defects and the median for ‘ fruity ’ . By this is understood the median of the negative attribute perceived with greatest intensity. The value of the robust variation coefficient for this negative attribute must be no greater than 20 %.

(a)

extra virgin olive oil : the median of the defects is 0 and the median for ‘fruity’ is above 0;

(b)

virgin olive oil : the median of the defects is above 0 but not above 2,5 and the median for ‘fruity’ is above 0;

(c)

ordinary virgin olive oil : the median of the defects is above 2,5 but not above 6,0; or the median of the defects is not above 2,5 and the median for ‘fruity’ is 0;

(d)

lampante virgin olive oil : the median of the defects is above 6,0.

From 1 November 2003 categories c) and d) are replaced by:

(c)

lampante olive oil : the median of the defects is above 2,5; or the median of the defects is not above 2,5 and the median for ‘fruity’ is 0.

5.4. Special case U.K.

If the median of a positive attribute other than ‘ fruity ’ is above 5,0 the panel head must note this on the analysis certificate.

APPENDIX A

APPENDIX B METHOD OF CALCULATING MEDIAN AND CONFIDENCE INTERVALS

Median U.K.

The median is the real number Xm characterised by the fact that the probability (P) that the values of the distribution (X) are below that number (Xm) is not more than 0,5 and that simultaneously the probability (P) that the values of the distribution (X) are not above Xm is not less than 0,5. Another definition considers the median to be the 50th percentile of a distribution of numbers ranked in order of increase. In other terms the median represents the central value of an ordered series of uneven numbers or the average of the two central values of an ordered series of even numbers.

Robust standard deviation U.K.

To obtain a reliable estimate of the variability that arises around the median recourse is required to the Stuart and Kendall method of estimating the robust standard deviation. The formula for the asymptotic standard deviation S involves N and IQR. N is the number of observations and IQR the interquartile range, i.e. the robust estimate of the variability of the data under consideration (the interquartile range covers exactly 50 % of the cases of any probability distribution). The interquartile range is given by calculating the size of the deviation between the 75th and the 25th percentiles.

The percentile is the value Xpc characterised by the fact that the probability (P) that the valves of the distribution are below Xpc is not more than a determined hundredth and that simultaneously the probability (P) that the valves of the distribution are not above Xpc is not less than the said hundredth. The hundredth indicates the distribution fraction used. In the case of the median this is 50/100.

In other words the percentile is the distribution value corresponding to a determined area plotted from the distribution or density curve. For example, the 25th percentile represents the distribution value corresponding to an area equal to 0,25 or 25/100.

Robust variation coefficient % U.K.

The RVC represents a pure number, i.e. without dimension, that indicates the percentage of variability of the series of numbers analysed against the Av value of the median. For that reason it is very useful for verifying the reliability of the panel members.

Confidence intervals at 95 % on the median U.K.

The confidence intervals (C.I.) at 95 % (value of the error of first kind equal to 0,05 or 5 %) represent the range in which the value of the median would be able to vary should it be possible to repeat the experiment an infinite number of times. In practice this interval indicates the range of variability of the test under the operating conditions selected should it be possible to repeat the test several times. The interval helps evaluate, as in the case of the RVC, the reliability of the test.

where c in the case of a confidence interval of 0,95 is equal to 1,96.

Grading is effected by comparing the median values with the reference ranges set in section 5.3. The software package permits a visualised grading on a table of the statistics or on a graph.]

(1)

[F1But may refrain from tasting if they note some extremely intense negative attributes; they will note this exceptional circumstance on the profile sheet.]

Textual Amendments