RESOLUTION OIV/VITI 371/2010

OIV GENERAL FORM FOR THE SENSORIAL ANALYSIS OF TABLE GRAPES

The GENERAL ASSEMBLY

According to the proposal of the Sub-commission “TABLE GRAPES, RAISINS AND UNFERMENTED VINE PRODUCTS” after having noted the work carried out in March 2008 and 2009,

CONSIDERING that the seeded and the seedless table grapes are two different categories that are differently appreciated,

DECIDES to adopt the “OIV General Form for the Sensorial Analysis of Table Grapes”,

RECOMMENDS that Member States use this form as the basis for the implementation of national or regional evaluations,

RECOMMENDS the use of the OIV GENERAL FORM FOR THE SENSORIAL ANALYSIS OF TABLE GRAPES for the characterisation and the evaluation, in preference, of new varieties, created by genetic improvement, and for the appreciation of the commercial value of varieties. It could be part of market studies and be used for pomological contests.

OIV GENERAL FORM FOR THE SENSORIAL ANALYSIS OF TABLE GRAPES

1.      Introduction

The quality of table grapes has generally been evaluated through sensorial analysis and in particular using sight, smell, taste and touch.

However, the approaches used for sensorial analysis may be different. The approach offered in this resolution is a descriptive analytical approach.

2.      Applications

In sensorial evaluation of table grapes, it is possible to give an immediate assessment:

• on the results of genetic improvement (comparison of new and standard cultivars);
• on the different cultivation techniques tested;
• on the influence of cultivation areas;
• on the efficiency of the sector

3.      The descriptors

3.1.      Visual – concerning the whole cluster, the stalk and the berries (entire or dissected).

Cluster:

• General appearance
• Detachment of berries from pedicels
• Uniformity of colour

Stalk:

• Colour
• Turgidity
• Presence of rot and/or lesions
• Browning of the peduncle

Berries:

• Uniformity of colour
• Presence of shrivelling
• Ease of detachment from pedicel
• Presence of rot (only on grapes kept in refrigerated conditions)
• Presence of sulphurous marks (only on grapes kept in refrigerated conditions)

Skin:

• Marks of pesticide residues or black mould
• Browning of the skin

Bloom: distribution

Flesh (on a dissected berry):

• Browning of the flesh
• Presence of seeds

3.2.      Olfactive – concerning the dissected berry

Flesh:

• Intensity of aromas

On grapes kept in refrigerated conditions there may be aromas emanating from the entire berries:

• Sulphurous aroma
• Odour of mould

3.3.      Gustative and tactile – concerning the berry broken down into skin, flesh and seeds (if present)

Berry:

• Crispness

Flesh:

• Consistency (in a peeled berry)
• Intensity of aromatic sensation
• Gustative balance (sweet/acid)

Skin:

• Thickness
• Astringency
• Persistence of skin in mouth

Seeds (if present):

• Perception (sensation of their dimensions)
• Hardness (resistance to crushing)
• Astringency

4.      Analytical assessment

For each descriptor identified, it is proposed to give an assessment using a scale from 1 to 10. Value 1 represents the less qualitative description of a characteristic, whilst 10 represents its highest value.

There are some descriptors that cannot be assessed using a scale. For these descriptors, an objective assessment will be given.

4.1.      Visual:

• Colour of the skin (yellow, green, pink, blue-black, etc.)
• Colour of the flesh (colourless, pink, etc.)

4.2.      Gustative:

• Aroma of the flesh (muscat, special, etc.)

In addition, as a summary of the tasting, a general assessment is given, taking account all the elements evaluated.

5.      Mode of grape sampling

In the case of the use of the form for the description of new varieties, for the evaluation of agronomic techniques etc., uniformity of cluster sampling must be taken into account (at least on 10 clusters per variety and sample to be tested, with the 1st cluster taken from the central shoot of a fruiting cane).

Berries for tasting must be taken from the central part of the cluster.

Annex OIV form for the sensorial analysis of table grapes

	Collector’s name:
	Date of analysis:
Sample data	Producer:
	Date picked:
	Variety:
	Sample:
	Category:	fresh;  refrigerated
		with seeds; seedless
	Other:
Objective analysis	Flesh colour:
	Skin colour:
	Flesh aroma:
	Descriptors	Scale	Value
Visual examination	Cluster – General appearance	(1=badly shaped; 10=well shaped)
	Cluster – Detachment of berries from pedicels	(1=low resistance; 10=high resistance)
	Cluster – Uniformity of colour	(1= ≥ to 30% of berries with colour defects; 10=all coloured)
	Stalk - Colour	(1=brown; 10= bright green)
	Stalk – Turgidity	(1=shrivelled; 10=turgid)
	Stalk – Presence of rot and/or lesions	(1=all rotten; 10=all healthy)
	Stalk – Browning of the peduncle	(1=all brown; 10 all green)
	Berry – Uniformity of colour	(1= < to 30% of the surface coloured; 10=all coloured)
	Berry – Presence of shrivelling	(1=all shrivelled; 10=all healthy)
	Berry – Ease of detachment from the pedicel	(1=low resistance; 10=very resistant)
	Skin - marks of pesticide residues or black mould	(1= completely covered ; 10= no marks)
	Skin – Browning of the skin	(1=clearly visible; 10= browning not visible)
	Bloom: distribution	(1= irregular ; 10= uniform)
	Flesh – Browning of the flesh	(1=clearly visible; 10= browning not visible)
	Flesh - Presence of seeds  (in dissected berry)	(1=clearly visible; 10=not visible)
Olfactive examination	Intensity of aromas  (in dissected berry)	(1=neutral; 10=many aromas)
Gustative and tactile examination	Berry - Crispness	(1=low; 10=very crisp)
	Flesh - Consistency	(1=deliquescent; 10=very firm)
	Flesh – Intensity of aromatic sensation	(1=not very intense; 10=very intense)
	Flesh – Gustative balance (sweet/acid)	(1=not very well balanced; 10=very well balanced)
	Skin - Thickness	(1=thick; 10=thin)
	Skin - Astringency	(1=astringent; 10=not tannic)
	Skin – Persistence of skin in mouth	(1=very persistent ; 10= little persistent)
	*Seeds - Perception (sensation of their dimensions)	(1=unpleasant; 10=not perceptible)
	*Seeds - Hardness  (resistance to crushing)	(1 =very hard; 10=little resistance)
	*Seeds - Astringency	(1=astringent; 10=not tannic)
General assessment		(1=minimum; 10=maximum)
Defects from keeping in refrigerated conditions	Berries – Presence of rot	(1=all rotten; 10= all healthy)
	Berries – Presence of sulphurous marks (scorching)	(1=all berries affected; 10 all healthy)
	Sulphurous odour (on entire berry)	(1=unpleasantly pungent; 10=absent)

* if present