Procedure for measuring the colour of wine and grapes in situ.

Kurzfassung

A small Italian Research Organisation has developed a spectrophotometric procedure for colour measurement of must, wine, and grapes during the ripening phase, based on the adoption of CIE recommendations. Advantages include the possibility of objective and repeatable measurement in situ. The organisation is looking for research centres interested in further development and different applications of the procedure, and industrial partners (winemaking industry) interested in using the procedure.

Details

The technology is addressed particularly to the wine production sector. It measures wine and grapes colour in a standardised and repeatable way, giving a great contribution for the on line quality control of the product. It can be easily adapted for the utilisation with other agro-industrial products and with all those products in which the colour measure is an important aspect in the quality control.
The proposed standardised technology is based on the whole transmission spectrum of the sample in the visible light region, through the use of a spectrophotometer. Parameters fixed by CIE international Recommendations for the colour measurement are utilised to express the colour (Publication CIE 15.2 1986). The procedure has been optimised to take measures in situ, through the use of an optic fibre portable spectrophotometer.

Innovative Aspects:
Wine colour is usually valued through visual analysis, in accordance with prefixed chromatic categories, with all limits due to the subjectivity and non-repeatability of valuation. Moreover official currently used methods, based on the use of absorption measures in correspondence of low wavelength, don't satisfy CIE international Recommendations for the colour measurement and don't ensure a satisfying colour valuation.
The offered procedure, based on aforementioned recommendation, allows an objective instrumental measure, repeatable and comparable, in space and time, with other measures made through the same technique. Moreover it allows to take measures in situ, avoiding problems connected with the transport of the sample to the laboratory and giving the possibility of immediate and non-destructive colour valuations.

Main Advantages:
The main advantages are:
- possibility of objective instrumental measurement of wine colour and grapes in situ, and of its expression with numerical world-wide fixed parameters;
- repeatability and comparability of measured data in space and time, having the possibility to build historical data base about the colour of different products;
- possibility to fix objectively chromatic features typical of each product;
- possibility to correlate between them visual and instrumental valuations of the colour;
- possibility to correlate the colour with other physic and chemical-analytical features of the product;
- better control of wine production process considering the standardisation of final product chromatic features.