The determination of the phenolic maturity trend is an essential element in order to manage and determine the correct winemaking technique, considering the importance that the phenolic components such as colour, astringency, body and flavour have on the wine's final characteristics. The MT00 unit can measure the same phenolic values usually calculated in the laboratory with chemical procedures, having the advantage of a very simple method, very fast analysis, and without the use of any reagents. The MT00 is a diffuse reflectance spectrophotometer that uses led sources of specific wavelengths further refined by interference filters. The unit sees the optical density at these wavelengths and the data is proportional to the concentration of the component at that wavelength. The use of diffuse reflectance spectrophotometry has the advantage of analysing unfiltered samples without the need for treatment with highly pollutant chemical reagents. The measurement method requires the mixing of a volume of around 200 de-stemmed berries. The instrument is supplied together with a mixer and a timer for correct regulation of the mixing times. The result of the analysis is displayed and recorded in the instrument's database, enabling the creation of new maturation curves of different plots, the graphical comparison among plots in different years and new statistical calculations.
|Application:||Measurement of polyphenols in liquidized red grapes
|Type of measurement:||The MT00 analysis unit operates in the UV – VIS – NIR range measuring diffused reflectance
|Preparation of the analysis sample:||Minimum quantity of fresh product: 200 grape berries.
Liquidizing time: 5 minutes.
Minimum: waiting time (after liquidizing): 10 minutes.
|Characteristics of the product “en measure”||Measurement limits:
Minimum turbidity value 200 FTU
Minimum sample volume 100 ml
Measurement time 10 s
Wavelength range 280…900 nm
10...40 °C (50…104 °F)
Dew point on the speculum:
Product at 10 °C with an ambient temperature of 15 °C and relative humidity at 75%
Total Anthocyanins and Anthocyanin Extractability
±10% of the given reading
|Total Polyphenol Index||Measurement limits:
±20% of the given reading
±1% of the given reading
|MP% index||Measurement limits:
|Phenolic Quality||Measurement limits:
90…300 PQ units
±1 PQ units
±0.50 PQ units
|Notes:||Tonality and Phenolic Quality (PQ) index measurements are specifically for the delivery phase. Please remember that the values of these measurements depend on the grape sample preparation system and in particular on pigment extraction efficiency. Hence the values given by must obtained from a worm screw truck sampling probe and those given by must from a liquidizer cannot be compared.