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Determining the color of rosé wines by spectrophotometry (CAT#: STEM-PPA-0086-LJX)

Introduction

The color of rosé wines is extremely diverse and a key element in their marketing. It is due to the presence of anthocyanins and of additional pigments derived from them and from other wine constituents. To explore the pigment composition and determine its links with color, 268 commercial rosé wines were analysed. The concentration of 125 polyphenolic compounds was determined by a targeted metabolomics approach using ultra high-performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-QqQ-MS) analysis in the Multiple Reaction Monitoring (MRM) mode and the color characterised by spectrophotometry and CieLab parameters.




Principle

The principle of the high-precision spectrophotometer is as follows: under a certain light source condition, the light is illuminated on the liquid sample, reflected to the grating spectrophotometer, and then the light signal is converted into an electrical signal, and finally into a digital signal, so as to evaluate the parameters of the liquid transmittance, absorbance, concentration, chroma and so on. By comparing the color parameter difference between the sample solution and the standard color level, the color difference between the sample solution and the standard color level can be judged.

Applications

For the determination of liquid color

Procedure

1. Power on: switch on the power source of the spectrophotometer and turn on the power switc
2. Correction: black and white correction as a benchmark for colorimetric measurement, be sure to be accurate
3. Standard sample measurement: set the light source conditions during measurement and measure the color parameters of the standard sample
4. Sample measurement: put the liquid to be measured into the colorimetric dish, and then put it in the measuring port of the spectrophotometer for sample measurement
5. Get the result: after the sample measurement is completed, the instrument will display the measurement result, that is, the color bias compared to the current standard sample and the sample

Materials

• Sample Type:
Rosé wines

Notes

1. When there is a large difference between the black-and-white correction environment and the current sample test environment (such as sharp temperature fluctuations), the instrument needs to be re-calibrated in time.
2. Clean the working surface of the whiteboard regularly, and properly store it under the conditions of avoiding light, dust and dry.