IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Hyperspectral imaging and Raman spectroscopy, nondestructive methods to assess wine grape composition

Hyperspectral imaging and Raman spectroscopy, nondestructive methods to assess wine grape composition

Abstract

Grape composition is of high interest for producing quality wines. For that, grape analyses are necessary, and they still require sample preparation, whether with classical analyses or with NIR analyses. The aim of the study was to test the ability of two nondestructive analyses, directly on grapes, hyperspectral imaging (HSI) and Raman spectroscopy to assess their composition.
For that, 7 grape varieties were analyzed for 2 vintages. Each grape was characterized by its technological ripening (levels of sugars, organic acids and pH) and its phenolic ripeness (total phenolic, total flavonoids, total anthocyanins contents, as well as extractable phenolic, extractable flavonoids, extractable anthocyanins, values obtained from a model wine maceration from skins, and color intensity). Spectra were recorded on 100 and 40 fresh berries per date and variety respectively with hyperspectral imaging and Raman. Raw data underwent different pretreatments (SNV, 1st and 2nd derivative) and PLS-R were then realized in order to provide models to assess grape composition.
The results showed that the 1st derivative data pretreatment generated better models and was then kept for all following analyses. Both methods, Raman spectroscopy and hyperspectral imaging, showed good ability to assess technological ripening parameters (sugar and acid contents) as well as phenolic content (TPI, Total Phenolics, Total Anthocyanins, Total Flavonoids and their extractable equivalents) (with globally R² > 0.81). However, it was not possible to reach the color intensity of grapes.
Even if both methods have the potential to assess wine grape quality on 11 important parameters, the quality of the models generated in our study was dependent on the quality parameter, the type of grapes (color) and the method, except for fructose, TSS and Extractable Anthocyanin contents, which were equivalent. Thus, the glucose concentration and the Total Phenolic Index (TPI) were better assessed by Raman spectroscopy, whereas Extractable Phenolics content was better estimated by HSI for both white and red grapes as well as Total  Anthocyanin content. Tartaric acid, Total Flavonoids, Color Intensity and extractable Flavonoids were better assessed by HSI for red grapes but by Raman for white grapes.
The quality of the generated models was yet dependent on the color of grapes and the parameter considered. More data would be necessary to strengthen the models but the proof of concept was successful with this study

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

Maury Chantal¹, Gabrielli Mario², Ounaissi Daoud¹, Lançon-Verdier Vanessa¹, Julien Séverine¹and Le Meurlay Dominique ¹

¹USC 1422 GRAPPE, INRAE, Ecole Supérieure d’Agricultures, SFR 4207 QUASAV
²Dipartimento di Scienze e Tecnologie Alimentari per una filiera agro-alimentare Sostenibile, Università Cattolica del Sacro Cuore

Contact the author

Keywords

wine grape, hyperspectral imaging, Raman spectroscopy, phenolics, composition

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Bioanalytical workflow for exploring the chemical diversity and antioxidant capacity of grape juice peptides

The oxidative stability of white wines is related to a flow of chemical reactions involving a number of native wine containing compounds composing their antioxidant metabolome.

Influence of temperature and light on vegetative growth and bud fruitfulness of grapevine cv. Semillon

Aim: To investigate the effects of different levels of temperature and light intensity on grapevine vegetative growth and bud fruitfulness, which includes the number and size of inflorescence primordia in primary buds.

Under-vine management effects on grapevine production, soil properties and plant communities in South Australia

Under-vine (UV) management has traditionally consisted of synthetic herbicide use to limit competition between weeds and grapevines. With growing global interest towards non-synthetic chemical use, this study aimed to capture the effects of alternative UV management at two commercial Shiraz vineyards in South Australia, where the sole management variables were UV management since 2016. In adjacent treatment blocks, cultivation (CU) was compared to spontaneous vegetation (SV) in McLaren Vale (MV), and herbicide was compared to SV in Eden Valley (EV). Soil water infiltration rates were slower and grapevine stem water potential was lower in CU compared to SV in MV, with the latter having a plant community dominated by soursob (Oxalis pes-caprae) during winter; while in EV, there was little separation between the treatments. Yields were affected at both sites, with SV being higher in MV and HE being higher in EV. In MV, the only effect on grape must was a lower 13C:12C isotope ratio in CU, indicating greater grapevine water stress. In the grape must at EV, SV had higher total soluble solids, total phenolics, anthocyanins, and yeast available nitrogen; and lower pH and titratable acidity. Pruning weights were not affected by the treatments in MV, while they were higher in HE at EV. Assessments revealed that the differing soil types at the two sites were likely the main determinants of the opposing production outcomes associated with UV management. In the silty loam soil of MV, the higher yields in SV were likely due to more plant-available water, as a potential result of the continuous soil bio-pores formed by winter UV vegetation. Conversely, in the loamy sand soils of EV with a lower cation exchange capacity, the lower yields and pruning weights in SV suggest the UV vegetation competed significantly with the grapevines for available water and nutrients.

Le terre dei Lambruschi modenesi

La superficie vitata della provincia di Modena é per circa il 70% interessata dai Lambruschi, famiglia di vitigni tipica dei territori pianeggianti emiliani. Tra questi, i più rappresentativi sono il Lambrusco di Sorbara, il Lambrusco salamino e il Lambrusco grasparossa che, unico esempio, predilige gli ambienti collinari della provincia. Nel quinquennio 2001-2005 la Provincia di Modena ed il C.R.P.V. hanno coordinato la zonazione viticola di tutto il territorio dei Lambruschi modenesi, i cui risultati hanno consentito di individuare, in ciascuna zona D.O.C., alcune Terre in cui cias.

Phenolic composition of Xinomavro (vitis vinifera L.cv.) grapes from different regions of Greece

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.20.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...