italianoenglishfrançaisdeutschespañolportuguês
Language
Search
  • » Macrowine 2021
  • » Development of a new commercial phenolic analysis method for red grapes

Development of a new commercial phenolic analysis method for red grapes

Makalisa A1., Lambrecht K.N.1, 1Aleixandre Tudo J.L.1, Bindon K.2,  Du Toit W.J.1
1South African Grape and Wine Research Institute, Department of Viticulture and Oenology, Stellenbosch
University.
2Australian Grape and Wine Research Institute, Adelaide.

Email contact:  24768340[@]sun.ac.za

 

Grape phenolic content is an important quality factor that influences the appearance and mouthfeel of premium red wines. The wine industry uses a variety of commercial phenolic assays to determine phenolic maturity in red grapes. Some of these assays, however, are dated more than 20 years ago and do not always accurately reflect wine phenolic content from grape phenolic extracts. The aim of this study is to develop an adjusted phenolic sample preparation and extraction protocol so it can be used in commercial wineries and/or laboratories.In this study, six grape cultivars (Pinotage, Cabernet Sauvignon, Merlot, Shiraz, Cinsualt and Pertit Verdot) were collected from 42 different vineyards from across 15 different farms. Representative samples were taken from the grapes of each block. Grape extractions were done in duplicates using four different methods namely Glories, Iland, Modified Iland and a custom made Machine crushed method. The Glories, Iland and modified Iland methods produces homogenized grapes, while the machine crushed method uses grape samples where only the skins were crushed. The modified Iland and machine crushed extraction methods were exposed to microwave treatment and extracted in a 50% alcohol solution for 30 min and 1 hour and 3h, 24h and 40h, respectively.Wines were made from every grape samples. Phenolic analyses were done for anthocyanins, tannins, total phenols index and colour density on the grapes and wines. Variation in the phenolic composition of the grapes where the different extraction methods were observed. Correlations between grapes and wines phenolic data with the different grape extraction methods will also be shown.

 

References:

Lee, J. and Rennaker, C., 2011. Influence of extraction methodology on grape composition values. Food Chemistry, 126(1), pp.295-300.
Sommer, S. and Cohen, S.D., 2018. Comparison of different extraction methods to predict anthocyanin concentration and color characteristics of red wines. Fermentation, 4(2), p.39.

Published on 06/17/2018
Pictures
Related sheets
© All Right Reserved
ISSN 1826-1590 VAT: IT01286830334
powered by Infonet Srl Piacenza
Privacy Policy
This website and its related third-party services make use of cookies necessary for the purposes described in the cookie policy. If you want to learn more about cookies or how to disable them (either totally or partially), please see the cookie policy. By closing this banner, scrolling through this page, clicking on a link or continuing navigation in any other way, you consent to the use of cookies.
More informationOK

- A +
ExecTime : 1,5625