# Development of a Wine By‐Product‐Based Beverage and Study of Its Potential to Postprandial Glycemia Regulation in Healthy Individuals: A Proof of Concept Study

## TL;DR

This study explores using wine by-products to create a beverage that may help manage blood sugar levels after meals in some healthy individuals.

## Contribution

A novel functional beverage made from wine by-products is developed and tested for its potential to regulate postprandial glycemia.

## Key findings

- The wine by-product-based beverage showed a tendency to reduce blood glucose levels in some individuals.
- High interindividual variability limited the statistical significance of the observed effects.
- Phenolic compounds in responders' blood were not directly linked to reduced postprandial hyperglycemia.

## Abstract

Aligned with the principles of the circular bioeconomy, this study explores the use of winemaking by‐products as a source of bioactive phenolic compounds. Skins and seeds from Tempranillo and Graciano grapevine varieties were conditioned to prepare a phenolic‐rich beverage. To study its hypoglycemic properties, a pilot trial was conducted to evaluate postprandial glycemia after the intake of the wine by‐product‐based beverage (WBB). The postprandial glycemia of 10 healthy adults was measured after the intake of: (i) water + sugar solution, (ii) WBB + sugar solution, and (iii) WBB + water. In parallel to blood glucose measurement, blood samples were also collected using dried blood spot cards to determine the phenolic metabolites by UHPLC‐QqQ‐MS/MS. Although blood glucose levels tended to decrease after WBB intervention, these changes were not statistically significant related to the interindividual variability. The volunteers showing a reduction in blood glucose were classified as “responders”, and those who showed no changes were classified as “non‐responders”. Wine by‐products can be effectively used in functional beverages formulation to increase bioactive compound content and manage postprandial glucose in some individuals.

The postprandial glycemia of healthy adults is not downregulated by the coadministration of a sugar solution and a wine by‐product enriched beverage due to the high variability in the response. Blood phenolic compounds of responders’ volunteers are not associated with the reduction effect of postprandial hyperglycemia.