Sustainable recovery of grape skins for use in an apple beverage with antiglycation properties

An apple puree formulated with red grape skins was developed on pilot scale as a new beverage with antiglycation properties. The addition level of grape skins was selected by a liking test with 70 consumers. The selected formulation was a fibre-rich source and delivered grape anthocyanins, flavonols and flavanols resulting in similar to twofold higher antiglycation activity than the apple puree. Pasteurisation (3-D in the target microorganism Alicyclobacillus acidoterrestris) did not affect the antiglycation activity, which decreased by 30% upon sterilisation. Storage for 1 month in the temperature range 15-35 degrees C affected the contents of anthocyanins, monomeric, dimeric and oligomeric flavanols, while chlorogenic acid, flavonols and dihydrochalcones were stable. About 90% antiglycation activity was retained after one-month storage at 15 degrees C. The use of red grape skin as ingredient could represent an opportunity for the apple processing industry to develop a value-added product.