The Italian researchers looked at the impact of adding powdered barbera (Vitis vinifera L.), a red grape variety collected from wineries in the Italian region of Piedmont, on moisture, soluble solids, water activity, polyphenol and antioxidant contents, color and texture.
The researchers said fortification with grape-skin (GS) powders increased the anthocyanin, flavonol and procyanidin contents of the candies, resulting in increased antioxidant activity, which remained stable during processing. The candies also maintained good texture properties despite having greater fiber content.
The fortified candies contained over 60 g of fiber per kilogram, meaning they could be labelled as “high in fiber” according to European regulation (EC) No 1924/2006.
“In general, the addition of GS promoted the reduction of the processing time, the replacement of a significant amount of fruit puree with a low-cost and high-nutritional winemaking by-product, as well as the delivery of beneficial compounds, thus highlighting the high potentialities associated with the use of GS in the confectionery industry,” the researchers wrote.
Upcycling by-products
Three fruit candies, made from GS powders milled and sieved to three different particle sizes of less than 125 micromolas (μm), between 25 and 250 μm or between large 250 and 500 μm, were produced and analyzed during the dehydration process. A regular control candy made from fruits, sugars, pectin and organic acids was also made for comparison.
Processing time was reduced by three hours as a result of the shortened dehydration time, something the researchers said would have a “clear impact on energy consumption”. While they said further savings could potentially be made through the replacement of a significant amount of fruit puree with the low-cost winemaking by-product.
The final mixture for control candy was made up of 631 g/kg of fruit puree, while the GS candy samples comprised of 568 g/kg of fruit puree and 63 g/kg of the GS fractions
Source: LWT- Food Science and Technology
Available online ahead of print, doi: 10.1016/j.lwt.2014.07.039
“Fruit candies enriched with grape skin powders: physicochemical properties”
Authors: C. Cappa, V. Lavelli and M. Mariotti