Berry Integrity and Extraction of Skin and Seed Proanthocyanidins during Red Wine Fermentation

• Published in: Journal of agricultural and food chemistry Vol. 56; no. 19; pp. 9006 - 9014
• Main Authors: Cerpa-Calderón, Fiorella K, Kennedy, James A
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 08.10.2008
• Subjects: alcoholic fermentation; Biological and medical sciences; Chemical Changes Induced by Processing/Storage; chemical concentration; Chromatography, High Pressure Liquid; crushing; exocarp; extraction; Fermentation; food composition; Food engineering; Food industries; food processing quality; Fruit - chemistry; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; General aspects; grape seeds; grape skin; maceration; phloroglucinolysis; phytochemicals; Proanthocyanidin; proanthocyanidins; Proanthocyanidins - isolation & purification; red wine fermentation; red wines; Seeds - chemistry; Vitis - chemistry; Vitis vinifera; Wine - analysis; wine grapes; winemaking; Proanthocyanidin; maceration; extraction; phloroglucinolysis; red wine fermentation; Seeds; Fruit; Berry; Fermentation; Red wine; Flavonoid; Alcoholic beverage; Polyphenol; Extraction; Skin; Maceration; Integrity
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf801384v

In this study, microscale fermentations were conducted on Vitis vinifera L. cv. Merlot. Five treatments were established varying from 0−100% crushed fruit (25% increments × 5 replicates). Caps were kept submerged throughout the experiment, and fermentation temperatures were maintained at 25 °C. Samples were collected throughout fermentation and from the free run and press wine at the time of pressing. Proanthocyanidins were determined by acid-catalyzed depolymerization in the presence of phloroglucinol, followed by reversed phase, high performance liquid chromatography (RP-HPLC). Total proanthocyanidin extraction increased with time in all treatments. In addition, crushing increased the rate at which proanthocyanidins were extracted. When the extraction of skin and seed proanthocyanidins were monitored separately, skin proanthocyanidin extraction rate exceeded that for seed proanthocyanidins and followed a Boltzmann sigmoid extraction model. The highest proanthocyanidin concentration for skin (435 mg/L) and seed (344 mg/L) was observed for the 75% crushed fruit treatment at the time of pressing (17 days). The highest skin proanthocyanidin proportion (79%) was observed for the 75% crushed fruit treatment on day 9 with a total proanthocyanidin concentration of 439 mg/L. For all treatments, skin proanthocyanidin extraction reached a plateau concentration prior to pressing, with the plateau concentration increasing with crushing. Seed proanthocyanidin concentration increased throughout maceration.