Influence of Heat, Cultivar and Maturity on the Anthocyanidin—3,5—diglucosides of Muscadine Grapes

In order to assess the effects of heat, cultivar and maturity upon muscadine grape anthocyanins (Acys), the Acys were extracted from heated muscadine juices, from 11 cultivars of muscadines, and from muscadines separated into levels of maturity. Individual Acys were separated by thin‐layer chromatography (TLC) and quantitated by densitometry. Heating resulted in relative increases in the 3,5‐diglucosides of cyanidin (Cy), malvidin (Mv) and peonidin (Pn) at the sacrifice of delphinidin (Dp) and petunidin (Pt)‐3,5‐diglucosides. Except for an initial sharp loss of Mv, Dp degraded most rapidly with heating followed by Pt, Cy, Mv, and Pn. Total Acys in the 11 cultivars ranged from 40 to 403 mg/lOOg fruit with wide variations in the relative contents of individual Acys. Dp was usually the most prevalent Acy in the pigment complex followed by Cy or Pt, Pn and Mv. Cultivars with relatively high Mv and total Acys contents yielded juices and jellies with the highest quality and most stable colors. Harvest date influenced relative percentages of Pn, Mv, and Dp. Maturity level influenced the relative percentage of Mv and concentrations of all Acys.