Resumen de Biosynthesis of flavour compounds in Muscat Gordo Blanco grape berries
M. Gholami, Yoji Hayasaka, Bryan G. Coombe, J.F. Jackson, Simon P. Robinson, P.J. Williams
Inflorescences of the floral grapevine cv Muscat Gordo Blanco (syn. Muscat of Alexandria) were grown on their own shoots until maturity or, after approach‐grafting before flowering, on the shoots of the non‐floral cv Shiraz (in the glasshouse) or Sultana (in the field). The flavour compounds of their berries were compared with those in the berries of the non‐floral cultivars, grown either on their own shoots or, by grafting, on the shoots of the Muscat cultivar. For this, monoterpene glycosides were isolated from the fruits, enzymatically hydrolysed and the released monoterpene aglycons were liquid‐liquid extracted and analysed by GC‐MS. The Muscat Gordo Blanco berries of ungrafted bunches and of bunches grafted onto Shiraz or Sultana vines yielded fruit with monoterpenes at levels and types typical of this floral grape variety. The berries of Shiraz and Sultana bunches contained only low levels of monoterpene glycosides both on their own shoots or grafted onto Muscat shoots. The lack of difference between flavour compounds in grafted and non‐grafted fruit indicate that aroma compounds are synthesised in the berries and that their presence is determined by the genotype of the grape bunch rather than by the genotype of the vine.
