The Sugars of Grapevines. II. Identification and Seasonal changes In The Concentration of Several Trace Sugars in Vitis Vinifera

Abstract

Sucrose, raffinose, stachyose, melibiose, and maltose were identified in the berries, leaves, and phloem of eight varieties of Vitis vinifera by paper chromatography, radioautography, and enzymatic techniques. Galactose was also found in some berry samples. Sucrose and raffinose were present in berries at all stages of fruit development except the first 2 to 3 weeks after berry set. These sugars were present in low concentrations (less than 0.05%) until after the total soluble solids reached 10 to 18°B; they were at their highest level during berry maturity, and generally decreased slightly during overmaturity. The maximum concentrations of sucrose and raffinose in the different varieties respectively varied from 0.019 to 0.18% and from 0.015 to 0.34%. The concentration of sucrose and of raffinose in mature `Thompson Seedless' and 'Semillon' berries was greater in the basal part than in the middle or tip sections.