The effects of cane girdling on berry texture properties and the concentration of some aroma compounds in three table grape cultivars

Abstract

Context and purpose of the study – The marketability of the table grapes is highly influenced by the consumer demand; therefore the market value of the table grapes is mainly characterized by its berry size, colour, taste and texture. Girdling could cause accumulation of several components in plants above the ringing of the phloem including clusters and resulting improved maturity. The aim of the experiments was to examine the effect of girdling on berry texture characteristics and aroma concentration.

Material and methods – Three table-grape cultivars (Melinda, Pölöskei muskotály, Árkádia) were selected for the experiments, which were carried in Mátra Wine region, Hungary in 2017. The girdling was conducted at the beginning of the ripening. Sugar concentration, pH and acidity were measured by a WineScan instrument (Foss, Hilleroed, Denmark). Basic texture parameters, such as berry hardness (BH), berry skin thickness (Spsk) skin hardness (Fsk) etc. were scanned with a TA.XT Plus Texture Analyser (Stable Micro Systems, London, UK). Some aroma compounds of the must samples were also investigated by GC-MS (Agilent, Palo Alto, USA).

Results – The gridled samples presented higher average berry weight, sugar concentration and titratable acidity compared to the control. Berry hardness of the girdled treatment was higher compared to the non-treated vines. However, berries of girdled vines had lower skin hardness, probably due to the accelerated maturity. Furthermore, girdling resulted in thicker skins in the case of Melinda and Árkádia cultivars. In addition, the concentration of the measured aroma compounds (linalool, citronellol, geraniol) was higher in the treated berries compared to the control ones.