Optical Properties of Berry Epicuticular Waxes in Four Georgian Grape Cultivars (Vitis vinifera L.)

Abstract

The epidermis of plant shoot organs is generally covered by epicuticular waxes. The role of this layer is related mainly to the protection of the inner tissues from biotic and abiotic stresses. In this study, attention is focused on the optical properties of the berry epicuticular waxes of the grapevine (Vitis vinifera L.) at fruit ripening. The reflectance of the berry surface was measured before and after chloroform treatments in four Georgian grape cultivars grown in northern Italy. Epicarp optical properties were underlined at different wavelengths (341 to 1025 nm) for each cultivar. The results show that the berry waxes have several optical properties; it is possible that their main eco-physiological effect is to provide specific protection against different types of radiation. Besides the physiological aspects, the results are interesting also from a technical point of view in the field of interpretation of reflectance measurements carried out by non-invasive instruments.

Chlorophyll role in berry sunburn symptoms studied in different grape (Vitis vinifera L.) cultivars

“…For each sample, 60 berries were considered in the experimental plan, resulting in a total of 3600 analyzed fruits. Twenty berries were selected to represent the control blank and kept in dark conditions at 24 • C. Other 20 berries were exposed to artificial light after epicuticular wax removal (to maximize chlorophyll excitation avoiding light filtration according to Rustioni et al (2012)) for a 4 h period. Two LED lighting systems (version LumiGrowTM Pro 325, LumiGrow, Novato, CA, USA) were used.…”

From the Laboratory to The Vineyard—Evolution of The Measurement of Grape Composition using NIR Spectroscopy towards High-Throughput Analysis

“…3.79) [31]. Rustioni and collaborators investigated the spectral properties of the epicuticular waxes of Vitis vinifera L. grape berries during ripening [32]. This experiment demonstrated that berry waxes have specific reflectance properties which are useful to monitor grape ripeness and maturity at harvest based on their wax content [32].…”

Phenolic content and antioxidant activity of Armenian cultivated and wild grapes

“…The Folin-Ciocalteu method was used for the determination of the total polyphenols as suggested by L. Rustioni et al, 2014 [14]. In brief, an aliquot (0.5 ml) of the appropriate diluted skin and seed extracts were added to a 10 mL volumetric flask, containing 2.5 ml of distilled water.…”