Evaluation of the antioxidant capacity of 10 strawberry cultivars and advanced selections

Aurélie Gagneux did a two-month internship at the HRDC which involved comparing some known strawberry cultivars with several advanced selections in terms of antioxidant capacity, using the ABTS cation radical-scavenging assay.

Grey mould (better known as Botrytis cinerea), the most damaging disease of strawberry, sometimes causes losses of 50% or greater. Moreover, because of the susceptibility and perishability of the fruit, storage time and fruit quality are substantially reduced. Antioxidants, more specifically the phenol compounds of various fruits, have been shown to protect plant tissues against a diversity of external stresses and to enhance disease resistance. Phenols can act as antifungal compounds, extending the storage period of the fruit and increasing disease resistance. They can also preserve the organoleptic qualities of fruit, enhancing flavour, colour and antioxidant properties.

The new strawberry selections developed at the HRDC in St. Jean sur Richelieu are undergoing evaluation to determine their antioxidant capacity and to compare them with known cultivars used as controls. During the analysis of results, the researchers will look at whether the trait under study exhibits genetic variability and evaluate the potential relationship between antioxidant capacity and disease resistance, storage life and fruit quality.

Summary of work

A number of research stages were carried out during the two-month period:

1. Strawberry harvesting
2. Freeze-drying and grinding of the different samples
3. Extraction of the three phases: crude, lipophilic and aqueous
4. ABTS cation radical-scavenging assay using a spectrophotometer
5. Analysis of results

Results and prospects

Significant differences were found in antioxidant capacity among the genotypes studied. Some promising selections show a markedly greater antioxidant capacity than the cultivars used as controls. The results will be combined and compared with the findings from the parallel research on antioxidant activity, phenol composition and fruit characteristics (firmness, storage life, grey mould resistance, etc.) in order to establish a correlation between antioxidant level and disease resistance and storage period.

If a correlation is found, the assays will play a very important role in the process of selecting and naming.

Address :
Aurélie Gagneux
Institut National Polytechnique
École Nationale Supérieure Agronomique de Toulouse
Avenue de l'Agrobiopole - Auzeville-Tolosane
BP 107- F 31326 Castanet-Tolosan Cedex
tél. : 33 (0)5 62 19 39 00 - fax : 33 (0)5 62 19 39 01

 

The persons in charge of the training course: Shahrokh Khanizadeh & Djamila Rekika