Secondment of Gokhan Durmaz from University of Reading (UK) to Casa Emma (IT) (1st-30th September 2018)

Dr. Gokhan Durmaz visited Azienda Agricola Casa Emma (Casa Emma) with the aim of witnessing the production of wine and seeing the wastes produced during this process in place.

A meeting was organized with Dr. Alessandro Bucalossi, who represents the company, about the FODIAC project. He gave some details about the company and their vision about the valorisation of the wastes generated during the production. Dr Durmaz gave some information about the research activities and capabilities of the University of Reading and in particular Department of Food and Nutritional sciences.

The visit was started by exploring the production area and orchard of the Casa Emma. It is located near the village named San Donato in Poggio, Florence, Italy.

The production line was composed of mainly;

  • Harvesting
  • Destemming/crushing
  • Fermentation
  • Pressing
  • Clarification
  • Aging/bottling

The harvest time is determined by the experts of the company by measuring brix, acidity, pH and sensorial properties of the grapes.

The harvested grapes were brought to the winery and immediately processed.

During wine production, mainly two waste material appear; stem that is separated at the beginning and the marc that remains after taking the fermented juice. Marc is mainly composed of skins and seeds (if the variety contains seed). Both wastes are quite rich in phenolic compounds and can be valorised with different purposes. Indeed, the company already utilizes grape marc powder in the production of a kind of pasta. To produce the powder, marc is dried in a tray drier until 5% moisture. The stems on the other hand decomposed and used as fertilizer in the vineyard.

Dr Durmaz also visited Dr.Giorgia Spigno’s lab in Department for Sustainable Food Process, Università Cattolica del Sacro Cuore, Piacenza, Italy. Dr.Spigno who is one of the partners of the FODIAC project gave some information about the research activities of her group in the context of the project. Especially enzyme assisted extraction and the effect of surfactants on the extraction of bioactive compounds were discussed during the meeting.

The samples taken from Casa Emma were analysed and the results submitted to the meeting called “Mission 10000” which will be held on 17th of October in Braga, Portugal.

According to the results it was observed that enzyme treatment positively affected the recovery of bioactive compounds from grape marc during water extraction. Additionally, it was also observed that, surfactants can cause an increase in the recovery rate of anthocyanins probably by facilitating the accessibility of enzymes to the substrate molecules. In the meantime, increase in the solubility of anthocyanins in water with the presence of surfactant could also cause the increase in the extraction efficiency.

As most of the varieties utilised in wine making are red varieties, they contain significant amount of anthocyanins. Especially skin is the richest part of the fruit in anthocyanins. As grape marc almost completely composed of skins, it is a good source for anthocyanins. The samples collected form Casa Emma will be used as sample in the laboratory of Department of Food and Nutritional Sciences, University of Reading for further analyses.