Sustainable and innovative use of wastes from grape and fruit processing

Project studies problem of waste from grape and fruit processing industry as a source for sustainable use in agriculture. Improved technologies for pomace composting and ensiling will be main results. Obtained products will be tested for nutritive value as animal feed and fertilizer in production.

Residues from grape and fruit processing industry represent about 30% of total processed raw fruit material. Large amount of waste (pomace) which has 15 to 30% of dry matter is ballast for storage, relocation and treat for the environment. Pomace (57% pulp, 25% skins, 8% seeds and 10% stems) contains significant amount of nutrients, but high water concentration which very often causes uncontrolled decomposition, mouldering, leakage of waste fluids and bad odour spreading from the storage lot which have negative impact to the environmental protection. Through new technologies of composting and ensiling, this problem of waste stockpiling can become solvable and due to this the wine and juice industry can accomplish new profit income. Research topic of this EUREKA project is resolving the waste problem from grape and fruit processing industry through different sustainable technologies of pomace ensiling, composting and dehydration in cost-effective and environmental friendly way. Two different packages of research will be conducted: The first is investigation of pomace suitability for organic fertiliser production and definition of the best technology for grape pomace composting. After the grapes are pressed to make wine, the seeds, skins and stems remain. This waste can be recycled in different ways, but most appropriate approach to maximise profit and help wineries stay ecologically functional is composting. Due to low pH, grape pomace alone composts relatively slowly, but with addition of different substances and co-composting materials this process accelerates. Generally grape pomace composting is a 6 to 10 months long process, dependent on pomace composition and applied technology (turning frequency, regulation of moisture and temperature in piles or windrows). During this project several different treatments with numerous factors to improve composting will be conducted in cooperation with vineries and fruit processing factories from SERBIA, the CZECH REPUBLIC and TURKEY. Complete chemical analysis of final product will clarify which technologies and composts are pre-eminent. At the end of this first experimental phase finest composting technology and obtained compost will be implemented in different fertilising systems to verify its usefulness as organic fertiliser on sown grasslands, eroded areas in hydro-sowing system and in re-cultivation of ash dumps in thermal power plants. The implementation of these results is planned in grape and fruit processing facilities and in plant production industry which utilise high quality organic fertiliser. This way, grape and fruit processing industry can achieve extra profit. The second research package is related to possibility and suitability of fruit pomace for ensiling and dehydration and definition of technologies for production of roughage (silage) and concentrated livestock feed. Between 25 and 35 % of the fresh weight of the fruit (apple) is retained in the pomace after pressing in juice processing. It can be used for ethanol, vinegar or other by-products, but it is also used for livestock feed. It has significant energy and nutrient value with about 4.5% of crude protein, 38-40 % of fibre and 2 -3% of fat. But concerning it consists large quantity of water (only 27.7 % of dry matter), fresh fruit pomace spoils rapidly and must be used quickly or be preserved by dehydration or ensiling. In this project apple and grape pomace will be mixed with other feed materials (alfalfa or grass hay, corn and inoculants) for ensiling, because if ensiled alone it will result in a very high moisture product with considerable losses in quality. That way it is possible to obtain good silage which can substitute a part of the concentrate or roughage in the diets of cows, goats and sheep and solve problem of waste disposal at the same time. All silages will be analysed to different chemical parameters of quality, suitability for ensiling and fermentation process, and also for microbial concentrations and activity. Also dehydrated pomace will be incorporated in concentrate diet. Finally, the study on dairy farm will be performed to determine the ability of fruit pomace silage to increase milk yield in dairy cows and to define the rate of fruit pomace silage in the diet of lactating cows. Potential users of this obtained technology and silage will be all farms with animal husbandry production (dairy cattle, beef cattle, goats and sheep).
Project ID: 
6 742
Start date: 
Project Duration: 
Project costs: 
680 000.00€
Technological Area: 
Biotreatment / Compost / Bioconversion
Market Area: 
Viticulture and Fruit Tree Cultivation

Raising the productivity and competitiveness of European businesses through technology. Boosting national economies on the international market, and strengthening the basis for sustainable prosperity and employment.