The European market of vegetal beverages, such as drinks from soy and other grains or fruits, in particular oats, rice, almonds and coconuts, is continuously growing even during the recent economic crisis, because these products are an attractive alternative to cow milk for vegans, vegetarians, and flexitarians or people with health problems, such as lactose intolerance or cardiovascular disease. The general manufacturing procedure foresees pressing of the raw materials in the presence of water: the liquid phase is the final beverage and the solid phase is a press cake, which is used as feed ingredient. This represents a waste, since these press cakes still contain many valuable proteins, which are an underutilized material. In order to be competitive and to ensure sufficient food supply to consumers in the future it will become compulsory to use this source.
The DISCOVERY project is exploring the use of new and innovative techniques such as – ultrasonic wave cavitation – for the processing of vegetable waste resulting from the processing of vegetables, in order to increase yields and produce other intermediate value added products. By applying a relatively simple technical solution to the production of vegetable beverages – ultrasonic wave cavitation is proposed. It will be possible to organize a waste free process of vegetable processing, thereby contributing to the reduction of pollution and having a positive environmental impact.
Ultrasonic technology has been applied in food processing for various purposes, but not yet in vegetal beverage processing. Fraunhofer uses an innovative test unit that will be applied for the press cakes treatment. The disaggregation of the press cake leads to two further fractions. One is similar to the regular vegetable drink, but can consist of a different quality. The enzymatic treatment and the concentration of this liquid fraction is investigated in this project. It is expected to achieve an overall 75 % increase of the liquid fraction. Further processing of the liquid fraction with membrane technology allows concentrating the by-products by enriching valuable proteins that can be used for food production. The other fraction consists of high quality fibers at a different degree of purification, which could be generally used as ingredient in meat analogues, bread, pastries, etc. This fraction is analyzed with regard to the most applicable usage and possible further treatments, such as enzymatic treatment or fermentation. All measures will be accompanied by a nutritional and food quality analysis.
After implementation of the project, the concept of cake biodegradation will be developed and methods for optimal use of secondary products will be selected.