Beer is one of the most popular drinks, obtained by the fermentation process of wort, composed by malt, hops and water. It is the second most consumed alcoholic beverage in Europe. Alcohol abuse represents a worldwide serious problem with strong impact on both health and society. On the other hand, beneficial effects linked to moderate consumption of beer were widely evidenced, mainly due to the healthy properties of natural polyphenols, especially hydroxybenzoic acids, highly contained in beer.
The interest in the production of low-alcohol beer is increasing worldwide, and a strong impact on the global market could be expected for low-alcohol beer with high sensory and health-promoting qualities.
The present project aims to develop an integrated zero discharge low alcohol beer production process by dealing with both aspects: production of high quality low alcohol beer, and waste water treatment.
A combined membrane process is proposed to produce low alcohol beer from commercial beer: diafiltration to lower the alcohol content of the beer, and pervaporation to infuse flavour to the beer. The quality of low alcohol beer will be then evaluated with respect to the commercial one especially in terms of the phytochemicals.
The waste water treatment aims on one side to the recovery of polyphenols and on the other side to have a wastewater stream compatible to the municipal sewer system. Nanozeolite will be synthesised in the project and their ability to adsorb and desire polyphenols will be assessed.
Finally, brewer¿s spent yeast will be treated to extract beta-glucans and mannoproteins for the food industry. The extraction methods will benchmark natural deep eutectic solvents of different formulations.
The worldwide increasing interest in producing low-alcohol beer, up today a secondary product of brewing industry, arises from the high impact these alternative beverages could have on the global market, if keeping in mind for example the increasing legislative interventions restricting or the possible incoming to market in countries where alcohol consumption is forbidden for religious reasons or young people consumers. Further, there is an increasing awareness of consumers in healthy products and beverages.
Efforts are required to produce these alternative beverages maintaining sensorial and healthy qualities. The proposed study aims to combine a new membrane process for dealcoholization of beer with the phytochemical characterization of original and dealcoholized beer, to evaluate advantages, disadvantages and possible upgrading of this process to obtain high quality healthy low-alcohol beer. Moreover, the developed process will valorise all waste streams, with a residue compatible to municipal sewer system discharge.
The use of green solvents for the extraction process of beta-glucans and mannoproteins from Brewer¿s spent yeast represents a further innovation of the project with respect to the state of the art. In particular the solvent class which will be investigated is that of natural deep eutectic solvents (NaDESs), that are formed from natural substances and, hence, are intrinsically safe.The group is engaged in deploying these solvents to simplify microbial biomass fractioning, in particular microalgae, into its industry-relevant fractions, i.e. proteins, carbohydrates, and lipids. In particular, the group is devising solid-liquid extraction (SLE) and liquid-liquid extraction (LLE) schemes. Recently, the proposer (Prof. M. Bravi) has drafted an initiative with the leader of GreenCentre Canada, Prof. P. Jessop of Queen¿s University (Canada), the inventor of the very concept of switchable solvents, to target the discovery of food-grade switchable solvents, as this is a strong expectation of the whole food and industrial biotech industry.
Furthermore, the use of nanozeolites for the adsorptive downstream processing of polyphenols from waste water is proposed to overcome the disadvantages (limited capabilities and longevity)
of commercial materials commonly used. On the other hand, the main constraint in using synthetic nano zeolites is the difficulty to produce large quantities required by the market at competitive costs. The advantages of synthetic zeolites may be sensibly improved by producing nanostructured zeolite materials by a bottom up approach. The production of nanostructured zeolite may be profitable for some of the industrial applications, in particular focusing on:
1. the synthetic nanostructured zeolites will all exhibit uniform quality, composition, porosity, and as a consequence, efficiency.
2. the synthetic nanostructured zeolites can be functionalized to specific needs during synthesis, thus guaranteeing homogeneous functionalization.
The ZEPROMEM project will exploit the possibility to produce synthetic nanostructured zeolites by a bottom-up approach. The advantages of this approach to the current state of the art are expected to be:
1. Reduced production costs by avoiding the synthesis of micro material to be furthermore post-processed to nano powders.
2. Increased chemical and physical uniformity of properties, thus resulting in a higher quality product.
3. Comparable efficiencies in industrial applications if compared to other synthetic nano zeolite products.
4. Comparable aspect and handling of the final product similar to the zeolite actually used in industry by pelletizing the material to bigger particles at the micron and at milli scale.
In order to reach these objectives, the production of the nanostructured zeolite will be performed by means of a spinning disk reactor. The technique qualifies within EU project as TRL7, and is of high industrial interest (high quality, high rates, continuous production). During previous research, members of the research team (M.Stoller and G. Savino) have already studied and experimentally demonstrated the possibility of nanozeolite (type A) production by means of the SDR technology. Details of this procedure is now submitted to Sapienza patent office for patenting purpose.