RICERCA ITALIANA     

THE "MADE IN ITALY" FOOD PRODUCTS PROMOTION: THE CASE OF THE GRAPPA

Università degli Studi di Padova

Abstract

In the 2003 WTO meeting in Cancun, the European Community has thrown the bases of a new founded Common agricultural policy on quality assurance, health promotion, environment defense and the valorization of the territorial origin of the agricultural products. In the light of these considerations also the grappa, produced only in Italy, can become one of the products that well represent the "made in Italy" to the foreign countries.
Grappa is an original Italian product obtained by processing marcs from must or wine at the end of the alcoholic fermentation.
The peculiar raw materials used for its production influence its characteristics, the technological history and determine the difficulties found during the manufacturing procedure and therefore its preciousness. Grappa is obtained from the most aromatic part of the grape, the peel, where compounds responsible for fragrances present in different quantities and kinds depending on vine, soil and climatic conditions, are concentrated.
Scientific data on the grappa production process and of the numerous chemical, biochemical and microbiological reactions involved are quite scarce, particularly if compared with those of the neighbouring oenological sector.
The proposed project represents perhaps the first attempt of a multi-disciplinary approach towards this kind of product that is receiving increasing interest, as it is confirmed by the institution of the "Accademia della Grappa" which involves some universities and national research institutes, along with the existence of an annual meeting (Mondograppa) and specific sections in enological meetings.
As regards the multi-disciplinary approach, the project will examine various aspects, through collaborations among units with different but sometimes complementary expertise:
- technological aspects related to the control of the production of toxic substances by enzymes and microorganisms will be evaluated;
- the convenience of the use of selected yeast strains specific for this production, as it is common for the enological sector will be explored;
- the content and quality of antioxidant substances present in the vegetal material will be studied, in relation to their importance for their beneficial effects on consumers' health;
- from the health-care side, we will aim at providing the consumer with some guidelines for the consumption of this kind of products;
- the economical importance of the grappa business will be assessed, along with the trend of this kind of market.
With the aim of reaching a wide level of diffusion, the results of the project will be published on national and international journals; some seminars will be held and at the end of the project a one-day meeting will be organized devoted to producers, consumers and researchers to communicate our most interesting and useful findings. <<<

Principal Investigator

Paolo SPETTOLI Università degli Studi di PADOVA

Research Objectives

In order to bring innovation into the world of spirits, such as the grappa, a typical alcoholic beverage made in Italy, it is necessary to look for effective means capable of controlling defects while increasing quality attributes. This objective has to be reached taking into account economic aspects, costs for innovation and protection of consumer's health.
In this respect, it has to be considered that in recent years important laws for consumer protection, such as the HACCP systems in the production line, have been promulgated.
The storage of grape marcs after must separation in the winemaking process and before distillation is a crucial step in relation to grappa quality, since microbial and enzymatic activities could produce in this period harmful substances, such as methanol and ethyl-carbamate. It appears therefore important to study the biochemical and microbial mechanisms involved in their production and to set up new control strategies which could positively influence commercial aspects too. To specifically examine aspects involving product quality and the market, a dedicated research units has been added to the project. It will be placed side by side to the unit with medical competences in a position to estimate the assumption of superalcoholic drinks, proposing guidelines in a correct and scientifically manner, easily useable by the public.
The results obtained during this project, along with other data already obtained by our research groups, will be helpful in answering some questions coming from the producers, which sometimes need to take important technical decisions, that also imply an economical effort, without having a clear scientific ground to support them. The improvement of production quality can balance the costs for innovation.
The possibility of reducing the presence of toxic substances will also determine a simplification of the industrial process. For instance, a decrease in methanol content will reduce the need for redistillation using the methanol column, which has a negative side effect on other aromatic compounds. Working in this direction, the grappa will contain an even more faithful memory of what the grapevine has synthesized in its fruits.
It is noteworthy that exausted grape pomaces, which are used as ferlilizers or biofuel, are to be considered as an important source of bio-active phenolic compounds.
For this reason, their recovery in grappa processing byproducts could represent an interesting advance in distillery promotion. Since polyphenols present in fruit pomaces are among the most potent free radical scavenger, a research unit will develop and set-up new methodologies for the simultaneous evaluation of the antioxidant capacity and efficiency of grape byproducts and will study the various aspects of their antioxidant action and of their molecular mechanisms. <<<

First Results

From this phase of the project, different and articulate series of information on marketing and consumption aspects is expected to be collected (by means of questionnaires, interviews, data bank, ...)From this phase of the project new methods for the microbiological and enzymatic characterization of marc and for the simultaneous evaluation of the antioxidant capacity and efficiency of grappa by-products will be developed. From this step information and tools to be used for the analyses on the successive phases will be provided.From the marc ensilage experiment, aliquots will be collected for the determination of enzymatic and microbiological data to be analyzed during the next phase. Part of the sampled aliquots will undergo distillation to evaluate chemical and sensory parameters. The evaluation of marc antioxidant activity at different points of the production process will allow the determination of how these operations can influence the composition and characteristics of their antioxidant content.At the end of this stage all data collection and analysis will be completed and should be ready for their diffusion. <<<

Timescale

24 months

National and international background

In the 2003 WTO meeting in Cancun, the European Community has thrown the bases of a new founded Common agricultural policy on quality assurance, health promotion, environment defense and the valorization of the territorial origin of the agricultural products. In the light of these considerations also the grappa, produced only in Italy, can become one of the products that well represent the "made in Italy" to the foreign countries.
The word spirit, synonymous of the italian term "acquavite", is ascribed to all the beverages obtained from the distillation of different raw vegetable materials. The italian root of the word derives from the latin "aqua vitae", literal translation for "water of life", linked to its likely use as an ancient medicine.
Grappa is an original Italian product obtained by processing marcs from must or wine at the end of the alcoholic fermentation.
The peculiar raw materials used for its production influence its characteristics, the technological history and determine the difficulties found during the manufacturing procedure and therefore its preciousness. Grappa is obtained from the most aromatic part of the grape, the peel, where compounds responsible for fragrances present in different quantities and kinds depending on vine, soil and climatic conditions, are concentrated. On the other hand marcs, the raw material, are difficult to handle both during the storing phase of the production process and during distillation. In this context, delveloping procedures to remove defects and the originating causes, to emphasize the quality while respecting the vine characteristics and the need to differentiate the products on the bases of grape variety, environmental characteristicts and distillation style are the main goals of the research in this technological field. Moreover, experimentation has to take into account all the problems concerning public health and consumer's protection. As regards this distillate, the Italian government has implemented a set of regulations to impose supervision on hygenic conditions of the whole production process (D.L. 155/97), and to use specific denomination (considering the geographic area of production, the vine and the distillation procedure) when precise production conditions are respected (D.Lgs.297/97). These limitations deal with the possibility to identify the different kinds of marcs and to separate the different parcels of Grappa produced in the distilleries.
The technological steps of the production elapsing between marcs separation from must and their introduction into the still are the most problematics. In fact, none of the distillation protocols are able to remedy the defects of a distillate coming from an altered raw material. During storage marcs are conserved in different manners, using silos of various sizes and material or smaller containers such as plastic tunnels, for period lasting from few days to several weeks, depending on the company organization, the quality of the marks and the capacity of the distillation plant.
Marcs, particularly those not fermented, are characterized by low pH (although not excessively acid), large quantity of energetic compounds and presence of oxygen-rich zones. All these features make this material the ideal substrate for the activity of grape enzymes and microorganisms able to carry on chemical transformations of its constituents. The main chemical process is sugar degradation and alcohol production, carried out by yeasts, although a large number of molecules with positive (aromatic substances) or negative (off-flavours and toxic compouds) effect can develop from the activity of the microflora. Moreover, by means of distillation, volatile compounds are extracted from the marcs, the alcoholic fraction containing the valuable aromatic molecules is concentrated and, at the same time, the negative substances are eliminated. Therefore the distillation plants can only contribute to improve a potentially good product, but they are totaly unable to transfom a low quality raw material into a good distillate.
Grappa is a typical product from some italian regions where the grapevine cultivation is largely diffused. Originally this spirit was home-made by farmers that were used to distillate with artisanal instruments the marcs obtained as a residue from the wine making process. Originally this product was not subjected to any organoleptic and sanitary inspection, particularly concerning the presence of substaces that today are demonstrated to be toxic, like methanol and ethyl-carbamate.
Nowadays all kind of distillates, included grappa, are emerging on the market as "meditation drinks", and are included among the typical regional products. Moreover the quality has become more and more crucial as the new kind of consumer is frequently trained by tasting courses.
Modern distilleries have developed technological supports to avoid spoiling of the product due to unsuitable storing conditions, with the aim to i) improve pH condition; ii) avoid temperature increase; iii) preserve anaerobic environment; iv) manage microbial populations by means of selected yeast introduction. However, the technical choices in the distilleries come frequently from practical experiences rather than scientific basis. This trend is the opposite considering the cognate oenological field, where the number of researchers and available data are relevant. Concerning the case of grappa, international studies are almost absent, as the production is limited by the legislation to our national territory.
Particularly this project will try to develop a multidisciplinary approach that conjugates the sanitary aspects of the process, linked to the production of toxic compounds due to microrganisms and grape enzyme activity with the health claim linked to the availability of antioxidants, without ignoring the aspects connected with the marketing and the spread of the product. <<<