•Monographs

Catalonia has many traditional vegetable varieties of recognised gastronomic value, i.e. their sensory characteristics (texture, taste, smell and appearance) are highly appreciated by consumers. Some of these varieties are cultivated by Catalan farmers in extremely small crops with low yields. In addition, these varieties are often vulnerable to disease and plagues.

In order to recover prestigious traditional varieties and justify their high prices, they need to be characterised and improved as much as possible. In addition, contamination with other varieties must be reduced.

The Group for Improving the Organoleptic Characteristics of Vegetables—part of the UPC’s School of Agricultural Engineering of Barcelona (EUETAB-ESAB)—is led by Francesc Casañas. It aims to assess traditional Catalan vegetable varieties whose gastronomic value has enabled them to withstand competition from genetically improved varieties. The group first assesses the taste of as many existing varieties as possible. It then selects the best of the varieties that have a high sensory value and could compete in the current markets. The first stage has already been completed for bean varieties. The second stage of selecting from the superior varieties is being carried out with the Mongeta de Ganxet, the Mongeta Tavella Brisa (Sant Pau), Tomàquets de Montserrat (tomatoes), the Pera i de Penjar (pear), the Ceba Blanca de Lleida (scallion), and the Carxofa del Prat (artichoke).

Environmental effects, genetic components and agricultural practices all make a major contribution to the sensory value of vegetable products. In the process of recovering varieties, it is essential to establish the environmental conditions in which each variety best expresses its gastronomic potential. Thus, a binomial of variety-environment is established, which consumers can appreciate and makes them loyal to a particular product from a specific origin.

There are several stages in the process of recovering traditional varieties. The first stage involves assessing the gastronomic value of all traditional varieties of Catalan vegetables. This stage is very slow, which is a problem as varieties are rapidly becoming contaminated by cross-fertilisation with “neighbours” or disappearing due to lack of use. Once the varieties with the best sensory qualities have been identified, the following stages can begin.

First, as many seeds as possible are collected from the areas that still cultivate these varieties. Next, a comparative field experiment is carried out to define the morphological characteristics and the taste of the product, in order to describe the sensory characteristics and all of their variants. This data is then be used to draw up an ideotype or picture of the ideal plant that has the maximum number of positive characteristics (the highest sensory value and an acceptable yield). Frequently, the ideotype is similar to old forms of the plant, as varieties used to be selected for taste over yield. However, the remaining traditional varieties have usually been cross-fertilised with other plants, which has led to changes in their characteristics. As a result, varieties have higher yields than 50 years ago, but have also lost some of their sensory value. Studies with molecular markers sometimes need to be carried out to detect the foreign material in a variety and eliminate it through selection processes.

The next stage involves designing a selection programme on the basis of the collected seeds, in order to obtain one or more new varieties that come close to the ideotype. Any agronomic problems are corrected by processes of genetic improvement.

The final stage of the improvement process involves distributing the new seed to the producers. Indeed, from the start of the process, all of the programmes are carried out in collaboration with the producers and by means of agreements with their associations.

Simultaneously, the Group studies environmental influences on gastronomic characteristics. The aim is to draw up a map of a variety’s traditional cultivation area that shows where the highest sensory values are obtained. All of these data are used in the application for Protected Denomination of Origin (PDO) or Protected Geographical Indications (PGI) status. The first PDO to be requested is about to be officially recognised for Mongetes Ganxet del Vallès Maresme. Currently, a PDO application for Fesols de Santa Pau is being drawn up. The Group also plans to undertake this process for tomatoes, artichokes, scallions and other species.

The EUETAB-ESAB’s tasting room is run by Roser Romero del Castillo and used to describe the sensory characteristics of the vegetables. Tasting rooms for sensory analyses must contain standardised cubicles (ISO regulation 8589, 1988), equipped with a small sink and tap, a door through which the food to be tasted can be introduced, and a set of coloured lights to disguise the colour of the food. For example, green lights are used when the texture and taste of tomatoes are being analysed, so that the colour of the tomato does not influence the assessment. The EUTAB-ESAB tasting room contains 15 standardised cubicles and an isolated kitchen, to prevent cooking smells from influencing the tasters.

Taste or sensory analysis training is also governed by regulations (ISO 8585-1 and 2, 1993). The first step in the tasting process involves clearly defining the objectives, i.e. what needs to be found out about the food and what sensory characteristics will be analysed (smell, texture, taste and/or colour). Then, a taste panel is selected. Members will have undergone general training, to exclude those individuals who are inappropriate for the task. Once the panel has been formed, the product’s attributes are defined and some references chosen, on the basis of which training for each attribute is undertaken. Each taster’s training can last one or two years. During this period, exercises are carried out to validate the panel, i.e. to discover whether the tasters assess the attributes in the same way, and whether they repeat their evaluations in different sessions. All of the results are subjected to statistical analyses to analyse the tasters’ consistency. When the panel has been validated and is consistent, the sensory analyses can begin.

Even when a taste panel has been formed, validation tests have to be carried out on a regular basis. This is like calibrating a machine: it is important to check whether the panel continues to give reliable assessments and to find out whether its members need retraining.

The EUETAB-ESAB tasting room is also used for Sensory Analysis students’ practicals, and to carry out taste sessions for projects and theses which include sensory analysis components. Therefore, many kinds of products are tasted in this room and comparisons are often made with commercial products.