Caratterizzazione qualitativa di alcuni ortaggi tipici del Veneto

RADICCHIO Experiment 1: Variegato di Castelfranco SUMMARY For Veneto region, chicories unquestionably represent an unique living patrimony in its kind. The specific organoleptic characteristics, the strong link with the territory and the long history make them an extremely precious reality, worthy to be safeguarded. Among chicories the "Variegato di Castelfranco", is one of the most appreciated and sought vegetable that grows during the winter period. Thanks to its qualitative characteristics this kind of chicory has become more and more famous and sought not only by Italian consumers but also by Europeans (Germany, France, United Kingdom, Austria and Switzerland) and others from overseas (United States, Canada, Mexico, Chile). Besides it obtained the IGP label in July 2006. In the last years, the demand of the market, have become more and more strict from the qualitative point of view, especially towards the salubriousness and the nutritional and healthy characteristics. Starting from these objectives, a study has been conducted to appraise the influence of the environment on some quanti-qualitative parameters of the plant, such as productivity, and dry matter, protein, nitrogen, nitrates, antioxidants, polyphenols content. Particularly a variety trial has been conducted among chicories of 4 different classes of precocity. Four places (Cavallino, Cavarzere, Lendinara, Monselice) were taken in account. In the different locations, 5 plants, representative of the whole population, have been sampled in each plot. Each plant was then divided into external, intermediate and inner leaves, external, intermediary and inner leaf blades, external, intermediate and inner veins, stem and roots. Each different samples have been analyzed and the resulting data have been submitted to ANOVA. The results in this experience underlined higher averaged weights of the inner leaves in the case of the plants of class precocity 3 and 4. Higher dry matter content was observed in plants grown on sandy soils while as far as nitrogen content is concerned, the greatest concentrations were noticed in the inner leaves of plants sampled in clay soils of Cavarzere and Lendinara, probably because of the higher N availability of this kind of soils as a consequences of reduced nutrient leaching. The content of nitrates underlined a smaller accumulation in the sandy soils in comparison to that clay, probably due to the elevated retention of water in the former that mostly makes nitrogenous mixtures more available for the plant. Anyway, with the exception of roots and the stem, the presence of nitrates in the remaining edible portions of the plant did not overcome the most restrictive limits imposed by the UE. This allows to say that the chicory "Variegato di Castelfranco", from this point, is a healthy vegetable for the consumer. About antioxidants content, results showed that plants with a longer growing cycle had higher content of these compounds. Such result is justified by the longer period of exposure to adverse low temperatures which stimulated the production of inhibitors of oxidation. Among portions of the plant, external leaf blades were the richest of antioxidants mainly because they were submitted to prolonged factors of stress during the whole growing cycle in field. The quantities of polyphenols in the plant, being compounds with antioxidant action, followed the courses introduced by the inhibitors of the oxidation. Experiment 2: Rosso di Treviso tardivo SUMMARY There is currently a great deal of interest in phytochemicals as bioactive components of food, especially antioxidant compounds that could benefit human health. Radicchio Rosso di Treviso tardivo (Cichorium intybus L., group rubifolium), a typical vegetable of north-eastern Italy, has gained increasing commercial interest in recent years due to its particular shape and culinary features. These properties are obtained by a forcing process that could affect quality and nothing is known about changes during the forcing process. The experiment was conducted in Veneto (north-eastern Italy, 45°36’N; 12°10’E) with plants grown in a loamy soil and analyzed at harvest and during the forcing process (0-10 and 20 forcing days-FD). Results showed that the antioxidant capacity (AOC), phenols and ascorbic acid contents of this chicory decreased with different intensity during the forcing process. The outer inedible leaves displayed high AOC, which could provide phenolic extracts that could be used as natural antioxidants or to functionalize foods. Concerning nitrogen compounds, nitrate and nitrite contents in edible portions never exceed the most restrictive EU limits. A continuous reduction in NO3 content was observed during the forcing process, while NO2 showed a peak at 10 FD. Organic N significantly increased during the forcing process due to NO2 reduction. The properties verified so far mean that this chicory can be considered an interesting and healthy vegetable for the consumer, also after the forcing process. ASPARAGO Experiment 1: Asparago bianco SUMMARY The asparagus is a well known vegetable in Veneto, especially in those areas (Bassano and the Pianura Padana) where it is considered a typical product. In the last years the market and singles consumers are increasingly asking for qualitative food, especially regarding healthy and nourishing food features. Concerning the white asparagus, few analysis and evaluations were made in the past years. This was the main reason to conceive a test, an analysis which aimed to evaluate the contents of nitrates, nitrites, antioxidants and polyphenols contained in the spear of the regional varieties. Qualitative tests on white asparagus stems were realized in 2008 at the Department of environmental Agronomy and Vegetal Productions (University of Padua), considering material coming from the Experimental Flower and Vegetable Centre “Po di Tramontana” located in Rosolina -RO- (45° 4' N- 12° 14'E). Since 2005, 31 hybrids of white asparagus have been compared in this centre: the most examined Italian varieties have been “Eros” and “Zeno” together with the Dutch one “Grolim”. After the picking stage occurred in April, three harvests were performed on 15/4, 22/4 and 29/4, each of them named R1, R2, R3 respectively. Later the spears were cut, washed, and left at the temperature of 4°C, in order to keep them fresh after the picking. The day after, only extra stems were selected (Ø 16mm) for the qualitative tests: they were weighed and cut 220 mm from the apex, dividing the discard portion from the good one. Then they were cut horizontally in three equal parts and diced, in order to evaluate the expected qualitative variations from the apex to the basis. The results confirm that “Grolim” shows heavier stems and the higher percentage of dried substance. It has also demonstrated in all types of varieties the higher levels of dried substance in the apex, probably due to the great presence of bracts. Asparagus also indicates low contents of nitrates and nitrites, showing a decrease of nitrates from the basis to the apex, while nitrites decrease from the apex to the basis. About antioxidants and phenols content, the test has pointed out a concentration of them at the top, especially in the “Grolim” variety. This result is probably due to stress. In fact when plants are overstressed, they try to overcome this unpleasant condition by producing more antioxidants, as apex is embedded, during its emerging effort, it products oxidation depressors. Experiment 2: Asparago verde SUMMARY Asparagus is a very popular vegetable in the Veneto region especially in areas of Bassano and the Po Valley where it is considered a typical product. In recent years the demands of the market and especially of the consumer have become more and more driven in terms of quality, particularly in respect of health, nutrition and healthy food. As for the green asparagus, the information on these issues are limited. In this regard has been set a test to assess the content of nitrates, nitrites, antioxidants and polyphenols and pigments present in the shoot of a green asparagus variety (Eros), cultivated in two areas of Veneto. The qualitative analysis in green shoots, were made in 2008 at the Department of Environmental Agronomy and Crop Productions of the University of Padova on material from Barbona (PD) and Piombino Dese (PD). The first asparagus plantation has been implanted since three years and the second since eight. During the shoots harvest, which took place in April and May, six sampling moments were performed on 10/4, 17/4, 24/4, 2/5, 8/5 and 15/5 identified with R1, R2, R3, R4, R5, R6, respectively. Once cut the shoots were calibrated, washed and placed at 4°C to keep the product until destructive analysis made on the day after the harvest. In this moment we took the extra class shoots (diameter >16 mm) to use for qualitative analysis. They were weighted and then cut to 270 mm from the apex in order to separate waste portion from the commercial one. This fraction was cut perpendicular to the longitudinal axis in order to obtain three equal parts (90 mm each) to assess any changes in shoot quality characteristics. The results obtained in this experiment showed that asparagus of Piombino Dese had a lower content of dry matter but a greater weight. The nitrate content was not influenced by location, while in shoot parts a decreasing trend from the base to the apex was observed and even with the advancing of the harvest season. For nitrites there were no significant changes. The pigments content increased during the advancing of the harvest season in Piombino Dese that showed the highest shoot values. The content of these chemical compounds grew exponentially from waste to the apex portion and the chlorophyll a content was higher than the chlorophyll b and xanthophylls + carotenoids. The antioxidants and polyphenols determination showed that the apical part is the place where they

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