Wild edible plants as environmental indicators and as ingredients for the creation of new functional and enriched products

In recent years, wild edible plants (WEPs) have been the subject of scientific studies highlighting their beneficial effects when consumed through the diet. This is possible due to the presence and high amounts of bioactive compounds, including vitamin A, vitamin E, hydrosoluble vitamins, polyphenols, minerals, etc., that are found in WEPs. One of the main objectives of the thesis was to assess the presence and quantities of bioactive compounds (carotenoids, tocols, hydrosoluble vitamins) in two WEPs present in the Molise Region, in order to use them as ingredient to create a functional bread with health benefits for the consumer. Furthermore, given the wild nature of WEPs, the second objective involved determining the content of the main chemical contaminants (polycyclic aromatic hydrocarbons and heavy metals) potentially present in WEPs and evaluating their use as indicators of environmental contamination. The two WEPs species chosen were Malva Sylvestris and Foeniculum Vulgare. The contents of carotenes (α-carotene, β-carotene, 9-cis-βcarotene and 13-cis-β-carotene), xanthophylls (violaxanthin, neoxanthin, lutein, zeaxanthin and β-cryptoxanthin), tocols (α-tocopherol, β-tocopherol, γ-tocopherol and δ-tocopherol), and hydrosoluble vitamins (thiamine and riboflavin) were determined on both plants. Extraction and instrumental analysis methods already developed in the food technology laboratory of the University of Molise were used. In addition, among the chemical contaminants, the levels of benzo[a]pyrene (BaP), arsenic (As), cadmium (Cd) and nickel (Ni) were determined. These substances are all classified as “certainly carcinogenic” to humans and listed in Group 1 by the International Agency for Research on Cancer (IARC). They therefore require special attention and continuous monitoring in all environmental matrices, including air, water, soil and consequently in food. BaP was extracted from the leaves using cyclohexane and ultrasonic bath and then identified and quantified by gas chromatography with mass spectrometry detection (GC/MS). As, Cd and Ni were analysed after acid digestion of the sample and analysis by atomic emission spectroscopy (ICP-AES). From the results obtained, the consumption of 100 grams of Malva Sylvestris and Foeniculum Vulgare largely covered the 15% of the Recommended Daily Allowance (RDA) of vitamin A, vitamin E and thiamine so, according to EU Regulation n.1169/2011, they can be declared as “source of vitamin A, E and thiamine”. Specifically, maximum values of Retinol Equivalent (R.E.) of 2233 µg/100g on fresh weight (FW), Tocopherol Equivalent (T.E.) of 8.9 mg/100g FW and Thiamine of 79.8 mg/Kg FW, representing 279, 74 and 725% of the respective RDAs. Taking into account the quantities of bioactive compounds, a functional bread was made by replacing 7.5 per cent “0” type flour with freeze-dried Malva Sylvestris. The functional (M2) and control (CTRL) bread were evaluated for vitamin A, vitamin E and thiamine content. The contents of vitamin A (as R.E.), vitamin E (as T.E.) and thiamine were 337 µg/100g FW (42% of the RDA), 1.8 mg/100g FW (1.6% of the RDA) and 3.8 mg/Kg FW (34% of the RDA) for M2 and 8.6 µg/100g FW (1% of the RDA), 0.4 mg/100g FW (3% of the RDA) and 2.6 mg/Kg FW (24% of the RDA) for CTRL, respectively. The developed functional bread cover the 15% of the RDA for vitamin A and thiamine and can be declared as “source of vitamina A and thiamine”. The bread was also characterised for rheology and subjected to sensory analysis, and was highly appreciated by the group of expert panelists involved in the evaluation. With regard to BaP levels in the Malva Sylvestris used to make bread, values below the detection limit (LOD) of 1 µg/Kg FW were found. The same situation for Cd, which was below the LOD (5 ng/Kg FW). In contrast, As and Ni levels are higher (16.7 ± 2.1 and 3.0 ± 0.1 µg/Kg FW respectively). These data may provide a basis for conducting further evaluations in terms of contaminant quantities and assessment of population exposure through the diet. In this context, Chapter 4 describes the state of the art on atmospheric deposition, which is the main mechanism of contamination of vegetation and consequently of the food to which the consumer is then exposed. Finally, Chapter 5 shows how the use of Malva Sylvestris leaves can be useful in defining the contamination status of an area and the main emission sources. In conclusion, WEPs represent an excellent ingredient for the development of food products enriched in health-beneficial compounds, as well as a valuable raw material for reducing environmental impacts and social gaps related to food needs. However, their use can also be important in assessing the contamination status of an area, where together with classical monitoring methods, they can provide useful data for evaluating consumer exposures to chemical pollutants.