Roberto Calandrelli

Agricultural and food waste recycling reduces natural resource losses, contributing significantly to the development of new green markets through the creation of redesigned products. In order to cycle valuable molecules, the peels from Italian cantaloupe (Cucumis melo L.) cultivars were studied and successfully characterized for high-added biomolecules to verify their possible exploitation as wealthy biomasses. Peels were investigated for their cell wall-modifying and browning enzymes, as well as for total polyphenols, ortho-diphenols, flavonoids, tannins, and antioxidant properties. The results of the analyses displayed great promise in one of the three cultivars investigated. Later on, a preliminary study using the best peel extract as a dietary supplement was carried out by preparing fortified seawater to enhance its antioxidant power. The effects of storage time (60 days) were examined at two temperatures through the determination of the stability of the polyphenol content. The kinetic parameters of degradation were also calculated. The “enriched sea water” retained great antioxidant activity in refrigerated conditions, demonstrating that there is good potential for melon by-products to add their natural compounds for food fortification. These findings may provide valuable data for scale-up, from the lab to the pilot or industrial application.

The biochemical changes that occur during the growth and ripening of fruit and vegetable tissues, especially for color and firmness, are the most important factors affecting the quality of fresh products. Cantaloupe (Cucumis melo, L.) is one of the main economically important fruits in the world and its quality parameters, e.g., sweetness, nutritional factors, and texture, influence consumer preferences. Hence, these two features, appearance and texture changes, were investigated in three different genotypes of netted melon, all characterized by an extended shelf life but with different ripening phases. In particular, in all melon cultivars, the cell wall-modifying enzymatic activities and indicators of softening as well as total polyphenols, ortho-diphenols, flavonoids, and tannins, and antioxidant activity were studied. One variety with excellent shelf-life displayed the best nutritional and healthy qualities, in the early stages of ripening, and the lowest degree of browning. The lytic enzyme activities were reduced in the initial stages and after they increased gradually until the overripe stage, with the same trend for all varieties under investigation. The antioxidant activities declined with increasing time of ripeness in all genotypes. The outcomes confirm that the activities of both classes examined, antioxidant and cell wall-modifying enzymes, may vary significantly during ripeness depending on the genotype, suggesting the involvement in determining the postharvest behavior of these fruits.

Essential oils (EOs) obtained from aromatic plants are widely used worldwide, especially in cosmetic and food products due to their aroma and biological properties and health benefits. Some EOs have significant antimicrobial and antioxidant activities, and thus could effectively increase the shelf lives of foodstuff and beverages. In this study, fourteen essential oils (clove, eucalyptus, fennel, lavender, oregano, palmarosa, pepper, star anise, tea tree, turmeric, Chinese yin yang, Japanese yin yang, and ylang ylang) from different medicinal plant families were screened by gas-chromatography–mass spectrometry (GC–MS) for their different chemical profiles and bioassays were performed to assess their antifungal and antioxidant activities. The results obtained were assessed by principal component analysis (PCA). PCA distinguished six groups characterized by different terpene chemotypes. Amongst the EOs studied, the clove EO showed the strongest antioxidant activity characterized by an EC₅₀ of 0.36 µL/mL. The oregano EO had the greatest antiyeast activity characterized by a minimal inhibitory concentration of 10 µL/mL. In conclusion, clove and oregano EOs are strong antifungal and antioxidant agents, respectively, with great potential in the food industry to avoid spoilage and to increase shelf life.

The effect of untreated olive mill wastewater (OMW) spreading on chemical and biological soil properties of two different fields located in Campania (Italy) was investigated. Fields were irrigated since 2003 with quantities of about 30 m³ ha⁻¹ year⁻¹, a volume lower than the maximum limit of 80 m³ ha⁻¹ year⁻¹ established by Italian law. Results showed that the addition of OMW, even if repeated for many years, had little impact on pH, electrical conductivity, organic matter, concentrations of main cations and polyphenolic content of both soil plots; moreover, microbial respiration was low during the winter time, but an increase was evident in the second sampling carried out in warm season. This study suggests that OMW, without pre-treatments, can be annually used for crops and tree irrigation. As a consequence, OMW should be a readily and inexpensive source of nutrients that could replace chemical fertilizers which are extensively employed in agricultural practices of Mediterranean countries.