Giuseppe Pignata

Fresh baby leaves are commercially marketed in various mixing ratios and packaging amounts, creating very distinct microenvironmental conditions that significantly affect the postharvest quality of the fresh product. This study investigated the synergistic effect of mixing ratio (50LB, 50% lettuce + 50% spinach; 75LB, 75% lettuce + 25% spinach; 100LB, 100% lettuce) and packaging amount (125F, 125 g; 250F, 250 g) on the antioxidant qualities of baby lettuce and spinach mixes during 9 days of storage at 4 °C. The results showed that 50LB × 250F inhibited the degradation of chlorophyll and carotenoids and preserved 28% higher total antioxidant capacity (TAC), 43% higher total phenolic compounds (TPC), and 20% higher vitamin C (Vit.C) than the mean values of all samples, resulting in 0.8% lower O₂ and 14.7% higher CO₂ levels at the end of storage. TPC, Vit.C, and carotenoids were the main contributors to TAC, with strong correlations (p < 0.001). The total bacterial (TB) and yeast + mold (Y + M) counts were only affected by the mixing ratios, with TB increasing by only 1 Log₁₀ cfu g⁻¹ FW, and Y + M remaining within the same order of magnitude over time. After 9 days of storage, the leaves were still fresh and marketable. This study not only provides a practical strategy for the fresh-cut industry to enhance product quality but also underscores the significance of multifactorial synergism in salad mix packaging.

Nitrogen (N) availability often limits primary productivity in terrestrial ecosystems, and arbuscular mycorrhizal fungi (AMF) can enhance plant N acquisition. This study investigated the interactive effects of N fertilization and AMF inoculation on N uptake, plant performance and phenolic acid content in Hyssopus officinalis L., with the aim of promoting sustainable N management in H. officinalis cultivation. A factorial randomized complete block design was employed to evaluate four AMF inoculation strategies (no inoculation, root inoculation, soil inoculation and combined root–soil inoculation) across three N application rates (0, 0.5 and 1,1 g N pot⁻¹ (7 L)) in a controlled greenhouse environment. Combined root and soil AMF inoculation alongside moderate N fertilization (0.5 mg N pot⁻¹) optimized N use efficiency, maximizing plant biomass and bioactive compound production. Compared to non-inoculated controls, this treatment combination increased N uptake by 30%, phosphorus uptake by 24% and potassium uptake by 22%. AMF colonization increased chlorophyll content and total phenolic compounds under moderate N supply. However, excessive N application (1 g N pot⁻¹) reduced AMF effectiveness and secondary metabolite accumulation. Notably, AMF inoculation without N fertilization yielded the highest levels of anthocyanin and salicylic acid, indicating differential N-dependent regulation of specific biosynthetic pathways. The interaction between AMF and N demonstrated that moderate N fertilization (0.5 g N pot⁻¹) combined with dual inoculation strategies can reduce total N input requirements by 50%, while maintaining optimal plant performance. These findings provide practical insights for developing N-efficient cultivation protocols in medicinal plant production systems, contributing to sustainable agricultural practices that minimize environmental N losses.

Herb production in soilless culture systems (SCSs) requires precise composition of hydroponic nutrient solutions (HNSs) to optimise growth, yield and quality. This study aimed to investigate the effect of four nutrient solutions having different ion concentrations on the yield, quality and safety of basil grown in a New Growing System (NGS ^® ) at two harvest times. The results showed that as ion concentration increased, yield and leaf fresh weight decreased, while total dry matter varied with harvest time. Lower levels of phosphorus and potassium in the HNS increased nitrate concentration in basil leaves, with higher nitrogen specifically increasing nitrate levels, and the second harvest showed the highest concentration in the N12P2K6 (nitrogen: 12 mmol · L ⁻¹ ; phosphorus: 2 mmol · L ⁻¹ ; potassium: 6 mmol · L ⁻¹ ) treatment. This study showed that SCS was successful in reducing the growth of microbial contamination, with the lowest levels of mould and yeast contamination detected in nutrient solutions containing N6P4K12. HNS affected the contents of essential oil compounds such as linalool (the highest amount at the lowest ion concentration) and (E)-α-bergamotene (the highest amount at the highest ion concentration). In conclusion, the quantity, quality and microbiological contamination of basil grown in NGS ^® depend on the HNS used and harvesting time.

Ziziphora clinopodioides L. is a valuable medicinal and aromatic plant; however, its special requirements for proper growth and enhanced secondary metabolite composition have limited its production and availability. The lack of appropriate fertilizer dosage recommendations is one of these limiting factors for ex situ conservation and large-scale cultivation. This study investigated the effects of nitrogen (N) fertilization on Z. clinopodioides in both open field and unheated greenhouse conditions. The determined research factor was N dosage (0, 40, 80, and 120 kg N ha⁻¹ in the field) and (0, 200, 400, and 600 mg N pot⁻¹ in the greenhouse). It was found that Z. clinopodioides plants could grow successfully outside their natural habitat with sufficient N fertilization yielding a satisfactory amount of metabolites per plantation area. Specifically, among the tested dosages, the 120 kg N ha⁻¹ (which showed no significant difference from 80 kg N ha⁻¹) and 400 mg N pot⁻¹ fertilizers increased the aboveground dry and fresh biomass, essential oil (EO) content, and yield. Nitrogen fertilization showed a direct correlation with menthone, neo-menthol, menthol, pulegone, E-ocimenone, and spathulenol, but a negative correlation with α-pinene, β-pinene, limonene, 1,8-cineol, trans-pulegol, and iso-menthone. This study is the first to evaluate the effects of N fertilization on the genus Ziziphora. The results indicate that utilizing N fertilizer at a moderate rate (80 kg N ha⁻¹ in the field and 400 mg N pot⁻¹ in the greenhouse) can improve the agronomic traits and EO of Z. clinopodioides.

The optimal fertilizer concentration for Mentha plants is contingent on the growing systems and harvest time, serving as operational solutions to control and enhance quality and yield. This study aimed to determine the effects of three macronutrients concentration in hydroponic nutrient solution (HNS) during three harvest times on the growth, quality, yield, and shelf life of three mint species (M. spicata L. var. viridis (MV); M. piperita L. (MP); M. spicata L. var. rubra (MR)) grown in a New Growing System (NGS^®). Total dry matter (DM), nitrate (NO₃⁻), phosphate (PO₄³⁻), and calcium carbonate (CaCO₃) concentrations were increased with the addition of higher levels of nutrient fertilization in three species. When the ion concentration of the HNS was increased, total fresh yield decreased. The highest total bacterial count (TBC) was obtained in MR species in the three harvests in all the levels of HNS. The lowest browning potential (BP) and soluble o-quinone (So-Q) levels were observed at second harvest in the MR species with the application of one of the two HNS high in nitrogen (N). In conclusion, the combination of optimal HNS ion concentration and appropriate species is considered essential to obtain suitable yield, quality, and ensure shelf life of mint.

Different types of baby leaf vegetables (BLV) are often mixed and packaged as salad mixes. This work has evaluated the effects of BLV mixing ratios (100% lettuce ‘Lollo Bionda’, 100 LB; 75% lettuce + 25% rocket, 75 LB; 50% lettuce + 50% rocket, 50 LB) and the weight filling amount (125 g filling amount, 125F; 250 g, 250F) on the antioxidant properties and browning potential (BP) of lettuce and rocket baby leaves during storage for 9 days at 4 °C in the dark. The samples were packaged in thermos-sealed bags previously prepared using polypropylene film. The results showed that the 50 LB mix had preserved high amounts of chlorophylls and internal nutrients on d9, regardless of the filling amount. No visible browning symptoms were detected in the 50 LB samples. The 50 LB × 125F mix was found to be the most efficient strategy to maintain the antioxidant property of BLV. Thus, the optimisation of the mixing ratio and its combination with an appropriate filling amount could represent an effective postharvest practice.

The physiological changes and phytochemical pathways of processed watercress (Nasturtium officinale R. Br.) undergone during storage are not well known. The objective of this work was to evaluate the respiration rate and the inherent and external quality of watercress inoculated with B. subtilis and packaged as a fresh-cut product and stored at 4 °C for 11 days. Watercress was grown using continuous flotation (FL) in a greenhouse using substrate disinfection and inoculated or not with Bacillus subtilis as a plant-growth-promoting rhizobacteria (PGPR). The fresh-cut watercress respiration rate and phytochemical profile changed during the shelf life. The inherent phytochemical compounds were retained during the storage of the fresh-cut salad bags. The best results were found in watercress grown in a disinfected substrate but were less satisfactory when seeds and substrates were inoculated with PGPR. In general, the external quality and the pigment contents progressively decreased during the shelf life and the browning enzyme activities responsible for phenolic oxidation increased at different intensities throughout storage. At the end of the shelf-life period, the fresh weight loss of the fresh-cut product was less than 1% of the original weight. The results demonstrated that watercress grown in FL is a standardised baby leaf vegetable that is suitable for processing in the fresh-cut industry and for storing for more than 10 days. Unclear results were obtained for Bacillus subtilis in the postharvest period due to the inconsistent responses of the different analysed parameters.

New cultural techniques have been developed to improve the yield and raw material quality at harvest, and enhance the postharvest shelf life, by standardizing the growing system. Among the different Soilless Cultivation Systems, the New Growing System (NGS^®) is a closed-recirculating system that was designed for open fields and protected cultivations. The aim of this work was to investigate the structural setting of the system and its functioning to harness the full potentiality of NGS^®. A lab-scale pilot plant (LSPP) was designed with NGS^® technology and the technical aspects have been set up to have a standardized and reproducible growing system. The trials were conducted on growing mature-leaf vegetable species; that is, on both head and multi-leaf vegetables, and on culinary herbs at high plant densities. Positive yield results were found for culinary herbs and leafy vegetables. Mints showed high yields for the two re-growths carried out after the first harvest. The LSPP can also be used in a series of reliable experiments and enable researches to test several species, substrates, hydroponic nutrient solutions, and fertigation scheduling.

The Veronica genus, with more than 200 species, belongs to the Plantaginaceae family and is distributed over most of the Northern Hemisphere and in many parts of Southern Hemisphere. These plants are traditionally used in medicine for wound healing, in the treatment of rheumatism, and in different human diseases. This paper reviews the chemical composition of some valuable Veronica species, the possibilities Veronica extracts have in food preservation and as food ingredients, and their functional properties. Veronica species represent a valuable source of biological active secondary metabolites, including iridoid glycosides and phenolic compounds. In particular, due to presence of these phytochemicals, Veronica species exhibit a wide spectrum of biological activities, including antimicrobial and antioxidant. In fact, some studies suggest that some Veronica extracts can inhibit foodborne pathogens, such as Listeria monocytogenes, but only a few of them were performed in food systems. Moreover, anticancer, anti-inflammatory, and other bioactivities were reported in vitro and in vivo. The bioactivity of Veronica plants was demonstrated, but further studies in food systems and in humans are required.