Emanuela Fontana

Producing garden cress (Lepidium sativum L.) for the fresh-cut chain using a soilless culture system

SUMMARY A soilless culture system (SCS) can improve the quality of raw material at harvest and enhance post-harvest shelf-life in many fresh-cut vegetables. Fresh-cut produce has been targeted to satisfy the increasing demand for convenience products for modern society. Recently, there has been growing interest to introduce garden cress into the fresh-cut supply chain. A standardised growing system is required to obtain suitable fresh-cut raw material in terms of marketable stage, low nitrate content, and long shelf-life. Four experiments were carried out to investigate a floating SCS and post-harvest management to produce marketable garden cress and to preserve its freshness during shelf-life. Various total N levels (6, 8, 12, or 16 mM), NO3–-N:NH4+-N ratios (25:75, 50:50, 75:25, or 40:60) in the growing nutrient solution, storage temperatures (4°C, 8°C, or 16°C), and five polypropylene (PP) films used during shelf-life, were tested. The research showed that garden cress is suitable for production in a SCS and that this technique leads to greater commercial production than soil culture, reaching > 600 g m–2 in 14 d, and > 4,700 g m–2 in 34 d. Total N at 12 mM was too high to obtain leaves with an acceptable nitrate content (< 2,500 mg kg–1 FW). Polypropylene film and storage temperature significantly influenced the loss of FW during shelf-life; however, this loss was always below 2%. The optimal storage temperature to maintain freshness was 4°C, while the five PP films tested showed inconsistent results.

Postharvest management affects spearmint and calamint essential oils

BACKGROUND The objectives of this work were to evaluate the phytomass yield, essential oil (EO) content and EO yield of Mentha spicata L. var. rubra, M. spicata L. var. viridis and Calamintha nepeta Savi in Piedmont (Italy), and to study how postharvest management (hydrodistillation of EO from fresh, dehumidified or oven-dried herbs) can affect the EO content and profile of the three species. RESULTS Mentha spicata L. var. rubra gave the greatest phytomass yield (1997 g m(-2)), which was statistically different from M. spicata L. var. viridis and C. nepeta. The highest EO yield was obtained from C. nepeta (3.75 g m(-2)), which was significantly different from the Mentha genus. Postharvest management significantly affected both the EO content and the EO profile of each species, with the dehumidifying process leading to a significantly higher EO content than the oven-drying process. The EO profile was different not only from species to species but also because of the postharvest management. CONCLUSION The dehumidifying process is a relatively new postharvest technology that has shown positive results in terms of EO yield, and it can be applied to species which have a high EO value, after evaluation of the resulting EO profile.