Phyto-squalane: A new active ingredient to prevent superficial scald on pears

Abstract

Superficial scald (SS) is a detrimental postharvest physiological disorder on apples and pears during mid and long-term cold storage. Since diphenylamine (DPA) and ethoxyquin were banned from European markets, there has been an active search for new chemical alternatives. Different phyto-squalane (PSQ-E) treatments (0.1–4.0% w/v) applied at harvest were evaluated in pears from different growing areas and harvest maturity during four consecutive seasons. Fruit quality (external appearance, firmness, soluble solids, ethylene production), SS development, and biomarkers for SS (α-farnesene, CTols) were evaluated at different times during cold storage (up to 210 d, −0.5 to 0.5 °C, > 90%RH). In general, PSQ-E emulsions (0.1–4.0% w/v) applied at harvest were able to significantly reduce or completely prevent SS development in pears from different growing areas, seasons, and maturity levels at harvest. Treated fruit had reduced levels of conjugated trienes (TC281, TC269), but not α-farnesene content. PSQ-E treatments reduced fruit softening, de-greening, and ethylene production compared to the untreated control (UTC) or DPA. Phyto-squalane is a novel new active ingredient that could replace current crop protectants, such as diphenylamine and ethoxyquin, to control superficial scald on pears.