Alternative treatments for the control of postharvest physiological deterioration (PPD) in cassava (Manihot esculenta Crantz) through the induction of resistance to oxidation

Abstract

Introduction. Postharvest physiological deterioration (PPD) poses a major constraint to the commercialization of fresh cassava roots (Manihot esculenta Crantz), particularly in international markets seeking environmentally friendly and synthetic-free products. Objective. To evaluate the effectiveness of alternative treatments (ethanol, citric acid, and sodium metabisulfite) for inducing oxidative resistance in cassava roots (Valencia variety) as a strategy to control PPD. Materials and methods. Two trials were conducted: A) The first one developed a visual scale for PPD severity under different storage temperatures and durations; B) The second one assessed the impact of postharvest treatments on physical (incidence, severity, weight loss, respiration, luminosity) and chemical parameters (antioxidant capacity, total phenolic content). Results. Our results showed that 70% ethanol and 250 ppm sodium metabisulfite significantly reduced PPD incidence and severity, with effects comparable to paraffin, yet without its environmental drawbacks. Storage at 15 °C resulted in lower deterioration compared to 5 °C, suggesting that low temperatures may adversely affect cassava root physiology. Conclusions. Our findings support the use of sustainable alternatives to paraffin for extending the postharvest shelf life of cassava intended for export.