Management of preharvest and postharvest factors related to quality and safety aspects of leafy vegetables

M.I. Gil
The main objective for growers and processors is to guarantee the quality and safety of their products. The focus of this paper is on leafy greens, particularly fresh-cut lettuce and baby leaves, and the main causes of quality loss and food safety issues as affected by different preharvest and postharvest factors. Raw material variability remains a challenge as many preharvest factors such as genotype, environmental conditions, agricultural practices, maturity at harvest, harvest time and preprocessing handling affect quality and shelf life of the processed product. Among all pre and postharvest factors the role of water quality on the microbial and chemical safety aspects has been of great relevance during recent years. Chlorine derivatives have been the sanitizers of choice of the AgriFood sector because of their effectiveness, broad- antimicrobial spectrum and low cost. However, food alerts associated with the detection of disinfection by-products (DBPs) such as trihalomethanes and chlorates have brought their use into question. For irrigation water, several disinfection technologies, including electrolyzed water (EW) and stabilized chlorine dioxide, have been recommended as mitigation strategies to reduce microbiological contamination and the risk of exposure to plant diseases in intensive agricultural production regions. The presence of chlorates in irrigation water and/or wash water might cause chemical accumulation during crop production and/or washing; avoidance of out-of-tolerance chlorate levels favors selection of non-chlorine sanitizers. For washing fresh-cut vegetables, the use of different sanitizers based on chlorine such as sodium hypochlorite, calcium hypochlorite, chlorine gas and electrolyzed water was examined to understand the impact of: 1) the type of product; 2) the type of disinfectant including the concentration, the time elapsed from manufacture and the pH regulator; and 3) improvement in the washing process, taking into account the impact of pre-washing, water renewal rate and rinsing steps as an integration concept for the sanitation of the wash water and the prevention of DBP formation. Promotion of biodegradable and compostable packaging materials for ready-to-eat leafy vegetables to avoid introducing waste into the environment is being promoted, but packaging design and material selection are needed.
Gil, M.I. (2021). Management of preharvest and postharvest factors related to quality and safety aspects of leafy vegetables. Acta Hortic. 1319, 1-12
DOI: 10.17660/ActaHortic.2021.1319.1
genotypes, environmental conditions, agricultural practices, postharvest handling, washing, sanitizers, disinfection by-products, packaging

Acta Horticulturae