Nitrate in fruits and vegetables

• Published in: Scientia horticulturae Vol. 237; pp. 221 - 238
• Main Authors: Colla, Giuseppe, Kim, Hye-Ji, Kyriacou, Marios C., Rouphael, Youssef
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 14.07.2018
• Subjects: air; buds; calcium; carbon dioxide; cultivars; Fertilization; fruit products; fruits; fungi; Genotypes; green leafy vegetables; herbs; Horticultural crops; inflorescences; leaf development; Light; light intensity; molybdenum; morphs; Mushrooms; Nitrates; nitrites; nutrients; photoperiod; photosynthesis; plant growth; plant tissues; root zone temperature; roots; Salinity; seeds; stems; storage conditions; tubers; turgor; Fertilization; Mushrooms; Light; Horticultural crops; Nitrates; Genotypes; Salinity
• ISSN: 0304-4238; 1879-1018
• DOI: 10.1016/j.scienta.2018.04.016

•Scientific advances on nitrate accumulation in plant tissues are reviewed.•Genetic, agroenvironmental and postharvest factors are critically examined.•Horticultural commodities are classified based on nitrate level of edible product.•The physiological and developmental role of nitrate as osmoticum is examined.•Nitrate management practices and future research warranted are highlighted. The current article provides an updated review of scientific advances regarding nitrate accumulation in plant tissues and a critical examination of the genetic, agroenvironmental and postharvest factors that can modulate nitrate levels in a wide range of horticultural crops, including herbs, roots and tubers, inflorescences, buds, seeds, stems, and leafy vegetables, fungi as well as fruits. A refined classification of horticultural crops is presented according to the nitrate content of their edible product. The role of plant cultivar/morphotype and tissue age in nitrate accumulation is discussed along with the physiological role of nitrate as osmoticum in maintaining turgor and driving leaf expansion under conditions of variable photosynthetic capacity. Nitrate accumulation is examined in respect to key cultural practices, such as the timing-rate-form of N application and the use of plant biostimulants (natural substances and microbial inoculants), as well as the potential interaction with other nutrients (e.g., P, Ca, Mo and Cl). The influence of environmental conditions during plant growth (light intensity, spectral quality, photoperiod, air and root-zone temperature and atmospheric CO2 concentration), harvest stage and diurnal timing of harvest is assessed. Postharvest storage conditions (temperature, light, and duration) are discussed in respect to their effects on the putative endogenous conversion of nitrate residues to nitrites. Several approaches that may be adopted to reduce nitrate content in vegetables, fruits and herbs are analysed and warranted future research subjects are identified.