PREDICTION OF SPINACH QUALITY BASED ON PRE- AND POSTHARVEST CONDITIONS

Autor: Judith A. Jernstedt, Trevor V. Suslow, E. Gutiérrez-Rodríguez, J.H. Lieth
Rok vydání: 2012
Předmět:
Zdroj: Acta Horticulturae. :1141-1148
ISSN: 2406-6168
0567-7572
DOI: 10.17660/actahortic.2012.934.153
Popis: Nitrogen amendments and water availability have a significant effect on the nutritional quality of spinach. Despite this established knowledge, the specific influence of these interacting factors on overall postharvest quality is poorly understood. Determined by interviews with multiple growers, current agronomic practices in California and Arizona routinely include the application of 100 to 350 kg/ha total N. Preharvest trials and postharvest evaluations with field and hydroponically-grown spinach were conducted to elucidate how this fertility management practice influences quality. Additionally, quantitative evaluations were performed to identify predictors of market quality at harvest and during storage. Preharvest nitrogen availability greater than 100 ppm coupled with high temperature during cultivation reduced the overall quality of spinach. Color (hue) of spinach grown under various N rates and stored at 7.5°C (in perforated polymer-film packaging) did not reliably predict the key phytonutrient composition and marketable shelf life. Marketable shelf life was initially defined as a combination of visual quality score (OVQ) ≥6.5 (on a 9 point hedonic scale), decay 3.5 mg/g FW at harvest were negatively associated with quality retention. Although storage temperatures significantly affect quality retention in spinach, the initial quality at harvest is the main factor that influences inherent postharvest potential. Spinach pre- and postharvest quality is best predicted by analysis of TOA, sugar concentrations and the relationship between ammonium and GS at harvest while during storage OVQ, TOA and ammonium concentrations were practical descriptors of marketable shelf life.
Databáze: OpenAIRE
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