Effect of Compost Extract Addition to Different Types of Fertilizers on Quality at Harvest and Shelf Life of Spinach

Spinach is rich in minerals, vitamins, phytochemicals and bioactive compounds with health-beneficial effects; however, this plant also tends to accumulate oxalates nitrates their leaves. Apart from genotype, nutrition the pre-harvest factor that mostly affects quality attributes at harvest. Particularly, application of compost extracts (CE) may induce resistance against soil-borne diseases favour secondary metabolism, increasing antioxidant capacity. The objective study was evaluate effects different types fertilization or without addition CE, on harvest shelf life minimally processed spinach (Spinacia oleracea, var. Shrike RZ) stored during 12 days 4 °C. A extract prepared by mixing a agri-food wastes (vine pruning, leek waste olive mill waste) deionized water. CE foliar applications were done 28 56 after sowing. treatments applied were: Control; Control + CE; NPK (inorganic fertilizer 15-15-15); DMPP (ENTEC Nitrofoska® plus nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP)) CE. After harvest, leaves packaged generate passive modified atmosphere. Nitrate content control treatment reduced although rest treatments, did not produce any effect. For nitrite contents, lowest value obtained for Moreover, oxalate decreasing trend throughout storage. showed highest initial total phenolic very similar values end those observed all treatments. differences color as regards detected DMPP. Microbial loads increased between them. atmosphere reached cold storage same cases, CO2 O2 around 10 kPa each one °C, above limit usability, acceptable consumption. results found indicate might be convenient obtaining low concentrations antinutritional factors, affecting microbial load final product.