Low irradiance pulses improve postharvest quality of spinach leaves (Spinacia oleraceae L. cv Bison)

• Published in: Postharvest biology and technology 2013-03, Vol.77, p.35-42
• Main Authors: Gergoff Grozeff, Gustavo E., Chaves, Alicia R., Bartoli, Carlos G.
• Format: Article
• Language: English
• Subjects: Ascorbic acid; Biological and medical sciences; Ethylene; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Glutathione; Light pulses; Senescence; Spinach
• ISSN: 0925-5214; 1873-2356
• DOI: 10.1016/j.postharvbio.2012.10.012

► Spinach leaves were treated with low light brief pulses (LPs) during dark storage. ► LP delayed the progress of spinach senescence increasing antioxidants during storage. ► LP applied with 1-MCP (LP+MCP) duplicated glutathione accumulation. ► In addition LP+MCP kept ascorbic acid content, highly reduced like leaves at harvest. The aim of this work is to extend and improve the postharvest life of mature spinach leaves using clean technologies like the use of short pulses of light at low irradiance. After harvest spinach leaves were immediately sealed in polyethylene bags in the laboratory. These bags were placed in a dark chamber at 23°C under continuous dark or with the application of light pulses (LP) consisting of 15min each 2–6h or 7min each 2h for 3d. The chosen irradiance, 30μmolm−2s−1 PPFD, corresponded to the light compensation point previously measured in spinach plants under greenhouse conditions. After the leaves were treated with LP for 3d, all the samples were transferred to a chamber at 4°C under continuous dark for another week. Senescence was triggered in leaves under continuous dark after 3d of storage and delayed in those receiving LP. In addition ascorbic acid and glutathione contents were kept higher in LP-treated than in untreated spinach. These trends were conserved after storage under continuous dark and refrigeration for another week. When LP was applied in combination with 1-MCP the antioxidant capacity was further improved. These results demonstrate that short LP of low irradiance can be used to extend and to improve postharvest life of mature spinach leaves.