Location: Food Quality Laboratory
Title: Effect of light exposure on sensorial quality, concentrations of bioactive compounds and antioxidant capacity of radish microgreens during low temperature storage Authors
Submitted to: Journal of Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 28, 2013
Publication Date: November 22, 2013
Citation: Xiao, Z., Lester, G.E., Luo, Y., Xie, Z., Yu, L., Wang, Q. 2013. Effect of light exposure on sensorial quality, concentrations of bioactive compounds and antioxidant capacity of radish microgreens during low temperature storage. Journal of Food Chemistry. 151:472-479. Interpretive Summary: Microgreens, a new class of leafy vegetables, are becoming increasingly popular among health conscious consumers. However, optimal commercial handling practices that maintain quality and nutritional value are lacking. USDA-ARS, Food Quality Laboratory scientists determined optimal storage and retail conditions for packaged daikon radish microgreens. These included use of film bags highly porous to oxygen and storage in darkness at refrigeration temperature during distribution and retail display. Under these conditions, radish microgreens retained product quality and shelf life, and health promoting compounds such as vitamin C and E. These research findings benefit growers, distributors, and retail store managers.
Technical Abstract: Daikon radish microgreens constitute a good source of bioactive compounds. However, the quality deteriorates rapidly during postharvest storage. In this study, we investigated the effects of light exposure and modified atmosphere packaging conditions on changes in sensorial quality and retention of bioactive compounds and antioxidant capacity during storage. Radish microgreens were packaged in polyethylene film bags with an oxygen transmission rate (OTR) of 29.5 pmol s-1 m-2 Pa-1 or in micro-perforated bags. The packaged microgreens were placed in either continuous darkness or under white light (30 µmol·s-1·m-2) at 5 °C for 16 days. Results showed that light exposure during storage increased ascorbic acid concentration but had no effect on a-tocopherol or total phenolic concentrations. Dark versus light storage resulted in higher hydroxyl radical scavenging capacity and carotenoid retention, but had no effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity. Packaging radish microgreens with selected OTR films maintained quality and extended shelf life better than storage in micro-perforated bags under both light and dark conditions. On the basis of these findings, it is recommended that radish microgreens be packaged in relatively high OTR bags and stored in darkness at refrigerated temperatures during postharvest handling, transportation, and retail display.