Preserving broccoli quality from harvest to retail : use of 1-MCP

Despite broccoli's image as a healthy, nutritious and flavoursome vegetable, sales in the Australian market have been constrained by poor quality at retail and disappointing shelf life. In a series of experiments across three broccoli growing regions, we tested the potential of SmartFresh™ InBox, a new delivery system for the ethylene inhibitor 1-methylcyclopropene (1-MCP), to enhance broccoli retail quality. We added 2, 4, or 8 'InBox' sachets to broccoli packed in either standard perforated low-density polyethylene (LDPE) liner or the broccoli specific 'Ripelock™' liner. Compared to untreated controls (i.e., liners alone), applying 2-4 InBox sachets, especially when combined with the RipeLock™ liner, improved the retention of green colour and overall visual quality of broccoli, thus increasing marketability by 5-7 days when heads were transported and held at 5-7°C for up to 3 weeks. In addition, the percentage of marketable heads increased from 0 to 72-100% during simulated retail display at 7°C for up to 2 weeks. There were more modest treatment differences in rots development and no differences on broccoli weight loss. Delaying application of 1-MCP by 24 h after harvest had little impact on its effectiveness. The InBox/RipeLock™ system generally provided broccoli with equal or better protection from fluctuating cold chain temperatures than the standard industry practice of top icing in polystyrene. Results suggest the InBox/RipeLock™ system can potentially replace top-icing, especially in situations of long transport/storage and/or under temperatures higher than optimal. An additional benefit is that the effects of InBox are retained once broccoli is transferred to warmer temperatures, as typically occurs during retail and consumer handling.