Shelf life of broccoli in different packages stored under two temperature regimes

Broccoli (Brassica oleracea var. italica) is a perishable vegetable with limited shelf life, and improved postharvest routines are needed in order to reduce food waste. Although storage at 0-1°C is recommended, broccoli is commonly exposed to a wide temperature range from harvest to consumption in Norway. The aim of this study was to evaluate the performance of three different packaging materials for broccoli, with unpackaged product as control, under conditions that simulate transport, distribution, retail sale and consumer storage. Quality and shelf life were evaluated during 16 days of storage in darkness at 4°C (‘Cold storage’) or during 4 days in darkness at 4°C + 3 days in light at 19°C + 9 days in darkness at 4°C (‘Realistic storage’). The different packages were 1) polypropylene (PP) flowpack film with 40 needle perforations per package, 2) PP flowpack film with a row of 560 needle perforations per 10×10 cm in the middle, and 3) polyethylene (PE) cling film. The respective weight losses for packaged and unpackaged broccoli were <1.2 and 16% after ‘Cold storage’ and <4 and 27% after ‘Realistic storage’. Temperature had little effect on the firmness of broccoli heads, whereas packaged broccoli retained firmness better than unpackaged broccoli. Development of decay (mold, soft rot) was observed in all packaged products during ‘Realistic storage’. ‘Realistic storage’ resulted in severe yellowing of the broccoli flower buds, whereas packaging had little effect on colour deterioration. The results demonstrate the importance of packaging to prevent weight loss and retain firmness in broccoli, but none of the packages tested could prevent yellowing or decay development during the period at room temperature. Hence, to prolong shelf life, broccoli should be packaged and kept cold during the whole distribution chain, including retail display.