Production and Application of Active Packaging Film with Ethylene Adsorber to Increase the Shelf Life of Broccoli (Brassica oleracea L. var. Italica)

摘要

Broccoli (Brassica oleracea L. var. Italica) florets were packaged in low-density polyethylene (LDPE) bags with or without ethylene adsorber under passive modified atmosphere and then stored at 4℃ for 20 days. LDPE films with (8％ Tazetut~® masterbatch, M2) or without ethylene adsorber (M1) were tested. The effects of modified atmosphere packaging treatments on gas concentrations (O_2, CO_2 and ethylene) in the headspace, the mass loss, colour, texture, pH, total soluble solids, chlorophyll content, total phenolic content and sensory quality of packaged broccoli were determined by comparing with unpackaged (control) florets. Results revealed that deterioration occurred quickly in control broccoli, manifested mainly by mass loss, chlorophyll degradation and stem hardening. Also, it was found unacceptable by sensory panel after 5 days. Conversely, in those florets packaged under modified atmosphere packaging, especially for LDPE with ethylene adsorber (M2), all changes related with loss of quality were significantly reduced and delayed with time. Additionally, total soluble solids and total phenolic content remained almost unchanged during the whole period. Ethylene concentration was determined as 61.8 ppm in Ml and 0.33 ppm in M2, respectively, at the end of the storage. Thus, broccoli packaged with M2 firms had prolonged storability up to 20 days with high quality attributes, this period being only 5 days in unpackaged control broccoli. Oxygen concentration decreased below 1％ after 5 days of storage in Ml, and the shelf life of broccoli in these bags was limited to 5 days because of risk for anaerobic fermentation.