HOT-WATER DIPS EXTEND THE SHELF-LIFE OF FRESH BROCCOLI

Freshly harvested heads of 'Cruiser' or 'Paragon' broccoli (Brassica o leracea L. Italica group) were heat ed by immersing in water at 42, 45 , 48, 50, or 52C. Immersion times were decreased as treatment temperat ures were increased and ranged from 20 to 40 minutes at 42C to 1 to 3 minutes at 52C. Control heads, dipped in 25C water for 0, 10, or 40 mi nutes, began to turn yellow after approximate to 3 days storage at 20C and 80% to 90% relative humidity. Immersion in 42C water delayed yell owing by 1 or 2 days; immersion in 45 48, 50, or 52C prevented yellowi ng for ($) under bar< 7 days. Water loss of broccoli during storage at 20C increased by ($) under bar< 1% per day by some hot-water treatmen ts. Immersion in hot mater decreased the incidence of decay during sto rage at 20C. Immersion in 50 or 52C water for 2 minutes was most effec tive in controlling decay development. Broccoli immersed in 52C water for 3 minutes had a distinct off-odor. Control and treated broccoli he ld at 0C for 8 days following hot-water dips were similar in quality. Yellowing of heat-treated broccoli was inhibited when broccoli was war med to 20C following storage at 0C. Hot-water treatments also delayed senescence at 20C when broccoli was treated following 3 weeks of stora ge at OC. Immersion of broccoli in 50C water for 2 minutes was the mos t effective treatment for reducing yellowing and decay while not induc ing off-odors or accelerating weight loss.