Improving Postharvest Cabbage (Brassica oleracea L. var. capitata) Quality Using Alum and Newspaper Wrap

Three handling experiments with 4 treatments each (i.e., control, newspaper wrap, alum, alum with newspaper wrap) were conducted to verify the benefits of alum spray and newspaper wrapping in reducing soft rot incidence in cabbage (cv. Rareball). The cabbages were packed in polyethylene bags and transported from the trading post in La Trinidad, Benguet (in Northern Luzon) to Los Baños, Laguna (in Southern Luzon). In experiment A, the lowest soft rot infection upon arrival and opening of the bags was noted in heads sprayed with a single application of 15% alum and then wrapped with newspaper. The same trend was shown in experiments B and C. Alum sprayed singly resulted in slightly greater disease than when alum spray was followed by newspaper wrapping. Disease incidence, however, was lesser relative to the control heads and those which were wrapped with newspaper without alum spray. Disease reduction was more evident in the applied part (i.e., the butt end) compared to the head portion of the cabbage. Both alum spray and newspaper wrapping reduced disease incidence, the latter providing a drier condition for the cabbage during transport. Mechanical damage was least in the cabbages either wrapped in newspaper or treated with alum initially prior to wrapping. Sorting a day after removing the cabbages from the polyethylene bags can further reduce disease incidence. Alum and newspaper are readily available local materials. In decreasing the incidence of soft rot infection in cabbages, the commodity maintains the consistency of its quality and, thus, its acceptability in the market