Production and Postharvest Assessment of Tropical Pumpkin Flowers Harvested for Consumption

Abstract

Consumption of staminate (male) flowers of squash and pumpkin (Cucurbita sp.) has generally been limited to summer squash (Cucurbita pepo), a species of temperate regions or highland tropical environments. In the lowland tropics of the Caribbean Basin, tropical pumpkin (Cucurbita moschata) is better adapted and more widely grown. We evaluated flower production in Lajas, Puerto Rico, and postharvest attributes (shelf life, chemical and nutritional properties, sensory quality) of flowers of four tropical pumpkin and two summer squash cultivars. Tested cultivars varied slightly among experiments. Passive and active modified atmosphere packaging (MAP) were compared. For passive MAP, packages were sealed without further intervention. Under active MAP, packages were adjusted to 6% to 7% oxygen (O2) and 12% to 13% carbon dioxide (CO2) during sealing. Sensory quality of fresh and canned tropical pumpkin flowers was evaluated by panelists. Production ranged from 1.8 to 4.0 flowers/plant per day. Flower weight and length were up to 50% greater in tropical pumpkin compared with summer squash. Packaged flowers turned more orange but with less color saturation as they aged. In active MAP packages, decreases in O2, and increases in CO2 observed after 5 days were small or not significant compared with initially established atmospheres at day 0. Storage temperature generally had no effect on changes in O2 and CO2. Packaged flowers lost about 27% of their initial weight after 5 days. Type of MAP had no consistent effect on the appearance of packaged flowers. Storing flowers at 5 °C often improved appearance compared with storage at 10 °C. The rate of deterioration was slower in packaged flowers of tropical pumpkin compared with summer squash, but by day 6 the poor appearance of flowers of all cultivars made them unmarketable. Compared with fresh flowers, packaged flowers stored for 5 days exhibited a decrease in soluble solids, total acidity, ascorbic acid, antioxidant capacity, and total phenolics, and generally an increase in pH. Beta-carotene often increased in stored flowers although this varied by cultivar. Storage temperature and type of MAP had inconsistent effects on chemical attributes of stored flowers. Panelists rated fresh flowers as “like moderately” to “like very much” for texture, taste, and overall acceptability, whereas canned flowers were rated as “like moderately” for overall acceptability. Male flowers of tropical pumpkin are suitable for human consumption but deterioration after 5 days of storage limits their market potential unless better packaging methods are developed. Canned tropical pumpkin flowers may be an alternative to packaged flowers.