GAINESVILLE, FLStrawberries are very fragile and highly susceptible to mechanical injury during commercial production. Growers interested in ways to increase profits and reduce product loss are seeking improved handling and temperature management techniques. Collaborative research from scientists from the Brazilian Agricultural Research CorporationEmbrapa and the University of Florida contains several findings that show promise to significantly improve commercial strawberry handling.
Because of their fragile nature, strawberries must be harvested when they are ripe to minimize bruising, a critical concern leading to product and revenue losses for growers. Bruising is caused by impact, compression, and vibration forces. Impact bruising results from a sudden sharp forcefor example when a fruit falls onto another fruit or onto a hard surface, or when an object strikes the fruit. Compression bruising occurs when tissue is subjected to a constant force such as during hand-harvest (finger pressure), or when the fruit is on the bottom layer of a container.
To replicate commercial handling conditions, the research team used forced-air or hydrocooling with three strawberry cultivars ('Chandler', 'Oso Grande', and 'Sweet Charlie') to reach pulp temperatures of 1 or 30C, then subjected the fruit to compression and impact forces. The fruit was subsequently evaluated for bruising; each berry was sliced through the center of the impact area and was considered to be bruised if damaged tissue was visible below the impact area.
Strawberries with a pulp temperature of 24C exhibited sensitivity to compression but greater resistance to impacts. As pulp temperature decreased, fruit were less susceptible to compression, as shown by up to 60% reduction in bruise volume. In contrast, strawberries at 1C pulp temperature had more severe impact bruising, with up to 93% larger bruise volume than at 24C, depending on the cultivar.
|Contact: Michael W. Neff|
American Society for Horticultural Science