Efficacy of pulsed light treatment to prolong shelf-life of strawberries

DUARTE, FERNANDO; GÓMEZ, PAULA; ALZAMORA, STELLA M.

Las Vegas

Congreso; IFT 2012 -Institute of Food Technologists Annual Meeting; 2012

IFT

The effect of pulsed light (PL) on fungal decay and firmness of strawberries was investigated. The PL treatment was performed with a Xenon RS-3000B Steripulse-XL system, which generated high intensity pulsed light of polychromatic radiation (200 to 1100 nm). Samples were exposed to irradiation for 2 to 40 s at 10 cm from the lamp (fluence ranging between 2.4 and 47.8 J/cm2). Irradiated strawberries were compared to a control (non-irradiated fruit) throughout 8 days of storage at 4-5 ºC. Puncture tests were performed at selected intervals. The presence of macroscopic fungal growth was visually evaluated and the results were expressed as percentage of decayed fruit. Light microscopy observations of tissues were made after processing and storage. PL-treated strawberries at all doses tested showed a decrease in fungal growth during storage compared to non-treated fruits. There were significant differences in the mechanical behavior between control and irradiated fruits. After 8 days of storage, strawberries irradiated at the highest doses (23.9 and 47.8 J/cm2) kept firmer than control. Rheological response of treated and non-treated fruit tissues was partially correlated with the microstructure observations. Results suggest that PL treatment at an appropriate fluence could help in reducing fungal decay and maintaining firmness of strawberries during refrigerated storage.