Quality of fresh-cut radicchio cv. Rosso di Chioggia (Cichorium intybus L. var. foliosum Hegi) as affected by water jet cutting and different washing procedures

摘要

The objective of the present study was to evaluate the effect of water jet cutting (nozzle diameter 0.1 mm, pressure 2,500 bar) versus conventional blade cutting as well as washing (4 A degrees C, 120 s) prior to and after shredding on the quality of fresh-cut radicchio, respectively. For this purpose, fresh-cut radicchio cv. Rosso di Chioggia was produced on pilot-plant scale applying five different processing lines. Throughout storage (4 A degrees C, up to 12 days), O-2 and CO2 levels in the modified atmosphere of the consumer-sized sample bags were monitored, as well as phenylalanine ammonia lyase activities, levels of anthocyanins and bitter sesquiterpene lactones (SLs). Furthermore, bacterial viable counts of fresh-cut products and process waters, and the chemical oxygen demand of the process waters were assessed. Throughout storage, water jet cutting did not alter the physiological condition nor the microbiological quality of the fresh-cut produce compared to blade cutting using a newly sharpened blade. Moreover, leaching of SLs through washing was comparable in blade and water jet cut samples. Thus, a similar degree of tissue wounding due to both cutting techniques applied may be assumed. Washing radicchio prior to shredding resulted in reduced leaching of SLs and a lower degree of microbial and organic contamination of the process water. However, compared to conventional washing, pre-washing was slightly less effective in reducing microbial counts on the produce. While levels of anthocyanins remained constant throughout storage, unaffected by different processing, SL profiles substantially changed in samples of all processing lines.