Bruin verkleuren en slap worden van sperziebonen: September 2016

Browning is considered to be the most important quality-limiting factor in green beans for both the fresh and cut bean markets. For the fresh market, we determined the duration at which green beans can be stored at optimal and suboptimal temperatures while retaining an acceptable quality. Furthermore we assessed the effects of bean surface moisture and a decontaminating washing step on bean browning during storage. For cut bean market, we determined the duration green beans can be stored at 3°C prior to cutting and packaging and still retain an acceptable quality after a 7 day shelf life period. The experiments were carried out using both the fresh market cultivar ‘Domino’ and the cut market cultivar ‘Stanley’. Besides browning, the occurrence of loss of firmness limited the quality of fresh beans considerably. Both cultivars were able to cope with 2 days storage at 3 - 9°C while retaining an acceptable quality. Despite ‘Domino’ having a better quality score than ‘Stanley’, both cultivars obtained an acceptable score. For ‘Domino’ loss of firmness was the most important factor limiting quality, while in ‘Stanley’ browning was more limiting. Both cultivars could not withstand 4 days of storage without loss of quality. Bean surface moisture due to condensation or washing limited browning, but increased loss of firmness. Decontaminating the beans did not influence the quality of fresh green beans. Neither washing, condensation or decontamination affected the percentage of intact beans. Concerning cut and packaged beans, the maximum storage time of green beans at 3°C prior to cutting and packing, followed by a shelf life of 3 days at 4°C plus 4 days at 7°C, was determined. ‘Domino’ could be stored 2 days at a maximum with an acceptable loss of quality; ‘Stanley’ resisted 4 days storage without quality loss and 7 days with an acceptable quality loss according to the standards of Bakker Barendrecht.