Changes in Soluble and Bound Peroxidases During Low‐temperature Storage of Green Beans

Storage of green beans at 5°C or ‐4°C significantly affected the distribution of peroxidase fractions. Activity of the soluble peroxidase fraction, extracted with a low ionic strength buffer, decreased while the ionically bound peroxidase fraction extracted with 1M sodium chloride increased with time. This behavior was particularly noticeable at ‐4°C. The covalently‐bound fraction, extracted after treatment with cellulase and pectinase, remained constant during storage at all temperatures. Storage at ‐40°C had no effect on the distribution of the peroxidase fractions. The relative concentrations of isoperoxidases present in each peroxidase fraction changed with storage time; however, no new isoperoxidases appeared and none disappeared as a result of the treatments applied.