Residual peroxidase activity as influenced by blanching, SO₂ treatment and freezing of cauliflowers

Abstract

ABSTRACT

Evolution of ascorbic acid and peroxidase during industrial processing of broccoli

“…Also in cauli¯ower, Ramaswamy and Ranganna 21 found similar results to ours, in that peroxidase activity was maintained more in stems than in¯owers. These authors found that the sensorial quality of frozen cauli¯ower was related to residual levels of peroxidase activity, which ranged from 1 to 5.5%.…”

Effects of Blanching Method on the Quality Characteristics of Frozen Peas

“…Storage time had no effect on the texture of peas (data not shown). This is in contrast to the results reported by Ramaswamy and Ranganna (1989) where storage time and freezing negatively affected the texture of carrots and sweet potatoes. Unblanched peas were the toughest on both initial and consecutive bites, and were also the most intact internally (Table 3).…”

“…All blanched treatments at all storage times had peroxidase activity of <85 units. While, in some cases, enzyme activity appears to regenerate over time (Pinsent 1962; Ramaswamy and Ranganna 1989), that was not observed in this study. The lack of regeneration during frozen storage is not entirely without precedent.…”

Assessment of Enzymatic Browning and Evaluation of Antibrowning Methods on Dates

“…This suggests that modification in enzyme structure took place at the time of treatment. Similar results were reported with foliage [31] and cauliflower treated with SO 2 [32]. In addition, incomplete inactivation of POD enzyme could be attributed to presence of POD isoenzymes with limited presence of thiol/disulfide bonds in POD enzymes; therefore, nominal effect was seen by the treatment.…”