ISSN:
1750-3841
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Lipoxidase demonstrated a typical protein inactivation response to heat as a function of pH when heated at 65°C and 0.1 molar buffer. The enzyme was found to be very sensitive to ionizing energy when irradiated in pH 7 buffer. This sensitivity was shown by a relatively low D, value (9 × 104 rad) and a rapid loss of enzyme activity during post-irradiation storage. The results of combined treatment of the enzyme, in buffer, by heat and radiation showed that treatment order was important. Heating prior to irradiation produced inactivation proportional to the sum of the separate treatments, whereas the reverse order produced inactivation greater than that calculated from the effect of each treatment. This is in agreement with the above, where post-irradiation storage at 0°C may be likened to a mild heat treatment. Addition of 20% pea solids to a. buffered solution of the enzyme afforded a six to ten fold protection with respect to inactivation by heat, and a seventy fold protection against inactivation by ionizing radiation. Combined heat and irradiation treatment of soybean lipoxidase, in the presence of 20% pea solids, showed that, in contrast to the results obtained in buffer, heat prior to irradiation produced greater enzyme inactivation than the reverse order of application of the two types of energy.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.1962.tb00091.x
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