Application of Electromagnetic Radiations and Superheated Steam for Enzyme Inactivation in Green Bell Pepper.

The effect of electromagnetic radiation (microwave and infrared) based dry
blanching and superheated steam enzyme inactivation on product quality of green
bell pepper was evaluated and the performance was compared with that of water
and steam blanching. Processing conditions (time and temperature) were standardized
mainly on the basis of degree of inactivation of peroxidase enzyme.
Superheated steam and water blanching required lesser duration (110 and 140 s,
respectively) when compared to steam (180 s), microwave (230 s) and infrared
(580 s) blanching. The retention of ascorbic acid (91.1%) and soluble protein
(91.6%) was higher in microwave and superheated steam-blanched slices, respectively.
Although texture of infrared blanched slices was firmer compared to
unblanched as well as blanched by other methods, it had higher retention of
β-carotene (131.2%) and chlorophyll (136.4%) compared to unblanched.
PRACTICAL APPLICATIONS
Blanching is one of the preprocessing steps before drying, freezing and canning of
most of the vegetables. Conventional water and steam blanching has many drawbacks
such as loss of water soluble nutrients and effluent generation. The electromagnetic
radiation-based dry blanching methods employed in the present study
can overcome these drawbacks and result in a continuous process. This study also
explored that superheated steam blanching can be effectively used for enzyme
inactivation which in turn requires lesser processing time besides minimizing the
loss of nutrients. This research area has ample scope for further studies and the
techniques have great potential to be used as an alternative to conventional
blanching methods.