Study Of An Innovative Combination Between Microwaves And Enzymes Applied To Bakery Products

摘要

Microwave food processes offer a lot of advantages such as less start-up time, faster heating, energyefficiency, space savings, precise process control, selective heating and food with high nutritional quality.However, microwave baked products have quality problems: reduced height of the product, dense or gummytexture, crumb hardness, an undesired moisture gradient along a vertical axis in the final baked product andno browning on surface of product.The aim of this research was to combine enzymatic and microwave treatments in order to improve productsbaked by microwaves. For this purpose the single and interactive effects of some commercial enzymesactivity (amylase, glucoamylase and protease) and processing parameters (power % and time of enzymaticpre-treatment) on production of reducing sugars, colour and structural characteristics of cookie roasted bymicrowaves (bulk density and breaking strength) were evaluated.This research was carried out on model system (like wafer) made up of running water and wheat flourwithout ingredient normally used to produce wafers in order to better understand the effect of enzymeactivity on biopolymers of flour in absence of other substances that could influence enzymatic kinetic.The best operating conditions, to obtain a good colour and the lowest bulk density (0.38 g/ml) of samples,were the highest time of enzymatic pre-treatment (30 minutes) and power percentages of 90%. All enzymeshad a positive effect on production of reducing sugars, colour and texture of samples only if added togetherand at middle amounts (0.5 g/kg protease and 0.05 g/kg amylase and glucoamylase). Moreover, the proteaseshowed a positive and significant effect on decrease of breaking strength values.