EFFECT OF PRACTICING OF MICROWAVE THAWING ON QUALITY OF CONCANTRATED FRUIT JUICES
Project no. 1310 · Status: Kapanmış · 2016
Summary
In the food industry, though clarified fruit juices can be concentrated up to high brix values, pulpy fruit juices can be concentrated up to low brix values. For this reason, after concentration process, concentrated pulpy fruit juices are frozen to prevent microbiological deterioration and quality loses. However, traditional thawing methods cause loss of nutritional value and organoleptic properties of the food product. In recent years, the novel thawing methods have been developed to prevent unfavorable changes in food quality caused by traditional thawing methods. Microwave thawing is one of the emerging thawing methods could be alternative to traditional thawing methods. The aim of this study is to investigate the effects of microwave thawing and room temperature thawing methods on the some quality properties of frozen concentrated apricot and peach juices and to specifiy the proper process. However, the vitamin C content of peach juice was retained by microwave thawing method. It was verified that thawing methods applied had no effect statistically important on the pH and total acidity values of concentrated apricot and peach juices. The impact of microwave and room temperature thawing methods on the color of concentrated apricot juice was found to be statistically significant. However, it was determined that the both of thawing methods had similar effect on the color values of concentrated apricot juices. After the thawing processes applied, the color values (L*, a*, b*) of concentrated peach juices was increased dramatically when compared to control sample. It was verified that the difference between thawing methods was statistically important. In conclusion, it was confirmed that microwave thawing and room temperature thawing methods had similar effect on the physicochemical properties and bioactive compounds analyzed of concentrated apricot and peach juices. However, microwave thawing method shortened the thawing time required significantly. Microwave thawing method was determined to be feasible and a promising method to fruit juice industry in thawing of concentrated pulpy fruit juices.