FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY

Authors

DOROTA WALKOWIAK-TOMCZAK

Title

The effect of freezing process on quality of estructured strawberries

Abstract

Restructuring makes it possible to utilize less valuable raw material and waste products, providing them with an attractive form. Restructured products may be dried, frozen or heated. Restructured fruit is used as filling for pies and cakes, or additives for ice-creams, desserts or yoghurts. The aim of the presented study was to determine the effect of the freezing process on the quality of restructured strawberries produced by internal setting. Products were subjected to sensory examination of colour, taste and aroma, and instrumental measurements of colour and texture, before freezing and after defrosting. Three groups of products were analyzed, differing in the content of fruit puree (66, 76, 86 g/100g) and sucrose (30, 20, 10 g/100g, respectively). Quality of produced fruit depended on its composition (strawberry mash content). Taste and aroma in all samples, both before and after freezing, received high scores, apart from samples with the highest fruit puree content, in which taste and aroma, as well as colour and texture were found to deteriorate. The change in values of colour parameters (XYZ, L*a*b*) indicated slight darkening of samples and changes in the colour tone towards yellow, which was probably connected with enzymatic browning. On the basis of instrumental texture analysis it was found that hardness of fruits after defrosting was by 50% lower in comparison to original samples. In spite of these changes, products received good scores in sensory analysis of desirability, ranging from 3 to 5 points, depending on the fruit puree content.

Keywords

strawberries, restructured fruit, alginate, freezing

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