FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY

Authors

KATARZYNA SKUPIEŃ, BARBARA WÓJCIK-STOPCZYŃSKA

Title

Quality estimation of ‘Kent’ cultivar strawberry homogenates

Abstract

The objective of the study was to determine quality changes of fresh and frozen (after 6 and 12 months of storage) ‘Kent’ cultivar strawberry homogenates. There were 3 variants of purée prepared: without sugar, with 5% and 10% sugar addition. Dry weight, vitamin C, total polyphenol and total acidity were determined. Further both in fresh and frozen homogenates (after 2 days, 6 and 12 months) total count of mesophilic aerobic bacteria, yeasts and moulds as well as coliform and enterococci titre were estimated. During 12 months of freeze-storage the least alterations were found for total acid and dry weight content and the greatest for vitamin C content. The highest decline of vitamin C content was noticed during first 6 months of storage. Sugar addition did not influence vitamin C level during pulp freeze-storage. Neither sugar addition, nor time of storage exerted significant influence on total polyphenol content in purée obtained from this cultivar. Protective effect of sugar towards microorganisms was observed in the process of freezing and freezing storage. It was reflected in higher bacteria, yeasts and moulds counts in homogenates with 5 and 10% of sugar supplement compared to non-sugar variant. In all freshly frozen homogenates the total number of bacteria was releatively low (the level 103 cfu g-1) but contamination by moulds and yeasts was high (>103 cfu g-1). After 6 months of freezing storage practically only rudimental fungal flora in all homogenates was observed and the number of bacteria reduced to the level 101 and 102 cfu g-1 respectively in variant without sugar and in homogenates with its addition.

Keywords

strawberry, fresh and frozen homogenate, nutritive constituents, microbiological quality

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