Effect of freezing prior to ripening on the peptid

Authors: Bárbara E Meza Roxana A Verdini Amelia C Rubiolo

Publish Date: 2013/05/30

Volume: 93, Issue: 6, Pages: 691-698

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Abstract

Freezing was proposed as an alternative preservation technique to extend the shelf life of soft cheeses However the freezing process freezing frozen storage and thawing can affect a number of cheese quality parameters such as the watersoluble nitrogen content at pH 46 which is related to the maturation index of cheeses The objective of this work was to assess the effect of the freezing process prior to ripening of lowfat soft cheese containing microparticulated whey proteins as fat replacer The freezing process consisted of freezing at −25 °C frozen storage at −25 °C during 33 days and thawing at 6 °C Refrigerated cheeses stored at 6 °C were selected as control samples Highperformance liquid chromatography was used for analyzing the evolution of peptides present in the watersoluble fraction at pH 46 at different ripening times Principal component analysis was applied to reduce the dimensionality of the data obtained from chromatograms Results indicated that peptide profile was affected by the freezing process Areas of peaks with hydrophilic characteristics increased during the ripening time from 1 to 48 days in both refrigerated and frozen cheeses Furthermore areas of hydrophilic peaks were higher in frozen cheeses than in refrigerated cheeses at 21 and 48 days of maturation However areas of peaks with hydrophobic characteristics increased in refrigerated cheeses but stayed invariable in frozen cheeses during all the studied ripening periods In this case areas of hydrophobic peaks were lower in frozen cheeses than in refrigerated cheeses at the same day of ripening timeThis work was done with the financial support of Universidad Nacional del Litoral Consejo Nacional de Investigaciones Científicas y Técnicas and the Agencia Nacional de Promoción Científica y Tecnológica of Argentina The authors acknowledge Dr Guillermo A Sihufe for technical assistance in RPHPLC tests

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