Properties of acid casein gels made by acidification with Glucono-δ-lactone. 1. Rheological properties

J.A. Lucey, T. van Vliet, K. Grolle, T. Geurts, P. Walstra

Research output: Contribution to journalArticleAcademicpeer-review

141 Citations (Scopus)

Abstract

The effects of gelation temperature (20, 30 or 40 °C), assay temperature, concentration of glucono-δ-lactone (GDL) added, and NaCl concentration on the rheological properties of acid casein gels were studied at small and large deformations. Gels prepared at a high incubation temperature had very low storage moduli (G′), whereas those made at a low incubation temperature had extremely high G′ values. A higher concentration of GDL resulted in faster gelation but slightly lower G′ values of aged gels. Addition of NaCl resulted in longer gelation times and a slower rate of increase of G′. Cooling of gels prepared at 30 or 40 °C resulted in an increase in G′. However, for gels formed at 20 °C, G′ decreased initially on cooling but returned to its original value on holding at 5 °C. The loss tangent (tan δ) of gels formed at 20 or 30 °C was independent of frequency; however, for gels formed at 40 °C, tan δ was lower at low frequencies. As gels were cooled to 5 °C, tan δ increased. Fracture stress (σfr) of gels formed at 20 °C was much greater than that of the gels formed at higher temperatures. Heating gels to temperatures higher than the gelation temperature resulted in a decrease in σfr. At low gelation temperatures, young gels had very high (σfr values.
Original languageEnglish
Pages (from-to)381-388
JournalInternational Dairy Journal
Volume7
Issue number6-7
DOIs
Publication statusPublished - 1997

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