Monitoring the effects of divalent ions (Mn+2 and Ca+2) in heat-set whey protein gels

Öztop, Halil Mecit
MCCARTHY, Michael J.
Exploring the effects of cations in whey protein-based gels (WPG) is of importance when these gels are used for controlled release applications in food systems. The objective of this study was to evaluate both water uptake and cation release from heat-set WPGs. Magnetic Resonance Imaging and NMR relaxometry were employed to study the uptake and release. A non-paramagnetic (Ca+2) and a paramagnetic cation (Mn+2) were incorporated into the WPG as model divalent cations. Cylindrical pieces of WPGs with manganese were immersed in water (pH 2.40, 7.00, 10.40) or in EDTA solution whereas WPGs with calcium were immersed in water at pH 2.40. Water uptake by the gels was influenced by both ionic environment and pH. The release of Mn+2 from WPG was enhanced by the presence of EDTA. Relaxation spectra of Mn+2-loaded gels were significantly influenced by pH of the suspending fluid and by the presence of EDTA. Results of relaxometry experiments, obtained with Ca+2-loaded gels immersed in water at pH 2.40, indicated a strong correlation (R-2 > 0.99) between relative areas of the proton pools and the amount of calcium released to the medium. Results support the use of MRI and NMR to monitor cation release and water uptake in WPG, non-destructively.


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Gels prepared from whey proteins can be used for controlled release of nutrients or active ingredients in food systems. The objective of this study was to characterize the water uptake by these hydrophilic gels to aid in the design of release systems. Whey protein isolate (WPI) gels (17% w/w protein) of different aspect ratios were submersed in aqueous solution at pH 7.0. Modeling of mass uptake is presented in terms of Case I (Fickian diffusion) and Case II (kinetic) models. Due to the extent of swelling, ...
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Filtration rate and resistance are affected by the operations prior to filtration in fruit juice production lines. In this research, the effects of depectinization and clarification on filtration resistance and rate were evaluated. Filtration studies on raw juice, depectinized juice and depectinized plus clarified juice were compared It was observed that pretreatments reduce the resistance considerably.
Correlation between physical and sensorial properties of gummy confections with different formulations during storage
Tireki, Suzan; Şümnü, Servet Gülüm; Şahin, Serpil (Springer Science and Business Media LLC, 2021-01-01)
Gummy confections are popular products formulated with sucrose, glucose syrups, gelling agents, acids, flavourings and colouring agents. They have various commercial types in terms of formulation, texture, taste and colour, however, there is inadequate investigation on storage behavior of these products. The aim of this study is to investigate the effects of glucose syrup:sucrose ratio (1.1 and 1.5), starch (0% and 1.5%) and gelatine concentration (3% and 6%) on texture profile, colour and sensory propertie...
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In this study, the production of citric acid has been achieved by using Aspergillus niger conidiaspores, entrapped in polyacrylamide gels, and the factors that affect this production have been investigated. On citric acid production the effect of starting sucrose concentration (100-180 g/l), the initial nitrogen concentration (0-0.3 g/l), the effect of the methanol concentration in 100ml feeding medium (0-6 ml), and finally the effect of ethanol concentration (0-6 ml) in 100 ml feeding medium were studied a...
Citation Formats
H. M. Öztop, M. J. MCCARTHY, and M. ROSENBERG, “Monitoring the effects of divalent ions (Mn+2 and Ca+2) in heat-set whey protein gels,” LWT-FOOD SCIENCE AND TECHNOLOGY, pp. 93–100, 2014, Accessed: 00, 2020. [Online]. Available: