Dr Yacine Hemar
Research | Current
My research interests are related to the physical-chemical characterisation of food systems such as proteins and polysaccharides and their mixtures in solution, gel or emulsion states. Of specific interest the Structure-Function properties of biopolymer networks, and how these properties are affected by different stressors, such as shear, heat, pH etc.
- Milk Protein, Polysaccharides and Milk Protein-Polysaccharide Interactions
The aim of this activity is to characterise the physico-chemical characterisation of proteins and polysaccharides and their mixtures, using a battery of analytical methods, including rheology and scattering techniques. The characterisation exercise is performed with the view of relating the microscopic properties to the macroscopic mechanical behaviour of these systems.
- Encapsulation, Release and Digestion of Bioactives
We are currently investigating the use of different technologies for the encapsulation and the target release of food bioactives. The physical behaviour of the encapsulating system and the release kinetics of the bioactive during digestion are investigated in-vitro under simulated gastrointestinal conditions. This activity is part of a broader research area on the “rheo-physiology of structured foods”.
- Novel Process Technologies
We are interested by the effect of Novel Process Technologies, such as High Hydrostatic Pressure, Pulsed Electric Field and Ultrasound on the physico-chemical properties of food systems. We are also currently developing methodologies to the real-time in-situ investigation of food-based systems when subjected to the stresses (electro-mechanical, pressure, cavitation effects etc...) resulting from the application of these Processes.
- Development of Light Scattering Techniques to characterise Food Systems
In the recent years we developed Diffusing Wave Spectroscopy (DWS) as a particle sizing method for concentrated dispersions. In addition, we have used DWS to measure the micro-rheological, high-frequency, behaviour of biopolymer systems, and to investigate the mechanical behaviour of fluids under shear. Currently we are extending this capability to Multiple Speckle Diffusing-Wave Spectroscopy (MSDWS), a CCD-Camera based technique, for the study of non-ergodic media.
Selected publications and creative works (Research Outputs)
- Liu, D., Li, J., Zhang, J., Liu, X., Wang, M., Hemar, Y., ... Zhou, P. (2017). Effect of partial acidification on the ultrafiltration and diafiltration of skim milk: Physico-chemical properties of the resulting milk protein concentrates. Journal of Food Engineering, 212, 55-64. 10.1016/j.jfoodeng.2017.05.019
- De Leon-Rodriguez, L. M., Hemar, Y., Mitra, A. K., & Brimble, M. A. (2017). Understanding the metal mediated assembly and hydrogel formation of a β-hairpin peptide. Biomaterials science10.1039/c7bm00512a
Other University of Auckland co-authors: Alok Mitra, Luis De Leon Rodriguez, Margaret Brimble
- Lam, E., Holt, C., Edwards, P., McKinnon, I., Otter, D., Li, N., & Hemar, Y. (2017). The effect of transglutaminase treatment on the physico-chemical properties of skim milk with added ethylenediaminetetraacetic acid. Food Hydrocolloids, 69, 329-340. 10.1016/j.foodhyd.2017.02.002
- Sinthusamran, S., Benjakul, S., & Hemar, Y. (2017). PHYSICAL AND SENSORY PROPERTIES OF GELATIN FROM SEABASS (LATES CALCARIFER) AS AFFECTED BY AGAR AND Κ-CARRAGEENAN. Journal of texture studies10.1111/jtxs.12280
- Liu, D., Yu, Y., Zhang, J., Liu, X., Wang, M., Hemar, Y., ... Zhou, P. (2017). Biochemical and physico-chemical changes of skim milk during acidification with glucono-δ-lactone and hydrogen chloride. Food Hydrocolloids, 66, 99-109. 10.1016/j.foodhyd.2016.12.030
- Bai, W., Hébraud P, Ashokkumar, M., & Hemar, Y. (2017). Investigation on the pitting of potato starch granules during high frequency ultrasound treatment. Ultrasonics sonochemistry, 35 (Pt B), 547-555. 10.1016/j.ultsonch.2016.05.022
- De Leon-Rodriguez, L. M., Hemar, Y., Mo, G., Mitra, A. K., Cornish, J., & Brimble, M. A. (2017). Multifunctional thermoresponsive designer peptide hydrogels. Acta biomaterialia, 47, 40-49. 10.1016/j.actbio.2016.10.014
Other University of Auckland co-authors: Jillian Cornish, Alok Mitra, Margaret Brimble, Luis De Leon Rodriguez
- Xu, Y., Liu, D., Yang, H., Zhang, J., Liu, X., Regenstein, J. M., ... Zhou, P. (2016). Effect of calcium sequestration by ion-exchange treatment on the dissociation of casein micelles in model milk protein concentrates. Food Hydrocolloids, 60, 59-66. 10.1016/j.foodhyd.2016.03.026