Characterization of Whey Protein Oil-in-Water Emulsions with Different Oil Concentrations Stabilized by Ultra-High Pressure Homogenization
Hebishy, Essam (Universitat Autònoma de Barcelona. Departament de Ciència Animal i dels Aliments)
Zamora, Anna (Universitat Autònoma de Barcelona. Departament de Ciència Animal i dels Aliments)
Buffa, Martín Nicolás (Universitat Autònoma de Barcelona. Departament de Ciència Animal i dels Aliments)
Blasco-Moreno, Anabel (Universitat Autònoma de Barcelona. Servei d'Estadística Aplicada)
Trujillo, Antonio-José (Universitat Autònoma de Barcelona. Departament de Ciència Animal i dels Aliments)

Data:	2017
Resum:	In this study, the effect of ultra-high-pressure homogenization (UHPH: 100 or 200 MPa at 25 ◦C),in comparison to colloid mill (CM: 5000 rpm at 20 ◦C) and conventional homogenization (CH: 15 MPa at 60 ◦C), on the stability of oil-in-water emulsions with different oil concentrations (10, 30 or 50 g/100 g) emulsified by whey protein isolate (4 g/100 g) was investigated. Emulsions were characterized for their microstructure, rheological properties, surface protein concentration (SPC), stability to creaming and oxidative stability under light (2000 lux/m2). UHPH produced emulsions containing lipid droplets in the sub-micron range (100-200 nm) and with low protein concentrations on droplet surfaces. Droplet size (d3. 2, µm) was increased in CH and UHPH emulsions by increasing the oil concentration. CM emulsions exhibited Newtonian flow behaviour at all oil concentrations studied; however, the rheological behaviour of CH and UHPH emulsions varied from Newtonian flow (n ≈ 1) to shear-thinning (n < 1) and thixotropic behaviour in emulsions containing 50% oil. This was confirmed by the non-significant differences in the d4. 3 (µm) value between the top and bottom of emulsions in tubes left at room temperature for nine days and also by a low migration velocity measured with a Turbiscan LAB instrument. UHPH emulsions showed significantly lower oxidation rates during 10 days storage in comparison to CM and CH emulsions as confirmed by hydroperoxides and thiobarbituric acid-reactive substances (TBARS). UHPH emulsions treated at 100 MPa were less oxidized than those treated at 200 MPa. The results from this study suggest that UHPH treatment generates emulsions that have a higher stability to creaming and lipid oxidation compared to colloid mill and conventional treatments.
Drets:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Llengua:	Anglès
Document:	Article ; recerca ; Versió publicada
Matèria:	Ultra-high pressure homogenization (UHPH) ; Whey protein ; Submicron emulsions ; Physical and oxidative stabilities
Publicat a:	Processes, Vol. 5 Núm. 1 (february 2017) , p. 6, ISSN 2227-9717

DOI: 10.3390/pr5010006

18 p, 2.0 MB

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