Development of iron-rich whey protein hydrogels following application of ohmic heating Effects of moderate electric fields

• Autor(a) principal: Pereira, Ricardo N.
• Data de Publicação: 2017
• Outros Autores: Rodrigues, Rui M., Altinok, E., Ramos, Óscar L., Malcata, F. Xavier, Maresca, Paola, Ferrari, Giovanna, Teixeira, J. A., Vicente, A. A.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/47484
• topic: Whey protein isolate; Electric fields; Iron; Cold gelation; Transmission electron microscopy; Science & Technology

The influence that ohmic heating technology and its associated moderate electric fields (MEF) have upon production of whey protein isolate cold-set gels mediated by iron addition was investigated. Results have shown that combining heating treatments (90 °C, 5 min) with different MEF intensities let hydrogels with distinctive micro and macro properties i.e. particle size distribution, physical stability, rheological behavior and microstructure. Resulting hydrogels were characterized (at nano-scale) by an intensity-weighted mean particle diameter of 145 nm, a volume mean of 240 nm. Optimal conditions for production of stable whey protein gels were attained when ohmic heating treatment at a MEF of 3 V  cm 1 was combined with a cold gelation step using 33 mmol  L 1 of Fe2 +. The consistency index of hydrogels correlated negatively to MEF intensity, but a shear thickening behavior was observed when MEF intensity was increased up to 10 V  cm 1. According to transmission electron microscopy, ohmic heating gave rise to a more homogenous and compact fine-stranded whey protein-iron microstructure. Ohmic heating appears to be a promising technique, suitable to tailor properties of whey protein gels and with potential for development of innovative functional foods.