Physical properties of pregelatinized and granular cold water swelling maize starches at different pH values.
The aim of this study was to investigate the influence of pH changes (3, 5, 7 and 9) on physical properties of pregelatinized (PG) and granular cold water swelling (GCWS) maize starches. In acidic pH, PG starches were fragmented; however, GCWS starches mainly reserved their granular integrity but were shriveled. For both modified starches the water absorption, cold water viscosity, textural parameters, turbidity and freeze-thaw stability of the samples decreased whereas water solubility increased at pH 3 and 5. On the other hand, alkaline pH did not bring about evident changes on morphology of PG starch but the surface of GCWS starch became smoother. Water absorption, solubility, rheological and mechanical properties, freeze-thaw stability and turbidity of the starch pastes increased at high pH values. Overall, both starches were more stable at alkaline pH compared to acidic pH values and GCWS starch was more resistance to pH changes than PG starch.
Department of Food Science and Technology, Ferdowsi University of Mashhad (FUM), Mashhad, Iran. Electronic address: sara_hedayatiii@yahoo.com.
Sara
S
Hedayati
Department of Food Science and Technology, Ferdowsi University of Mashhad (FUM), Mashhad, Iran. Electronic address: fshahidi@um.ac.ir.
Fakhri
F
Shahidi
Department of Food Science and Technology, Ferdowsi University of Mashhad (FUM), Mashhad, Iran. Electronic address: koocheki@um.ac.ir.
Arash
A
Koocheki
Department of Food Science and Technology, School of Agriculture, Shiraz University, Shiraz, Iran; ARC Industrial Transformation Training Centre for Functional Grains, Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, New South Wales, 2650, Australia; School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, New South Wales, 2650, Australia. Electronic address: afarahnaky@csu.edu.au.
Asgar
A
Farahnaky
Department of Food Science and Technology, School of Agriculture, Shiraz University, Shiraz, Iran; NSW Department of Primary Industries, PMB Pine Gully Road, Wagga Wagga, 2650, Australia. Electronic address: majzoobi@shirazu.ac.ir.
Mahsa
M
Majzoobi
D003080:Cold Temperature; D006863:Hydrogen-Ion Concentration; D013213:Starch / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D003313:Zea mays / Q000737:chemistry*
D014867:Water; D013213:Starch
Granular cold water swelling starch; Maize starch; Physical properties; Pregelatinized starch; pH