- Title
- Effect of proteins and low molecular weight surfactants on spray-drying and powder properties of sugar-rich foods
- Creator
- Jayasundera, Mithila
- Date
- 2011
- Type
- Text; Thesis; PhD
- Identifier
- http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/64008
- Identifier
- vital:4607
- Abstract
- The effect of proteins and low molecular weight surfactants on spray-drying and powder properties of sugar-rich foods has been studied. This PhD study was aimed at quantifying both the extent and effects of the migration of protein and surfactant to the powder surface of spray-dried sugar-rich foods and their implications for powder formation yields and the powder properties such as moisture content, water activity, particle size, glass transition temperature, amorphous/crystalline nature, surface protein coverage, surface stickiness and reconstitution (solubility). The use of proteins and to a lesser extent surfactants as drying aids for sugar rich foods is novel. Sodium caseinate can act as a ‘smart’ drying aid in producing powders out of sugar-rich foods due to their higher solubility and better film-forming property. The remarkable behaviour of sodium caseinate as a drying aid, especially for sucrose is a very significant result both scientifically and commercially. The surface protein coverage and the recovery of the powder in sucrose–protein systems were found to be very sensitive in the presence of low molecular weight surfactants as the concentration of the sodium caseinate in the bulk was below its critical micelle concentration. However, the type of low molecular weight surfactants had no effect on the amorphous nature of fructose–protein powders mainly due to higher protein content (higher than critical micelle concentration) in these powders. It has been found that the nature of the sugar (sucrose or fructose), especially its glass transition temperature determines the extent of protein required to achieve a comparable powder recovery. The maximum solubility of the protein content of sugar–protein and sugar–protein–surfactant powders was achieved within 5 minutes of dissolution.; Doctor of Philosophy
- Rights
- Open Access
- Rights
- This metadata is freely available under a CCO license
- Subject
- Proteins; Sugar-rich foods; Stickiness; Surfactants; Emulsions; Spray drying
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