Abstract
Octenyl succinic anhydride-modified starch has been successfully used as an emulsifier, e.g., as an encapsulating agent for fish oils, fat-soluble vitamins and flavours, in making bread, cake and cookies. Enriched dried emulsions stabilised with modified starches can also be used as an ingredient in cereal products to play a functional role and fortify.
In general, redispersible dry emulsions stabilized with biopolymers have a tendency to cake and agglomerate particularly during storage under humid conditions. Moisture uptake may therefore play a key role in the functional properties of these powders such as flow behaviour, bulk density, dissolution rate and caking during storage or transport to the customer if the environmental relative humidity is not controlled. In this work, a model oil-in-water emulsion containing 2.0 wt% octenyl succinic anhydride-modified starch acting as an emulsifier was produced using a jet homogenizer and was subsequently freeze-dried. The water sorption characteristics of freeze-dried oil-in-water emulsions were then studied using a dynamic vapour sorption (DVS) apparatus. The water sorption isotherms showed a noticeable increase in equilibrium moisture content (EMC) values above 65% RH, suggesting a change in the mechanism of water sorption by starch molecules. The experimental water sorption isotherms were fitted to three mathematical models: Brunauer-Emmett-Teller (BET), Guggenheim-Anderson-de Boer (GAB) and Oswin. Comparison of predicted values of EMC with experimental values using E (Mean percentage deviation modulus) and R2 (coefficient of determination) value showed that all three models were satisfactory for predicting the isotherms of oil-in-water emulsions. Also, it was shown that the GAB model provides the best fit for describing both sorption and desorption isotherm of freeze-dried emulsion.
In general, redispersible dry emulsions stabilized with biopolymers have a tendency to cake and agglomerate particularly during storage under humid conditions. Moisture uptake may therefore play a key role in the functional properties of these powders such as flow behaviour, bulk density, dissolution rate and caking during storage or transport to the customer if the environmental relative humidity is not controlled. In this work, a model oil-in-water emulsion containing 2.0 wt% octenyl succinic anhydride-modified starch acting as an emulsifier was produced using a jet homogenizer and was subsequently freeze-dried. The water sorption characteristics of freeze-dried oil-in-water emulsions were then studied using a dynamic vapour sorption (DVS) apparatus. The water sorption isotherms showed a noticeable increase in equilibrium moisture content (EMC) values above 65% RH, suggesting a change in the mechanism of water sorption by starch molecules. The experimental water sorption isotherms were fitted to three mathematical models: Brunauer-Emmett-Teller (BET), Guggenheim-Anderson-de Boer (GAB) and Oswin. Comparison of predicted values of EMC with experimental values using E (Mean percentage deviation modulus) and R2 (coefficient of determination) value showed that all three models were satisfactory for predicting the isotherms of oil-in-water emulsions. Also, it was shown that the GAB model provides the best fit for describing both sorption and desorption isotherm of freeze-dried emulsion.
| Original language | English |
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| Publication status | Published - 29 Mar 2021 |
| Event | 16th ICC Cereal and Bread Congress - Lincoln University, Lincoln, New Zealand Duration: 29 Mar 2021 → 31 Mar 2021 https://icbc2020.icc.or.at/en/ |
Conference
| Conference | 16th ICC Cereal and Bread Congress |
|---|---|
| Country/Territory | New Zealand |
| City | Lincoln |
| Period | 29/03/21 → 31/03/21 |
| Internet address |