Publicação
Development of bio-based nanoemulsions to improve physical and chemical stability of omega-3 fatty acids
| Resumo: | Nowadays there is a high interest by the food industry to develop nutritional food products. This concept promoted the development of bio-based structures to encapsulate bioactive compounds and thus enhance their physical and chemical stability from storage up until consumption. Omega-3 (ω-3) is known for its functional properties such as improving cardiovascular health, decrease inflammation, increase cognitive function. However, ω-3 fatty acids are highly susceptible to oxidation, have intense odour and low water solubility, which makes its direct application in foods extremely difficult. In order to reduce these problems, nanoencapsulation, through nanoemulsions can be used. With this in mind, lactoferrin (Lf), a protein derived from milk with a wide range of reported biological activities (e.g. antioxidant, antimicrobial, cancer prevention) was used as natural emulsifier for the development of oil-in-water nanoemulsions for ω-3 encapsulation. The nanoemulsions were characterized and assessed by physical and chemical stability during storage. Nanoemulsions were also dried by freeze-drying and nanospray-drying and further characterized. ω-3 nanoemulsions were successfully produced through high pressure homogenization, with results showing that the concentration of Lf influenced size and superficial charge of the nanoemulsions droplets obtained. Nanoemulsions revealed physical stability when stored at 4 ºC for 69 days, while presenting instability at room temperature. The antioxidant capacity of the nanoemulsions did not show significative alterations over storage while a significative increase in oxidation was registered. Only the nanoemulsions dried by nanopray-drying presented defined structures. The rehydration of the powders resulted from freeze-drying was possible while powders obtained by nanospray-drying were not able to be rehydrated. Overall the results suggest that ω-3 nanoemulsions with physical stability can be produced using Lf while chemical stability was not achieved. The Lf nanoemulsions can also be dried to obtain powders with defined submicron particles but its rehydration its limited. This work provides important information that can be useful for the design of nanoemulsions and dry capsules aiming the encapsulation of lipophilic compounds for pharmaceutical and food applications. |
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| Autores principais: | Pereira, Beatriz D’Avó |
| Assunto: | ω-3 Lactoferrin Nanoemulsion Oxidation Stability Freeze-drying Nanospray-drying Lactoferrina Nanoemulsão Oxidação Estabilidade Liofilização Nanospray-drying Ciências Naturais::Ciências Biológicas |
| Ano: | 2017 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | Nowadays there is a high interest by the food industry to develop nutritional food products. This concept promoted the development of bio-based structures to encapsulate bioactive compounds and thus enhance their physical and chemical stability from storage up until consumption. Omega-3 (ω-3) is known for its functional properties such as improving cardiovascular health, decrease inflammation, increase cognitive function. However, ω-3 fatty acids are highly susceptible to oxidation, have intense odour and low water solubility, which makes its direct application in foods extremely difficult. In order to reduce these problems, nanoencapsulation, through nanoemulsions can be used. With this in mind, lactoferrin (Lf), a protein derived from milk with a wide range of reported biological activities (e.g. antioxidant, antimicrobial, cancer prevention) was used as natural emulsifier for the development of oil-in-water nanoemulsions for ω-3 encapsulation. The nanoemulsions were characterized and assessed by physical and chemical stability during storage. Nanoemulsions were also dried by freeze-drying and nanospray-drying and further characterized. ω-3 nanoemulsions were successfully produced through high pressure homogenization, with results showing that the concentration of Lf influenced size and superficial charge of the nanoemulsions droplets obtained. Nanoemulsions revealed physical stability when stored at 4 ºC for 69 days, while presenting instability at room temperature. The antioxidant capacity of the nanoemulsions did not show significative alterations over storage while a significative increase in oxidation was registered. Only the nanoemulsions dried by nanopray-drying presented defined structures. The rehydration of the powders resulted from freeze-drying was possible while powders obtained by nanospray-drying were not able to be rehydrated. Overall the results suggest that ω-3 nanoemulsions with physical stability can be produced using Lf while chemical stability was not achieved. The Lf nanoemulsions can also be dried to obtain powders with defined submicron particles but its rehydration its limited. This work provides important information that can be useful for the design of nanoemulsions and dry capsules aiming the encapsulation of lipophilic compounds for pharmaceutical and food applications. |
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