In-vitro release profile of microencapsulated α-tocopherol under simulated gastrointestinal conditions

Vieira, Dalila; Amaral, Joana S.; Barreiro, M.F.

Publication

In-vitro release profile of microencapsulated α-tocopherol under simulated gastrointestinal conditions

2014Conference object

dc.contributor.author	Vieira, Dalila
dc.contributor.author	Amaral, Joana S.
dc.contributor.author	Barreiro, M.F.
dc.date.accessioned	2018-04-09T10:26:41Z
dc.date.available	2018-04-09T10:26:41Z
dc.date.issued	2014
dc.description.abstract	Alpha-tocopherol, the most common form of Vitamin E in nature, is a well-known antioxidant compound for its effective inhibition of lipid oxidation both in food and biological systems. Additionally, due to its preventive action against reactive oxygen species (ROS), α-tocopherol has been associated with risk decreasing of diseases associated with oxidative stress, such as cardiovascular disease and cancer [1]. The recommended ingestion of Vitamin E varies among the countries and according to criteria such as sex and age. In the USA, the recommended daily allowance (RDA) for an adult is 15 mg/day, whereas in Europe it is 4-15 and 3-12 mg α-tocopherol/day for man and women, respectively. Although α-tocopherol is naturally present in several foods, such as vegetable oils and tree nuts, owing to its antioxidant capacity it is frequently included in food supplements and used in the food industry to extend the shelf-life of several products. Nevertheless, due to α-tocopherol instability and sensitivity towards oxygen and light and its poor aqueous solubility, it is generally administered in the acetate or succinate form. However, these forms are considered to have a lower intestinal absorption compared to α-tocopherol [2]. To overcome these problems, the encapsulation of α-tocopherol in protective matrixes to avoid its oxidation and increase shelf life has been suggested. In fact, during the last years, encapsulation technology has been increasingly important in the food industry as it permits the formation of a physical barrier between the external medium and sensitive core materials, being also used for controlled release of active molecules, formulation stability enhancement, and flavor and taste masking. In this context, it is important to assess α-tocopherol release pattern from microparticles as it can restrain its different applicability. In this work, α-tocopherol microspheres were produced using alginate as a polymeric matrix. This polymer, a linear polysaccharide obtained from brown algae consisting of β-mannuronic acid and α-guluronic acid units, was chosen due to its biocompatibility, biodegradability and non-toxicity. Moreover, it presents a high stability at acidic pH, being easily swollen under mild alkali conditions. Alginate microspheres (ME) loaded with α-tocopherol were produced using a NISCO Var J30 atomization unit, following a previously optimized methodology. The produced microspheres were evaluated for encapsulation efficiency and α-tocopherol release profile by measuring the absorbance at 297 nm using a spectrophotometer. The encapsulation efficiency was calculated both by directly measuring the maximum content released after ME disruption and by quantifying the nonencapsulated α-tocopherol present in the CaCl2 coagulation solution and in the wash solution. α-Tocopherol in-vitro release profiles were determined under simulated gastric (pH 1.2) and intestinal (pH 7.4) media during a period of 24 hours. Additionally, a sample of ME were mixed in gastric media during 1h and then transferred to intestinal media until a total of 24h to simulate gastrointestinal conditions. During the testing period samples of the supernatant were periodically taken to determine the amount of released α-tocopherol. Results evidence a very low % of α-tocopherol release under acidic conditions while an almost complete release is achieved when ME were submitted to simulated intestinal conditions suggesting that the proposed approach can constitute an interesting solution to protect α- tocopherol, allowing for its release in the intestine after ingestion. The next steps in this work in progress will include the evaluation of release profiles of ME added to different food matrices.	pt_PT
dc.description.sponsorship	The authors thank FCT for the financial support LSRE (PEst-C/EQB/LA0020/2011 strategic project).	pt_PT
dc.description.version	info:eu-repo/semantics/publishedVersion	pt_PT
dc.identifier.citation	Vieira, Dalila: Amaral, J.S.; Barreiro, M.F. (2014). In-vitro release profile of microencapsulated α-tocopherol under simulated gastrointestinal conditions. In 12º Encontro de Química dos Alimentos. Lisboa	pt_PT
dc.identifier.uri	http://hdl.handle.net/10198/16767
dc.language.iso	eng	pt_PT
dc.peerreviewed	yes	pt_PT
dc.relation	Strategic Project - LA 20 - 2011-2012
dc.rights.uri	http://creativecommons.org/licenses/by/4.0/	pt_PT
dc.title	In-vitro release profile of microencapsulated α-tocopherol under simulated gastrointestinal conditions	pt_PT
dc.type	conference object
dspace.entity.type	Publication
oaire.awardTitle	Strategic Project - LA 20 - 2011-2012
oaire.awardURI	info:eu-repo/grantAgreement/FCT/6820 - DCRRNI ID/PEst-C%2FEQB%2FLA0020%2F2011/PT
oaire.citation.conferencePlace	Lisboa, Portugal	pt_PT
oaire.citation.endPage	38	pt_PT
oaire.citation.startPage	38	pt_PT
oaire.citation.title	12º Encontro de Química dos Alimentos	pt_PT
oaire.fundingStream	6820 - DCRRNI ID
person.familyName	Amaral
person.familyName	Barreiro
person.givenName	Joana S.
person.givenName	Filomena
person.identifier.ciencia-id	5319-7DE8-BEDA
person.identifier.ciencia-id	3418-47D5-5746
person.identifier.orcid	0000-0002-3648-7303
person.identifier.orcid	0000-0002-6844-333X
person.identifier.rid	L-9802-2014
person.identifier.scopus-author-id	57188719717
project.funder.identifier	http://doi.org/10.13039/501100001871
project.funder.name	Fundação para a Ciência e a Tecnologia
rcaap.rights	openAccess	pt_PT
rcaap.type	conferenceObject	pt_PT
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