The new study – published in Food and Chemical Toxicology – reports to be the first to evaluate the genotoxicity and antigenotoxicity of a microencapsulated compound in vivo.
The researchers, led by Alexandre Ferro Aissa from from the University of São Paulo, Brazil, noted that effects of microencapsulation on the quality and efficacy of functional ingredients is unknown, “because only few in vivo biological studies have been performed on microencapsulated compounds.”
“By comparing the same doses of the pure and microencapsulated compound, we found that microencapsulated beta-carotene was anti-genotoxic in all the analyzed tissues, demonstrating the efficacy of beta-carotene in protecting against DNA damage even when microencapsulated,” said Ferro Aissa and his colleagues.
“Our results suggest that when beta-carotene is microencapsulated, it does not lose its antigenotoxic properties; however, the observed antigenotoxic effect was directly related to the beta-carotene concentration. Thus, when microencapsulated, a lower dose of beta-carotene had no effects, whereas a higher dose was antigenotoxic,” they explained
The researchers noted that beta-carotene is one example of a widely used natural food colorant that is added to many kinds of foods to make them appear healthier and more appealing. However, the carotenoid is also a well known antioxidant and anti-genotoxic agent that is widely touted for the prevention of diseases associated with oxidative stress.
However, the ingredient is famous for its instability, and is susceptable to degredation from a number of agents: “The major cause of carotenoid destruction during the storage and processing of food is oxidation. Therefore, the oxidative damage of carotenoids in functional foods has the potential to impair the quality and bioactivity of the product,” said the researchers.
Ferro Aissa noted that one possible solution for the incorporation of carotenoids such as beta-carotene into foods, either as colorants or as functional ingredients, without affecting their properties would be the use of microencapsulation. However, they said that it is important to study how encapsulation of beta-carotene in foods affects its biological activity compared to free beta-carotene.
The research team tested the potential genotoxic and anti-genotoxic effects of the encapsulated beta-carotene against identical doses of ‘pure’ beta-carotene in rats.
The team used two doses of carotenoid compound – administering either 2.5 or 5 mg per kg of body weight for 14 days. The final administration of the compouns was followed by an injection of harmful doxorubicin (DXR) – which is known to cause DNA damage.
The researchers found that none of the doses of microencapsulated beta-carotene were genotoxic.
Ferro Aissa said that when the microencapsulated compound was administered alongside DXR, only the higher dose was effective in protecting against DNA damage.
“As a compound with better stability and solubility, microencapsulated beta-carotene could be effectively used in food processing,” said the researchers. “Although beta-carotene does not lose its properties when microencapsulated, a higher dose should be used to ensure that the carotenoid retains its antigenotoxic effect,” they advised.
Source: Food and Chemical Toxicology
Publsihed online ahead of print, doi: 10.1016/j.fct.2012.02.030
“Comparative study of β-carotene and microencapsulated β-carotene: Evaluation of their genotoxic and antigenotoxic effects”
Authors: A. Ferro Aissa, M.L.P. Bianchi, J. Carvalho Ribeiro, L.C. Hernandes, et al