Encapsulation of Hibiscus sabdariffa L. anthocyanins as natural colours in yeast.
Food Res Int
; 107: 275-280, 2018 05.
Article
em En
| MEDLINE
| ID: mdl-29580486
ABSTRACT
Hibiscus sabdariffa extracts, a rich source of anthocyanin, were subjected to encapsulation in yeast cells. An encapsulation yield (EY) of 208⯵g/100â¯mg of cells and an encapsulation efficiency (EE) of 27%, were reached after optimisation of the ratios (0.5â¯g wet yeast cells for 5â¯ml of anthocyanin extracts at 1â¯g·L-1) and with 10% of ethanol. The storage stability of encapsulated pigments was investigated in water and buffer pHâ¯1.5 at 5 & 37⯰C for 10â¯days and 90⯰C for 30â¯min. The percentage of loss of colour was determined by colourimetry assays. The microparticles made of yeast with or without heat treatment exhibited different protecting effects (Pâ¯<â¯0.01). At 37⯰C, the percentage of loss of colour in water was of 2.5% for heat-treated and 36.5% for non-treated yeast microparticles, suggesting that yeast enzymes would be responsible for the loss of anthocyanin during storage. These results are confirmed by the percentage of loss of colour which was far lower in conditions of low enzymatic activity 3.1% at 5⯰C for non-heat-treated cells in water. The pH of solvent had also an important effect on the degradation of encapsulated anthocyanin; in buffer at pHâ¯1.5 and 37⯰C with the non-heat-treated cells, the degradation decreased strongly to 9.4% compared with 36.5% in water. These results show that yeast cells are a good mean of encapsulation of pigments for a colouring purpose and that they provide anthocyanins a good protection as long as their enzymes are inactivated.
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Base de dados:
MEDLINE
Assunto principal:
Pigmentos Biológicos
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Saccharomyces cerevisiae
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Hibiscus
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Antocianinas
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article