Improvement of oxidative stability of menhaden fish oil by microencapsulation within biocapsules formed of yeast cells

Authors:

• Adrian Czerniak,
• Piotr Kubiak,
• Wojciech Białas,
• Tomasz Jankowski

Abstract

Fish oil, rich in polyunsaturated fatty acids, is a valuable addition to human diet. Its composition makes it difficult to handle as it is prone to oxidation and its strong smell is repelling to many. Encapsulation in yeast cells is a possible solution to these issues. The aim of this study was to determine the best pretreatment approach, optimize the process of microencapsulation and verify the stability of the oil encapsulated in Saccharomyces cerevisiae. Pretreatment by autolysis, chemically facilitated autolysis and enzymatic cell wall digestion was tested. Autolysis at 55 °C supported by addition of 1.5% ethyl acetate was an effective pretreatment method. Process parameter values (temperature, stirring rate and emulsifier addition) were optimized, improving efficiency to ca. 90%. The encapsulated oil was shown to be stable when stored for 30 days at relative humidity below 70%. Additional coating with hydroxypropyl methyl cellulose allowed to improve storage stability.