Application of modified breadfruit (Artocarpus altillis) starch by Octenyl Succinic Anhydride (OSA) to stabilize fish and microalgae oil emulsions
This research was aimed to examine the ability of breadfruit OSA starch (BOSA) to stabilize fish and microalgae oil emulsions. Fifteen percent of BOSA or pre-heated BOSA (7.5%) and maltodextrin (7.5%), or mixture of unheated BOSA (7.5%) and maltodextrin (7.5%) were used to stabilize 10% fish and microalgae oils. Characterization of native starch and BOSA included measurement of moisture, starch and amylose content, degree of substitution (DS), emulsification capacity, starch microstructure and thermal properties. The emulsion stability was monitored by emulsification index (EI), mean droplet size (D32), microstructure using photomicroscope and Peroxide Value (PV). Modification of starch (DS, 0.0243) caused decreasing in starch and amylose content to 75.34% and 27.62%, respectively. Starch thermal properties also decreased the onset temperature to 71.23°C (BOSA). Emulsions prepared with pre-heated mixture of BOSA and maltodextrin both in fish and microalgae oils have the smallest droplet size (D32 4.45 ± 0.09 μm and 3.54 ± 0.22 μm, respectively). Microalgae oil emulsions showed significantly (p<0.05) higher in stability towards oxidation compared to fish oil emulsions (PV, 4.65 ± 0.64 meq/kg oil). This research reveals that breadfruit OSA starch is highly recommended as a potential emulsifier to stabilize emulsion of essential oil containing polyunsaturated fatty acids (PUFAs).