Production of porous starch microparticles as a vehicle for chia oil for potential food applications

PILONI, ROXANA; BARRERA, GABRIELA NOEL; BORDÓN GABRIELA; MARÍA CECILIA PENCI; MARTINEZ MARCELA; PABLO D. RIBOTTA

Simposio; III International Conference of la ValSe-Food Network and VI Symposium Chia-Link; 2021

CYTED

In the present work, corn starch was used for the production of porous microparticles by enzymatictreatments for its subsequent impregnation with chia oil. A predetermined amount of alpha-amylase(AM, 500 FAU/g), glucoamylase (GAM, 3300 U/g) and a mixture of both (AM/GAM) were evaluated.Briefly, 5 g of starch were mixed with the enzymes and 25 mL of buffer. The treatments were carried outat 50 °C for 24 h with continuous agitation. Then, the mixture was centrifuged and washed twice withdistilled water. The supernatant was discarded and the porous starch was dried at 45 °C for 24 h. Theporous microparticles were characterized by the following determinations: water and oil adsorptioncapacity and SEM. With these results, the best starches were selected for the impregnation assays withchia oil under vacuum conditions. Therefore 2 g of starch were mixed with increasing percentages of oil(from 10 to 55 %), homogenized and submitted to vacuum (> 0.1 mm Hg) during 15 min. Afterimpregnation, chia oil oxidative stability was determined by Rancimat method (impregnated starch: 0.5g, temperature: 100 °C, air flow: 20 L/h). According to the characterization results, starches treated withAM/GAM were selected for impregnation tests due they presented elevated oil and water absorptioncapacities (2.46-2.63 and 2.01-2.22, respectively) and they showed through SEM a conserved granularstructure and large amount and diversity of pores. The oxidation test demonstrated that the starchstructure exert a protective effect on impregnated chia oil oxidative stability.Acknowledgments. This research was financed with grants from CONICET, SeCyT-UNC and FONCyT(BID PICT 2019-01122) from Argentina and the Iberoamerican Project Ia ValSe-Food-CYTED(119RT0567).