Buriti Oil Emulsions as Affected by Soy Protein Isolate/High-Methoxyl Pectin Ratio, Oil Content and Homogenization Pressure

Author(s)

Faria Freitas, Mirian Luisa ^[1] ; Badan Ribeiro, Ana Paula ^[2] ; Nicoletti, Vania Regina ^[3]

Affiliation

^[1] Fed Univ Grande Dourados UFGD, Sch Engn Men, Dourados Itahum Rd Km 12, Cidade Univ, BR-79804970 Dourados, MS - Brazil

^[2] Univ Estadual Campinas, Dept Food Technol DTA, Sch Food Engn FEA, UNICAMP, Bertrand Russel St, Cidade Univ, BR-13083970 Campinas, SP - Brazil

^[3] Sao Paulo State Univ UNESP, Inst Biosci Humanities & Exact Sci IBILCE, Campus Sao Jose Rio Preto, 2265 Cristovao Colombo, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

• Document type: Journal article
• Source: Food Technology and Biotechnology; v. 58, n. 2, p. 159-172, APR-JUN 2020.
• Web of Science Citations: 0

Abstract

Research background. Emulsion technology is a suitable way of encapsulating, protecting and releasing hydrophobic bioactive compounds for application in food industries, but they are thermodynamically unstable systems. Good results have been achieved for emulsions stabilized by protein-polysaccharide complexes subjected to high-pressure homogenization. Improved stabilization of oil-in-water emulsions results from electrostatic complexes formed between proteins and polysaccharides at pH lower than the protein isoelectric point, which adsorb at the oil-water interface. In addition, polysaccharides contribute to emulsion stability by increasing viscosity of the continuous phase. The aim of this work is to investigate the production of carotenoid-rich buriti oil emulsions using soy protein isolate and high-methoxyl pectin as stabilizers. Experimental approach. Using a rotatable central composite experimental design, we assessed the effects of oil content, soy protein isolate/high-methoxyl pectin ratio and homogenization pressure on the stability, droplet size, electrical conductivity, electrical charge, microstructure and rheological behaviour of the emulsions. Results and conclusions. An optimized emulsion was produced with 28 buriti oil, 55% soy protein isolate, and homogenization pressure of 380.10(5) Pa. This emulsion was stable for at least seven days, presenting reduced average droplet size, low electrical conductivity and high modulus of negative charges. The mechanical spectra showed that the emulsion behaved as a viscoelastic gel under oscillatory, non-destructive shearing, whereas shear-thinning behaviour took place under steady shear conditions. Novelty and scientific contribution. The optimized buriti oil emulsions stabilized by soy protein isolate and high-methoxyl pectin could be suitable for fat substitution, energy reduction and carotenoid enrichment in food products, such as dairy and bakery products, ice cream, salad sauces and vegetable-based cream. (AU)

• FAPESP's process: 14/02910-7 - O/W emulsions stabilized by electrostatic interactions between proteins and polysaccharides: application as fat replacers and as bioactive compound microencapsulation
• Grantee: Vânia Regina Nicoletti Telis
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/08520-6 - Preparation and characterization of emulsions and microcapsules of buriti oil (Mauritia flexuosa) using isolated soy protein and high-methoxy pectin as stabilizer
• Grantee: Mírian Luisa Faria Freitas
• Support Opportunities: Scholarships in Brazil - Doctorate