Investigation of physichochemical and antioxidant properties of emulsions stablised by protein and wild sage seed gum conjugates

Abstract

stract Backgrounds Salvia splendens plant belongs to the Lamiaceae family. At present, few studies have been conducted on the extraction of the gum from sage. Sage seeds are small round seeds, which swell quickly in water and give mucilaginous gums. Sage seed gum is a galactomannan with a ratio of galactose to mannose (1:1.93-1.78) which has 2.28-2.32% is uronic acid and due to its physicochemical and rheological properties, it can be used as a stabilizer and emulsifier in food products. Various studies have shown that theglycation reaction between protein and polysaccharide increases the functional properties of the obtained compound. The advantages of this method include not using chemicals and having good chemical properties such as antioxidant, emulsifier, and antimicrobial, its cost-effectiveness, and the possibility of doing it under controlled conditions of pH, temperature, time, and humidity. As a result, the aim of the present project is to investigate the chemical and antimicrobial properties of the conjugates obtained from safflower gum (SSG) and egg white protein (EWP) in order to achieve the maximum emulsifying property and to investigate its effect on pathogenic micro-organisms. Material and methods: To extract gum from milled Sage seeds, degreasing was done using hexane and ethanol in the continuation of the gum extraction process. The obtained powder was stored in glass containers in the refrigerator. The best ratio of gum and protein was selected for the Maillard reaction and subjected to the Maillard reaction at a temperature of 60 degrees Celsius and for different times (3, 5, 7 and 10 days). The amount of free amino acids, the intensity of browning, and the antimicrobial and antioxidant properties of the samples were measured, and FTIR and electrophoresis were used to characterize the resulting conjugates. By measuring the diameter of emulsion particles and rheological characteristics, the best conjugate treatment was used to make oil-in-water emulsion. Emulsions stabilized by 5-day conjugation of SSG-EWP, SSG-EWP mixture and EWP compared in terms of stability (temperature, salt concentration and pH). Results: Results suggested foaming capacity, foaming stability, emulsification activity index (EAI) and emulsification stability index (ESI) remarkably improved by 5 days, and the antioxidant properties were improved in the 7-day conjugate. Antimicrobial activity of SSG and EWP and 3 and 5 day conjugates was observed against Salmonella typhimurium and Bacillus cereus bacteria. However, continued incubation up to 10 days improved the antimicrobial activity. Comparison of oil in water (O/W) emulsions stabilized by 5-days EWP-SSG conjugate and EWP-SSG mixture with unmodified EWP revealed better physical stability behavior against different NaCl concentrations (0, 5, 10 and 20 mM), pH values (3, 5, 6 and 8) and thermal treatment (25, 37, 72 °C), suggesting possible application in different food processing conditions. Conclusions: The findings showed that the choice of incubation time should be considered as an important factor, so that the most compact structures were obtained after 7 days of conjugation and the best technical-functional characteristics were obtained after 5 days. In addition to having antimicrobial and antioxidant activity, emulsions stabilized with EWP-SSG conjugate showed better stability to acidic pH, heat treatment and salt concentration than EWP and EWP-SSG mixture, which can be used in most products. Food industry is useful Keywords: Emulsifying, Physical stability, Conjugation, Maillard reaction, Apparent viscosity