Evaluation of rheological and textural structure of composite gels using oleosome and sesame seed protein

In the present study, a composite gel was prepared based on gelatin and sesame seed protein containing a fixed amount of oleosome. The different ratios of sesame protein to gelatin (30:70, 50:50, 70:30 w/w%) and a constant amount of 20% (w) oleosome were used to prepare the composite gel. Then the physicochemical properties of sesame seeds, oleosomes and their extraction efficiencies were determined. The rheological, textural and microstructural properties of the gels were also investigated. Protein and oleosome extraction efficiencies from sesame seeds were 21±1.23% and 68.96±1.41%, respectively. The results showed that the amount of sesame seed protein had significant effect on the gelation behavior and gel hardening, and the storage modulus and loss modulus increased in the samples with the decrease of the process temperature from 50 to 4 degrees Celsius. With the increase of sesame protein ratio, the amount of storage modulus and loss modulus at 4 degrees Celsius temperature increased from 258 pascals to 149400 pascals and from 46.7 pascals to 37648 pascals, respectively. The accumulation of protein molecules in the gel structure was observed with increasing the proportion of sesame protein to 70% by light microscope. The results of the present research confirm that sesame seed oleosome can be used as a substitute for fat particles in food products.