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Background and Objective: Walnut oil has a high omega-3 unsaturated fatty acid and antioxidant component content, providing nutritional and functional properties including improvement of the gastrointestinal system, decrease in blood cholesterol level, eventually leading to a decrease in the risk of cardiovascular disease. The present study examined the possibility of the production of emulsion based on walnut oil and the effect of preparation on its stability. Materials and Methods: Walnut oil with tween 80 and span 80 (as emulsifiers) was used in emulsion production. Ultrasonic waves were applied for homogenization and the effect of homogenization time, oil content, and emulsifier concentration on particle size, emulsion stability, and turbidity loss rate was studied. Results: Ultrasonic time had a reverse effect on particle size and turbidity loss rate and a direct effect on emulsion stability. The particle size and turbidity loss rate of prepared emulsions had a direct relation with oil concentration and a negative effect on emulsion stability. Emulsifier concentration had a positive effect on emulsion stability, a negative effect on emulsion stability, and had no significant effect on turbidity loss rate. Conclusion: Walnut oil can be used to produce emulsions with high stability an evaluation of emulsion stability using creaming tests showed that samples have appropriate stability during storage time. Keywords: Emulsion, Stability, Walnut oil, Response surface methodology, Turbidity

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Background and Objectives: Pectin is a complex mixture of polysaccharides that is widely used in the food industry as a gelling agent, stabilizer and emulsifier. The aim of this study was to compare the production yield and physicochemical properties of microwave-assisted extracted pectin from pineapple, samsuri and galia melons peels.

Materials and Methods: Pectins were extracted from pineapple, samsuri and galia melon peels assisted by microwave under the power of 700 W, time of 3 min, pH of 1.5 and liquid/solid ratio of 15:1 (v/w). Then the physicochemical properties of the extracted pectins such as galacturonic acid content, degree of esterification, emulsifying properties, solution behavior and FT-IR spectra were investigated.

Results: The results showed that pectins obtained from all the three products have a reseaonable yield (14-15%) and degree of purity (with galacturonic acid content above 65%). the study of degree of esterification showed that pectins obtained from pineapple and samsuri melons were LMP, and the galia melon peel pectin was HMP. The pectins’ emulsifying activity of all the three products was low. The viscosity results illustrated that the pectin solutions obtained from pineapple and samsuri melons have Newtonian flow behavior at all concentrations, but the solution of galia melon peel pectin showed different flow behavior at various concentrations. 

Conclusions: The high yield, good degree of purity and acceptable physicochemical properties of obtained pectin show that this agricultural waste can be used as a promising source for pectin production.

Keywords: Pectin, Microwave, Pineapple melon, Samsuri melon, Galia