In this study, effect of Qodume shahri (Lepidium perfoliatum) and cress (Lepidium sativum) on rheological properties of ice cream were investigated. The gums were added to the ice cream formulation and different quality attributes including pH, acidity, melting characteristics, viscosity, overrun, texture analysis and sensory evaluation were determined. Results showed that ice cream formulations containing both the gums had improved overrun, melting rate, first dripping time, viscosity, hardness and adhesiveness. The gum concentrations beyond 0.2% level led to a negative effect on gumminess and chewiness of ice cream. Both the gums addition to improved quality attributes and textural properties of ice cream.

In this research, maltodextrin (0, 1 and 2% w/w) and resistant starch (0, 1 and 2% w/w) were used in the formulation of low-fat ice cream (4% fat) and their effects on the physicochemical and sensory properties were investigated. The optimum levels of maltodextrin and resistant starch were determined by response surface methodology. Increment of maltodextrin and resistant starch increased acidity, viscosity, melting rate, time of dripping and overrun but decreased melting rate of ice cream. Results showed that the incorporation of maltodextrin and resistant starch at 0 and 2% w/w respectively, resulted into ice cream with suitable viscosity, melting rate, first dripping time, overrun and acidity.

BACKGROUND There is a growing demand in the food industry for the replacement of synthetic preservatives with their natural alternatives. This has led to the development of novel methods such as encapsulation of plants essential oil with appropriate physicochemical stability, and antibacterial and organoleptic properties. This study aimed to prepare an optimal nanoemulsion of Thymus daenensis L. essential oil for use as a natural preservative in mayonnaise. RESULTS The analysis of droplet diameter, polydispersity index, zeta potential, encapsulation rate, and intrinsic stability showed that out of nine T. daenensis essential oil‐containing nanoemulsions, two preparations of A and B had high stability scores. In vitro antibacterial tests showed the adverse effect of Tween 80 volume on the antibacterial properties of nanoemulsions. One nanoemulsion (essential oil:Tween 80, ratio 1:1, 15 min sonication) was considered to be optimal based on its long‐term stability and antibacterial effects on Salmonella Typhimurium, Escherichia coli, and Listeria monocytogenes. However, compared to the optimal nanoemulsion, the pure essential oil showed more antibacterial effects. The bacterial control in mayonnaise was close to equal for sodium benzoate (in maximum limit 1 g kg−1) and the optimal nanoemulsion (½ MIC) for 24 h. The optimal nanoemulsion achieved significantly higher sensory scores (taste, appearance, and mouthfeel) than the pure essential oil in mayonnaise (P < 0.05). CONCLUSION The results demonstrated similar antibacterial effects for the optimal nanoemulsion and sodium benzoate. The optimal nanoemulsion, due to its desirable sensorial attributes, long‐term stability, and slow release of volatile compounds, can be considered an appropriate alternative to synthetic preservatives.

The demand for consuming low‐fat or nonfat dairy products, especially fat‐free yoghurt, has increased considerably because of the effects of high‐fat diet on human health during the two past decades. Generally, consumers prefer low‐fat products to the same high‐fat products. For this reason, manufacturers are looking for an ideal source for replacing fat substitute. In this research, the effect of grape seed oil (GSO) as a fat replacement on different quality attributes of the produced set yoghurt was determined. The effect of diverse ratios (3:0, 1.5:1.5, and 0.5:3%) of milk fat and GSO on the change in the quality attributes of the set yoghurt for up to 22 days of refrigeration period (4 ± 1°C) was investigated. Statistical analysis revealed that increase in GSO concentration leads to a significant increase (p < .05) in viscosity, acidity, and water‐holding capacity (WHC), whereas syneresis and pH value decreased during the storage time. Furthermore, increasing the proportion of fat replacement to 3% (w/w) in set yoghurt increased the samples hardness while in case of cohesiveness; negative effect was observed because of the action of fat globules within the protein system. Result of fatty acid analysis revealed that the yoghurt samples containing GSO have higher unsaturated fatty acid content than the control yoghurt sample. In conclusion, the best fat replacement concentration of GSO in producing low‐fat yoghurt was found in 1.5%, which also had the highest overall acceptance score between different yoghurt samples containing different levels of GSO.

Herbal extracts containing natural bioactive substances with numerous beneficial effects have been recently noticed as appropriate alternatives for synthetic food preservatives. In this study, we aimed to optimize the effects of different sumac (Rhus coriaria) fruit extracts (SFE) on oxidative stability of soybean oil under accelerated conditions compared to a synthetic antioxidant. Hydro‐ethanolic extracts (70%) of sumac fruits were prepared by three methods of immersion (I‐SFE), ultrasound (U‐SFE), and microwave (M‐SFE). According to the response surface methodology (RSM), 13 runs were considered in the concentrations of 0, 500, and 1000 ppm of each extract that were added to the soybean oil and stored at 60°C for a 20‐day period. All of the treatments were significantly (p < .05) efficient in preventing the chemical and sensory changes of soybean oil compared to the control in the dose‐dependent manner during storage period. I‐SFE treatment showed the lowest peroxide value (PV) (0.000063 meq (milliequivalents) O2/kg oil), thiobarbituric acid reactive substances (TBARS) (115.06 MDA (malondialdehyde)/kg oil), and acid value (0.0169 mg KOH (potassium hydroxide)/kg oil) among the other extracts at the end of the storage period. Furthermore, I‐SFE treatment earned the highest sensory scores (flavor, color, odor, and overall acceptability) of soybean oil in the range of 4–5 in comparison to the other treatments and synthetic antioxidant during storage time. According to the analysis of RSM, I‐SFE in the concentration of 999.998 ppm could optimally enhance the shelf life of soybean oil for 11.3614 days under accelerated conditions. It was concluded that I‐SFE with the same efficiency as synthetic antioxidants can be considered as a suitable alternative in soybean oil with various health benefits.