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Ultrasonic waves cause an increase in oil extraction efficiency through their mechanical effects, cavitation, and the energy generated by this phenomenon. Temperature, time, solvent to sample ratio, solvent type, and ultrasonic power are the most effective factors in the ultrasound-assisted extraction of oils. Temperature increase reduces the surface tension and vapor pressure of the solvent, leading to a rise in the solvent diffusion into the cell, and thus, the extraction efficiency increases. However, as the temperature approaches the solvent boiling point, its vapor pressure rises. Due to the smaller pressure difference between the interior and exterior of the cavitation bubbles, they collapse less intensively and cause the extraction efficiency to decrease. The increase in ultrasonic power has a similar effect on extraction efficiency. An elevation of the extraction time improves this parameter in the early minutes of extraction, by destroying the cell walls and making the oil diffuse out of the cell-matrix. An increase in the solvent to sample ratio up to an optimal level elevates the concentration gradient of the solvent towards the sample matrix by reducing the solution viscosity and brings about an improvement in the extraction efficiency. The application of the solvents with high vapor pressures results in a decrease in the cavitation energy because of the pressure difference between the cell interior and exterior. Therefore, such solvents do not have a positive effect on the extraction efficiency. Each of the aforementioned factors has its optimum level to enhance the ultrasound-assisted extraction efficiency. [ABSTRACT FROM AUTHOR]

Contamination of food and water with radioactive substances is a serious health problem. There are several methods to detect and measure radioactive materials, some of which have been developed in recent years. This paper aims to discuss the methods of detecting and measuring radioactive substances in food and water. The principles and the advantages and disadvantages of each method have been discussed. The results showed that some of these methods, such as spectrometry γ-ray high-purity germanium, portable radon gas surveyor SILENA, RAD7, and inductively coupled plasma mass spectrometry, have a higher sensitivity for detection and measurement. The spectrometry γ-ray high-purity germanium method has attracted more attention than other methods because it can measure a wide range of radionuclides with high resolution. [ABSTRACT FROM AUTHOR]

[Display omitted] • The importance of safety and increasing the shelf life of oil-in-water nanoemulsion. • Oxidative instability and toxic metabolites leads to the health related threats. • Stimulation of physical and oxidative instability by emulsifiers at the interface. • Dependence of emulsifier choice on chemical structure and functional properties. The thermodynamic instability of food nanoemulsions may occur during production and storage due to environmental stress or reaction with other constituents, appearing in the forms of sedimentation, creaming or oil oxidation. Such instabilities reduce the tendency to consumption and threaten consumers' health. The present study aimed to review the effects of emulsifiers on the physicochemical stability of oil-in-water nanoemulsions. Emulsifiers were selected considering several factors, including the preparation and processing methods, nature, concentration, hydrophilic-lipophilic balance, molecular weight, particle surface charge, ambient temperature, pro-oxidants and antioxidants, and type of the food matrix. Emulsifiers often include proteins, esters of polyoxyethylene (e.g., Tween), fatty acids, polysaccharides, and phospholipids, which play a key role in the formation and stability of food emulsions through adsorption at the oil–water interface. Determining the impact of emulsifiers on the control of instability at the interface contributes to the production of the healthiest, safest, and most stable nanoemulsion-based structures. Since emulsifiers have individual structures and different functional properties, they should be selected based on the desired product properties. Therefore further research is required to identify novel emulsifiers or a combination of emulsifiers with different properties for food applications. [ABSTRACT FROM AUTHOR]

Background and Objectives Falafel is one of the most popular artisanal foods in Iran, especially in Khouzestan province. However, no comprehensive study has been performed to evaluate its microbiological and chemical properties. This study aims to evaluate microbiological and chemical properties of falafel samples collected from street food market in Ahvaz, Iran. Subjects and Methods Microbiological tests including total viable count (TVC), psychrophilic count, Escherichia coli test, staphylococcus aureus test, coliform count, bacillus cereus test, Salmonella test, and mold count were performed to evaluate microbiological properties of falafel samples (cooked and uncooked). The chemical properties were assessed by performing protein test, ash, carbohydrate, lipid, salt, peroxide, and acidity tests. All tests were done according to the methods described by the Institute of Standards & Industrial Research of Iran (ISIRI). Results Microbiological tests revealed that TVC (108 cfu/g), coliform count (3.7×10³ cfu/g) and mold count (1.3×107#179; cfu/g) were significantly higher than the amounts set by the ISIRI (P<0.05), indicating high contamination of uncooked falafel samples. The major problems observed by chemical tests was the high content of lipid (20.11%) and peroxide value (47.85 meq/kg) which were significantly higher than the values set by the ISIRI (P<0.05). Conclusion Microbiological and chemical properties of falafel are poor, indicating the poor hygienic conditions of its preparation in street food market. We recommend more attention to and supervision on the preparation of artisanal foods such as falafel in Iran. [ABSTRACT FROM AUTHOR]