Buket Yalcin

Phenolic compounds analysis of root, stalk, and leaves of nettle.

Types of nettles (Urtica dioica) were collected from different regions to analyze phenolic compounds in this research. Nettles are specially grown in the coastal part. According to this kind of properties, nettle samples were collected from coastal part of (Mediterranean, Aegean, Black sea, and Marmara) Turkey. Phenolic profile, total phenol compounds, and antioxidant activities of nettle samples were analyzed. Nettles were separated to the part of root, stalk, and leaves. Then, these parts of nettle were analyzed to understand the difference of phenolic compounds and amount of them. Nettle (root, stalk and leaves) samples were analyzed by using High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) to qualitative and quantitative determination of the phenolic compounds. Total phenolic components were measured by using Folin-Ciocalteu method. The antioxidant activity was measured by using DPPH (2,2-diphenyl-1-picrylhydrazyl) which is generally used for herbal samples and based on single electron transfer (SET).

Food Chemistry and Nanoscience

Food Chemistry and Nanoscience Nanotechnology is a rapidly developing area of technology and science, which is generally interested in particles between 1-100 nm. This technology shows great potential to provide new biological, physical and chemical features to materials in molecular or atomic scale. By comparison with macrosize materials, nanoscale structures have been shown advanced and novel features, hereby they are interested in many kind of fields especially electronic, computer, textile and pharmaceutical industries. Applications of nanotechnology in the food industry have been developing more slowly than other areas because of their complex structures and sensitivity. Some applications in the food industry are improving the uptake, absorption, and bioavailability of nutrients and supplements in the body, producing new or improved tastes, and textures of foods, improving food packaging materials, developing nanosensors that can give information about the freshness or spoilage of products during transportation, storage of food products. According to these parameters, the application of nanotechnology in food industry is based on chemical process between food materials, food contact materials (packaging materials) and nanomaterials, as a principle of chemical interactions.

Storage characteristics of microencapsulated extra virgin olive oil powder: physical and chemical properties

In this study, physical and chemical properties of microencapsulated extra virgin olive oil powder (MEVOP) produced through spray drying were investigated during storage under different temperatures (4, 25 and 60 °C). The effect of homogenization methods in terms of rotor–stator (RSH) and ultrasonic (UH) were also examined on MEVOP along storage period. The physical and chemical properties of MEVOP obtained either RSH or UH showed that water activity, tapped density, Carr index (flowability), caking degree, surface oil content, peroxide value (PV) and free fatty acid (FFA) significantly increased, while bulk density, microencapsulation efficiency (ME), total phenolic content and antioxidant capacity significantly decreased during storage at 4, 25 and 60 °C. However, as the particle size of MEVOPs stored at 4 °C decreased along storage time, particle size of samples stored at 25 and 60 °C increased due to increase in surface oil content and particle–particle cohesion. The MEVOPs stored 4 and 25 °C had higher particle density compared to the sample stored at 60 °C during storage. Rapid changes in antioxidant capacity and total phenolic content of MEVOP were also determined during storage with increased storage temperature. There was a significant effect of homogenization method on particle size, for this reason physical and chemical properties of powder changed. When all quality characteristics and oxidative stability were evaluated, MEVOP should be stored at ambient or lower temperature in order to increase its shelf life.

Strategic Role of Nanobiosensor in Food: Benefits and Bottlenecks

Nanotechnology has recently become one of the most exciting forefront fields in biosensors fabrication. Nanotechnology has been changing the area of biosensor for many kinds of fields as food. Nanobiosensor, an integration of molecular engineering, physical sciences, chemistry, biology and biotechnology, holds the possibility of manipulating and detecting molecules and atoms using nano-devices/machines, which have the potential for a wide range of both domestic and industrial applications. The role of nanobiosensors in food analysis and detection of chemical and biological compounds in food is an interesting and important area. Biosensors permit the detection of a wide spectrum of analyte in complex sample matrices and have denoted great promise in areas like food analysis. There has been a steadily growing use of biosensor technology for the detection of food contaminants such as food dyes, processing contaminants, veterinary drugs, marine toxins and mycotoxins. On the other hand, there are both some benefits and bottlenecks of nanobiosensors in food fields.