Alev Akpinar Borazan

Drying effects on the antioxidant properties of tomatoes and ginger.

In this study, the effects of four different drying processes, sun drying (SD), oven drying (OD), vacuum oven drying (VOD) and freeze drying (FD) for tomatoes (Solanum lycopersicum) and ginger (Zingiber officinale) in terms of thiolic and phenolic contents have been studied. Thiol content, total phenolic content (TPC), ascorbic acid (AA) content, and cupric ion reducing antioxidant capacity (CUPRAC) were determined in fresh and dried samples. Glutathione (GSH) and cysteine (Cys) were determined as the thiol contents of tomatoes and ginger. Significant losses were observed in the contents of TPC, AA, GSH and Cys and CUPRAC values in all samples that were dried using the thermal method. There was a statistically significant difference in the losses of the TPC, AA, and thiol contents between the use of thermal drying and freeze drying (except Cys in tomatoes) methods. Freeze dried tomato and ginger samples have been found to have better antioxidant properties.

The influence of pectolytic enzyme addition and prefermentative mash heating during the winemaking process on the phenolic composition of Okuzgozu red wine.

The effects of pectolytic enzyme addition and mash heating prior to fermentation on the phenolic component of Okuzgozu red wine during the winemaking and ageing processes were investigated. In general, the highest concentration of total phenolics was found in the mash-heated wines, whereas the total flavan-3-ol and total anthocyanin contents in all of the wines, decreased notably during the winemaking and ageing processes. As determined by HPLC, hydroxycinnamic acids were the major phenolic acids in the red wines. After 6 months in the bottle, the enzyme-treated wines had lower phenolic acid concentrations than had the control and mash-heated wines, but no significant (p<0.05) differences were found in the concentration of total phenolic acids between the control and mash-heated wines. All of the phenolic acid levels decreased with the winemaking and ageing processes whereas only gallic acid increased. The wines treated by the pectolytic enzyme addition had a lower monomeric flavan-3-ol content than had the other wines, and the amount of monomeric anthocyanins extracted did not increase with the addition of enzymes.

Pine Cone and Boron Compounds Effect as Reinforcement on Mechanical and Flammability Properties of Polyester Composites

Abstract Natural fibers are known to be environmentally friendly, and they can be used as an alternative to glass and carbon fibers because of their low cost. Pine cone fibers are a good choice for use in composite manufacturing because they mainly consist of cellulose, hemicelluloses, and lignin macromolecules which provide a hydrophilic character.The potential pine cone forest reserve of Turkey is 54,000 ha. Boron compounds such as borax, boric acid. and zinc borate are generally used for their flame-retardant effect. In this study, three kinds of boron compounds, boron oxide, borax pentahydrate and borax decahydrate, were used to provide better mechanical properties and better incombustibility. The synergistic effects of both waste pine cone and boron compounds were sampled for the manufacture of polyester composites by using a casting process. The composites produced with different fiber contents were characterized by some mechanical properties (bending strength, flexural modulus, izod impact); physical analyses (water absorption, swelling thickness, open porosity, bulk density); flame retardancy (LOI); and TGA, SEM-EDS, and FT-IR analyses. According to mechanical test results, boron oxide showed better bending strength and flexural modulus compared to the other boron compounds. The LOI of composites with a boron compound was higher than the composites with only pine cone reinforcement. Graphical Abstract