Microwave assisted extraction of phenolic compounds from tomato and sour cherry pomaces

Şimşek, Meriç
The objective of this study was to compare microwave assisted extraction (MAE) and conventional extraction methods for the extraction of total phenolic compounds (TPC) from tomato and sour cherry pomace. Antiradical efficiency (AE) of the extracts and also the concentration of phenolic compounds were determined. In MAE, the effects of microwave power (400 and 700 W), solvent type (water, ethanol and ethanol-water mixture at 1:1 v/v), extraction time (8-20 min) and solvent to solid ratio (10, 20 and 30 ml/g) were studied to observe the change of TPC and AE of the extracts. Conventional extraction was conducted for 6 h using different solvent to solid ratios (10, 20 and 30 ml/g) and solvent types (water, ethanol and ethanol-water mixture at 1:1 v/v). When the power increased from 400 W to 700 W, TPC and AE values increased. In MAE, maximum TPC and AE values were obtained at a solvent to solid ratio of 20 ml/g. The highest TPC and AE values were obtained when the ethanol-water mixture was used for both MAE and conventional extraction. The highest TPC and AE of tomato pomace extracts was determined as 3.76 mg gallic acid equivalent, GAE/g sample and 4.84 mg 1,1-diphenyl-2-picrylhydrazyl, DPPH/g sample, respectively in MAE using power level of 700 W, ethanol-water mixture, solvent to solid ratio of 20 ml/g and extraction time of 14 min. The major phenolic acids detected in tomato pomace extract were gentisic acid and vannilic acid. For sour cherry pomace extracts, the highest TPC and AE was found as 14.14 mg GAE/g sample and 28.32 mg DPPH/g sample, respectively in MAE using power level of 700 W, solvent to solid ratio of 20 ml/g, ethanol-water mixture and extraction time of 12 min. Epicatechin was found to be the major phenolic acid in sour cherry pomace. There was no significant difference in different extraction methods in terms of TPC. On the other hand, AE value and concentration of major phenolic acids of tomato and sour cherry pomace increased when MAE was used.


The effects of hydrogen peroxide, gallic acid and resveratrol on growth and catalase production of aspergillus fumigatus
Doğan, Tunca; Ögel, Zümrüt Begüm; Department of Food Engineering (2008)
The aim of this study was to analyze the effect of hydrogen peroxide and selected phenolic compounds on growth and catalase production of Aspergillus fumigatus. As a result of growing A. fumigatus at different temperatures it was observed that, growth and catalase production of this species were highest at 37 °C. Catalase production was highest in the presence of 1 mM H2O2, yielding a significant 3 fold increase with respect to the control. Biomass was also increased by 1,44 fold with respect to the control...
Optimization of microwave- infrared roasting of hazelnut
Uysal, Nalan; Şümnü, Servet Gülüm; Şahin, Serpil (Elsevier BV, 2009-01-01)
In this study, the possibility of using microwave-infrared combination oven for roasting of hazelnut was investigated. in addition, regression models for the responses: L* value, a* value, textural properties and moisture content of hazelnuts were obtained and the optimum roasting conditions were determined by using response surface methodology. Conventionally roasted hazelnut at 150 degrees C for 20 min was considered for comparison. For hazelnuts, 2.5 min roasting time at 90% microwave power, 60% upper ha...
Investigation of sensory and instrumental methods to predict shelf-life of jelly gums
Tireki, Suzan; Şümnü, Servet Gülüm; Şahin, Serpil; Department of Food Engineering (2017)
The main aim of this study was to correlate sensorial changes with instrumental techniques to predict shelf life during storage of jelly gums. Effects of glucose syrup:sucrose ratio, starch and gelatine content on quality and sensorial properties of jellies were investigated. Glucose syrup: sucrose ratio, starch and gelatine contents affected hardness significantly. Moisture content, water activity, total soluble solids, pH, springiness and gumminess was influenced by only glucose syrup:sucrose ratio. Moist...
Cinnamon oil nanoemulsions by spontaneous emulsification: Formulation, characterization and antimicrobial activity
YILDIRIM, Simge Tutku; Öztop, Halil Mecit; Soyer, Yeşim (Elsevier BV, 2017-10-01)
The goal of this study was to formulate stable cinnamon oil nanoemulsions (NEs) exhibiting high anti-microbial activity by using the low-energy approach: spontaneous emulsification (SE) and compare it with two high-energy methods. To prepare the nanoemulsions by SE, oil phase containing cinnamon oil (CO) and carrier oil (coconut oil (CNO)) at different ratios (2:8-10:0) and surfactant (Tween 80) at 10% (w/w) was titrated into an aqueous phase (distilled water). For antimicrobial activity, agar disc diffusio...
Physical characterization of high methoxyl pectin and sunflower oil wax emulsions: A low-field H-1 NMR relaxometry study
Akkaya, Sinem; Özel, Barış; Öztop, Halil Mecit; YANIK, DERYA KOÇAK; GÖĞÜŞ, FAHRETTİN (Wiley, 2020-12-01)
Pectin-wax-based emulsion systems could be used to form edible films and coatings with desired water permeability characteristics. Pectin is often used in food industry due to its gelling and viscosity increasing properties. Physical properties of pectin are highly dependent on its esterification degree. Waxes are commonly used as edible coatings to enhance the water barrier properties of food products. This study focuses on preparing emulsions with sunflower oil wax (SFW) and high methoxyl pectin (HMP) at ...
Citation Formats
M. Şimşek, “Microwave assisted extraction of phenolic compounds from tomato and sour cherry pomaces,” M.S. - Master of Science, Middle East Technical University, 2010.