Huseyin Ayvaz

Antiproliferative and Antioxidant Properties of Anthocyanin Rich Extracts from Blueberry and Blackcurrant Juice

The present study was aimed at evaluating the antiproliferative potential of anthocyanin-rich fractions (ARFs) obtained from two commercially available juices (blueberry and blackcurrant juices) on three tumor cell lines; B16F10 (murine melanoma), A2780 (ovarian cancer) and HeLa (cervical cancer). Individual anthocyanin determination, identification and quantification were done using HPLC-MS. Antioxidant activity of the juices was determined through different mechanism methods such as DPPH and ORAC. For biological testing, the juices were purified through C18 cartridges in order to obtain fractions rich in anthocyanins. The major anthocyanins identified were glycosylated cyanidin derivatives. The antiproliferative activity of the fractions was tested using the MTT assay. The antiproliferative potential of ARF was found to be associated with those bioactive molecules, anthocyanins due to their antioxidant potential. The results obtained indicated that both blueberry and blackcurrants are rich sources of antioxidants including anthocyanins and therefore these fruits are highly recommended for daily consumption to prevent numerous degenerative diseases.

Characterization and Quantitation of Anthocyanins and Other Phenolics in Native Andean Potatoes

Andean potatoes are gaining popularity not only for their appealing colors and culinary uses but also for their potential higher content of polyphenolic compounds. The objective of this study was to identify potato varieties with increased phenolic content. This was achieved through characterization and quantitation of the phenolic composition in 20 varieties of native Andean potatoes from 4 different Solanum species with different colors. Major quantitative and qualitative differences among evaluated samples were more dependent on the coloration of the extracted sample rather than on the species. The most predominant anthocyanidins were petunidin-3-coumaroylrutinoside-5-glucoside and pelargonidin-3-coumaroylrutinoside-5-glucoside in purple and red potato extracts, respectively, while chlorogenic acid and its isomers were the main phenolic compund (43% of the total phenolic content). Our study suggested that the appropriate selection of native potatoes could provide new sources of polyphenolics with health promoting properties and natural pigments with increased stability for food applications.

Improving the screening of potato breeding lines for specific nutritional traits using portable mid-infrared spectroscopy and multivariate analysis

Efficient selection of potato varieties with enhanced nutritional quality requires simple, accurate and cost effective assays to obtain tuber chemical composition information. In this study, 75 Andean native potato samples from 7 Solanum species with different colors were characterized and quantified for their anthocyanin, phenolics and sugar content using traditional reference methods. IR (infrared) spectra of potato extracts were collected using a portable infrared system and partial least squares regression (PLSR) calibration models were developed. These models were validated using both full cross-validation and an independent sample set giving strong linear correlation coefficients of prediction (rPred)>0.91 and standard error of prediction (SEP) of 24mg/100g phenolics, 7mg/100g monomeric anthocyanins, 0.1g/100g reducing sugars and 0.12g/100g sucrose. Overall, portable infrared system with PLSR showed great potential to facilitate potato breeding and certain aspects of crop management, material selection for potato processing and related research by providing alternative prediction models.

Quantification of soybean oil adulteration in extra virgin olive oil using portable raman spectroscopy

Extra virgin olive oil is produced through either a cold press procedure or a centrifugation with no thermal and chemical treatments and it is considered as the best quality oil under the category of olive oils. The superior properties of olive oil due to its rich in phenolic and antioxidant content and its contribution to prevent several health problems has increased the demand for olive oil over the years. Consequently, it is nowadays sold at remarkably higher price than regular vegetable oils in the market. Unfortunately, extra virgin olive oil (EVOO) has been adulterated with other cheap oils due to potential high commercial profit. Even though, there are methods available to detect the adulteration in EVOO (such as chromatographic methods and PCR), alternative simpler and faster methods are being studied. In this study, performance of portable Raman spectroscopy to quantify soybean oil (SO) adulteration [up to 25 % (w/w)] in EVOO has been evaluated. Partial Least Square Regression (PLSR) calibration models were developed and both internally (using cross-validation, leave-one-out approach) and externally (using an independent sample set) validated. The model gave standard error of prediction (SEP) of 1.34 % (w/w) SO in EVOO and correlation coefficient of prediction (rPred) of 0.99. Additionally, the residual predictive deviation (RPD) value calculated for the model was found to be 5.71, indicating that the model was considered as “good” and could be used for routine analysis and quality control applications.

Melanoma Inhibition by Anthocyanins Is Associated with the Reduction of Oxidative Stress Biomarkers and Changes in Mitochondrial Membrane Potential

AbstractAnthocyanins are water soluble pigments which have been proved to exhibit health benefits. Several studies have investigated their effects on several types of cancer, but little attention has been given to melanoma. The phytochemical content of nine different berry samples was assessed by liquid chromatography followed by electrospray ionization mass spectrometry (LC-ESI+-MS). Twenty-six anthocyanins were identified, after a previous C18 Sep-pak clean-up procedure. Chokeberry and red grape anthocyanins rich extracts (C-ARE and RG-ARE) were selected to be tested on normal and melanoma cell lines, due to their different chemical pattern. C-ARE composition consists of cyanidin aglycone glycosylated with different sugars; while RG-ARE contains glucosylated derivatives of five different aglycones. Both C-ARE and RG-ARE anthocyanins reduced proliferation, increased oxidative stress biomarkers and diminished mitochondrial membrane potential in melanoma cells, having no negative influence on normal cells. A synergistic response may be attributed to the five different aglycones present in RG-ARE, which proved to exert greater effects on melanoma cells than the mixture of cyanidin derivatives with different sugars (C-ARE). In conclusion, C-ARE and RG-ARE anthocyanins may inhibit melanoma cell proliferation and increase the level of oxidative stress, with opposite effect on normal cells. Therefore, anthocyanins might be recommended as active ingredients for cosmetic and nutraceutical industry. Graphical Abstractᅟ

The potential of near and mid-infrared spectroscopy for rapid quantification of oleuropein, total phenolics, total flavonoids and antioxidant activity in olive tree (Olea europaea) leaves

Natural foods and food-related antioxidants such as phenolic phytochemicals are of great interest due to their preventive properties against oxidative damage. Olive tree leaves contain high quality and amount of phenolic compounds including oleuropein and therefore considered as nutraceutically valuable materials. The composition of olive leaves, its phenolics and antioxidant power are influenced by numerous factors causing great variation among samples. Additionally, traditional analytical methods performed to quantify these parameters in each product entail long and complicated sample preparation procedures, the use of toxic chemicals, skilled labors, instrumentation and sophisticated laboratory conditions. One appealing alternative is the use of infrared spectroscopy since it gives information about the food composition quickly and it is a multi-parametric and environmentally friendly choice. Therefore, we investigated the oleuropein, total phenolic content, total flavonoid content and antioxidant activity levels of 23 common cultivars of olive leaves harvested from Turkey and Italy using traditional reference methods and also developed near and mid-infrared based partial least squares regression (PLSR) models to predict these parameters without the need of sample preparation. Internal validations of the PLSR calibration models were done using full cross-validation and yielded very high correlation coefficients (≥ 0.95) and low errors in predictions (% standard error of cross-validation for parameters were lower than 7.54%). The levels of all the parameters of interest could be successfully predicted using both NIR and MIR instrumentation within seconds. Overall, infrared spectroscopy along with chemometrics exhibited great potential for future olive leave studies.

Infrared and Raman Spectroscopy

Infrared (IR) spectroscopy is currently widely used in the food industry for both qualitative and quantitative analysis of ingredients and finished foods. Mid-IR, near-IR, and Raman spectroscopy requires much less time to perform quantitative analysis than do many conventional wet chemical or chromatographic techniques. This chapter describes the techniques of mid- and near-IR and Raman spectroscopy, including the principles by which molecules absorb IR radiation, the components and configuration of commercial IR spectrometers, sampling methods for IR spectroscopy, and qualitative and quantitative applications of these techniques to food analysis. Infrared (IR) spectroscopy refers to measurement of the absorption of different frequencies of IR radiation by foods or other solids, liquids, or gases. IR spectroscopy measures the absorption of radiation in the near-IR (λ = 0.8–2.5 μm) or mid (λ = 2.5–15 μm) regions by molecules in food or other substances. By using multivariate statistical techniques, infrared instruments can be calibrated to measure the amounts of various constituents in a food sample based on the amount of IR radiation absorbed at specific wavelengths.