Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
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Article Citation - WoS: 27Citation - Scopus: 29Differentiation of Wines With the Use of Combined Data of Uv-Visible Spectra and Color Characteristics(Academic Press Inc., 2016) Şen, İlknur; Tokatlı, FigenUV-visible spectra and color parameters of monovarietal wines with orthogonal partial least square-discriminant analysis (OPLS-DA) were shown to be practical and rapid methods for classification purposes. Red and white wines from the 2006-2009 vintages were characterized in terms of color, anthocyanin content and UV-visible spectra. Syrah and Cabernet Sauvignon wines had high color density and intensity. Kalecik Karasi wines had the highest CIELab parameters and the lowest color density. Boğazkere and Öküzgözü wines showed similarities with respect to their high red color parameters and were distinct from other wines. Merlot, Syrah and Öküzgözü wines had the highest total anthocyanin content (61.9-55. mg/L as median values). White wines made from Chardonnay, Muscat and Emir grapes were found to have different color characteristics. The vintage-based discrimination of red wines was mostly apparent in total anthocyanin contents. Different UV wavelength regions were found to be effective in classification with respect to variety and vintage. Correct classification rates in the validation set were 100% and 75%, for varietal and vintage classifications, respectively. This study demonstrated the potential of combination of UV-visible spectra and color characteristics to be used in the authentication of wines.Article Citation - WoS: 12Citation - Scopus: 13The Discrimination of Raw and Uht Milk Samples Contaminated With Penicillin G and Ampicillin Using Image Processing Neural Network and Biocrystallization Methods(Academic Press Inc., 2013) Ünlütürk, Sevcan; Pelvan, Merve; Ünlütürk, Mehmet S.This paper utilized a neural network for texture image analysis to differentiate between milk, either raw or ultra high temperature (UHT) with antibiotic residues (e.g., penicillin G and ampicillin) and milk without antibiotic residues. The biocrystallization method was applied to obtain biocrystallogram images for milk samples spiked with penicillin G and ampicillin at different concentration levels. The biocrystallogram images were used as an input for a designed neural network called the image processing neural network (ImgProcNN). The visual differences in these images that were based on textural properties, including the distribution of crystals on the circular grass underlay, the thin or thick structure of the crystal needles, and the angles between the branches and the side needles, were used to discriminate the antibiotic-free milk samples from samples with antibiotic residues. The visual description and definition of these images have major disadvantages. In this study, the ImgProcNN was developed to overcome the shortcomings of these visual descriptions and definitions. Overall, the neural network achieved an average recognition performance between 86% and 100%. This high level of recognition suggests that the neural network used in this paper has potential as a method for discriminating raw and UHT milk samples contaminated with different antibiotics.Article Citation - WoS: 115Citation - Scopus: 135Antioxidant Activity and Phenolic Content of Fresh and Dry Nuts With or Without the Seed Coat(Academic Press Inc., 2009) Arcan, İskender; Yemenicioğlu, AhmetTotal antioxidant activities based on ABTS free radical scavenging activity and phenolic content of fresh or dry hazelnuts, walnuts and pistachios assayed with their seed coats changed between 3063 and 11,076 μmol trolox equivalents/100 g d.w. and 256 and 755 mg gallic acid equivalents/100 g d.w., respectively. The walnuts used in this study showed the highest antioxidant activity, followed by pistachios and hazelnuts. The removal of seed coat reduced the total antioxidant activity of hazelnuts, walnuts and pistachios almost 36, 90 and 55%, respectively. The total antioxidant activities of investigated fresh and dry nuts are not considerably different. However, phenolic content and antioxidant activity in hydrophilic and ethanolic fractions obtained by successive extraction of nuts showed some variation. The antioxidant activity in 1-serving portion of fresh or dry walnuts is equivalent to that in almost 2-serving portions of black tea, and 1.2-1.7-serving portions of green and Earl Grey tea. One-serving portions of dry hazelnuts and fresh or dry pistachios contained antioxidant activity equivalent to that in 0.7-1-serving portions of black tea. The antioxidant activity measurements correlated with phenolic content (r2 = 0.70). This study showed the potential of using fresh or dry nuts to develop functional foods with high antioxidant activity.