Browsing by Author "Capanoglu, Esra"

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Citation Count: 6
Bioaccessibility of terebinth (Pistacia terebinthus L.) coffee polyphenols: Influence of milk, sugar and sweetener addition
(Elsevier Sci Ltd, 2022) Kamiloglu, Senem; Ozdal, Tugba; Bakir, Sena; Capanoglu, Esra
In this study, terebinth coffee formulations were prepared with whole or skimmed milk with or without sugar/ sweetener in order to study the matrix effect on the bioaccessibility of terebinth polyphenols. Quercetin glycosides and catechin were the major flavonoids identified in the terebinth formulations, whereas gallic, protocatechuic, syringic and ellagic acids were determined as the non-flavonoid compounds. The in vitro gastrointestinal digestion model results revealed that addition of whole milk to terebinth coffee increased the total bioaccessible flavonoids significantly (45%) (p < 0.05), whereas skim milk addition did not result in any significant change. Furthermore, antioxidant capacity results measured with CUPRAC assay showed that addition of milk alone or together with sugar/sweetener increases the bioaccessibility of terebinth coffee antioxidants (36-70%) (p < 0.05). Overall, terebinth coffee + whole milk + sugar formulation was found to contain the highest amount of bioaccessible flavonoid and non-flavonoid compounds (42.71-47.07 mg/100 g).
Citation Count: 9
Chemistry of Protein-Phenolic Interactions Toward the Microbiota and Microbial Infections
(Frontiers Media Sa, 2022) Yilmaz, Hilal; Gultekin Subasi, Busra; Celebioglu, Hasan Ufuk; Ozdal, Tugba; Capanoglu, Esra
Along with health concerns, interest in plants as food and bioactive phytochemical sources has been increased in the last few decades. Phytochemicals as secondary plant metabolites have been the subject of many studies in different fields. Breakthrough for research interest on this topic is re-juvenilized with rising relevance in this global pandemics' era. The recent COVID-19 pandemic attracted the attention of people to viral infections and molecular mechanisms behind these infections. Thus, the core of the present review is the interaction of plant phytochemicals with proteins as these interactions can affect the functions of co-existing proteins, especially focusing on microbial proteins. To the best of our knowledge, there is no work covering the protein-phenolic interactions based on their effects on microbiota and microbial infections. The present review collects and defines the recent data, representing the interactions of phenolic compounds -primarily flavonoids and phenolic acids- with various proteins and explores how these molecular-level interactions account for the human health directly and/or indirectly, such as increased antioxidant properties and antimicrobial capabilities. Furthermore, it provides an insight about the further biological activities of interacted protein-phenolic structure from an antiviral activity perspective. The research on the protein-phenolic interaction mechanisms is of great value for guiding how to take advantage of synergistic effects of proteins and polyphenolics for future medical and nutritive approaches and related technologies.
Citation Count: 0
Comparison of Physicochemical Properties, Antioxidants, and Aroma Profiles of Water- and Sodium-Hydroxide-Treated Natural Cocoa Powder
(Amer Chemical Soc, 2024) Barla Demirkoz, Ayşe Aslı; Ceylan, Fatma Duygu; Demirkoz, Asli Barla; Karaca, Asli Can; Capanoglu, Esra; Beslenme ve Diyetetik / Nutrition and Dietetics
Cocoa powder alkalization is an essential process in chocolate manufacturing, and traditionally, this process involves the use of alkaline agents, such as sodium hydroxide (NaOH), potassium hydroxide (KOH), and potassium carbonate (K2CO3). However, these methods involve harsh chemicals and energy-intensive procedures, raising significant environmental concerns. Water (H2O) has emerged as a promising alternative due to its safety, minimally harmful byproducts, and accessibility. Green chemistry principles have gained importance across industries, especially in food production, where sustainable practices are highly valued. This study aimed to develop a greener process by investigating the alkalization potential of H2O and comparing the results with those of NaOH. The particle size distribution, pH, color, antioxidant capacity, phenolic composition, and aroma profile of cocoa powders treated with H2O and NaOH were evaluated. The alkalization temperature significantly affected the color of the cocoa powders, and the alkali solution ratio influenced the L* values of H2O-treated powders. In industrial and commercial specifications, an Delta E value below 3 is considered standard for color measurements. Both H2O-treated and NaOH-treated natural cocoa powders had Delta E values exceeding 3 compared to the untreated powder, indicating that H2O treatment darkens the color in a similar way to that of traditional methods. While NaOH produced a darker color, process optimization allowed both H2O and NaOH treatments to achieve similar color attributes (Delta E < 3). Significant differences were observed in the antioxidant capacity and total phenolic content (TPC) between the H2O-treated and NaOH-treated cocoa powders. H2O treatment positively impacted the antioxidative properties of the cocoa powder. The antioxidant capacity, measured by the DPPH and CUPRAC methods, was significantly higher in H2O-treated samples (295.5-317.7 TEAC mg/100 g and 835-1542 TEAC mg/100 g, respectively) compared to NaOH-treated samples (256.6-306.2 TEAC mg/100 g and 171-849 TEAC mg/100 g, respectively). Additionally, the TPC of H2O-treated cocoa powder [281.3-321.6 gallic acid equivalent (GAE) mg/100 g] was significantly higher than that of NaOH-treated powder (100.0-298.6 GAE mg/100 g). The significant differences in the phenolic profiles suggested that the alkalization process affects individual phenolic compounds differently. Moreover, H2O-treated cocoa powders had significantly higher trimethylpyrazine/tetramethylpyrazine (TrMP/TMP) ratios than those of NaOH-treated samples, indicating notable differences in aroma profiles. This study suggests that H2O can replace NaOH in the alkalization process of the cocoa industry, particularly for lightly treated alkalized cocoa powders that maintain high antioxidant activity and TrMP/TMP ratios. This offers a more environmentally friendly, easily manageable, and sustainable process for cocoa powder alkalization.
Citation Count: 92
Effect of food matrix on the content and bioavailability of flavonoids
(Elsevier Science London, 2021) Kamiloglu, Senem; Tomas, Merve; Ozdal, Tugba; Capanoglu, Esra
Background:Dietary flavonoids have drawn great interest owing to their potential positive effects on health, which considerably rely on their bioaccessibility, transport and further metabolism in the body. One of the key parameters that influence the flavonoid bioavailability is the interaction of these compounds with other nutrients present in the human diet. Scope and Approach:This review highlights the current findings on the influence of co-ingestion of flavonoids with other macro- (carbohydrates, lipids and proteins) and micro-constituents (vitamins, minerals, and other micronutrients) in foods. Key Findings and Conclusions:Majority of both in vitro and in vivo studies in the literature suggest that proteins, dietary fiber, and minerals may induce disadvantageous impact on the bioavailability of flavonoids. On the other hand, lipids, digestible carbohydrates, vitamins, alkaloids, carotenoids and other flavonoids are likely to improve flavonoid bioavailability. Nevertheless, interaction of flavonoids with food matrix components is a complicated parameter that needs to be explored further in order to ensure utmost positive health effects to humans.
Citation Count: 13
Effects of Honey Addition on Antioxidative Properties of Different Herbal Teas
(inst Animal Reproduction & Food Research Polish Acad Sciences Olsztyn, 2015) Toydemir, Gamze; Capanoglu, Esra; Kamiloglu, Senem; Firatligil-Durmus, Ebru; Sunay, Asli E.; Samanci, Taylan; Boyacioglu, Dilek
Tea and herbal infusions are among the major contributors of phenolic compounds, specifically flavonoids, in our daily diet. Honey is another antioxidant-rich food that is widely used as a natural sweetener. In this work, the effects of honey addition on antioxidant properties of different herbal teas were investigated. For this purpose, 2 different types of honey (flower and pine honey) were added into 9 different herbal teas (melissa, green tea, rosehip, sage, echinacea, fennel, linden, daisy, and ginger) at 4 different temperatures (55 degrees C, 65 degrees C, 75 degrees C, and 85 degrees C), and the changes in the content of total pheolics, total flavonoids, and total antioxidant capacity were determined. The total phenolic content and the total antioxidant capacity of the honey-added-tea samples were found to be increased (up to 57% for both), especially with pine honey and at higher temperatures of honey addition. The findings of this study supported the use of honey as a natural sweetener in tea in order to be able to benefit from the health-enhancing antioxidative properties of these two promising food products.
Citation Count: 62
The effects of juice processing on black mulberry antioxidants
(Elsevier Sci Ltd, 2015) Tomas, Merve; Toydemir, Gamze; Boyacioglu, Dilek; Hall, Robert; Beekwilder, Jules; Capanoglu, Esra
Black mulberry fruit is processed to juice at significant scale in Turkey. The effect of industrial-scale juice production on black mulberry antioxidants was evaluated using samples collected from the main steps of processing; including the selection of fruits, washing, mechanical milling, mashing, cold pressing, pasteurization, and filling-packing. Two major anthocyanins (cyanidin-3-glucoside and cyanidin-3-rutinoside), two phenolic acids (3- and caffeoylquinic acid) and 3 flavonols (rutin, quercetin-3-glucoside, and quercetin-malonyl-glucoside) were identified using LC-QTOF-MS and were quantified using HPLC. Approximately, 60-70% of the fruit anthocyanins were retained in the final juice, which also contained high levels of caffeoylquinic acids, relative to the fruit. Mashing and pressing were the steps which were effective for the recovery of fruit polyphenolics into the juice fraction. Moreover, an in vitro gastrointestinal digestion model, applied to determine the effect of processing on the bioavailability of mulberry antioxidants, indicated a higher anthocyanin bioavailability for the fruit matrix than for the juice matrix. (C) 2014 Elsevier Ltd. All rights reserved.
Citation Count: 21
Evaluation of Turkish propolis for its chemical composition, antioxidant capacity, anti-proliferative effect on several human breast cancer cell lines and proliferative effect on fibroblasts and mouse mesenchymal stem cell line
(Taylor & Francis Ltd, 2018) Ozdal, Tugba; Sari-Kaplan, Gulce; Mutlu-Altundag, Ergul; Boyacioglu, Dilek; Capanoglu, Esra
Propolis is an extremely complex resinous natural compound collected by honey bees from various plant sources and exhibits pharmacological and biological properties attributed to the presence of polyphenols. This study examined the total phenolic and flavonoid contents as well as the total antioxidant capacity using 2,2 '-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), cupric-reducing antioxidant capacity (CUPRAC), and ferric-reducing antioxidant power (FRAP) methods. Turkish propolis has very high total phenolic (314.36 +/- 3.65 mg GAE/g propolis) and total flavonoid contents (522.71 +/- 11.45 mg QE/g propolis). The highest antioxidant capacity value was obtained by the CUPRAC method (1184.94 +/- 63.27 mg TE/g propolis). Phenolic profile of Turkish propolis was also determined by high performance liquid chromatography with photodiode array detection (HPLC-PDA) method. The main phenolic compounds identified in Turkish propolis was flavonoids including pinocembrin > chrysin > galangin > pinobanksin > pinostrobin and phenolic acids including caffeic acid > p-coumaric acid > ferrulic acid > t-cinnamic acid. In the present work, anti-proliferative and proliferative effects of propolis extracts were also investigated on two different breast cancer cell lines; MDA-MB-231, UACC-3199 and on two normal cell lines; fibroblasts and mouse mesenchymal stem cell lines. According to the XTT results, Turkish propolis sample showed significant anti-proliferative effect on MDA-MB-231 and UACC breast cancer cell lines. Interestingly, Turkish propolis sample had proliferative effect on both fibroblasts and mouse mesenchymal stem cells. These results suggest that Turkish propolis can be considered as a potent agent on breast cancer treatment for further investigations.
Citation Count: 0
From carotene-rich waste-to-food: Extraction, food applications, challenges and opportunities
(Elsevier Science London, 2025) Tomas, Merve; Kamiloglu, Senem; Nemli, Elifsu; Ozdal, Tugba; Haque, Shafiul; Apak, Resat; Capanoglu, Esra
Background: Food waste products of industrial processing pose environmental and economic problems. Although there are existing studies in the current literature regarding the evaluation of carotene-rich waste, there is a need for innovative and up-to-date information on the valorization of these wastes. Scope and approach: This article aims to provide an extensive approach to food waste valorization, extraction of carotenoids from waste including potential sources of functional food ingredients, food applications, and life cycle assessment in terms of carotene-rich wastes. Key findings and conclusions: Recovery of carotene from food waste is an important strategic aim in terms of a sustainable agriculture system and the development of functional foods and natural food colorants. In this sense, various green extraction techniques are used for high yields and the best quality carotenoids. Combining green extraction methods including pulsed electric field (PEF) and ultrasound-assisted extraction (UAE) or pressurized liquid extraction (PLE) and supercritical fluid extraction (SFE) may be an efficient approach. However, research on the extended applications of these carotenoid-rich extracts is scarce, so future studies should focus on their potential use in various food materials. Therefore, further studies are required to cover the current gaps relating to the upcoming valorization of carotenes.
Citation Count: 40
Fruit Antioxidants during Vinegar Processing: Changes in Content and in Vitro Bio-Accessibility
(Mdpi, 2016) Bakir, Sena; Toydemir, Gamze; Boyacioglu, Dilek; Beekwilder, Jules; Capanoglu, Esra
Background: Vinegars based on fruit juices could conserve part of the health-associated compounds present in the fruits. However, in general very limited knowledge exists on the consequences of vinegar-making on different antioxidant compounds from fruit. In this study vinegars derived from apple and grape are studied. Methods: A number of steps, starting from the fermentation of the fruit juices to the formation of the final vinegars, were studied from an industrial vinegar process. The effect of each of the vinegar processing steps on content of antioxidants, phenolic compounds and flavonoids was studied, by spectroscopic methods and by high-performance liquid chromatography (HPLC). Results: The major observation was that spectrophotometric methods indicate a strong loss of antioxidant phenolic compounds during the transition from fruit wine to fruit vinegar. A targeted HPLC analysis indicates that metabolites such as gallic acid are lost in later stages of the vinegar process. Conclusion: The major conclusion of this work is that major changes occur in phenolic compounds during vinegar making. An untargeted metabolite analysis should be used to reveal these changes in more detail. In addition, the effect of vinegar processing on bio-accessibility of phenolic compounds was investigated by mimicking the digestive tract in an in vitro set up. This study is meant to provide insight into the potential of vinegar as a source of health-related compounds from fruit.
Citation Count: 290
Guidelines for cell viability assays
(Wiley, 2020) Kamiloglu, Senem; Sari, Gulce; Ozdal, Tugba; Capanoglu, Esra
Recently, the interest in the application of cell viability assays has been increasing in various fields. Cell viability assays may be broadly classified as (a) dye exclusion assays, (b) colorimetric assays, (c) fluorometric assays, (d) luminometric assays, and (e) flow cytometric assays. Dye exclusion assays include trypan blue, eosin, congo red, and erythrosine B stain assays, whereas 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT), 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT), 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H tetrazolium, monosodium salt (WST-1), 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt (WST-8), lactate dehydrogenase (LDH), sulforhodamine B (SRB), neutral red uptake (NRU), and crystal violet stain (CVS) assays are among the colorimetric assays. Similarly, resazurin and 5-carboxyfluorescein diacetate acetoxymethyl ester (5-CFDA-AM) assays are based on fluorometric measurements, whereas luminometric assays comprise adenosine triphosphate and real-time viability assays. Major flow cytometric assays include membrane asymmetry, membrane permeability, and mitochondria assays. In this guideline, the mechanisms and the practice of assessment of the most common cell viability assays applied in research labs are discussed in detail. An ideal cell viability assay should be safe, rapid, reliable, efficient, and time- and cost-effective, and should not interfere with the test compound. Overall, it can be concluded that more than one cell viability assay should be applied in order to obtain reliable results.
Citation Count: 91
Home-Processed Red Beetroot (Beta vulgaris L.) Products: Changes in Antioxidant Properties and Bioaccessibility
(Mdpi, 2016) Guldiken, Burcu; Toydemir, Gamze; Memis, Kubra Nur; Okur, Sena; Boyacioglu, Dilek; Capanoglu, Esra
In this study, the effects of home-processing on the antioxidant properties and in vitro bioaccessibility of red beetroot bioactives were investigated. For this purpose, fresh red beetroot and six different home-processed red beetroot products-including boiled, oven-dried, pickled, pureed, juice-processed, and jam-processed-were analyzed and compared for their total phenolic (TP) and total flavonoid (TF) contents, total antioxidant capacities (TAC), and individual anthocyanin contents. In addition, bioaccessibility of red beetroot antioxidants was determined using an in vitro simulated gastrointestinal digestion method. Dried, pureed, and fresh red beetroot samples had the highest TP, TF, and TAC values, which were 347 +/- 23 mg gallic acid equivalent (GAE)/100 g, 289 +/- 53 mg rutin equivalent (RE)/100 g, 3889 +/- 982 mg trolox equivalent antioxidant capacity (TEAC)/100 g, respectively. The in vitro digestion method revealed the highest recovery for TP (16%) and TAC (1.3%) in jam. This study provides comparative data to evaluate the effects of various home-processing techniques on antioxidant potential of red beetroot products.
Citation Count: 2
In vitro digestibility of plant proteins: strategies for and health implications
(Elsevier Sci Ltd, 2024) Kamiloglu, Senem; Tomas, Merve; Ozkan, Gulay; Ozdal, Tugba; Capanoglu, Esra
Plant proteins (PP) are gaining growing global attention, driven by increased consumer awareness on the importance of healthy nutrition, concerns for animal welfare, and emphasis on understanding environmental impacts. Digestibility of PP directly affects their nutritional value and health effects. Previous research has shown that the digestibility of PP can be improved by (i) conventional and emerging food processing technologies, including thermal treatment, fermentation, highpressure processing, pulsed electric field, cold plasma, and ultrasonication, (ii) chemical methods involving enzymatic hydrolysis and use of polyphenols and other agents to form complexes, and (iii) food formulation/matrix. Overall, the selection of a proper protein source, food processing or chemical technology, and food formulation can be used to improve the digestibility of PP.
Citation Count: 67
Investigation of antioxidant capacity, bioaccessibility and LC-MS/MS phenolic profile of Turkish propolis
(Elsevier, 2019) Ozdal, Tugba; Ceylan, Fatma Duygu; Eroglu, Nazife; Kaplan, Muammer; Olgun, Elmas Oktem; Capanoglu, Esra
Propolis is a resinous bee hive product that has many biological activities. In this study, a total of 11 raw propolis samples were collected from various geographical areas in Turkey. Phenolic compounds were extracted from all samples and analyses of total phenolics and flavonoids and total antioxidant capacities were performed. All the samples showed high total phenolic and flavonoid contents and antioxidant capacities. Moreover, the in vitro bioaccessibility of Turkish propolis samples were investigated according to simulated in vitro gastrointestinal digestion method. Bioaccessibility was increased through the gastric and intestinal phases. Furthermore, the composition of polyphenols (phenolic acids and flavonoids) in Turkish propolis extracts was investigated by LC-MS/MS method. A total of 32 phenolic compounds, including Caffeic acid phenylethyl ester (CAPE) which was observed in all samples, were identified in the samples. Higher CAPE contents were determined in the samples from the Marmara region which is in line with its higher antioxidant capacity values. As a conclusion, propolis samples collected from different geographical locations differ for their phenolic and flavonoid contents, individual phenolic profile and bioaccessibility.
Citation Count: 6
Oil matrix modulates the bioaccessibility of polyphenols: a study of salad dressing formulation with industrial broccoli by-products and lemon juice
(Wiley, 2022) Kamiloglu, Senem; Ozdal, Tugba; Tomas, Merve; Capanoglu, Esra
BACKGROUND The potential health-promoting effects of polyphenols depend considerably on their bioaccessibility, which is affected by the presence of other nutrients in the diet, including lipids. In this study, several salad dressing formulations were prepared using industrial broccoli by-product powder (BBP), lemon juice (LJ), and three different sources of oils (olive oil, hazelnut oil and sunflower oil) to both valorize polyphenol-rich industrial discards and also to investigate polyphenol bioaccessibility. The changes in the bioaccessibility of polyphenols from BBP and LJ were determined using the standardized in vitro digestion model. RESULTS Four groups of polyphenols (hydroxycinnamic acids, flavonols, flavones, and flavonones) were detected in BBP and LJ. The bioaccessibility of hydroxycinnamic acids and flavonols from BBP increased significantly in the presence of LJ and oils (0.3- to 5.8-fold), whereas there was no significant difference between formulations containing different oil types. On the other hand, the bioaccessibility of phenolic acids from LJ did not change notably after co-ingestion with BBP and oils, whereas flavonoids, including vicenin-2 and hesperidin, were found to be significantly more bioaccessible when LJ was co-ingested with BBP and oils (0.8- to 1.4-fold) (P < 0.05). CONCLUSION Overall, the current study highlighted that the bioaccessibility of polyphenols from BBP and LJ was modulated in the presence of an oil matrix. (c) 2022 Society of Chemical Industry.
Citation Count: 67
Potential Use of Turkish Medicinal Plants in the Treatment of Various Diseases
(Mdpi Ag, 2016) Ozkan, Gulay; Kamiloglu, Senem; Ozdal, Tugba; Boyacioglu, Dilek; Capanoglu, Esra
Medicinal plants are sources of health-promoting substances, including phytochemicals and phytoalexins that comprise polyphenols, flavonoids, carotenoids, vitamins A, C, E and several other constituents. Many studies have indicated that medicinal plants have been used to treat human diseases for thousands of years owing to their antimicrobial and antioxidant activities. Medicinal plants reduce the oxidative stress in cells and prevent cancer, cardiovascular and inflammatory diseases, neurodegenerative and digestive system disorders. These potential beneficial effects have been attributed to the presence of bioactive compounds that show antioxidant properties by acting as free radical scavengers or metal chelators, reducing the reactions that produce reactive oxygen and nitrogen species (ROS/RNS). Considering the importance of medicinal plants in terms of their beneficial health effects, some of the medicinally important plants grown in Turkey are covered in this review with respect to their antioxidant potential and phytochemical profile.
Citation Count: 43
Processing black mulberry into jam: effects on antioxidant potential and in vitro bioaccessibility
(Wiley, 2017) Tomas, Merve; Toydemir, Gamze; Boyacioglu, Dilek; Hall, Robert D.; Beekwilder, Jules; Capanoglu, Esra
BACKGROUNDBlack mulberries (Morus nigra) were processed into jam on an industrialised scale, including the major steps of: selection of frozen black mulberries, adding glucose-fructose syrup and water, cooking, adding citric acid and apple pectin, removing seeds, and pasteurisation. Qualitative and quantitative determinations of antioxidants in black mulberry samples were performed using spectrophotometric methods, as well as HPLC- and LC-QTOF-MS-based measurements. These analyses included the determination of total polyphenolic content, % polymeric colour, total and individual anthocyanin contents, antioxidant capacity, and in vitro bioaccessibility in processing samples. RESULTSJam processing led to a significant reduction in total phenolics (88%), total flavonoids (89%), anthocyanins (97%), and antioxidant capacity (88-93%) (P < 0.05). Individual anthocyanin contents, determined using HPLC analysis, also showed a significant decrease (approximate to 99% loss). In contrast, % recovery of bioaccessible total phenolics, anthocyanins, and antioxidant capacity (ABTS assay) increased after jam processing (16%, 12%, and 37%, respectively). CONCLUSIONFruit processing resulted in losses of polyphenols, anthocyanins, and antioxidant capacity of black mulberry jam. Optimisation of food processing could help to protect the phenolic compounds in fruits which might be helpful for the food industry to minimise the antioxidant loss and improve the final product quality. (c) 2016 Society of Chemical Industry
Citation Count: 0
Recent advances on anti-diabetic potential of pigmented phytochemicals in foods and medicinal plants
(Springer, 2024) Kamiloglu, Senem; Gunal-Koroglu, Deniz; Ozdal, Tugba; Tomas, Merve; Capanoglu, Esra
Type 2 diabetes is marked by elevated blood sugar levels and linked to impaired insulin secretion and resistance to insulin. Researchers are continuously investigating different classes of phytochemicals including natural pigments for their potential direct or indirect advantages in the prevention and/or control of diabetes. In this review, clinical trials, animal studies, and cell culture models, as well as in vitro enzyme inhibition assays and in silico molecular docking studies were covered for pigmented phytochemicals including anthocyanins, carotenoids, betalains, chlorophylls, curcumin, and phycocyanins. Recent research has shown that the anti-diabetic effects of pigments include (1) inhibition of ROS formation, (2) downregulation of inflammatory response like inhibiting COX, or regulation of pro-inflammatory cytokines (TNF-alpha, IL-1 beta, IL-6), (3) regulation of multiple signal pathways such as NF-kappa B, AMPK, MAPK, (4) inhibition of cell apoptosis, according to the ratio of Bcl-2/Bax; and cell proliferation via PI3K/Akt pathways, and (5) digestive enzyme inhibition, such as alpha-amylase and alpha-glucosidase, among others.
Citation Count: 549
The Reciprocal Interactions between Polyphenols and Gut Microbiota and Effects on Bioaccessibility
(Mdpi, 2016) Ozdal, Tugba; Sela, David A.; Xiao, Jianbo; Boyacioglu, Dilek; Chen, Fang; Capanoglu, Esra
As of late, polyphenols have increasingly interested the scientific community due to their proposed health benefits. Much of this attention has focused on their bioavailability. Polyphenol-gut microbiota interactions should be considered to understand their biological functions. The dichotomy between the biotransformation of polyphenols into their metabolites by gut microbiota and the modulation of gut microbiota composition by polyphenols contributes to positive health outcomes. Although there are many studies on the in vivo bioavailability of polyphenols, the mutual relationship between polyphenols and gut microbiota is not fully understood. This review focuses on the biotransformation of polyphenols by gut microbiota, modulation of gut microbiota by polyphenols, and the effects of these two-way mutual interactions on polyphenol bioavailability, and ultimately, human health.
Citation Count: 960
A review on protein-phenolic interactions and associated changes
(Elsevier, 2013) Ozdal, Tugba; Capanoglu, Esra; Altay, Filiz
Polyphenols have become an intense focus of research interest due to their health-beneficial effects especially in the treatment and prevention of several chronic diseases. Polyphenols are known to form complexes with proteins leading to changes in the structural, functional and nutritional properties of both compounds. In this review, the effects of protein-phenolic interactions under various conditions on protein and phenolic compound's structure and functionality are described. The parameters thatare defined to affect protein-phenolic interactions are basically temperature, pH, protein type and concentration, and the type and structure of phenolic compounds. Even though the exact mechanism of how proteins influence polyphenols is still not yet known, studies on the changes in the structure and functional properties were investigated. According to these studies, secondary and tertiary structures of the proteins are changed, and solubility of the protein is decreased whereas its thermal stability might be improved. In addition, the amount of some amino acids and protein digestibility might be reduced as a result of this interaction. It is also concluded that proteins significantly decrease the antioxidant capacity in general, but there are some controversial results which might be due to the differences in the analytical techniques performed in these studies. Similarly, different results were obtained in the bioavailability experiments. Factors affecting these results as well as lacking parts of these studies are discussed in detail in this review. In conclusion, interaction of proteins and phenolic compounds is a complex phenomenon and should be further investigated. On the other hand, optimum conditions should be studied in detail to improve the food processes and provide maximum beneficial health effects to the consumers with optimum nutritional and functional properties. (C) 2013 Elsevier Ltd. All rights reserved.
Citation Count: 157
A Review on the Effect of Drying on Antioxidant Potential of Fruits and Vegetables
(Taylor & Francis inc, 2016) Kamiloglu, Senem; Toydemir, Gamze; Boyacioglu, Dilek; Beekwilder, Jules; Hall, Robert D.; Capanoglu, Esra
The role of antioxidants in human nutrition has gained increased interest, especially due to their associated health beneficial effects for a number of chronic diseases, including cardiovascular diseases and certain types of cancer. Fruits and vegetables are perishable and difficult to preserve as fresh products. Dried fruits and vegetables can be easily stored, transported at relatively low cost, have reduced packing costs, and their low water content delays microbial spoilage. Air-, freeze-, microwave- and sun-drying are among the most thoroughly studied drying methods. This review provides an overview of recent findings on the effects of different drying techniques on major antioxidants of fruits and vegetables. In particular, changes in ascorbic acid, carotenoids, flavonoids, phenolic acids, total phenolics, and antioxidant activity are discussed in detail.