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.
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. 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.
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.
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.
The effects of addition of nitrite, lactic acid bacteria and propolis on the physicochemical, microbiological and sensory characteristics of traditional Turkish sucuk were studied during the ...sun-drying and storage stages. Microbiological and physicochemical analysis were performed at the beginning of sun drying period (3rd day), at the end of the sun-drying period (14th day) and in the storage period (28th day). According to the microbiological evaluation of the samples, analyses show that total bacteria, total yeast and mould and lactic acid bacteria counts varied significantly (P <0.05) with nitrite, lactic acid bacteria and propolis addition and time. Propolis decreased the total bacteria, mould and yeast counts compared to the control sample at the end of the 28th day with acceptable sensory properties. Therefore, it can be concluded that as a natural strong antimicrobial, propolis can be added to traditional sucuk formulations to substitute nitrite to avoid negative health effects.
Nitrit, laktik asit bakteri ve propolis ilavesinin, geleneksel Türk sucuklarının fizikokimyasal, mikrobiyolojik ve duyusal özelliklerine etkileri güneşte kurutma ve depolama aşamalarında incelenmiştir. Mikrobiyolojik ve fizikokimyasal analizler güneşte kurutma periyodunun başında (3. gün), güneşte kurutma periyodunun sonunda (14. gün) ve depolama sürecinde (28. gün) yapılmıştır. Örneklerin mikrobiyolojik analiz sonuçlarına göre, toplam bakteri, toplam maya, küf ve laktik asit bakteri sayıları nitrit, laktik asit bakterisi ve propolis ilavesiyle ve bunun yanında zaman ile istatistiksel olarak anlamlı bir değişiklik (p <0.05) göstermektedir. Propolisin, toplam bakteri, küf ve maya sayılarını kontrol numunesine kıyasla, 28. günün sonunda, kabul edilebilir duyusal özelliklere sahip olarak azalttığı sonucuna varılmıştır. Bu nedenle, doğal ve güçlü bir antimikrobiyal olarak, olumsuz sağlık etkilerinden kaçınmak amacıyla nitrit yerine geleneksel Türk sucuğu formülasyonlarına propolis ilave edilebileceği sonucuna varılmıştır.
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.
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 that are 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.
► The affecting factors on protein-phenolic interactions are discussed. ► Protein-phenolic interactions affect functional, nutritional properties of proteins. ► Determination of phenolic contents, total antioxidant capacities is also affected. ► Bioavailability of phenolics changes as a result of protein-phenolic interactions.
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.
•Co-ingestion of flavonoids with macro- and micro-constituents affects flavonoid bioavailability.•Proteins, dietary fiber and minerals may reduce the bioavailability of flavonoids.•Reduced bioavailability might be due to the entrapment of flavonoids to the food matrix.•Digestible carbohydrates, lipids, and vitamins may favorably affect flavonoid bioavailability.•Improved micellization might result in enhanced bioavailability of flavonoids.
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.
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•Biological activity of propolis is strongly related with climate, geographical changes and flora around the hive.•Bioaccessibility of propolis was increased in the gastric phase when compared to the oral phase.•The highest bioaccessibility values were reached in the intestinal phase.•32 phenolic compounds of Turkish propolis samples collected from different regions were identified using LC-MS/MS method.
Functional muffins were developed by whole wheat (Triticum aestivum L.), whole siyez wheat (Triticum monococcum L.), and whole oat (Avena sativa L.) flours with grape seed flour (GSF) at 7.5% and 15% ...ratio which is an important by‐product of the food industry. Antioxidant capacities, physicochemical, color, textural, and sensorial properties of muffins were evaluated. Total phenolic contents and antioxidant capacities of muffins were enhanced significantly (p < .05) with GSF addition. Whole oat flour muffins exhibited higher total phenolic contents and antioxidant capacities than others. Hardness and chewiness values (p < .05) of all muffins were significantly different from each other. L, a, and b values were decreased in crumb and crust with increased amounts of GSF. According to sensory analysis results, there were no significant differences (p > .05) between muffins of whole wheat, whole siyez, and whole oat flours. Based on the results, GSF can be used for the enrichment of bakery products to prepare functional food.
Practical applications
This study has been carried out to produce functional muffins that may provide additional health benefits, besides finding a solution of food waste management. Grape seeds have been associated with positive health effects according to their high antioxidant capacity related to their rich content of polyphenols. The processes of wine, fruit, pekmez, and vinegar produce significant quantities of solid organic waste and by‐products, including grape pomace, seed, and skins after pressing the grape. The usage of these valuable by‐products in food is important for the reduction of food waste, improvement of public health according to their high antioxidant capacity and sustainability. The present study focuses on total phenolics, antioxidant capacities, physicochemical, color, textural, and sensory properties of functional muffins. To the best of our knowledge, this is the first study that has focused on the effect of adding grape seed flour (in two different doses 7.5% and 15%) for the development of innovative functional muffins produced using different types of flours including whole wheat (Triticum aestivum L.) flour, whole siyez wheat (Triticum monococcum L.) flour, and whole oat (Avena sativa L.) flour.
•First study evaluating matrix effect on bioaccessibility of terebinth polyphenols.•Whole milk addition to terebinth coffee increased total bioaccessible flavonoids.•Skim milk did not cause a ...significant change in bioaccessibility of polyphenols.•Sugar/sweetener further enhanced bioaccessible flavonoids in terebinth + whole milk.•Terebinth + whole milk + sugar contained highest amount of bioaccessible polyphenols.
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).
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