Polyphenols In Samples Research Articles

Studies on Quantitative Determination of Polyphenols in Seven Harvesting Times of Salvia deserta Schang Leaves and its Stability Evaluation

Introduction: Leaves of Salvia deserta Schang at seven harvesting times in the same year were collected as the materials. Method: The polyphenols were determined by the Folin–Ciocaileu method and High-Performance Liquid Chromatography (HPLC) to compare the quality of samples. The stability of polyphenols was studied under different conditions (light, temperature, pH, common additives). Results: The results showed that the established method is fast, simple and reliable, which is fully validated in terms of outstanding validation data. High Performance Liquid Chromatography (HPLC) for the determination of total polyphenol content can be quickly and accurately detected, reducing the error of manual determination of the content. The study of polyphenol stability was carried out using a UV spectrophotometer (UV) in order to explore the potential factors affecting polyphenol stability as much as possible and to make the study as scientific and rigorous as possible. The results of quantitative determination showed that there are obvious differences in the content of polyphenols in seven samples. The contents of total polyphenols, rosmarinic acid (RA) and caffeic acid (CA) in the samples harvested in July reached the highest level of 41.37, 26.73 and 1.05 mg/g. Conclusion: The results of the stability assay found that light could damage the stability of polyphenols in samples, especially UV light. Polyphenols are quite sensitive to high temperatures. While polyphenols are less stable when exposed to high alkali conditions and salt treatment, they are much more stable when subjected to low concentrations of redox agents, carbohydrates, and preservatives. The developed methods and stability evaluation provide valuable basis information for quality evaluation and the following use of polyphenols in S. deserta Schang leaves.

Changes in the bioaccessibility of citrus polyphenols during industrial freezing process

SummaryCitrus fruits can be consumed fresh or they can be subjected to various processes including freezing to extend their shelf life. The aim of the current study was to evaluate the bioaccessibility of polyphenols in samples collected at different stages of the industrial freezing process of oranges and grapefruits. The major polyphenols were identified and quantified using UPLC‐ESI‐MS/MS and HPLC‐PDA, respectively. In addition, spectrophotometric methods were employed to determine the total phenolic and flavonoid contents along with total antioxidant capacity. The results showed that the bioaccessibility of flavonoids from frozen citrus fruits (26%–64%) was found to be lower than that of fresh fruits (27%–127%). Similarly, bioaccessibility of phenolic acids from frozen oranges (64%–76%) was significantly lower than that of fresh fruits (126%–152%). On the contrary, phenolic acids of frozen grapefruits were found to be more bioaccessible compared to fresh fruits (64%–217% and 50%–95%, respectively).

Effect of High Hydrostatic Pressure and Thermal Processing on the Shelf Life and Quality Attributes of Apple-Kiwi-Carrot Puree Blend

The effects of high hydrostatic pressure (HHP) (400 MPa/2 min and 500 MPa/2 min) and thermal processing (TP) (90°C/2 min) on the microorganisms, nutrition, color, endogenous enzyme activities, antioxidant capacity, and rheological properties of blended apple-kiwi-carrot puree were comprehensively evaluated after processing and during storage at 4°C. Results showed the microbiological shelf life of the HHP or TP products was at least 24 days. TP inactivated polyphenol oxidase activity more effectively, retaining more polyphenols in samples during storage, whereas HHP treatments were more beneficial for the preservation of ascorbic acid, total carotenoids, β-carotene, and antioxidant capacity. During storage, there was no significant difference in PME activity among all treated samples, but particle size distribution and viscoelasticity tests demonstrated that the 400 MPa treated samples were more stable in their textures. Moreover, the principal component analysis (PCA) intuitively revealed that the overall sensory and nutritional attributes of the HHP-treated samples were closer to the fresh product. These results demonstrated that HHP could be a better choice than TP for use in the production of high-quality puree blends.

POLYPHENOLS AND THEIR ANTIOXIDANT EFFECT IN BEERS FROM THE BOSNIA AND HERZEGOVINA MARKET

Data on the content of total polyphenols in beer is important both because of their negative effects on the stability of beer and the formation of turbidity, and because of the positive health effects. The aim of this study was to determine the content of total polyphenols and antioxidant capacity in 22 samples of light and dark beer using two methods: Folin–Ciocâlteu and DPPH method and to confirm the correlation between the total content of UP and AC beer. The content of shell polyphenols in dark beers was statistically significantly higher (p < 0.001) compared to the content of total polyphenols in samples of light beers from the same producer. The antioxidant capacity of dark beers is statistically significantly higher (p < 0.001) compared to the antioxidant capacity of light beers from the same producer.

Emulsion gels containing n-3 fatty acids and condensed tannins designed as functional fat replacers

The purpose of this study was to ascertain the potential of several food-grade emulsion (O/W) gels (GEs) for use as healthier fat replacers. The emulsions, formulated with a lipid phase rich in n-3 fatty acids and different emulsifiers (sodium caseinate, SC; whey protein isolate, WPI and isolated soy protein, ISP), were cold gelled after adding a natural extract rich in condensed tannins (CT). The GEs were characterized and their oxidative stability evaluated during storage (4 °C). All GEs formulated presented a solid-like structure showing generally excellent emulsion stability, which improved in GEs with the addition of CT. Non-extractable proanthocyanidins (NEPA) were the main source of polyphenol in samples enriched with CTs. The antioxidant activity of the systems was not affected by the use of different proteins as emulsifiers, but it was improved in GEs containing CT. The oxidation values recorded in the GE systems can generally be regarded as low even considering their enrichment with unsaturated fatty acids, which thus assures their suitability for use as fat replacers.

An improved and miniaturized analytical strategy based on μ-QuEChERS for isolation of polyphenols. A powerful approach for quality control of baby foods

An improved and miniaturized quick, easy, cheap, effective, rugged and safe (μ-QuEChERS) strategy combined with ultra-high pressure liquid chromatography coupled to a photodiode array detection system (UHPLC-PDA) was developed and optimized for the determination of twelve polyphenols in different baby foods samples. The proposed analytical approach proved to be highly cost-effective and environmentally friendly, since it showed good extraction efficiency using few amounts of sample (0.3g), organic solvents (1000μL), clean-up sorbents (87.5mg) and partitioning salts (0.2g), producing minimal waste disposal and reducing analysis time. Method performance was validated in terms of selectivity, linearity, limits of detection and quantification, matrix effects, precision and accuracy using different baby food matrices according to their composition. The overall average recoveries ranged from 71 to 100% with relative standard deviations lower than 6% (n=18). The method was successfully applied to commercial baby food samples (including pureed solids, juices and porridges), and their total phenolic content (TPC) and antioxidant capacity (RSA) were also investigated. Results allowed characterizing the abundance of the selected polyphenols in the samples, and the highest RSA and TPC were found in the fruit-based baby foods. Thus, this work represents a first approach to determine the nutritional quality of these products.

Biochemical Properties and Neuroprotective Effects of Compounds in Various Species of Berries.

Several species of berries, such as blueberries (Vaccinium angustifolium) and lingonberries (Vaccinium vitis-idaea L.), have attracted much scientific attention in recent years, especially due to their reported antioxidant and anti-inflammatory properties. Berries, as with other types of plants, have developed metabolic mechanisms to survive various environmental stresses, some of which involve reactive oxygen species. In addition, the fruits and leaves of berries have high amounts of polyphenols, such as flavonoids, which act as potent antioxidants. These compounds could potentially be beneficial for brain aging and neurodegenerative disorders. There are now several studies documenting the beneficial effects of various berries in cell models of neurotoxicity as well as in vivo models of neurodegenerative disease. In the current review, we discuss the metabolic strategies that plants and animals have developed in order to combat reactive oxygen species. We then discuss issues of bioavailability of various compounds in mammals and provide a synopsis of studies demonstrating the neuroprotective ability of berries and polyphenols. We also summarize findings from our own research group. For example, we have detected various polyphenols in samples of blueberries and lingonberries and have found that the leaves have a much higher antioxidant capacity than the fruits. Extracts from these species have also demonstrated neuroprotective effects in cellular models of toxicity and inflammation, which are being further pursued in animal models.

SELENIUM AND ITS INFLUENCE ON THE CONTENT OF POLYPHENOL COMPOUNDS IN ONION (ALLIUM CEPA L.)

Onions (Allium cepa L.) are important source of bioactive compounds including polyphenols and have potential beneficial properties for human health. Selenium (Se) is an essential micronutrient that is required in small amounts. The aim of the research was to find out how selenium (Se) treatment affects on the quality of onion (Allium cepa L.). The content of the total polyphenols was determined by using the Folin-Ciocalteu reagent (FCR). Antioxidant activity was measured using a compound DPPH˙ (2.2-diphenyl-1-picrylhydrazyl).The Se treatment increased the content of total polyphenols (TCA) and antioxidant activity (AA). The content of total polyphenols in samples of onion during vegatation period moved in the range from 508.16±27.59 to 607.56±23.15. In this work was watched also the influence of potassium on antioxidant activity, where values were in interval from 25.90±0.47 to 39.72±2.64.

POTASSIUM AND ITS EFFECT ON THE CONTENT OF POLYPHENOLS IN ONION (ALLIUM CEPA L.)

Onion (Allium cepa L.) is rich of chemoprotective compounds as polyphenols, flavonoids, anthocyanins, vitamins, sulphur compounds which have potential beneficial properties for human health. Potassium as important mineral abundant plays many vital roles in plant nutrition (reduces respiration, activates enzyme). In generally, potassium increases crop yield and improves quality of onion bulbs. The objectives of this work were to compare and evaluate the impact of potassium on the content of total polyphenols and antioxidant activity of onion (Allium cepa L.). The content of the total polyphenols was determined by using the Folin-Ciocalteu reagent (FCR). The absorbance was measured at 765 nm of wave length against blank. Antioxidant activity was measured using a compound DPPH˙ (2.2-diphenyl-1-picrylhydrazyl) at 515.6 nm in the spectrophotometer. The content of total polyphenols in samples of onion during vegatation period moved in the range from 505.6 mg GAE/kg ±25.18 to 621.49 mgGAE/kg ±13.41. In this work was watched also the influence of potassium on antioxidant activity, where values were in interval from 32.20 %± 0.58 to 44.67 % ±0.68.