Percentage Of Polyphenols Research Articles

Biobased and biodegradable polymers in a circular economy context: Understanding quercetin and gallic acid impacts on PHBV thermal properties

As they cannot massively accumulate in our eco-system, biodegradable polymers represent one of the solutions to mitigate plastic pollution. Meanwhile their ability to be recirculated before being biodegraded is important to maximize their economic value. Like all other polymers, their ability to be recycled and reused is highly dependant of their thermal stability, which also deserves to be investigated. Here, we clarify the potential impact of two natural phenolic additives, quercetin and gallic acid on the thermal stability of a promising microbial biodegradable polyester, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). The effect of the structure and the percentage of polyphenols (0 to 15 wt%) on the morphological behaviour and thermomechanical stability of PHBV was studied. Up to 5wt%, homogeneous blends characterized by intermolecular bonding interactions between the phenolic compounds and the polymer matrix were obtained. Above this percentage, a phase separation was observed in the presence of quercetin, while gallic acid crystals were embedded into the PHBV matrix, hindering its crystallization. It was concluded that regardless the additive percentage, the structural evolution of PHBV during the thermal treatment was strongly affected by the polyphenol structure: Quercetin slightly improved the structural integrity and thermo-mechanical stability of PHBV, while the carboxylic group of gallic acid contributed to auto-catalyse the polymer chain scission, accelerating its degradation.

Effects of Vermicompost, Tithonia Green Manure and Urea on Quality of Swiss Chard (Beta Vulgaris L. Var. Cicla L.) in Kenya

Swiss chard (Beta vulgaris L. var. cicla) is a popular vegetable because it is nutritious, robust, easy to grow. It requires regular applications of nitrogen, which causes accumulation of oxalates and nitrates within the plant. Oxalates and nitrates are known health hazards but the use of organic fertilizers have been shown to reduce their accumulation and to promote accumulation of beneficial phytochemicals. We therefore determined the effect vermicompost (VC), Tithonia diversifolia green manure (Tithonia) and urea on the quality of Swiss chard. The experiment was laid out in a Randomised Complete Block Design (RCBD) replicated three times with thirteen treatments. Leaf nutrient elements, TSS, polyohenols, Vitamin C and antioxidants were determined using standard procedures. Treatment effects were significant only for aluminum, phosphorus and calcium. The values were highest on VC 50 kg N ha-1 and Urea 50 kg N ha-1, Tithonia 50 kg N ha-1 + Urea 50 kg N ha-1, and VC 50 kg N ha-1, and VC 100 kg N ha-1 for aluminum, phosphorus and calcium, respectively. Lowest response was reported on Tithonia 50 kg N ha-1, control and Tithonia 50 kg N ha-1 + Urea 50 kg N ha-1 for aluminum, phosphorus and calcium, respectively. The treatments significantly influenced the percentage of polyphenols, vitamin C and the antioxidant capacity while no significance was reported for total soluble solutes. The polyphenols and vitamin C content were highest on Tithonia 100 kg N ha-1 and control, respectively. Low polyphenol and vitamin C contents were recorded on VC 50 kg N ha-1 and VC 100 kg N ha-1, respectively. A similar trend was observed for antioxidant activity since a positive correlation was observed between the polyphenols and vitamin C and the antioxidant activity. Tithonia green manure improves Swiss chard quality.

Study of Panchashirishadi Agad on the basis of physicochemical and phytochemical analysis

Background: Many antidotes are mentioned in the classical text for the management of animal poisoning. Panchashirishadi Agad is one of the formulations indicated for Kita Visha (insect bite). Aim: To assess the physicochemical and phytochemical properties of Panchashirishadi Agad.Setting and Design: This was an original analytical study. Materials and Methods: Five parts of Shirish (Albizia lebbeck) were collected from local area of Wardha (Sewagram) and Panchashirishadi Agad was formulated as per the reference of classical text. Result: After the analytical study, the physicochemical properties that include loss on drying at 105°C, total ash value, acid-insoluble ash, water-soluble extractive, alcohol-soluble extractive, pH, and particle size were analyzed and the obtained values were 12.0%, 10.0%, 1.0%, 11.0%, 13.0%, 5.45%, and 100 mesh, respectively. In the similar way, the herbal formulation is devoid of microbial contamination. Phytochemical analysis includes the presence of 48% polyphenols. Conclusion: As the formulation contains more percentage of polyphenols, it can be anticipated that it can act as antiallergic agent.

Characterization of Grape and Apple Peel Wastes’ Bioactive Compounds and Their Increased Bioavailability After Exposure to Thermal Process

80% of the grape harvest is used in the winemaking industry, resulting in huge amounts of waste which are still rich in phenolic compounds, while the same percentage of polyphenols are found in apple peel, whose total antioxidant capacity is five-to-six-fold higher than that of apple flesh. The aim of this research is the characterization of grape and apple peels waste, before and after the thermal treatment (10 minutes, 80°C), with respect to its bioactive compounds to evaluate their potential enhancement with respect to bioavailability. Based on the obtained results, the highest antioxidant activity and phenolic content was exhibited by thermally processed red-grape waste. After the thermal treatment, the caffeic acid 4-O-glucoside increased with a 27% in apple waste. As a conclusion, the grape and apple peels waste can be exploited for their bioactive compounds after the thermal process, whose bioavailability increased and can be added in food formulations as health promoting products.

Characterization of polyphenols from green tea leaves using a high hydrostatic pressure extraction

A new extraction technique, high hydrostatic pressure extraction (HHPE), was used to obtain polyphenols from green tea leaves. Various experimental conditions, such as different solvents (acetone, methanol, ethanol and water), pressure (100, 200, 300, 400, 500, 600 MPa), holding time (1, 4, 7, 10 min), ethanol concentration (0–100% mL/mL), and liquid/solid ratio (10:1 to 25:1 mL/g) for the HHPE procedure, were investigated to optimize the extraction. The optimal conditions were as follows: 50% (mL/mL) of ethanol concentration, 20:1 (mL/g) of liquid/solid ratio and 500 MPa of high hydrostatic pressure for 1 min. Under such conditions the extraction yield of polyphenols was up to 30 ± 1.3%. The extraction yields of polyphenols with HHPE for only 1 min were the same as those of extraction at room temperature for 20 h, ultrasonic extraction for 90 min and heat reflux extraction for 45 min, respectively. On the basis of the extraction yields of polyphenols, extraction time and the percentages of polyphenols in extracts, the HHPE is more effective than the conventional extraction methods studied.

Towards biomolecular aided agriculture: metabolic fingerprint of wild and cultivated Sicilian medicinal plants belonging to the folk tradition

For chemotaxonomic and agro-technological purposes, extracts of wild thyme (Thymus vulgaris L., 30 samples), oregano (Origanum vulgare L., 61 samples) and rosemary (Rosmarinus officinalis L., 57 samples) collected in different areas of the Sicilian region, as well as cultivated sage (Salvia officinalis L., 7 samples), were screened for their phenolic compound content. All these plants belong to Sicilian culinary tradition and folk remedies. In order to have as many details as possible on the composition of these plants and their variation, extracts of different polarity (lipidic and alcoholic) for each cultivar were obtained and analysed. Several groups of selected molecules, typical of the different species and a part of their secondary metabolism (chemotaxonomical markers), were chosen, containing flavonoids, terpenoids, and organic acids as more representative chemical classes. The markers were firstly identified in the extracts through exhaustive analyses using the LC/UV-DAD/MS technique and then processed with high-throughput HPLC to obtain qualitative and quantitative compositional data. These data, together with the yield of extractions from the vegetable material, provided enough information to build up an analytical matrix from which the best extract in terms of presence and percentage of polyphenols could be selected.