Total Phenolic Yield Research Articles

Phenolic extraction from grape (Vitis vinifera) seed via enzyme and microwave co-assisted salting-out extraction

The aim of this study was to develop an effective method for extracting total phenolic (TP) from grape seed using enzyme and microwave co-assisted salting-out extraction (EMASOE). The significant factors affecting TP yield were screened by Plackett-Burman design and then optimized by Box-Behnken design. Under optimum extraction conditions of 25% (w/w) ethanol/20% (w/w) ammonium sulfate, pectinase amount 540 U/g, enzymatic pH 4.5, microwave power 180 W, the maximum extraction yield of TP was 125.32 mg/g. Significant differences were found in the monomer phenolic compounds by different methods. Ten kinds of monomer phenolic compounds were analyzed by high pressure liquid chromatography (HPLC), only four were identified by Soxhlet extraction (SE), and eight by EMASOE. Moreover, the TP by this method possessed higher content and better antioxidant activities. Therefore, EMASOE could be used as an effective method to extract phenolics from natural plants.

Karakteristik Teh Herbal Daun Kelor (Moringa oleifera) dengan Pengkayaan Kolagen Ikan

Herbal tea is one of the types of drinks that is in demand by the public because herbal tea is one of the functional food types that has many benefits. In addition, herbal teas are also made from natural ingredients so that it is safe and easy to consume. Herbal tea is a term for beverage products made from ingredients other than tea leaves (Camellia sinensis). Therefore, there are many natural ingredients in the surrounding environment that can potentially be processed into herbal tea products. One of them is by utilizing moringa leaves, cinnamon, roselle and secang that known for it beneficial health effect.To increase the benefits for health also added fish collagen that can support the antioxidant and protein content in this moringa leaf herbal tea product. The purpose of this study is to find out which additional ingredients have the highest antioxidant activity and are best suited to support the content in moringa leaf herbal tea and to know the best concentration of fish collagen added.From the results of the study obtained the formulation of herbal tea drinks moringa leaves which is the best treatment in this study is the formulation of moringa: cinnamon (75:25) as well as the addition of fish collagen by 3% with a total phenol yield of 10.52 mgTAE/g; antioxidant activity of DPPH method 92.16%; antioxidant activity method FRAP 9,92 mgAAE/g; total dissolved protein 16.32%, taste value 1.95 and calcium content 94.29 ppm.

Process Development for Antioxidant Extraction from Wet Pomegranate Peel

HighlightsA novel process for antioxidant extraction from wet pomegranate peel (WPP) was developed using water as solvent.Effects of extraction parameters on extract yield, quality, composition, and color were quantified.Extraction from WPP achieved 10% higher extract yield compared with dried peel.The WPP extraction process is more energy-efficient than extraction from dried peel.Abstract. Pomegranate peel (PP) is underused as animal feed or discarded in landfills, causing environmental pollution, even though it has a unique polyphenol profile with health-promoting properties. Past research has focused on the potential utilization of dried pomegranate peel (DPP), involving extended processing time, energy usage, and potential quality loss. The objective of this study was to develop a process to extract water-soluble antioxidants from wet pomegranate peel (WPP) and compare its antioxidant attributes with that of DPP. The WPP was sliced and ground into two sizes, and phenolics were extracted in water at different temperatures (20°C, 30°C, 40°C, 50°C, and 60°C), solvent (water) ratios (1:1, 2:1, 4:1, 6:1, and 8:1), and extraction times (2, 3, 4, 5, and 6 min). WPP extraction was compared with DPP extraction using hot air (HA, 40°C) and infrared radiation (IR, 60°C). The total phenolic yield (TPY) from WPP ranged from 10.37% to 12.80%, and the extraction rate increased significantly with increasing extraction time, temperature, and solvent ratio. DPPH scavenging activity (DSA), an important indicator of antioxidant activity, was in the range of 5.366 to 6.591 g g-1 and decreased only with the increase in temperature. Extraction using WPP particles resulted in 10% more extract yield and 2.5% more TPY compared to DPP powders with similar DSA. This study demonstrated that WPP could be used for the extraction of phenolic compounds with high antioxidant activity and without energy-intensive drying. Keywords: . Infrared drying, Peel composition, Polyphenol, Principal component analysis, Wet pomegranate peel.

Effect of Enzymatic Hydrolysis on the Antioxidant Activity of Red and Green Seaweeds and Characterization of the Active Extracts

AbstractIn the present study, the effect of enzymatic hydrolysis on the antioxidant activity of three red seaweeds (Chondria cornuta, Chondria dasyphylla, and Murrayella periclados) and two green seaweeds (Cladophora sp. and Ulva lactuca) from the Kuwait coast were evaluated. The seaweeds were hydrolyzed with five carbohydrases and three proteases, and the resulting extracts were tested for antioxidant activity. The total phenolic content and yield of the extracts varied greatly depending upon the species and enzyme used for hydrolysis. Of the 40 enzymatic extracts screened for antioxidant activity, the Viscozyme and Alcalase extracts of M. periclados, Neutrase and Ultraflo extracts of Cladophora sp., and Neutrase extracts of C. cornuta had high antioxidant activity compared to other enzymatic extracts in various in vitro assays. Fractionation of the extracts revealed that the radical scavenging and reducing power of the extracts were mainly due to phenolic fractions. In contrast, the iron‐chelating ability was mainly due to protein fractions. The level of prevention of lipid oxidation in the liposome model system varied for different fractions of extracts and did not correlate with total phenolic content and other antioxidant properties. The results of the study show that, by hydrolyzing seaweeds with specific enzymes, customized seaweed extracts with specific bioactivity could be obtained.

Comparative Study of Polyphenolic Compound Extraction from Agroindustrial Waste

Polyphenolic compounds have many benefits, one of which being their efficacy as antioxidants. They can be extracted from various parts of plants and from agricultural waste. In this research, rice straw from three varieties, sugarcane pulp, and empty fruit bunches from the palm oil production were investigated as potential raw materials. This study aims to determine solvents and easy-to-perform extraction methods that show the highest effectivity in regard to total phenolic and flavonoid yield and the correlated antioxidant activity. Extraction methods comprised maceration, Soxhlet extraction, and ultrasound assisted extraction (UAE); solvents that were investigated included water, 70% methanol and 70% ethanol. The antioxidant activity was measured by the DPPH (diphenyl-2-picrylhydrazyl) method and FRAP (Ferric Reduction Ability of Plasma). Based on the amount of polyphenol compounds as well as the antioxidant activity, the experiments showed that Soxhlet extraction with 70% methanol as solvent worked best for palm bunch waste and sugar cane pulp. Results for rice straw biomass were inconclusive due to differences in growing conditions, however, the antioxidant activity of the extracts seemed rather promising.

Elaboration of mangaba vinegar by semi-solid fermentation combined with enzymatic activity: chemical characterization and sensory evaluation

ABSTRACT: The objective of this study was to produce vinegar from mangaba pulp using semi-solid alcoholic fermentation combined with the enzymatic activity of pectinase and to investigate the chemical composition and sensory characteristics of the final product. was evaluated for volatile acidity and the reduced dry extract was evaluated for ashes, alcohol content, sulfates, pH, total phenolic compounds, total carotenoids, color parameters, yield, productivity, and sensory analysis. Average and standard deviation was used for descriptive statistics. Principal component analysis (PCA) was applied to all variables except total carotenoid content. Physicochemical characterization of the raw and alcoholically fermented pulp was also carried out. The main results showed that, in the vinegar, the reduced dry extract, volatile acidity, pH, and ashes were 44.3±1.5 (g/L), 4.4±0.1 (% w/v), 3.1±0.0, and 3.0±0.41 (g/L), respectively. The total phenolic compound content and total carotenoid content for the mangaba vinegar were 19.2±8.20. mg/100 g and 2.6±0.6. mg/100 g, respectively. The conversion yield from ethanol to acetic acid was 90%. PCA showed that pH and volatile acidity had a strong influence on the product, and there was a strong positive correlation between color and aroma. The final product met all legal requirements, showing that it is possible to produce mangaba vinegar with antioxidant potential for consumers. In the sensory evaluation, it was favored by the tasters, demonstrating potential economic value in the Cerrado fruit.

Influence of fermentation and germination on some bioactive components of selected lesser legumes indigenous to Nigeria

This study assessed the effects of fermentation time (2, 3 and 4 days) and germination time (2, 3 and 4 days) on total phenolics, tannin, anthocyanin, carotenoids and flavonoids contents of lesser legumes: cowpea ( Vigna unguiculata L.), bambaranut ( Vigna subterranean L.), red bean ( Phaseolus vulgaris ), pigeonpea ( Cajanus cajan ), African breadfruit ( Treculia africana ) seeds, African yam bean ( Sphenostylis stenocarpa ) seed, African oil bean ( Pentaclethra mycrophylla Benth.) seed and groundnut ( Arachis hypogea L.). The antioxidant and reducing powers of a three day germinated samples were also evaluated. The result revealed that fermentation reduced the total phenolics, tannin, anthocyanin, carotenoid and flavonoid contents of the samples with increasing fermentation time; however, red bean showed minimal increase with increasing fermentation time. There was significant (p < 0.05) increase in the total phenolics of all the samples with increasing germination time but, tannin and flavonoid showed significant (p < 0.05) reduction with increasing germination time. Germination significantly (p < 0.05) reduced the carotenoid and anthocyanin levels in all the samples, however, red bean, pigeonpea and African oil bean showed increases with increasing germination time. Samples evaluated exhibited significantly (p < 0.05) different antioxidant capacities. African oil bean and groundnut had the highest antioxidant activities 52.18% and 52.16%, respectively while, African yam bean seed was the lowest (19.85%). Similar trend was observed in the reducing power of the raw samples where groundnut, bambaranut and African breadfruit showed significantly (p < 0.05) higher reducing power. Three (3) days germination significantly (p < 0.05) increased the antioxidant capacities by 14.65%, 18.42%, 53.58%, 52.84%, 17.24%, 14.56%, 53.18% and 43.03% in African oil bean, bambaranut, cowpea, red bean, African breadfruit, groundnut, African oil bean and pigeonpea, respectively. Therefore, for increase antioxidant activity in lesser known legumes, germination is more preferred over fermentation and for maximum yield of total phenolics, three and four days germination time are recommended. • Effect of fermentation and germination on legumes' selected bioactives were assessed. • Fermentation reduced the phenolic, tannin, anthocyanin, carotenoid and flavonoid. • Red bean showed minimal increase with increasing fermentation time. • Germination reduced the carotenoid and anthocyanin levels in all samples. • Three days germination increased the antioxidant capacities of all the samples.

Extraction of Bioactive Compounds from Haskap Leaves (Lonicera caerulea) Using Salt/Ethanol Aqueous Two-Phase Flotation

Aqueous two-phase flotation (ATPF) was used for the extraction and partial purification of bioactive compounds from haskap leaves. Two ATPF systems, ammonium sulfate/ethanol and sodium phosphate/ethanol, were compared. A Box-Behnken approach was used to investigate the operating parameters which included sample loading (5.0, 52.5, and 100.0 mg), flotation time (5, 62.5, 120 min), and air flow rate (11.4, 20.0, 28.6 mL/min). Response surface optimization was performed to maximize the yields of chlorogenic acid (CGA), flavonoids, and total phenolics (total phenolic content, TPC). At the optimized parameters for the ammonium sulfate/ethanol ATPF system (i.e., 5-mg leaves, 120-min flotation time, and air flow rate of 28.6 mL/min), the extraction efficiencies were 97.1%, 98.7%, and 99.6% for CGA, flavonoids, and TPC, respectively. The corresponding partition coefficients were 29.6 for CGA, 62.4 for flavonoids, and 231.4 for TPC. Quantitation of individual compounds using high-performance liquid chromatography showed that ATPF with ammonium sulfate/ethanol achieved yields of 0.031 mg CGA/mg dry mass leaves, 0.027-mg rutin/mg dry mass leaves, 0.006-mg luteolin-7-O-glucoside/mg dry mass leaves, and 0.007-mg diosmin/mg dry mass leaves. Based on the overall extraction performance, ammonium sulfate/ethanol ATPF is the preferred system in comparison to sodium phosphate/ethanol ATPF, for the extraction of bioactive compounds from haskap leaves.

Optimization of polyphenolic compounds extraction methods from Okra stem

Conventional solvent extraction (CSE), microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE) have used to recover phenolic substances from Okra stem (as a related agro-industrial waste). The influences of three extraction methods in terms of total phenolic content (TPC), antioxidant activities (AA) and extraction yield (EY) of Okra stem are investigated and compared. The DPPH, ABTS, FRAP, and β-carotene bleaching methods are used for determining AA. The phenolic compounds’ values existing in Okra stem are determined by High-performance liquid chromatography (HPLC) analysis. The optimized MAE has been compared with both optimized CSE and UAE. The results show that the former method gives the higher TPC (69.99 mg GAE g−1) in the shorter time as compared to CSE and UAE methods by about 89% and 78.17%, respectively. The UAE method shows the best performance in AA (53.06%, 60.10%, 0.94 mM TE g DE, and 69.27% for DPPH, ABTS, FRAP and β-carotene bleaching, respectively) and EY with the content of 19.24%. Regarding the phenolic profile, catechin derivative (9.45 mg g−1) is the main compound which is found in the extracts as well as hydroxycinnamic derivative (9.11 mg g−1) and flavonol (4.99 mg g−1). The obtained results indicate that Okra stems have the capability of being productive sources of phenolic compounds with antioxidant properties.

Modelling and Optimization of Ultrasound Assisted Extraction of Polyphenols Using Response Surface Methodology

Mango seed kernels are by-products of the consumption and transformation of mango fruits (Mangifera indica L.). Many ways of valorisation have been proposed, and among them, their phenolic compounds extraction. To increase the extraction yield, ultrasound-assisted extraction was modelled and optimized. The 4 factors Central Composite design associated with the Response Surface Methodology (RSM) were used to achieve that goal. The effect of extraction time, temperature, stirring rate and the Ultrasound Amplitude, on the total phenolic compound extraction yield and the total reducing power of the extract, were studied and modelled. The modelling allows us to do a multi-response optimization to identify the best-operating conditions to achieve at the same time the highest extraction yield and antioxidant capacity. The optimal operating conditions achieved were 41.82 min of extraction time, 54.75?C as extraction time, under 266.67 rpm as stirring rate, and 100% ultrasound amplitude. With an expected extraction yield of 71.35 mg GA/g, and 123.058 mg AA/g of total reducing power. 2 extraction cycles, under these conditions, are enough to extract a maximum of the phenolic content, under the described conditions.

Modelling and Optimization of Ultrasound Assisted Extraction of Polyphenols Using Response Surface Methodology

Mango seed kernels are by-products of the consumption and transformation of mango fruits (Mangifera indica L.). Many ways of valorisation have been proposed, and among them, their phenolic compounds extraction. To increase the extraction yield, ultrasound-assisted extraction was modelled and optimized. The 4 factors Central Composite design associated with the Response Surface Methodology (RSM) were used to achieve that goal. The effect of extraction time, temperature, stirring rate and the Ultrasound Amplitude, on the total phenolic compound extraction yield and the total reducing power of the extract, were studied and modelled. The modelling allows us to do a multi-response optimization to identify the best-operating conditions to achieve at the same time the highest extraction yield and antioxidant capacity. The optimal operating conditions achieved were 41.82 min of extraction time, 54.75⁰C as extraction time, under 266.67 rpm as stirring rate, and 100% ultrasound amplitude. With an expected extraction yield of 71.35 mg GA/g, and 123.058 mg AA/g of total reducing power. 2 extraction cycles, under these conditions, are enough to extract a maximum of the phenolic content, under the described conditions.

Effective Production of Phenolic Compounds with Health Benefits in Pigeon Pea [Cajanus cajan (L.) Millsp.] Hairy Root Cultures.

Phenolic compounds in pigeon pea possess various biological properties beneficial to human health. In this study, pigeon pea hairy root cultures (PPHRCs) were developed as an effective in vitro platform for the production of phenolic compounds. A high-productive hairy root line was screened and characterized, and its culture conditions were optimized in terms of biomass productivity and phenolic yield. The comparative profiling of 10 phenolic compounds in PPHRCs and pigeon pea natural resources (seeds, leaves, and roots) was achieved by ultra-high-performance liquid chromatography-tandem mass spectrometry analysis. The total phenolic yield in PPHRCs (3278.44 μg/g) was much higher than those in seeds (68.86 μg/g) and roots (846.03 μg/g), and comparable to leaves (3379.49 μg/g). Notably, PPHRCs exhibited superiority in the yield of the most important health-promoting compound cajaninstilbene acid (2996.23 μg/g) against natural resources (4.42-2293.31 μg/g). Overall, PPHRCs could serve as promising potential alternative sources for the production of phenolic compounds with nutraceutical/medicinal values.

Boron Biofortification of Portulaca oleracea L. through Soilless Cultivation for a New Tailored Crop

Purslane (Portulaca oleracea L.) is a wild edible plant, traditionally consumed in the Mediterranean area and recently proposed as a new ready-to-eat vegetable; it is also called the “vegetable for long life” because of the high contents of several healthy compounds. Although boron (B) is not considered to be essential for humans, a daily intake of about 2 mg to obtain positive effects on aging in adult men and women has been suggested. In this study, two genotypes of purslane (wild collected and commercial variety) are grown by using a hydroponic system with three boron (B) levels in the nutrient solution (NS) (0.3 mg/L—control, 3 mg/L—low level of biofortification, and 6 mg/L—high level of biofortification) in order to increase the B content in the edible parts of the plant. The crop yield, color traits, and content of glucose, fructose, total phenols, chlorophylls, carotenoids, mineral elements (Al, B, Ca, Cr, Fe, K, Mg, Mn, Na, and Zn), nitrate, and oxalate are analyzed. Independent of the genotype, the B content in edible purslane was successfully increased in comparison with the control, obtaining 1.8- to 10.7-fold higher values of B tissue concentrations by using, respectively, 3 and 6 mg/L of B in the NS without affecting crop performances. From a nutritional point of view, the average daily intake of B could be satisfied by consuming about 75 or 48 g of purslane, grown by using 3 and 6 mg/L B level in the NS, respectively. Apart from B and Fe, the content of mineral elements in edible parts of purslane was not strongly influenced by different B levels in the NS but it was affected by genotypes. A lower sugar content was found in wild purslane grown with the highest B level. A higher content of both chlorophylls and carotenoids was found in the control but only for the commercial genotype. No differences in oxalate content were observed among B levels in the NS, while only in the case of wild genotype, we found a lower nitrate content when a B concentration of 3 mg/L was used in the NS. In conclusion, we demonstrated the possibility of using the floating hydroponic system, combined with specific B concentrations in the NS composition, as a method to calibrate the B uptake in edible parts of purslane.

Catalytic fast pyrolysis of walnut shell with K/AC catalyst for the production of phenolic-rich bio-oil

Potassium supported on commercial activated carbon (K/AC) catalysts were prepared and used for catalytic fast pyrolysis (CFP) of walnut shell to produce phenolic-rich bio-oil. Pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS) and fixed-bed CFP tests were performed to reveal the influences of pyrolytic temperature, potassium loading and catalyst-to-biomass (C-to-B) ratio on the product distribution. The Py–GC/MS results showed that the K5.79/AC catalyst in which the potassium loading was 5.79% exhibited the maximal improvement on the yield of phenolic compounds. Pyrolytic temperature significantly affected the total phenolic yield, which achieved the maximum value at 450 °C whether with or without catalysts. Moreover, the C-to-B ratio also dramatically affected the yield of phenolic compounds. The total phenolic yield raised with increasing C-to-B ratio, whereas the excessive C-to-B ratio (higher than 3:1) would lead to an obvious decrease in total phenolic yield. Overall, the yield of total phenolic compounds achieved the maximum value of 145.65 mg/g (14.57 wt%) at 450 °C under C-to-B ratio of 3:1 in Py–GC/MS runs. Meanwhile, the lab-scale experiments obtained the maximal total phenolic yield of 135.13 mg/g (13.51 wt%) at 450 °C under C-to-B ratio of 1:3.

Pengaruh Perbandingan Bahan dengan Pelarut dan Waktu Maserasi terhadap Ekstrak Kulit Biji Kakao (Theobroma cacao L.) sebagai Sumber Antioksidan

The cocoa beans husk contains a polyphenol compound with total phenolic compounds 5.78 percent. Waste cacao beans husk can be used more optimally by extracting, its countent of polyphenol compounds which can be used as natural antioxidants. This study aims to determine the effect of the comparison of ratio between material and solvent and maceration time on the extract of cocoa beans husk powder as a source of antioxidants and to determine the best type of ratio between material and solvent and maceration time to produce extracts of cocoa bean powder as a source of antioxidants. This experiment was disegred by using factorial randomized block design. The first factor is a ratio between material and solvent consisting of 3 levels, namely 1:10, 1:15, 1:20. The second factor is maceration time for 24, 36 and 48 hours. The data were analyzed with analysis of variance and continued with the Tukey test. The results showed that the comparison of ratio between material and solvent and maceration time had a very significant effect on yield, total phenolic and antioxidant capacity of cocoa beans husk extract. Interactions between treatments had a very significant effect on total phenolic and antioxidant capacity but did not significantly affect the yield of cocoa pod husk extract. The yield of the best cocoa beans husk powder extract was using ratio between material and solvent 1:20 and 48 hours of maceration with a yield of 14.49±0.19 percent. The best total phenolic and antioxidant capacity results were using ratio between material and solvent 1:15 and 48 hours with a total phenolic yield of 85.50±1.74 mg GAE/g and antioxidant capacity 55.18±0.22 mg GAEAC/g.&#x0D; Keywords : cocoa bens husk, extraction, solvent, antioxidants.

Comparison of Total Phenolic Content, Antioxidant Activity and Extraction Yield from Apium Graveolens Waste Using Unconventional Extraction Methods

Apium graveolens is a medicinal and aromatic plant used in pharmaceutical industry, cosmetic industry, gastronomy and traditional medicine. Aerial parts of Apium graveolens (stems and leaves) are rich in bioactive compounds (flavonoids, phenols, furanocoumarins, volatile oils, sesquiterpene alcohols, fatty acids, etc.). It is known for its hepatoprotective, antioxidant, anticancer, antidiabetic, anti-inflammatory, antimicrobial, analgesic, anti-spasmolytic, anti-infertility, cardiotonic activities. This is why studies in this direction have not yet ceased and are increasingly pursuing the discovery of new, unconventional methods for identifying, quantifying and isolating bioactive compounds from Apium graveolens waste. The aim of this study was to determine and correlate the total phenolics, total flavonoids, antioxidant activity and extraction yield from ethanolic extracts (70%) of stems and leaves waste with different unconventional extraction methods. Apium graveolens aerial parts waste were obtained after aqueous extraction of the leaves and stems. The extraction yield was expressed as function of freeze-dried extracts, and the extraction methods were ultrasound assisted extraction, microwave assisted extraction and accelerated solvent extraction. Regarding the chosen extraction methods, numerous studies have shown, especially in the case of microwave assisted extraction, the presence of bioactive compounds in plant waste, in a reasonable percentage, therefore this study aimed to identify an optimal extraction method also in the case of Apium graveolens aerial parts waste. Total phenols content was determined by Folin-Ciocalteu spectrophotometric method, the flavonoids content waste determined by aluminium chloride spectrophotometric method and the antioxidant activity was studied using DPPH (2,2-Diphenyl-1-picrylhydrazyl) spectrophotometric method. The findings of this work indicated a positive dependence between the extraction yield of the waste material and the considerable content of bioactive compounds still present (phenols and flavonoids) for all considered extraction methods.

Effect of extraction variables on total phenol yield in some selected legumes indigenous to Nigeria

There are increasing research efforts on the possibilities of the utilization of natural sources of bioactive compounds for the dietary management of certain degenerative diseases due to their deleterious health effects associated with the the use of synthetic chemicals. Therefore, this study evaluated the yield of total phenol from bambaranut, cowpea, red bean and pigeon pea. A set of single factor experiments, namely solvent types (acetone, ethanol and methanol), solvent concentration (20 – 100 %, v/v), extraction time (30 – 50 min) and extraction temperature (40 – 60 °C), were evaluated for the optimization of total phenol recovery. The results show that extraction variables significantly (p &amp;lt; 0.05) affected the total phenol yield. Ethanol at 60% concentration (v/v) incubated at 50 °C for 40 min gave the highest total phenol (217.11 mg/100 g) yield in bambaranut. In cowpea, ethanol at 90% concentration (v/v) incubated at 50 °C for 50 min gave the highest total phenol (192.61 mg/100 g). Methanol at 100% concentration incubated at 50 °C for 40 min gave the highest total phenol (212.00 mg/100 g) in the red bean while methanol at 100 % concentration (v/v) incubated at 50 °C for 40 min gave the highest total phenol (196.33 mg/100 g) in pigeon pea.

Ultrasound-assisted extraction of total anthocyanins from Rubia sylvatica Nakai fruit and radical scavenging activity of the extract

Ultrasound-assisted extraction (UAE) of total anthocyanin (TA) and total phenolics (TP) from Rubia sylvatica Nakai fruit (RSF) was optimized using response surface methodology. On the basis of a single-factor experiment, six factors were screened using a Plackett-Burman experimental design to determine the variables that significantly influence the extraction yield of TA and TP, namely ultrasound power, liquid: solid ratio, ethanol concentration, pH value, extraction temperature, and extraction duration. Based on statistical significance analysis, ethanol concentration, pH value, and extraction temperature were selected for further optimization of the extraction process using a Box–Behnken design. Under the optimum conditions, yields of TA and TP were 22.50 ± 0.89 mg cyanidin-3-glucoside/g RSF and 36.20 ± 0.11 mg gallic acid/g RSF, respectively. The extract prepared under UAE exhibited excellent DPPH radical scavenging activity (IC50 1.21 ± 0.04 mg/mL). The results demonstrate that R. sylvatica fruit are rich in anthocyanins and show considerable potential as a source of colorants for use in the food industry.

Comparison of conventional extraction technique with ultrasound assisted extraction on recovery of phenolic compounds from lemon scented tea tree (Leptospermum petersonii) leaves

Leptospermum petersonii is a native Australian medicinal and aromatic plant. This study was designed to evaluate the influence of solvents and ultrasound-assisted extraction (UAE) parameters including time, temperature, and sonication power on the yield of phenolic compounds and antioxidant capacity from lemon scented tea tree leaves. Extraction efficiency of the optimal UAE conditions were compared with that of shaking water bath technique. The results show that extraction solvents significantly affect extraction yield of phenolic compounds and antioxidant properties, and 50% acetone in water was found to be the most suitable solvent. The UAE optimal conditions were 60 min, 50 °C and sonication power of 200 W. Under these optimal conditions the yields of total phenolics, flavonoids, proanthocyanidins were 98.91 ± 1.20 (mg GAE/g DW), 76.12 ± 0.79 (mg CE/g DW), 117.71 ± 2.18 (mg CE/g DW), respectively. Antioxidant properties from four assays including FRAP, CUPRAC, ABTS and DPPH were 581.29 ± 14.23, 5534.87 ± 19.56, 1636.18 ± 4.11, and 889.29 ± 20.68 (mM TE/g DW) respectively. The UAE extraction technique was found to be more efficient in extraction of total phenolics and antioxidant capacity in comparison with conventional shaking water bath extraction. This study also observed a strong correlation between phenolic compounds and antioxidant capacities. All three phenolic compound groups (TPC, TFC, and Pro.A) were contributed to both free radical scavenging and ion reducing properties in the lemon scented tea tree leaves extract. However, the order of the phenolic groups was TPC > Pro.A > TFC for antioxidant properties.

From winery waste to bioactive compounds and new polymeric biocomposites: A contribution to the circular economy concept

The paper aims at optimising and validating possible routes toward the full valorisation of grape agrowaste to produce bioactive molecules and new materials. Starting from Merlot red pomace, phenol complex mixtures were successfully extracted by using two different approaches. Extracts obtained by solvent-based (SE) technique contained up to 46.9 gGAeq/kgDW of total phenols. Depending on the used solvent, the prevalence of compounds belonging to different phenol families was achieved. Pressurized liquid extraction (PLE) gave higher total phenol yields (up to 79 gGAeq/kgDW) but a lower range of extracted compounds. All liquid extracts exerted strong antioxidant properties. Moreover, both SE and PLE extraction solid residues were directly exploited (between 5 and 20% w/w) to prepare biocomposite materials by direct mixing via an eco-friendly approach with PHBV polymer. The final composites showed mechanical characteristics similar to PHVB matrix. The use of pomace residues in biocomposites could therefore bring both to the reduction of the cost of the final material, as a lower amount of costly PHBV is used. The present research demonstrated the full valorisation of grape pomace, an agrowaste produced every year in large amounts and having a significant environmental impact.