Concept for the valorization of cereal processing waste: Recovery of phenolic acids by using waste-derived tetrahydrofurfuryl alcohol and biochar.

Valorization of agro-food waste by converting it into a renewable resource plays a crucial role in a bio-based circular economy. Therefore, this study was designed to evaluate the suitability of distillery stillage (DS), which comes from alcohol production from cereals, for producing value-added products that can be used synergistically. The main objective was to investigate the usefulness of two substances for the recovery of phenolic acids, which have antioxidant activity, from the liquid fraction of DS: namely, tetrahydrofurfuryl alcohol (THFA) as a solvent and biochar as an adsorbent, both produced from the solid fraction of cereal processing waste. The effect of THFA concentration (80 and 100%) on phenolic acid yield in ultrasound-assisted extraction was studied. The solubilization predictions of phenolic compounds by the Hansen solubility parameters were in accordance with the experimental results: the yield of phenolic acids in the extracts was highest (3.76 µg g-1 dry mass) with 80% THFA. Among the extracted phenolic acids, hydroxycinnamic acids predominated over hydroxybenzoic acids, which may affect the bioactive properties of the extracts and their future applications for industrial purposes. Phenolic acids from the extracts were adsorbed on 17-170 g biochar L-1 and desorbed into water at 40-60 °C. The phenolic acid recovery was highest (∼92%) when the biochar dose was 85 g L-1 and when desorption was performed at 50 °C. After adsorption/desorption, ∼95% of the antioxidant activity of the phenolic acids in the extracts was maintained. As biochar has a smaller specific surface area than commercial powdered activated carbon (PAC), the biochar dose should be about 5 times higher than an equivalent PAC dose for adsorption efficiency above 90%.

Valorization of distillery stillage by polyphenol recovery using microwave-assisted, ultrasound-assisted and conventional extractions.

An increasing understanding of the negative environmental effects of waste discharges has made valorization of distillery by-products to recover added-value compounds a sound option for distillery stillage management. In this study, the recovery of bioactive compounds, i.e. polyphenols, from distillery stillage was performed by microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE) and conventional solid-liquid extraction (CSLE) to investigate the effects of extraction time, the concentration of ethyl acetate (EA) in a solvent mixture with ethanol and water, and solid-to-solvent ratio on the recovery yield and antioxidant activity of the extracts. The highest yields of total polyphenol content (TPC) (3.73 mg gallic acid equivalent/g) and phenolic acid content (2.51 µg/g) were obtained with 8-min MAE with 70% EA. MAE provided 1.2- and 1.4-times higher yield of phenolic acids and 1.2- and 1.6-times higher antioxidant activity than UAE and CSLE, respectively. Due to the approximately 3-times higher rate of extraction, the ratio between energy consumption and extraction yield was better in MAE than in UAE. Principal component analysis (PCA) showed that the antioxidant activity of the extracts was positively correlated with TPC and phenolic acid content. Six phenolic acids that were identified were present mainly in their free forms (up to 95% of the total), with a predominance of ferulic (up to 0.80 µg/g) and p-coumaric (up to 0.72 µg/g) acids.

Processing of Distillery Stillage to Recover Phenolic Compounds with Ultrasound-Assisted and Microwave-Assisted Extractions.

This study investigated the effect of ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) conditions (extraction time, acetone concentration, solid-to-solvent ratio) on the efficiency of polyphenol recovery from distillery stillage and antioxidant activity of the extracts. The highest total polyphenol content, flavonoid content, and phenolic acid content were obtained with 10-min UAE and 5-min MAE at a solid-to-acetone ratio of 1:15 (w:v). Recovery yield was the highest with an aqueous solution of 60% acetone, confirming the results of Hansen Solubility Parameter analysis. Although UAE resulted in approximately 1.2 times higher extraction yield, MAE showed a better balance between extraction yield and energy consumption exhibited by its 3-fold higher extraction rate than that of UAE. Content of total polyphenols and phenolic acids strongly correlated with antioxidant activity, indicating that these compounds provide a substantial contribution to the bioactive properties of the extracts. Six phenolic acids were extracted, predominately ferulic and p-coumaric acids, and free forms of these acids constituted 91% of their total content, which opens various possibilities for their application in the food, cosmetics, and pharmaceutical industries.

Phenolics from the Bolivian highlands food plant Ombrophytum subterraneum (Aspl.) B. Hansen (Balanophoraceae): Antioxidant and α-glucosidase inhibitory activity.

The Balanophoraceae Ombrophytum subterraneum is an endemic highland food plant occurring in Bolivia, northern Argentina and Chile. The upper part of this parasitic plant is eaten fresh. The aim of this work was to characterize the compounds occurring in the edible part and to assess any differences between the inflorescence and tuber. Ethanol extracts of the different plant parts were analyzed for antioxidant activity by the ORAC, TEAC, FRAP, CUPRAC and DPPH methods as well as for the effect on enzymes related to metabolic syndrome (α-amylase, α-glucosidase and pancreatic lipase). The main constituents were isolated by a combination of gel permeation in Sephadex LH-20 and countercurrent chromatography (CCC). Five compounds were isolated and fully identified by spectroscopic and spectrometric means. The new 3',5,5',7-tetrahydroxyflavanone 7-O-ß-D-1 â†’ 6 diglucoside was isolated for the first time. HPLC-ESI-MS/MS analysis allowed the identification of 19 compounds, including flavanones, flavanols, flavonols, dehydroflavonols and lignans, mainly as glycosides. A strong inhibition towards α-glucosidase was observed for the edible parts (IC50: 1.46 µg/mL) as well as for the tuber and inflorescence (IC50: 1.56 µg/mL and 0.87 µg/mL, respectively). A significant correlation was established between the total phenolic and the antioxidant capacity of the extracts as well as with the content of the new flavanone diglucoside. This is the first comprehensive report on the naturally occurring antioxidants and enzyme inhibitors from this native highland food resource.

Supercritical Fluid Chromatography development of a predictive analytical tool to selectively extract bioactive compounds by supercritical fluid extraction and pressurised liquid extraction.

Selective extraction is a great concern in the field of natural products. The interest is to apply specific conditions favouring the solubility of targeted secondary metabolites and avoiding the simultaneous extraction of unwanted ones. Different ways exist to reach selective extractions with suited conditions. These conditions can be determined from experimental studies through experimental design, but a full experimental design takes time, energy, and uses plant samples. Prediction from varied solubility models can also be applied allowing a better understanding of the final selected conditions and eventually less experiments. The aim of this work was to develop and use a chromatographic model to determine optimal extraction conditions without the need for numerous extraction experiments. This model would be applied on the selective extraction of the desired antioxidant compounds in rosemary leaves (rosmarinic and carnosic acids) vs chlorophyll pigments to limit the green colour in extracts. This model was achieved with Supercritical Fluid Chromatography (SFC) and then applied to Supercritical Fluid Extraction (SFE) and Pressurised Liquid Extraction (PLE) assays. SFC models predicted low solubility of chlorophylls for low (5%) and high (100%) percentage of solvent in carbon dioxide. Also, low solubility was predicted with acetonitrile solvent compared to methanol or ethanol. This was confirmed with different extractions performed using SFE with different percentages of solvent (5, 30, and 70%) and with the three solvents used in the SFC models (acetonitrile, methanol and ethanol). Also extractions using PLE were carried out using the same neat solvents in order to confirm the SFC models obtained for 100% of solvent. Globally, extractions validated the SFC models. Only some differences were observed between ethanol and methanol showing the complexity of plant extraction due to matrix effect. For all these extracts, the content of carnosic acid and rosmarinic acid was also monitored and selective extraction conditions of bioactive compounds could be determined.

An integrated approach for the valorization of mango seed kernel: Efficient extraction solvent selection, phytochemical profiling and antiproliferative activity assessment.

A novel valorization strategy is proposed in this work for the sustainable utilization of a major mango processing waste (i.e. mango seed kernel, MSK), integrating green pressurized-liquid extraction (PLE), bioactive assays and comprehensive HRMS-based phytochemical characterization to obtain bioactive-rich fractions with high antioxidant capacity and antiproliferative activity against human colon cancer cells. Thus, a two steps PLE procedure was proposed to recover first the non-polar fraction (fatty acids and lipids) and second the polar fraction (polyphenols). Efficient selection of the most suitable solvent for the second PLE step (ethanol/ethyl acetate mixture) was based on the Hansen solubility parameters (HSP) approach. A comprehensive GC- and LC-Q-TOF-MS/MS profiling analysis allowed the complete characterization of the lipidic and phenolic fractions obtained under optimal condition (100% EtOH at 150 °C), demonstrating the abundance of oleic and stearic acids, as well as bioactive xanthones, phenolic acids, flavonoids, gallate derivatives and gallotannins. The obtained MSK-extract exhibited higher antiproliferative activity against human colon adenocarcinoma cell line HT-29 compared to traditional extraction procedures described in literature for MSK utilization (e.g. Soxhlet), demonstrating the great potential of the proposed valorization strategy as a valuable opportunity for mango processing industry to deliver a value-added product to the market with health promoting properties.

Saliva as a Diagnostic Tool for Measurement of Total Antioxidant Capacity in Children with Leprosy and Born to Leprosy Parent.

The aim of the study is to assess the role of saliva as a diagnostic tool for measurement of total antioxidant capacity in children with leprosy and children born to leprosy parent. One hundred fifty children in the age group of 4-15 years were split into three equal groups: children with leprosy (CL) and children born to leprotic parents (CLP) and healthy children. Vitamin C level was measured in saliva of children spectrophotometrically at 695nm by Phosphomolybdenum method. Data were determined with student's unpaired t test and one way ANOVA. The result of the study showed that children with leprosy exhibited significantly decreased salivary total antioxidant capacity as compared to healthy controls. Antioxidant Vitamin C was higher in the Paucibacillary leprosy (PB) than those of Multibacillary type (MB) (P < 0.001). As age advanced, there was a gradual increase in total antioxidant capacity in both the control and study groups and the results were highly significant statistically. Saliva is an easy medium.

Effect of selenium on growth and antioxidant enzyme activities of wine related yeasts.

The use of supplements in the diet is a common practice to address nutritional deficiencies. Selenium is an essential micronutrient with an antioxidant and anti-carcinogenic role in human and animal health. There is increasing interest in developing nutritional supplements such as yeast cells enriched with selenium. The possibility of producing beverages, namely wine, with selenium-enriched yeasts, led us to investigate the selenium tolerance of six wine related yeasts. The production of such cells may hamper selenium toxicity problems. Above certain concentrations selenium can be toxic inducing oxidative stress and yeast species can show different tolerance. This work aimed at studying selenium tolerance of a diversity of wine related yeasts, thus antioxidant response mechanisms with different concentrations of sodium selenite were evaluated. Viability assays demonstrated that the yeast Torulaspora delbrueckii showed the highest tolerance for the tested levels of 100 µg mL(-1) of sodium selenite. The evaluation of antioxidative enzyme activities showed the best performance for concentrations of 250 and 100 µg mL(-1), respectively for the yeast species Saccharomyces cerevisiae and Hanseniaspora guilliermondii. These results encourage future studies on the possibility to use pre-enriched yeast cells as selenium supplement in wine production.

Estresse oxidativo e micronutrientes na hanseníase / Oxidative stress and micronutrients in leprosy

Objetivo Avaliar o estresse oxidativo, perfil antioxidante e de micronutrientes em pacientes portadores de hanseníase multibacilar e paucibacilar antes do tratamento poliquimioterápico. Métodos Analisaram-se 52 amostras de soro de pacientes portadores de hanseníase - 38 multibacilares e 14 paucibacilares -, usuários do ambulatório de dermatologia de um hospital público universitário, além de 30 amostras controles. Quantificaram-se marcador de peroxidação lipídica malondialdeído pelo método de substâncias reativas ao ácido tiobarbitúrico, antioxidante glutationa reduzida pelo método baseado na quantificação de tiol solúvel em ácido, antioxidante vitamina E por cromatografia líquida de alta eficiência, minerais selênio, zinco, cobre, magnésio por espectrometria de massa com fonte plasma acoplado, e sorologia do anticorpo glicolipídio fenólico I pelo método Enzyme-Linked Immunosorbent Assay. Foi utilizado teste não paramétrico de Mann-Whitney para comparar as variáveis quantificadas neste estudo entre os diferentes grupos, e correlação de Pearson para verificar associação dessas variáveis com o anticorpo. O critério de significância adotado foi de p<0,05. Resultados Houve diferença significativa para o malondialdeído (p<0,001) e vitamina E (p<0,001) no grupo controle comparado aos grupos com hanseníase, multibacilar e paucibacilar. No entanto, essas mesmas variáveis não diferiram entre os grupos multibacilar e paucibacilar (p=0,495 e p=0,920 respectivamente). A glutationa reduzida foi superior no grupo controle em relação ao grupo com hanseníase (p=0,012) e multibacilar (p=0,001), no entanto não diferiu do grupo paucibacilar (p=0,920). Quando comparada com os multibacilares e paucibacilares, a glutationa reduzida também não diferiu (p=0,063). Quanto aos minerais, todos se apresentaram dentro da normalidade, exceto o magnésio, cujos níveis foram deficientes em todos os pacientes do estudo. Não foi possível observar correlação do ...

Objective To determine the oxidative stress and the antioxidant and micronutrient profile of patients with multibacillary and paucibacillary leprosy before polychemotherapeutic treatment. Methods Thirty control samples and fifty-two serum samples from leprosy patients who attended the dermatology outpatient clinic of a public university hospital were analyzed; 38 of them had multibacillary and 14 paucibacillarty. Malondialdehyde, a marker of lipid peroxidation, was determined using the thiobarbituric acid reacting substances assay; the antioxidant reduced glutathione was determined using a method based on the quantification of acid-soluble thiol; the antioxidant vitamin E was determined using High-Performance Liquid Chromatography; the minerals selenium, zinc, copper and magnesium were determined using coupled-mass spectrometry, and the serum phenol I glycolipid antibody was determined using Enzyme-Linked Immunosorbent Assay. The nonparametric Mann-Whitney test was used to compare the variables quantified in the present study between the different groups, and Pearson's correlation analysis was used to verify the association between these variables and the antibody. The significance level was set at p<0.05. Results There was a significant difference in the content of malondialdehyde (p<0.001) and vitamin E (p<0.001) between the groups with multibacillary and paucibacillary leprosy (p=0.495 and p=0.920, respectively) and the control groups. Reduced glutathione levels were higher in the control group compared with those of the group with leprosy (p=0.012) and multibacillary leprosy (p=0.001), but did it not differ from that of the paucibacillary group (p=0.920). Reduced glutathione levels did not differ between the multibacillary and paucibacillary groups (p=0.063) either. All minerals were within normal limits, except for magnesium; magnesium deficiency was detected in all groups studied. No correlation was observed between the ...

Improving downstream processes to recover tartaric acid, tartrate and nutrients from vinasses and formulation of inexpensive fermentative broths for xylitol production.

BACKGROUND: Vinasses, the main liquid wastes from the distillation process of grape marc and wine lees, are acidic effluents with high organic content, including acids, carbohydrates, phenols, and unsaturated compounds with high chemical oxygen demand, biological oxygen demand and solid concentrations. These wastes can be revalued to provide additional benefits when they are employed as feedstock of some compounds including tartaric acid, calcium tartrate and economic nutrients for the elaboration of fermentable broths. RESULT: This study attempts to recover tartaric acid and calcium tartrate from vinasses. All the tartaric acid initially solubilised was recovered in both processes. The residual streams can be successfully employed as economic nutrients for the xylose to xylitol bioconversion, achieving higher global volumetric productivities (Q(P, xylitol) = 0.232 g L(-1) h(-1)) and products yields (Y(xylitol/S) = 0.57 g g(-1)) than fermentations carried out using commercial nutrients (Q(P, xylitol) = 0.193 g L(-1) h(-1) and Y(xylitol/S) = 0.55 g g(-1) respectively). CONCLUSION: Tartaric acid can be recovered from vinasses in the form of tartaric acid crystals and calcium tartrate. The residual streams generated in the process can be used as economic nutrients for the production of xylitol by D. hansenii.