Antioxidant Properties of Artemisia annua Extracts in Model Food Emulsions

Artemisia annua is currently the only commercial source of the sesquiterpene lactone artemisinin. Although artemisinin is a major bioactive component present in this Chinese herb, leaf flavonoids have shown a variety of biological activities. The polyphenolic profile of extract from leaves of A. annua was assessed as a source of natural antioxidants. Total phenolic content and total flavonoid content were established and three assays were used to measure the antioxidant capacity of the plant extract. The measurement of scavenging capacity against the 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid #ABTS# radical cation, radicals, the oxygen radical absorbance capacity #ORAC# and the ferric reducing antioxidant power #FRAP# were 314.99 µM Trolox equivalents #TE#/g DW, 736.26 µM TE/g DW and 212.18 µM TE/g DW, respectively. A. annua extracts also showed good antioxidant properties in 10% sunflower oil-in-water emulsions during prolonged storage #45 days# at 32 °C. Artemisia extract at 2 g/L was as effective as butylated hydroxyanisole #BHA# at 0.02 g/L in slowing down the formation of hydroperoxides as measured by peroxide value and thiobarbituric acid reactive substances. The results of this study indicate that extract of A. annua may be suitable for use in the food matrix as substitutes for synthetic antioxidants.Postprint (published version

Extraction of antioxidants from borage (Borago officinalis L.) leaves—Optimization by response surface method and application in oil-in-water emulsions

Borage (Borago officinalis L.) is a typical Spanish plant. During processing, 60% are leaves. The aim of this work is to model and optimize the extraction of polyphenol from borage leaves using the response surface method (RSM) and to use this extract for application in emulsions. The responses were: total polyphenol content (TPC), antioxidant capacity by ORAC, and rosmarinic acid by HPLC. The ranges of the variables temperature, ethanol content and time were 50–90 °C, 0%–30%–60% ethanol (v/v), and 10–15 min. For ethanolic extraction, optimal conditions were at 75.9 °C, 52% ethanol and 14.8 min, yielding activity of 27.05 mg GAE/g DW TPC; 115.96 mg TE/g DW in ORAC and 11.02 mg/L rosmarinic acid. For water extraction, optimal activity was achieved with extraction at 98.3 °C and 22 min, with responses of 22.3 mg GAE/g DW TPC; 81.6 mg TE/g DW in ORAC and 3.9 mg/L rosmarinic acid. The significant variables were ethanol concentration and temperature. For emulsions, the peroxide value was inhibited by 60% for 3% extract concentration; and 80% with 3% extract concentration and 0.2% of BSA. The p-anisidine value between the control and the emulsion with 3% extract was reduced to 73.6% and with BSA 86.3%, and others concentrations had similar behavior.Postprint (published version

Avocado seed: A comparative study of antioxidant content and capacity in protecting oil models from oxidation

Increasingly, consumers want products containing little or no synthetic compounds. Avocado seeds, which are a residue of the food industry, could be used to obtain extracts with high antioxidant power. In the present study, the most popular radical scavenging methods are presented, establishing a comparison between them, besides working with two different extractions: pure methanol and ethanol–water (50:50 v/v). The radical scavenging assay methods ORAC and ABTS were performed, as well as a novel method: the reaction to methoxy radical, as determined by electron paramagnetic resonance (EPR). Peroxide value and thiobarbituric acid reactive compounds (TBARs) were used to monitor the oxidation of avocado seed oil, as well as the power of the avocado seed extract (ASE) to delay oil oxidation by oxidation induction time (OIT) and measured by differential scanning calorimetry (DSC). Radical scavenging methods have values between 1310–263 mol TE/g of mass dissolved for ORAC and ABTS, respectively. The individual contribution of each of the compounds present in the extract was analyzed. The sum of all of them contributed up to 84% of the total radical scavenging activity. The concentration of 0.75% ASE causes a delay in the oxidation that is close to 80%, as measured by OIT. This implies that avocado seed residue may have a use as a natural antioxidant source, providing added value to organic waste.Postprint (published version

Avocado seeds: extraction optimization and possible use as antioxidant in food

Consumption of avocado (Persea americana Mill) has increased worldwide in recent years. Part of this food (skin and seed) is lost during processing. However, a high proportion of bioactive substances, such as polyphenols, remain in this residue. The primary objective of this study was to model the extraction of polyphenols from the avocado pits. In addition, a further objective was to use the extract obtained to evaluate the protective power against oxidation in food systems, as for instance oil in water emulsions and meat products. Moreover, the possible synergy between the extracts and egg albumin in the emulsions is discussed. In Response Surface Method (RSM), the variables used are: temperature, time and ethanol concentration. The results are the total polyphenols content (TPC) and the antiradical power measured by Oxygen Radical Antioxidant Capacity (ORAC). In emulsions, the primary oxidation, by Peroxide Value and in fat meat the secondary oxidation, by TBARS (Thiobar bituric acid reactive substances), were analyzed. The RSM model has an R 2 of 94.69 for TPC and 96.7 for ORAC. In emulsions, the inhibition of the oxidation is about 30% for pure extracts and 60% for the combination of extracts with egg albumin. In the meat burger oxidation, the formation of TBARS is avoided by 90%Postprint (published version

Screening of antioxidant activity of Gentian Lutea root and its application in Oil-in-Water Emulsions

Gentiana Lutea root (G. Lutea) is a medicinal herb, traditionally used as a bitter tonic in gastrointestinal ailments for improving the digestive system. The active principles of G. Lutea were found to be secoiridoid bitter compounds as well as many other active compounds causing the pharmacological effects. No study to date has yet determined the potential of G. Lutea antioxidant activity on lipid oxidation. Thus, the aim of this study was to evaluate the effects of an extract of G. Lutea on lipid oxidation during storage of an emulsion. G. Lutea extracts showed excellent antioxidant activity measured by DPPH scavenging assay and Trolox equivalent antioxidant capacity (TEAC) assays. An amount of 0.5% w/w G. Lutea lyophilise was able to inhibit lipid oxidation throughout storage (p < 0.05). A mixture of G. Lutea with 0.1% (w/w) BSA showed a good synergic effect and better antioxidant activity in the emulsion. Quantitative results of HPLC showed that G. Lutea contained secoiridoid-glycosides (gentiopiocroside and sweroside) and post column analysis displayed radical scavenging activity of G. Lutea extract towards the ABTS radical. The results from this study highlight the potential of G. Lutea as a food ingredient in the design of healthier food commoditiesPeer ReviewedPostprint (published version

Specific Mathematics Learning Objectives Expressed by Teachers in Training

The formulation of learning objectives is considered an important task for teaching at all educational levels. However, teachers tend to trivialize learning objectives and consider them as part of an administrative requirement. This study sought to characterize the specific learning objectives for two school mathematics tasks posed by primary teachers in training, and to study the differences in the objectives proposed for each task. By means of a semantic questionnaire, the proposals were collected, classified and analysed using categories based on a triad of components for a specific objective: capability, content, and context. The responses show both an instrumental approach—where knowledge consists in mastering techniques and algorithms useful to furthering certain behaviours and attaining specific objectives—and a structural approach—where knowledge consists in a structured system of formalized rules and concepts based on the deduction. Moreover, this expectation depends on the kind of school task.Spanish Government PGC2018095765-B-I0

Unidades multidisciplinares de feridas crónicas: Clínica de feridas

As Unidades Multidisciplinares de Feridas Crónicas / Clínicas de feridas devem ser as líderes que garantam o direito a uma atenção que ponha ao serviço da pessoa com feridas crónicas todos os recursos técnicos e humanos em função das suas necessidades, sejam de prevenção, de atenção ao seu processo, dependendo obviamente das possibilidades do centro, sem que os cidadãos possam ser discriminados devido ao sexo, idade, raça, ideologia e condição socioeconómica. Possibilitar uma trama eficiente na atenção, prevenção, diagnóstico e tratamento independentemente do contexto assistencial e social das pessoas com feridas crónicas. Otimizar os recursos diagnósticos, preventivos e terapêuticos dirigidos às pessoas com feridas crónicas. Aglutinar a atividade investigadora e docente em matéria de feridas crónicas da sua área de influencia.info:eu-repo/semantics/publishedVersio

Study of the properties of bearberry leaf extract as a natural antioxidant in model foods

The common bearberry (Arctostaphylos uva-ursi L. Sprengel) is a ubiquitous procumbent evergreen shrub located throughout North America, Asia, and Europe. The fruits are almost tasteless but the plant contains a high concentration of active ingredients. The antioxidant activity of bearberry leaf extract in the 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical cation assay was 90.42 mmol Trolox equivalents/g dry weight (DW). The scavenging ability of the methanol extract of bearberry leaves against methoxy radicals generated in the Fenton reaction was measured via electron paramagnetic resonance. Lipid oxidation was retarded in an oil–water emulsion by adding 1 g/kg lyophilised bearberry leaf extract. Also, 1 g/kg of lyophilised bearberry leaf extract incorporated into a gelatin-based film displayed high antioxidant activity to retard the degradation of lipids in muscle foods. The present results indicate the potential of bearberry leaf extract for use as a natural food antioxidant.Postprint (published version

Unidades multidisciplinares de feridas crónicas: Clínica de feridas

As Unidades Multidisciplinares de Feridas Crónicas / Clínicas de feridas devem ser as líderes que garantam o direito a uma atenção que ponha ao serviço da pessoa com feridas crónicas todos os recursos técnicos e humanos em função das suas necessidades, sejam de prevenção, de atenção ao seu processo, dependendo obviamente das possibilidades do centro, sem que os cidadãos possam ser discriminados devido ao sexo, idade, raça, ideologia e condição socioeconómica. Possibilitar uma trama eficiente na atenção, prevenção, diagnóstico e tratamento independentemente do contexto assistencial e social das pessoas com feridas crónicas. Otimizar os recursos diagnósticos, preventivos e terapêuticos dirigidos às pessoas com feridas crónicas. Aglutinar a atividade investigadora e docente em matéria de feridas crónicas da sua área de influencia.info:eu-repo/semantics/publishedVersio