895 research outputs found

    Quality Evaluation of ‘Sunburst’ Cherries Harvested at Different

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    The sweet cherry ‘Sunburst’ is highly appreciated by consumers due to its organoleptic traits. Regional producers tend to harvest cherries sooner in order to increase their profits. With the aim of understanding the consequences of this we have tested the effect of different ripeness stages at the moment of harvesting on fruit quality. Quality parameters tested included external colour (L*, a*, b*), fruit texture, total soluble solids (TSS), and titratable acidity (TA). To evaluate nutritional quality total antioxidant activity was measured too. Once again, and in agreement with results obtained in previous studies, we conclude that there is no advantage in picking less ripe cherrie

    Combination of stable isotope analysis and chemometrics to discriminate geoclimatically and temporally the virgin olive oils from three mediterranean countries

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    The knowledge of the isotopic composition of virgin olive oil (VOO) allows the evaluation of authenticity and geographical origin, being an important tool against fraud. This study aimed to assess if VOOs produced in three Mediterranean regions could be discriminated on the basis of multivariate statistical analysis of geoclimatic and isotopic data. A total of 138 geo-referenced VOO samples from Portugal, France and Turkey from two different cultivation years were collected. The isotopic composition (δ13C, δ2H and δ18O) of VOOs was obtained using an elemental analyzer coupled to an isotope ratio mass spectrometer (EA-IRMS). One-way analysis of variance for δ13C, δ2H and δ18O showed some significant differences either between crop years or geoclimatic conditions. Based on multiple regression analyses using meteorological and geographical parameters, a meteoric water line for olive oil from Portugal, France and Turkey, in two harvest years, were created to assess the impact of climate change on their δ2H and δ18O values. Principal component analysis and Linear Discriminant Analysis, used to sort samples according to geoclimatic origin, performed best for French and Portuguese olive oils. In light of the results, multivariate isotopic analysis of VOO samples may discriminate not only between geoclimatic regions but also among cultivation years

    Optimization of an Enzyme-Assisted Extraction Method for the Anthocyanins Present in Açai (Euterpe oleracea Mart.)

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    Several investigations have proven the presence of anthocyanins in different parts of acai plants. These compounds are responsible for the notable therapeutic properties of acai such as antioxidant, antimicrobial, anti-inflammatory, anticancer, and anticonvulsant. We have therefore optimized an enzyme-assisted extraction method for the anthocyanins found in acai, to be subsequently applied in many fields such as agrifood, medicine, or cosmetics. A Plackett-Burman design with seven variables (time of extraction, pH, temperature, agitation, percentage of ethanol in the solvent, amount of sample, and units of enzyme) was employed to determine the predominant extraction variables, of which four were categorized as influential. Subsequently, a Box-Behnken design-response surface methodology made it possible to determine the degree of influence from these variables and their optimal values. The optimal conditions were established as 0.1 g of acai heated up to 60 degrees C and extracted using 15 mL of solvent with pH 4 and 40% ethanol, 500 units of enzyme per gram of sample, and agitation at 150 rpm for 15 min. The repeatability and intermediate precision of the developed method were confirmed by variation coefficients below 5%. Finally, the developed method was compared against the extensively used maceration and ultrasound-assisted extraction methods.info:eu-repo/semantics/publishedVersio

    The Impact of the Malolactic Fermentation in the Volatile Composition of Trincadeira Wine Variety

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    Use of commercial starters for malolactic fermentation (MLF) is a common practice, and outcomes of this procedure are very relevant for wine producers because aroma attributes might change according to the strain used. MLF was carried out in the Trincadeira wine variety in three batches: spontaneously and with inoculation of two different commercial starters. Wine extracts before and after MLF were obtained through liquid–liquid extraction. Gas chromatography/ion trap mass spectrometry analysis allowed the detection of 21 compounds, some of them tentatively identified through electron impact spectra comparison with a database, through interpretation of multistage mass spectrometry and chemical ionization mass spectrometry spectra and confirmation by comprehensive multidimensional gas chromatography/ time of flight-mass spectrometry (GC ¥ GC/ToF-MS). After MLF, an increase in ethyl lactate, g-butyrolactone and diethyl succinate and a drop in isoamyl acetate, ethyl octanoate, ethyl decanoate, 2,3-dimethyl-hexan-3-ol, propanol, isobutanol and 2,3-butanediol was observed. The concentrations of the 10 compounds are statistically different in wines before and after MLF, and wines after MLF show significant differences for the nine compounds

    Enhancing efficiency of enzymatic-assisted extraction method for evaluating bioactive compound analysis in mulberry: an optimization approach

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    The present investigation endeavors to optimize a method based on enzyme-assisted extraction for the efficient retrieval of bioactive compounds from mulberry, leveraging its notable health-promoting properties. A combined approach of Plackett-Burman design followed by Box-Behnken design was employed for determining the crucial extraction parameters and subsequently, refining the process. Optimal conditions consisted of heating 0.15 g of mulberry at 40 degrees C, using 15 mL of 70% EtOH as a solvent at pH 4, 38.46 enzyme units per g of sample, and shaking at 200 rpm. The optimum extraction time study revealed that 5 min of extraction was sufficient to reach the maximum concentration of the bioactive compound. The repeatability and intermediate precision assessment exhibited a coefficient of variation below 5%. Among the diverse mulberry varieties scrutinized, Morus nigra showed the highest anthocyanin content (27.90 +/- 2.14 mg/100 g), while Morus rubra showed the highest concentration of phenolic compounds (121.10 +/- 19.56 mg/100 g). Moreover, the extracted compounds showcased significant antioxidant and antimicrobial properties.Equipment for liquid chromatography by means of mass spectrometry and ion chromatography) of the State Subprogram of Research Infrastructures and Technical Scientific Equipment EQC2018-005135-Pinfo:eu-repo/semantics/publishedVersio

    Ultrasound-assisted extraction of betalains from opuntia fruit pulp of different color varieties

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    Betalains are water-soluble pigments that have exhibited important pharmacological properties such as antioxidant, anticancer, antilipidemic and antimicrobial activity. These compounds have been isolated in numerous purple plants or fruits, as is the case of the wild species under the Opuntia genus. The fruits of these species are often disregarded because of their small size as well as the frequent presence of prickles. Based on this, this research has as its objective the optimization of a method based on ultrasound-assisted extraction to obtain extracts enriched with betalains from a wild Opuntia species (Opuntia dillenii (Ker Gawl.) Haw.). Four variables (%EtOH in the solvent, temperature of extraction, ultrasound amplitude and cycle) were selected using a Box-Behnken design. The quadratic interaction of %EtOH and the interaction of %EtOH-cycle have proven to be influential variables at 95% confidence. The conditions to obtain the highest betalain concentration were 100 mg of pulp with 20 mL (60%:40% EtOH:H2O) solvent at 20 degrees C at 24% amplitude and 0.2 cycle for 10 min. The suitability and reliability of the method were evaluated with repeatability and intermediate precision tests obtaining CVs <5%. Finally, the developed method has been employed in the analysis of five Opuntia commercial samples and obtained significant antioxidant activity of the extracts, confirming its applicability.info:eu-repo/semantics/publishedVersio

    On the valorization of Arbutus unedo L. Pomace: Polyphenol extraction and development of novel functional cookies

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    The fruits of Arbutus unedo L. have a crimson colour and are enriched with remarkable concentrations of bioactive compounds such as anthocyanins and polyphenols. These fruits are commonly used in the production of a Portuguese Protected Geographical Indication distillate called “Aguardente de Medronho”. During this process, a solid pomace is generated and presently discarded without valuable applications. In this work, two strategies have been developed for the valorisation of A. unedo pomace. The first approach considers the extraction of polyphenols from this by-product through the optimization of an ultrasound-assisted method using a Box-Behnken design coupled with response surface methodology. The results indicate that the temperature and the percentage of methanol, along with their interaction, significantly influence the total concentration of polyphenols and the antioxidant activity of the extracts obtained. The optimal conditions identified consider the extraction of 0.5 g of sample with 20 mL of a solvent containing 74% MeOH (aq), at a pH of 4.8, maintained at 70 ◦C for 15 min. On the other hand, the second valorisation strategy considered the use of A. unedo pomace in the development of functional cookies. The incorporation of 15–20% pomace in the cookie formulation was well-received by consumers. This incorporation results in an intake of ca. 6.55 mg of polyphenols per gram of cookie consumed, accompanied by an antioxidant activity of 4.54 mg Trolox equivalents per gram of cookie consumed. Overall, these results encourage the employment of A. unedo pomace either as a reliable source of extracts enriched in polyphenols or as a nutraceutical active ingredient in functional cookies, thereby positively impacting human health.info:eu-repo/semantics/publishedVersio

    UCO physical rehabilitation: new dataset and study of human pose estimation methods on physical rehabilitation exercises

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    Physical rehabilitation plays a crucial role in restoring motor function following injuries or surgeries. However, the challenge of overcrowded waiting lists often hampers doctors’ ability to monitor patients’ recovery progress in person. Deep Learning methods offer a solution by enabling doctors to optimize their time with each patient and distinguish between those requiring specific attention and those making positive progress. Doctors use the flexion angle of limbs as a cue to assess a patient’s mobility level during rehabilitation. From a Computer Vision perspective, this task can be framed as automatically estimating the pose of the target body limbs in an image. The objectives of this study can be summarized as follows: (i) evaluating and comparing multiple pose estimation methods; (ii) analyzing how the subject’s position and camera viewpoint impact the estimation; and (iii) determining whether 3D estimation methods are necessary or if 2D estimation suffices for this purpose. To conduct this technical study, and due to the limited availability of public datasets related to physical rehabilitation exercises, we introduced a new dataset featuring 27 individuals performing eight diverse physical rehabilitation exercises focusing on various limbs and body positions. Each exercise was recorded using five RGB cameras capturing different viewpoints of the person. An infrared tracking system named OptiTrack was utilized to establish the ground truth positions of the joints in the limbs under study. The results, supported by statistical tests, show that not all state-of-the-art pose estimators perform equally in the presented situations (e.g., patient lying on the stretcher vs. standing). Statistical differences exist between camera viewpoints, with the frontal view being the most convenient. Additionally, the study concludes that 2D pose estimators are adequate for estimating joint angles given the selected camera viewpoints
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