Publications by authors named "Davy W H Chavez"

Introduction: Brazil nuts (BNs) result from sustainable extraction and are widely exploited in the Amazon region. Due to the production characteristics in the forest and the nutritional characteristics of these nuts, the occurrence of fungal contamination and the presence of aflatoxins are extensively discussed in the literature as a great aspect of interest and concern. This study aims to evaluate the microbial profile through DNA sequencing and amplification of 16S and ITS genes for bacterial and fungal analysis, respectively, and the presence of mycotoxins using high-performance liquid chromatography with fluorescence detection (HPLC-FD) from different fractions of the nuts processed.

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Roasted ground coffee has been intentionally adulterated for economic revenue. This work aims to use an untargeted strategy to process SPME-GC-MS data coupled with chemometrics to identify volatile compounds (VOCs) as possible markers to discriminate Arabica coffee and its main adulterants (corn, barley, soybean, rice, coffee husks, and Robusta coffee). Principal Component Analysis (PCA) showed the difference between roasted ground coffee and adulterants, while the Hierarchical Clustering of Principal Components (HCPC) and heat map showed a trend of adulterants separation.

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The effect of adding pink pepper (Schinus terebinthifolius Raddi) fruits during sardines canning to minimize cholesterol oxidation were investigated. Canning resulted in an exchange of fatty acids, cholesterol and cholesterol oxides between fish muscle and liquid medium (soybean oil). It also induced lipid oxidation, which was demonstrated by the degradation of fatty acids and the formation of cholesterol oxides.

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A lycopene-rich watermelon (Citrullus lanatus) concentrate was incorporated into snack cracker, fusilli pasta, and extruded snacks for coloring purposes. Changes in the L* and a* color coordinates and in the lycopene content were evaluated before and after thermal processes and monitored through 90 days of storage at ambient temperature. The products with the maximum lycopene degradation during processing were snack cracker and extruded snack (between 30 and 45%) whereas no degradation was observed in the fusilli pasta, except during cooking into boiling water (reduction up to 41%).

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This study evaluated the protective effect of parsley (Petroselinum crispum Mill.) against lipid and cholesterol oxidation in omelets prepared by air frying, pan frying, and microwaving. The bioactive composition and in vitro antioxidant capacity of parsley extract was characterized.

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The buritirana is a little-explored species of the Arecaceae family. The biometric and physicochemical characteristics, nutritional and chemical composition and antioxidant and antibacterial potential of the buritirana fruit fractions were evaluated here for the first time. The fruits presented an oblong shape.

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This study determined the bioactive composition and antioxidant potential of parsley, chives and their mixture (Brazilian cheiro-verde). Additionally, the effect of these herbs against cholesterol oxidation in grilled sardines (Sardinella brasiliensis) was also investigated. Ultra-high Performance Liquid Chromatography-Electrospray Ionization-Mass Spectrometry (UHPLC-ESI-MS) analyses revealed the presence of phenolic acids (caffeic, chlorogenic, and ferulic acids) and flavonoids (apigenin, kaempferol, catechin) in the herbs.

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A frozen banana pulp with functional properties was developed and characterized in this work. For this, 0 g, 3 g, 5 g and 7 g of psyllium in 100 g of banana pulp were added. The use of this fiber in industrialized products can contribute to the nutritional enrichment of the products and provide functional benefits already acknowledged, such as lowering LDL cholesterol, lowering blood glucose, increasing satiety and relieving constipation.

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Canned fish is submitted to processes that may degrade its lipids and form harmful compounds called cholesterol oxidation products (COPs). Samples of Brazilian commercial canned tuna were analyzed to evaluate the influence of different liquid mediums (oil and brine) on the fatty acid composition and formation of COPs. The exchange between fish lipids and the constituents of the covering liquid was highlighted by the high levels of linoleic acid found in tuna conserved in oil.

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Effects of high hydrostatic pressure (HHP) processing (200-400 MPa/5 or 10 min) on functional properties of cellulose acetate (CA) films were investigated. As for mechanical properties, HHP caused a reduction in tensile strength (TS), Young's modulus (YM) and an increase in elongation at break (EB). The pressurized films were more luminous, yellowish, reddish and opaque.

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The aim of this research was to optimize the growth parameters (pH, ethanol tolerance, initial cell concentration and temperature) for and its tolerance to gastrointestinal conditions for probiotic alcoholic beverage development. Placket-Burman screening was used to select only statistically significant variables, and the polynomial mathematical model for yeast growth was obtained by central composite rotatable design. Confirmation experiments to determine the kinetic parameters for yeast growth were carried out by controlling the temperature and pH.

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A cocktail of biomass hydrolytic enzymes was produced by solid-state fermentation (SSF) by the mutant strain Aspergillus niger 3T5B8, using as substrate a mixture of grape pomace and wheat bran, and compared to the production when wheat bran was used as the sole substrate. The two enzymatic cocktails were subsequently used for the extraction of bioactive compounds from grape pomace and the relationship between the activities of the cocktail and the release of phenolic compounds was evaluated. Although the wheat bran SSF process was more effective for enzyme production, the enzymatic cocktail produced by the grape pomace - wheat bran mixture was more effective for the extraction of compounds with higher proanthocyanidins content and higher antioxidant potential (p < 0.

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The aim of this study was to evaluate the effects of process conditions on the solid-liquid extraction of bioactive compounds from the Alicante Bouschet grape skin from the semi-arid region of Brazil. The influence of temperature (23-57 °C), ethanol concentration (16-84%) and citric acid concentration (0-4%) on the total phenolic content, monomeric anthocyanin content and on the antioxidant capacity of the extracts measured by oxygen radical absorbance capacity and cation radical scavenging activity (ABTS) methods was investigated. Ethanol concentration and temperature had a significant influence on total phenolic compounds extraction and antioxidant capacity while monomeric anthocyanins extraction was only affected by ethanol concentration.

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Tests were performed with cellulose acetate films (CA) incorporating 5, 10, 20, 30, and 50% (w/v) of glycerol with the purpose of evaluating the possible changes caused by the plasticizer on the functional properties of the packaging. The glass transition temperature (Tg) and relative crystallinity (RC) were are obtained by DSC and XRD, respectively. The results showed that, the presence of glycerol in the films caused increased thickness, water vapor transmission rate (WVTR), and optical properties for most treatments.

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Unlabelled: The high temperatures used to fry fish may induce thermo-oxidation of cholesterol, forming cholesterol oxidation products (COPs). COPs have been associated to coronary heart diseases, atherosclerosis, and other chronic diseases. Air fryers are an alternative thermal process technology to fry foods without oil, and are considered a healthier cooking method.

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