Publications by authors named "Laise C Da Silva"

Due to the complex characteristics and variable composition of apple pomace, sample preparation for chromatographic analysis is a great challenge. To solve this problem, we proposed using a solvent gradient using Pressurized Liquid Extraction (PLE), where the solvent gradually changes from water to ethanol during the extraction. Different dynamic gradients, static time, and temperatures were evaluated and showed relevant effects on the yields of target analytes.

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Citrus fruits (CF) are highly consumed worldwide, fresh, processed, or prepared as juices and pies. To illustrate the high economic importance of CF, the global production of these commodities in 2021 was around 98 million tons. CF's composition is considered an excellent source of phenolic compounds (PC) as they have a large amount and variety.

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This work aimed to develop an integrated method to extract and fractionate phenolic compounds from lemon (Citrus limon L.) peel by in-line coupling pressurized liquid extraction and solid-phase extraction (PLE-SPE). The effect of the adsorbent used in the SPE (Sepra™ C18-E, Sepra™ NH, and PoraPak Rxn), the combination of organic extraction-elution solvents (water-ethanol and water-ethyl lactate), extraction temperature (40-80 °C), and extraction water pH (4.

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Apple is one of the most consumed fruits worldwide and has recognized nutritional properties. Besides being consumed fresh, it is the raw material for several food products, whose production chain generates a considerable amount of by-products that currently have an underestimated use. These by-products are a rich source of chemical compounds with several potential applications.

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The comprehensive analysis of phenolic compounds from natural products comprises critical steps, including quantitative extraction, extract preparation, and chromatographic procedure. Performing these steps off-line requires a long time to obtain results, besides being laborious and more error-prone. This work discusses the concept and presents the details of assembling and validating a new system to comprehensively analyze phenolic compounds in natural products.

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Flavonoids are one of the main groups of polyphenols found in natural products. Traditional flavonoid extraction techniques are being replaced by advanced techniques to reduce energy and solvent consumption, increase efficiency and selectivity, to meet increased market demand and environmental regulations. Advanced technologies, such as microwaves, ultrasound, pressurized liquids, supercritical fluids, and electric fields, are alternatives currently being used.

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The objective of this work was the development of an on-line extraction/fractionation method based on the coupling of pressurized liquid extraction and solid-phase extraction for the separation of phenolic compounds from apple pomace. Several variables of the process were evaluated, including the amount of water of the first stage (0-120 mL), temperature (60-80 °C), solid-phase extraction adsorbent (Sepra, Isolute, Strata X and Oasis) and activation/elution solvent (methanol and ethanol). The best results were observed with the adsorbent Sepra.

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In this study it is proposed the introduction of an expansion gas in high pressure water to maximize the cavitation caused by the application of ultrasound to improve the extraction of phenolic compounds from pomegranate peel. Different combinations of ultrasound power (US-Pwr), expansion gas initial pressure (N-Pi), system pressure (SP) and particle size of sample were evaluated using water as solvent. The use of US-Pwr and N-Pi individually or combined improved the extraction process proving higher yields.

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