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This study aimed to determine the antioxidant activity of red onion peel extract using ultrasound extraction. Antioxidant activity was evaluated using DPPH, inhibition of β-carotene, ABTS and FRAP. The results indicated that the 130 W ultrasound power, in pulsed mode, and with 60% solvent favored flavonoids and total anthocyanins, FRAP and β-carotene. The highest levels of total phenolics were found using 60% solvent, at 130 W, and in continuous extraction mode. DPPH was influenced only by the 60% solvent, and the ABTS values were higher with the 80% solvent, in pulsed mode, and at 130 W of power. [ABSTRACT FROM AUTHOR]

Heavy metals and bromine (Br) derived from organic and industrialized fertilizers can be absorbed, transported and accumulated into parts of plants ingested by humans. This study aimed to evaluate in an experiment conducted under no-tillage for 10 years, totaling 14 applications of pig slurry manure (PS), pig deep-litter (PL), dairy slurry (DS) and mineral fertilizer (MF), the heavy metal and Br contents in soil and in whether the grains produced by corn ( Zea mays L.) and wheat ( Triticum aestivum L.) under these conditions could result in risk to human health. The total contents of As, Cd, Pb, Cr, Ni, Cu, Zn and Br were analyzed in samples of fertilizers, waste, soil, shoots and grains of corn and wheat. Afterwards, enrichment factor (EF), accumulation factor (AF), health risk index (HRI), target hazard quotient (THQ) and target cancer risk (TCR) were determined. Mineral fertilizer exhibited the highest As and Cr content, while the highest levels of Cu and Zn were found in animal waste. The contents of As, Cd, Cr, Cu, Ni, Pb and Zn in soil were below the limits established by environmental regulatory agencies. However, a significant enrichment factor was found for Cu in soil with a history of PL application. Furthermore, high Zn contents were found in shoots and grains of corn and wheat, especially when the plants were grown in soil with organic waste application. Applications of organic waste and mineral fertilizer provided high HRI and THQ for Br and Zn, posing risks to human health. The intake of corn and wheat fertilized with pig slurry manure, swine deep bed, liquid cattle manure and industrialized mineral fertilizer did not present TCR. [ABSTRACT FROM AUTHOR]

The analytical methods used for routine moisture determination are based on a loss on drying (LOD) approach performed by conventional heating in ovens, but infrared loss on drying (IRLOD) and microwave-assisted loss on drying (MALOD) drying methods have been used to reduce the analysis time. MALOD speeds up water removal from meat products 64 times in comparison to LOD and provided similar results (agreement between 98 and 101%), but with lower energy consumption (<1 and 31 kWh for MALOD and LOD, respectively) and higher sample throughput (60 samples/h). Infrared thermographies showed temperature of 107.8C in MALOD, which is similar to those used in conventional ovens (105 and 120C). For IRLOD the results were generally lower and its use for meat products should be carefully considered. A fast and accurate analysis of moisture in meat products could be achieved using microwaves, saving time and energy expenditure in agreement to green analytical chemistry. Practical Applications Moisture is a routine analysis performed in every industrial and academic laboratory interested on the study of meat and its products. However, different analytical methods are used for this purpose, and often different results are obtained. Therefore, in this study the performance of three methods based on loss on drying (using conventional, infrared or microwave heating) were evaluated. The results showed lower moisture content by the use of infrared balances for all samples and its use should be carefully evaluated to avoid systematic errors. Contrarily, the results obtained by the use of microwaves were comparable with those of conventional heating, but several advantages were found. The energy consumption was reduced at least 31 times and 15 samples could be processed simultaneously in only 15 min opening the possibility of use of this method to improve routine analysis or as an analytical technique for processing control. [ABSTRACT FROM AUTHOR]

A method for determination of propranolol hydrochloride in pharmaceutical preparation using near infrared spectrometry with fiber optic probe (FTNIR/PROBE) and combined with chemometric methods was developed. Calibration models were developed using two variable selection models: interval partial least squares (iPLS) and synergy interval partial least squares (siPLS). The treatments based on the mean centered data and multiplicative scatter correction (MSC) were selected for models construction. A root mean square error of prediction (RMSEP) of 8.2 mg g−1 was achieved using siPLS (s2i20PLS) algorithm with spectra divided into 20 intervals and combination of 2 intervals (8501 to 8801 and 5201 to 5501 cm−1). Results obtained by the proposed method were compared with those using the pharmacopoeia reference method and significant difference was not observed. Therefore, proposed method allowed a fast, precise, and accurate determination of propranolol hydrochloride in pharmaceutical preparations. Furthermore, it is possible to carry out on-line analysis of this active principle in pharmaceutical formulations with use of fiber optic probe. [ABSTRACT FROM AUTHOR]

Microwave-assisted solid sampling analysis coupled to flame furnace atomic absorption spectrometry (MW-SS-FF-AAS) was used for Cd and Pb determination in food-contact polymer samples, with the aim of minimizing reagents and laboratory waste. Operational parameters, such as the FF tube design, the oxygen flow rate, the flame stoichiometry, the sample mass, among others, were evaluated and optimized. Calibration was performed using only reference solutions, and the limits of quantification were 1.7 and 4.6 μg g−1 for Cd and Pb, respectively. Accuracy was assessed by the analysis of certified reference materials (CRMs), and by comparison with the results obtained by inductively coupled plasma mass spectrometry after microwave-assisted wet digestion. The MW-SS-FF-AAS results for the CRMs showed no statistical difference with the certified values, and good agreement was observed with the results of the digestion method. The MW-SS-FF-AAS method was considered suitable for Cd and Pb determination in food-contact polymers. The concentrations of Cd and Pb in the analyzed samples varied from <1.7 to 628 μg g−1, and from <4.6 to 614 μg g−1, respectively. As sample digestion is not necessary, the use of concentrated acids can be avoided by using the proposed MW-SS-FF-AAS method, greatly reducing waste generation. [ABSTRACT FROM AUTHOR]

The mineral content of 10 commercially available milk-based infant formulas widely consumed in Brazil was investigated. The levels of elements (Ca, Cu, Fe, K, Mg, Mn, Na, and Zn) were determined by inductively coupled plasma optical emission spectrometry after microwave-assisted wet digestion. The results were compared with the producers' label declarations and levels proposed by the Codex Alimentarius and the Brazilian National Health Surveillance Agency. The obtained results were in good agreement with certified reference materials, and the relative standard deviation of the measurements was always below 10%, with the exception of Cu (up to 14%). A high degree of variation between the experimental and producers' data was found for trace elements among different brands, with differences as high as 41 and 68% for Cu and Zn, respectively. The content of minerals in the starting formulas was in accordance with levels established by the Codex Alimentarius, with the exception of 1 brand that had a Zn level that was not in agreement with the Codex minimum value. Among follow-up formulas, 2 brands contained levels of Ca and K that were higher than the maximum established by Brazilian standards, and 1 brand contained less than the minimum value recommended for Zn. The guidance upper levels have not been established in the Codex Alimentarius for follow-up formulas, and the maximum value has been established for only 2 of the analyzed minerals. This lack of a standard could be a problem; as shown in the present study, if the Brazilian standard is used, several formulas could be considered out of specification. Despite the limited number of samples evaluated in this work, the levels of some elements were out of specification and special attention by the Brazilian government on the content of minerals in infant formulas is needed. [ABSTRACT FROM AUTHOR]