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This work aimed to optimize an aqueous extract rich in phenolic compounds and potential functional properties made of Ilex paraguariensis, Melissa officinalis, and Cymbopogon citratus. The lyophilized extract was used for the development of an ice cream. Total phenolics, FRAP, DPPH, Folin-Ciocalteu's reducing capacity, and total reducing capacity of different combinations of herbal extracts were tested and modeled using response surface methodology. Simultaneous optimisation was employed to maximize the bioactive compounds in the extract and the lyophilized optimum combination was added to ice cream. The lyophilized extract contained quercetin-3-rutinoside, hesperidin, isoquercetin, caffeic acid, and 5,7-dihydroxyflavone. The optimised extract, which showed antihypertensive, antidiabetic, and antioxidant activity using in vitro protocols, increased total phenolics and antioxidant activity in comparison to the control ice cream. The ice cream presented a sensory acceptance index of 83%. After 72 days of storage (-18 °C), total phenolics and antioxidant activity significantly decreased., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The statistical method of random uncertainties has been adopted for the uncertainty calculation of chemical measurements, since it is a good estimator of the overall uncertainty. Type B (inherited) uncertainties are usually insignificant when compared to type A (experimental) uncertainties. In quantitative measures, the mean is the most probable value of the measurand and the standard deviation of the mean is the best estimate of its standard uncertainty. Measurement uncertainty of qualitative measures may be estimated by the probability of taking right or wrong decisions. Thus, performance data of analytical methods are the main source of uncertainties. However, uncertainties obtained from limited observations should be used with caution to represent the overall uncertainty. This study demonstrated the influence of random uncertainties on the results of experimental approaches to estimate the uncertainty in chemical assays. The different profiles of uncertainty were demonstrated depending on the analytical technique and food composition., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

A simple extraction, rapid routine method for the simultaneous determination of sorbic acid, natamycin and tylosin in Dulce de leche, a traditional South American product, by liquid chromatography-tandem mass spectrometry has been developed and fully validated. The limits of detection were set to 24.41mgkg(-1) (sorbic acid), 0.10mgkg(-1) (natamycin) and 2μgkg(-1) (tylosin). Recoveries ranged from 95% to 110%. Proportionally, internal standardization was more efficient than external standard, resulting in a smaller measurement of uncertainty. In total, 35 commercial samples from Brazil, Argentina and Uruguay have been assessed. The proposed method was tested on other dairy desserts, demonstrating to be versatile. Although tylosin was not detected in any sample, a high rate of non-compliance was found, with 67.39% of samples above the maximum allowed for sorbic acid and a maximum concentration of 2105.36±178.60mgkg(-1). In two samples, natamycin was irregularly found., (Copyright © 2016 Elsevier Ltd. All rights reserved.)