Juliana Azevedo Lima Pallone

Chemometrics optimization of carbohydrate separations in six food matrices by micellar electrokinetic chromatography with anionic surfactant

Multivariate statistical design modeling and the Derringer-Suich desirability function analysis were applied to micellar electrokinetic chromatography (MEKC) results with anionic surfactant to separate carbohydrates (CHOs) in different food matrices. This strategy has been studied with success to analyze compounds of difficult separation, but has not been explored for carbohydrates. Six procedures for the analysis of different sets of CHOs present in six food matrices were developed. The effects of pH, electrolyte and surfactant concentrations on the separation of the compounds were investigated using a central composite design requiring 17 experiments. The simultaneous optimization of the responses for separation of six sets of CHOs was performed employing empirical models for prediction of optimal resolution conditions in six matrices, condensed milk, orange juices, rice bran, red wine, roasted and ground coffee and breakfast cereal samples. The results indicate good separation for the samples, with appropriate detectability and selectivity, short analysis time, low reagent cost and little waste generation, demonstrating that the proposed technique is a viable alternative for carbohydrate analysis in foods.

Quality evaluation of frozen guava and yellow passion fruit pulps by NIR spectroscopy and chemometrics

The present study investigated the application of near infrared spectroscopy as a green, quick, and efficient alternative to analytical methods currently used to evaluate the quality (moisture, total sugars, acidity, soluble solids, pH and ascorbic acid) of frozen guava and passion fruit pulps. Fifty samples were analyzed by near infrared spectroscopy (NIR) and reference methods. Partial least square regression (PLSR) was used to develop calibration models to relate the NIR spectra and the reference values. Reference methods indicated adulteration by water addition in 58% of guava pulp samples and 44% of yellow passion fruit pulp samples. The PLS models produced lower values of root mean squares error of calibration (RMSEC), root mean squares error of prediction (RMSEP), and coefficient of determination above 0.7. Moisture and total sugars presented the best calibration models (RMSEP of 0.240 and 0.269, respectively, for guava pulp; RMSEP of 0.401 and 0.413, respectively, for passion fruit pulp) which enables the application of these models to determine adulteration in guava and yellow passion fruit pulp by water or sugar addition. The models constructed for calibration of quality parameters of frozen fruit pulps in this study indicate that NIR spectroscopy coupled with the multivariate calibration technique could be applied to determine the quality of guava and yellow passion fruit pulp.

Method for assessing lead, cadmium, mercury and arsenic in high-density polyethylene packaging and study of the migration into yoghurt and simulant

The purpose of this paper was to assess the concentration of lead (Pb), cadmium (Cd), mercury (Hg) and arsenic (As) in high-density polyethylene (HDPE) packaging intended for contact with yoghurt and the migration of these elements using the food itself and 3% acetic acid as a food simulant in accordance to ANVISA, the Brazilian Health Surveillance Agency. In order to perform this study, it was necessary to develop and validate a method by inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis. For method validation, the parameters linearity, limits of detection (LODs) and quantification (LOQs), accuracy and precision were determined. Fifteen commercial samples of yoghurt, marketed in Campinas – São Paulo (Brazil), were used for the analysis. The packaging and yoghurt were digested in high-pressure ashing equipment (HPA) and the migration of the elements into simulant were determined directly in the solution. The validated method proved adequate and the results obtained showed that all the packaging had levels of Hg and Cd below the LOQ, corresponding to 1.0 and 1.5 μg l−1, respectively. The highest levels of As and Pb were 0.87 and 462.3 mg kg−1, respectively. The migration of these elements to the yoghurt after 45 days of contact at 4ºC was below the LOQ for all the samples assessed. The results of specific migration into 3% acetic acid simulant showed the concentrations of Cd, Hg and As below 5, 5 and 10 µg kg−1, respectively, which are the maximum limits set by ANVISA. However, for three samples the packaging lid showed migration of Pb into simulant ranging from 30.6 to 40.2 μg kg−1, exceeding the limit set by ANVISA of 10 μg kg−1. Graphical Abstract

Effect of different iron compounds on rheological and technological parameters as well as bioaccessibility of minerals in whole wheat bread

This study aimed at investigating the effect of iron compounds used in whole wheat flour (WWF) fortification, both on rheological properties of the dough and on bread technological quality. Furthermore, bioaccessibility of iron (Fe), zinc (Zn) and calcium (Ca) in the final breads was determined. Rheological properties (mainly dough development time, stability, mixing tolerance index, resistance to extension and ratio number) of the dough and the technological quality of bread (mainly oven spring and cut opening) were altered. However, producing roll breads fortified with different iron compounds was still possible. NaFeEDTA (ferric sodium ethylene diamine tetra acetic acid) proved to be the most effective iron compound in the fortification of WWF, since it presented the highest levels of solubility (44.80%) and dialysability (46.14%), followed by microencapsulated ferrous fumarate (FFm). On the other hand, the microencapsulated ferrous sulfate (FSm) and reduced iron presented the lowest solubility (5.40 and 18.30%, respectively) and dialysability (33.12 and 31.79%, respectively). Zn dialysis was positively influenced by NaFeEDTA, FSm, and ferrous fumarate. As for Ca, dialysis was positively influenced by FSm and negatively influenced by FFm. The data indicated that there is a competitive interaction for the absorption of these minerals in whole wheat roll breads, but all studied minerals can be considered bioaccessible.

Time-Domain Nuclear Magnetic Resonance (TD-NMR) and Chemometrics for Determination of Fat Content in Commercial Products of Milk Powder

This study shows the use of time-domain (TD)-NMR transverse relaxation (T2) data and chemometrics in the nondestructive determination of fat content for powdered food samples such as commercial dried milk products. Most proposed NMR spectroscopy methods for measuring fat content correlate free induction decay or echo intensities with the samples mass. The need for the samples mass limits the analytical frequency of NMR determination, because weighing the samples is an additional step in this procedure. Therefore, the method proposed here is based on a multivariate model of T2 decay, measured with Carr-Purcell-Meiboom-Gill pulse sequence and reference values of fat content. The TD-NMR spectroscopy method shows high correlation (r = 0.95) with the lipid content, determined by the standard extraction method of Bligh and Dyer. For comparison, fat content determination was also performed using a multivariate model with near-IR (NIR) spectroscopy, which is also a nondestructive method. The advantages of the proposed TD-NMR method are that it (1) minimizes toxic residue generation, (2) performs measurements with high analytical frequency (a few seconds per analysis), and (3) does not require sample preparation (such as pelleting, needed for NIR spectroscopy analyses) or weighing the samples.

Bioaccessibility of calcium, iron and magnesium in residues of citrus and characterization of macronutrients

The aim of this study was to estimate bioaccessibility of Ca, Fe and Mg in residues of orange, lime, and their mixture, in order to evaluate the effects of cooking in water on mineral bioaccessibility and also to determine the composition of macronutrients and myo-inositol phosphate content. The citrus samples contained on average 9.53g/100 g moisture, 6.09g/100 g protein, 3.23g/100g ash, 3.15g/100g lipids, 34.26g/100g insoluble fiber, 27.88g/100g soluble fiber and 25.64g/100g carbohydrates. The percentage of soluble and dialyzable minerals ranged from 19.36 to 77.33% and from 5.59 to 69.06% for Fe, from 33.34 to 60.84% and 14.71 to -26.13% for Ca, and from 29.95 to 94.20% and 34.42 to 62.51%, for Mg, respectively. It was verified that cooking influenced the minerals bioaccessibility and increased the dialyzable fraction of Fe and Mg, but decreased the fraction of Ca dialysate, except to orange. No myoinositol phosphate esters were detected. The Principal Component Analysis allowed the separation of different types of citrus residues, but did not discriminate the raw and cooked samples. This study pointed the potential of citrus residue to be used for human consumption and contribute to the necessary dietary minerals and macronutrients, with high content of soluble and insoluble fibers.

Influence of Maturation Stages in Different Varieties of Wine Grapes (Vitis vinifera) on the Production of Ochratoxin A and Its Modified Forms by Aspergillus carbonarius and Aspergillus niger

Ochratoxin A is the main contaminant mycotoxin of grapes produced mainly by Aspergillus niger and Aspergillus carbonarius. Besides, it is possible that the formation of modified mycotoxin occurs through the plant defense mechanism or also by fungus actions itself. The objective of this study was to evaluate the influence of grape variety and maturation stage on the formation of OTA and modified mycotoxin. The determination of OTA was performed by high-performance liquid chromatography, and a high-resolution mass spectrometry was used for the detection of modified ochratoxin. A positive correlation was observed between the following grapes physicochemical parameters: pH, total soluble solids, total glycosides in glucose, total anthocyanin, and OTA levels produced by A. niger and A. carbonarius. Therefore, the higher the concentrations of these parameters, the greater the production of mycotoxin in grapes. Among the elected targets, we identified the 14-decarboxy-ochratoxin A in Muscat Italia variety at veraison and 15 days after the beginning of veraison stages; and ethylamide-ochratoxin A as a biomarker in the Syrah variety at the ripeness stage.

Effect of enzymatic treatment on phytate content and mineral bioacessability in soy drink

The objective of this study was to evaluate in vitro bioaccessibility of calcium (Ca), iron (Fe) and zinc (Zn) in soy drink after phytase treatment and correlate it with the content of myo-inositol phosphates. Samples of commercial soy drink products and one sample produced in the laboratory by maceration were evaluated. Phytase was applied using 300 U per liter in 60 min considering the phosphate release. The content of myo-inositol tris-, tetrakis-, pentakis and hexakisphosphate was not observed after phytase treatment. The solubility assay showed an increase from 2.0% to 20.8% for Ca, 2.2% to 37.1% for Fe and 38.8% to 67.4% for Zn after phytase treatment with significant differences (p ≤ 0.05) for most samples. Dialysis assay demonstrated 1.0% to 9.5% for Ca after phytase treatment (p ≤ 0.05) except for one commercial sample. The phytase treatment is a valuable alternative process for improving mineral natural availability in soy drink and decreased the use of salts in the fortification.

Chemical and nutritional characterization of raw and hydrothermal processed jambu (Acmella oleracea (L.) R.K. Jansen)

Jambu (Acmella oleracea (L.) R.K. Jansen) is a neglected plant native to the Amazon Biome. Although it is very consumed in the north of Brazil, little is known about its chemical and nutritional composition. Thus, this study aimed to characterize jambu and to evaluate the effects of the boiling process on its chemical composition. The proximate composition, minerals, total amino acids, fatty acids levels, and phytosterols were determined. In comparison with conventional vegetables jambu presented higher levels of protein (24.01%), ash (10.92%), total fiber (62.61%) some mineral such as Ca (2551.56 mg/100 g), Mg (734 mg/100 g) and Cu (2.09 mg/100 g), and amino acids such as asparagine (32.01 mg/g), glutamic acid (28.26 mg/g), valine (14.55 mg/g) and isoleucine (14.19 mg/g). A significant reduction was observed in carbohydrates, total dietary fibers, minerals, unsaturated fatty acids, and in some amino acid levels after the boiling process, with an increase in ash content, protein, and saturated fatty acids in the heat-treated jambu. Lipids, phytosterols, and some amino acid levels were not significantly affected by the hydrothermal process. Thus, this study has shown that raw and processed jambu may be good alternatives for conventional vegetables, even with nutrients losses during boiling.

Erratum to: Antimony Assessment in PET Bottles for Soft Drink

The original version of this article unfortunately contained mistakes. Section BIntroduction^, fourth paragraph should read: In Brazil, RDC Resolution 17/2008 (BRASIL 2008), published by ANVISA, the National Health Surveillance Agency, establishes a positive list of additives for plastic materials intended for the production of packaging and equipment that comes into contact with food and has authorized the use of antimony trioxide in the manufacture of PET resin. It has fixed a specific migration limit for antimony in packaging of 40 μg kg, which is the same limit established by the EU regulation EC 10/2011 (EU 2011), while in Japan, the Japan External Trade Organization has established a limit of 50 μg L (JETRO 2011). The Food and Drug Administration (FDA) has not specified a migration limit for antimony from PET packaging materials (Welle and Franz 2011). The original article was corrected.