Ora-pro-nobis (Pereskia aculeata Mill) is an unconventional food plant (UFP) rich in proteins, vitamins, fibers, and antioxidants. In this study, ora-pro-nobis leaves were investigated as a proof of concept by near-infrared (NIR) spectroscopy concerning the storage time (from collection to 12 days), packaging system: styrofoam-based packaging covered with stretchable polychloride vinyl (PVC) film, and vacuum packaging (nylon/poly), temperature (at room temperature of 20 ºC, and in the refrigerator at 4 ºC), and sanitization condition (washed and without washing). Principal component analysis (PCA) was applied to augmented matrices, showing that unwashed leaves stored in the refrigerator with styrofoam-based packaging covered with PVC film were better preserved over time. Furthermore, it has been suggested that NIR absorptions are related to proteins, carbohydrates, lipids, vitamins, antioxidants, and water from ora-pro-nobis leaves and their physiological reactions over time. By combining NIR spectroscopy and chemometrics, a complete understanding of the shelf life of ora-pro-nobis leaves was achieved.

This work shows an alternative methodology based on a portable near-infrared (NIR) spectroscopy coupled to independent components analysis (ICA) in a pseudo-univariate calibration way to determine total anthocyanins (TA) concentration and antioxidant activity (AA) in whole grape juice. To this, the scores proportions more related to TA and AA were plotted against TA and AA obtained by its respective references methodology to build pseudo-univariate calibration models with correlation coefficients of 0.9699 and 0.9814, respectively. From the results, it is possible the suggestion that NIR spectra coupled to ICA enable to overcome interferences using first-order data and work properly when there is enough selectivity for the analyte profile in the sample data.

Partially hydrogenated soybean oil and palm olein are oils that are widely used in the food industry. Continuous contact with air may cause changes of the triglycerides chemical structure, to eventually produce substances of lower molar masses that may be toxic to mammals. This study aimed to determine the kinetic parameters for the thermal oxidation of these oils and of their residual used oils from the pre-frying industrial step on preparing breaded chicken meat. The main reactions were followed by thermogravimetry (TG) and differential scanning calorimetry (DSC); the formation of the produced substances was monitored by gas chromatography flame ionization detector (GC-FID) and Fourier transform infrared spectroscopy (FTIR). These analyses indicated different chemical pathways, according to the type of unsaturation and changes in the molecular structures of the fatty acids in the oils. From the thermal analysis, more than one decomposition event was observed during the thermal oxidation process. As the soybean oil has a lower oxidation onset temperature than palm olein, it has lower rate of mass loss, with a higher activation energy value.

Tilapia (Oreochromis niloticus) is the most cultivated fish species in Brazil. Studies have shown that fish consumption is related to the prevention of cardiovascular diseases due to its high contents of polyunsaturated fatty acids, as omega-3 (n-3) and omega-6 (n-6). In this sense, a new method to determine omega-3 and omega-6 by near-infrared (NIR) spectroscopy and multivariate calibration based on partial least squares (PLS) was proposed. Spectra of fillets of Nile tilapias packed under vacuum were obtained and compared to the reference method (gas chromatography) used for quantification of fatty acids. The outliers were evaluated in the models that were validated by calculation of the parameters for model performance estimation, showing promising results. The appropriate values achieved for accuracy, limits of detection and quantification, indicate that the NIR/PLS models can be an alternative to chromatography in the determination of omega-3 and omega-6 in fillets of Nile tilapia. Furthermore, the spectra acquisition on the vacuum-packed fillet contributes to the NIR/PLS method in terms of cost and quickness.

Digital images associated with chemometric tools, in a non-destructive approach, have been applied for the evaluation of the Brazilian monovarietal extra virgin olive oil. Independent component analysis (ICA) was employed in the image data evaluation of olive oils produced from distinctive olive varieties, and it was successful in highlighting the natural grouping among the samples based on the color histograms (red, green and blue (RGB) channels). The study’s proposal indicates the ability of accurate separation of the twenty-four samples considering their color. To conclude and support the hypothesis, principal component analysis (PCA) was applied in the visible spectra of the Brazilian monovarietal extra virgin olive oil, to observe the similarities between the samples, and the results are in agreement with those obtained by image analysis coupled with ICA. This method demonstrates the possibility for the characterization of olive oils respecting the principles of Green Chemistry.

Innovation and multidisciplinarity are the way to accelerate improvements in education, as well as the search for contextualized content. The multidisciplinarity between chemistry and Biology, allows to explore various contents, one of them is the environment. Works that offer alternatives to simpler experiments are of great help professors. In this context, this study suggests a didactic sequence using easily accessible materials to address chemical and Microbiological concepts of soil. The proposal is aimed at high school students and early undergraduate students. The contents were: hydrogen potentials (pH), mixture separation methods, soil liquid and gas phases and soil microbial population extraction involving bacterial DNA. Thus, the work shows a low cost alternative for the teaching of concepts related to soil, being a contextualized, multidisciplinary, dynamic and attractive proposal.

In order to provide an effective and environmentally correct alternative for oil extraction, subcritical n-propane was used under different temperature and pressure conditions to obtain Brazil nut oil. The composition of the oil was determined and compared to the oils obtained by conventional methods. The result of the extraction yield obtained using subcritical fluid extraction (SFE) at 60 ºC, 6 MPa and granulometry < 1.40 mm (63.13%) presented minor differences to the yield obtained by Soxhlet extraction (SE) (68.44%) and Bligh and Dyer extraction (BD) (59.54%). The composition in fatty acids was similar regardless of the method of extraction used. Oxidized triacylglycerols (TAGs) were found in the oils extracted by SE and BD while they were not detected in the oils extracted by SFE. The quantity of bioactive compounds was higher in the oils obtained by SFE. Thus, the SFE using n-propane preserves the nutritional characteristics and lipophilic components of the oil, besides improving the availability of bioactive compounds from an effective “green extraction” without the use of toxic solvents.

Abstract This aim of this study was to characterize five varieties of avocado for their proximal composition, physical properties, fatty acids composition, antioxidant capacity, carotenoids and minerals. Quintal variety presented the best result for total lipids, physical properties, carotenoids and minerals. All the varieties presented a predominance of monounsaturated fatty acids (60%). The major monounsaturated fatty acid was oleic acid. Among the varieties analyzed, Breda variety had greater activity results for FRAP (145%) and DPPH (1.1200 µmol TE/g) assays, Quintal had higher values for ABTS analysis, Ouro Verde presented better results for ORAC assay (23%), and Margarida had the best result for L-ORAC analysis (200 µmol ET/g).

Abstract A factorial categorical design totalling six treatments was applied to investigate the influence of the substitution of corn starch with whole and partially defatted chia flour under the technical characteristics (centesimal composition, instrumental analyses, and sensory evaluation) and nutritional disorders (composition of fatty acids and index of the nutritional quality of the lipid fraction) of ‘dulce de leche’ concentrated to 72 and 78 °B. The treatments with chia flour concentrated to 72 °B showed higher moisture content and lower compression force, and when the concentration range increased to 78 °B, the levels of total lipids amounted up to 1.40 times when compared to treatment with corn starch. The polyunsaturated fatty acids, particularly omega-3 and omega-6 levels, were higher in treatments with chia flour on both tracks of concentration, allowing a reduction in the atherogenic index and thrombogenic index effects and the n-6/n-3 ratio. The treatments of ‘dulce de leche’ with a lower concentration of soluble solids obtained greater acceptance and consumer purchase intention. The application of whole chia flour in small proportions and in the concentration of 72 °B was the most appropriate under the studied conditions, showing improvement in the nutritional quality and with good technical aspects of candy made with goat milk.

The investigation of the distribution of antioxidant compounds between emulsions phases, employing natural sources of these compounds directly in the emulsions, is rarely addressed. The use of ultra performance liquid chromatography coupled to a mass spectrometer (UPLC-MS), combined with accelerated oxidation tests and oxygen radical absorbance capacity method (ORAC), using the fluorescein (FL) decay curve (ORACFL) assay, enable an improved evaluation of the distribution of the antioxidant compounds and their lipid protection abilities. The lipid protection tendency observed was in agreement with the polar paradox theory. The ORACFL results reported here are higher than other reported in the literature, even when performing a sample extraction directly into one of the emulsion phases, thus demonstrating the effectiveness of this direct addition regarding the antioxidant activity. The analysis of the mass spectra of the emulsions enabled to verify the existence and distribution of some phenolic compounds in both phases. The direct extraction in the aqueous and oil phases of the emulsion increased, in a general way, the amount of identified compounds in each phase.

There is a great interest in developing suitable alternatives for the utilization of whey, a by-product from cheese production that contains high concentration of lactose. These alternatives allow the transformation of whey into several products, reducing its environmental impact and providing gains to the dairy industry through the development of new products. The goal of this study was to optimize the synthesis of lactulose from the permeate of bovine whey. The response surface methodology (RSM) was used to investigate the effect of two parameters, time of reaction (90, 135 and 180 min) and isomerization type (sodium sulfite, boric acid and b-galactosidase enzyme), aiming to obtain the highest reaction yield. According to the response surface and desirability function, the best experimental conditions for lactulose synthesis (where it was obtained 50.06 g of lactulose per 100 g of whey powder) consisted of a reaction time of 180 min with the use of enzymatic isomerization.

Abstract Whey (milk serum) is produced by the dairy industry during the manufacture of cheese. In addition to being a valuable source of functional and nutritional proteins, whey also presents almost all the lactose from the original whole milk. However, many industries still consider the whey as an effluent, which can cause serious environmental problems when not properly treated. Therefore, it is important to develop alternatives for the adequate use of whey. The lactose obtained from whey permeate can be converted into lactulose, a prebiotic which may be metabolized in the intestine by probiotic bacteria, such as Lactobacillus sp. and Bifidobacterium sp., through enzymatic isomerization or by using alkaline catalysts, with minimal secondary reactions and high yield. This manuscript provides information about various techniques used to produce lactulose, its purification and analysis, as well as its mechanisms of action and alternative applications in food products and medicines.

The proximate composition, mineral contents and fatty acid composition of different parts (peel, pulp and seeds) of seven tropical fruits were evaluated. Beyond that, this study aims to evaluate the effect of drying processing on peels. Pulp and peel showed highest moisture values (65.7-93.3%), while the seed ranged from 5.8 to 67.2%. The drying processing of peels decreased moisture values (2.3-18.7%). Furthermore, drying processing did not affect ash contents, total crude protein, lipids and fiber values and fatty acid composition for avocado, pineapple, banana, papaya, passion fruit, watermelon and melon. A wide range of mineral contents was noted in different parts of fruit and calcium and potassium were found in larger quantities (25.4 to 4808 mg per 100 g). The fruits exhibited essential fatty acids as omega-6 and omega-3 with the largest contents observed in the peels and seeds (31.4 to 1970 mg per 100 g).

Response surface methodology was used to optimize the total phenolic content (TPC) result in white rice, using a new methodology that employed Fast Blue BB (FBBB) reagent, which reacts more specifically with phenolic compounds, along with direct QUENCHER procedure. This is the first time in which such conciliation between FBBB reagent and QUENCHER was done. The obtained model allowed to evaluate how the factors influenced the method linearity (R2), improving the choice of the optimal system condition. Furthermore, the similarity between experimental results and values generated by the model indicated the method validity within the studied region. Thus, the optimal condition determined in the present work was 30 min reaction time, 0.17 mL FBBB reagent and use of 5% NaOH as the catalyst for the reaction. This optimized condition suggested that the combination of the method, which used FBBB reagent and the direct QUENCHER procedure, was rapid and effective, yielding high TPC values (1488.73 mg of gallic acid equivalent per 100 g).

A 23 factorial design with center point in triplicate was used to evaluate the application of different enzymes in extraction of sunflower oil, comparing its quality with the oil obtained by conventional methods (solvent and pressing) in relation to antioxidant capacity, phytosterol and tocopherol contents, and fatty acid composition. Three enzymes were used; Pectinex Ultra SPL, Celluclast 1.5 L and Alcalase 2.4 L; and three factors were evaluated: enzyme concentration, sample/water ratio and extraction time. Enzymatic aqueous extraction produced oil with better quality in relation to some of the evaluated parameters: highest antioxidant capacity against peroxyl radicals (371 µmol Trolox g-1 of oil), total phytosterols (183 mg 100 g-1 of oil) and omega-3 fatty acid content, as well the lowest content of saturated fatty acids. The application of enzymes in sunflower oil extraction represents an environmentally friendly methodology, free of toxic solvent residues and providing a final product of high quality.