Sandra Terezinha Marques Gomes

Subcritical extraction of flaxseed oil with n-propane: Composition and purity

Flaxseed (Linum usitatissimum L.) oil was obtained via subcritical n-propane fluid extraction (SubFE) under different temperatures and pressures with an average yield of 28% and its composition, purity and oxidative stability were compared to oils obtained via conventional solvent extraction methods (SEMs). When the oxidative stability was measured by differential scanning calorimetry, the oil was found to be up to 5 times more resistant to lipid oxidation as compared to the SEM oils. Direct infusion electrospray ionization mass spectrometry (ESI-MS) analysis showed characteristic and similar TAG profiles for SubFE and SEMs oils but higher purity for the SubFE oil. The flaxseed oil content of β-tocopherol, campesterol, stigmasterol and sitosterol were quantified via GC-MS. SubFE showed to be a promising alternative to conventional SEM since SubFE provides an oil with higher purity and higher oxidation stability and with comparable levels of biologically active components.

Efeito do tempo de fornecimento de ração suplementada com óleo de linhaça sobre a composição físico-química e de ácidos graxos em cabeças de tilápias do Nilo (Oreochromis niloticus)

The main of this study was to analyze the physical-chemical composition and, especially the fatty acids composition, in the total lipids of tilapia (Oreochromis niloticus) heads, submitted to different ration supply times (0, 10, 20, 30 days) with flaxseed oil (source of a-linolenic acid 18:3 n-3, LNA), in substitution to the sunflower oil. There were not significant differences among (P>0,05) the moisture, ash, protein, and total lipids values for the different treatments (times of supply). The values of total lipids found in the heads varied from 8.41 to 10.13%, and 27 fatty acids were found in these lipids in all treatments. The majority fatty acids were 18:2n-6, 18:1n-9 and 16:0. There was an increase in the LNA acid percentage values, in the omega-3 (n-3) sum, and a decrease of the n-6/n-3 reason, with significant differences among the treatment A (zero time) and other treatments that received flaxseed oil. There were not significant differences among the treatments in relation to polyunsaturated fatty acids/saturated fatty acids (PUFA/SFA) rate.

Evaluation of nutritional compounds in new amaranth and quinoa cultivars

This study evaluated the fatty acid quantification, proximate and amino acid compositions, antioxidant activity, total phenolic compounds, vitamin E, and mineral contents of new amaranth (BRS Alegria) and quinoa (BRS Piabiru) cultivars which were produced in order to adapt these pseudocereals to the climatic conditions of central-western Brazil. They showed superior levels of protein and total lipids in comparison to their native counterparts. The lipid profile of the amaranth BRS Alegria was revealed to be better than those of other native cultivars. Quinoa BRS Piabiru presented a higher antioxidant capacity and phenolic content than the studied amaranth cultivar, but lower contents of tocopherols. All of the obtained results confirm that these new grains possess an overall amount of nutritional compounds that is better than those reported for many native counterparts of the studied samples. The employed analytical methods in this work contributed to a better understanding of the quinoa BRS Piabiru and amaranth BRS Alegria chemical compositions. Therefore, the diversity and quantity of all of the studied compounds in the samples denote the considerable importance of these grains for food science research area.

Using chemometric techniques to characterize gluten-free cookies containing the whole flour of a new quinoa cultivar

Celiac disease is defined as intolerance to the gluten proteins present in certain cereals used to prepare foodstuffs. We developed and performed physico-chemical, sensory, and nutritional assessments of three formulations of gluten-free cookies containing Linum usitatissimum L. and different levels of whole Chenopodium quinoa BRS Piabiru flour. No gluten was detected in the prepared cookie formulations. The crude protein and total lipid contents ranged from 85.58 to 97.55 and 121.69 to 166.19 g per kg of sample, respectively. The polyunsaturated/saturated and n-6:n-3 fatty acid ratios ranged from 0.85:1 to 0.92:1 and 3.08:1 to 4.38:1, respectively. Formulation C had the best alpha-linolenic acid content, lipid fraction nutritional indices and mineral content per portion, with excellent sensory characteristics. Multivariate analysis highlighted the effect of the concentration of quinoa on the nutritional and sensory qualities of the product.

Chemometric Methods Applied to the Mineral Content Increase in Chocolate Cakes Containing Chia and Azuki

A 22 full factorial design (two factors at two levels) with duplicate was performed to investigate the influence of the percentages of chia and azuki (the two factors) added to gluten-free chocolate cake on the mineral contents (Ca, Cu, Fe, K, Mg , Mn and Zn). In the study, partially defatted chia flour and wholemeal azuki flour were used. The percentage factors of chia and azuki were significant and the increases in these values contributed positively to the responses. The interaction effect was not significant for the Ca, Fe, Mg and Zn responses. The principal component analysis (PCA) distinguished samples with higher content of chia by means of PC1, and PC2 separated the formulations with the highest levels of azuki from the ones with the lowest levels. Using analysis of variance (ANOVA) and response surface analyses, it was possible to conclude that the increase in mineral content was higher with the addition of 20% of both flours.

Effect of the addition of chia's by‐product on the composition of fatty acids in hamburgers through chemometric methods

BACKGROUND Hamburger is a meat-based food that is easy to prepare and is widely consumed. It can be enriched using different ingredients, such as chias by-product, which is rich in omega-3. Chemometrics is a very interesting tool to assess the influence of ingredients in the composition of foods. A complete factorial design 2(2) (two factors in two levels) with duplicate was performed to investigate the influence of the factors (1) concentration of textured soy proteins (TSP) and (2) concentration of chia flour partially defatted (CFPD) as a partial replacement for the bovine meat and porcine fat mix in hamburgers. RESULTS The results of proximal composition, lipid oxidation, fatty acids sums, ratios, and nutritional indexes were used to propose statistical models. The factors TSP and CFPD were significant, and the increased values contributed to improve the composition in fatty acids, crude protein, and ash. Principal components analysis distinguished the samples with a higher content of chia. In desirability analysis, the highest level of TSP and CFPD was described as the optimal region, and it was not necessary to make another experimental point. CONCLUSION The addition of chias by-product is an alternative to increase the α-linolenic contents and to obtain nutritionally balanced food.

Chemometric Study of Perilla Fatty Acids from Subcritical n-Propane Extracted Oil

O oleo de perilla (Perilla frutescens) foi extraido utilizando n-propano subcritico e tambem pela metodologia oficial de Soxhlet, para efeito de comparacao. Objetivou-se avaliar a influencia dos fatores temperatura e pressao sobre a composicao dos acidos graxos (FA), atraves de um fatorial 2 2 completo em triplicata com ponto central. Ambos os fatores analisados contribuiram significativamente para o rendimento dos FA extraidos. As superficies de resposta indicaram que o aumento da pressao e temperatura permitiu maior extracao de acidos graxos omega-3 e poli-insaturados (PUFA), e uma melhor razao entre PUFA e acido graxos saturados (SFA). Atraves da funcao de desejabilidade, a melhor condicao de extracao com n-propano foi temperatura de 80 ° C e pressao de 8 MPa. A analise multivariada distinguiu a condicao otima no grupo de maior conteudo de PUFA, com destaque para o acido alfa-linolenico, enquanto a metodologia de Soxhlet caracterizou-se com elevado teor de SFA. Oil from perilla (Perilla frutescens) was extracted using subcritical n-propane and also the Soxhlet official methodology, for comparison. This work aimed at assessing the influence of the temperature and pressure factors on the composition of fatty acids (FA), using a full 2 2 factorial design in triplicate with central point. Both factors were significant for increasing the yield of extracted FA. The response surfaces showed that increasing pressure and temperature allowed the extraction of higher levels of n-3 and polyunsaturated fatty acids (PUFA) and greater ratio values of PUFA and saturated fatty acids (SFA). According to the desirability function, the best condition of extraction using n-propane was 80 ° C for temperature and 8 MPa for pressure. In multivariate analysis the optimum condition was characterized by a higher content of PUFA, especially alphalinolenic fatty acid, while the Soxhlet methodology was characterized by high level of SFA.

Analysis of carotenoids, α-tocopherol, sterols and phenolic compounds from white bread enriched with chia (Salvia hispanica L.) seeds and carrot (Daucus carota L.) leaves

Each food matrix is unique. Thus, the endogenous antioxidants of an underexplored bakery product might show different responses regarding free radical scavenging/resistance to forced oxidation than what is expected for other foods previously reported in the literature. In this context, a Box-Behnken design and correlation studies were applied in order to obtain more information about how specific antioxidants affect the total antioxidant activity (TAC) and the degree of forced oxidation in white breads with chia seeds and carrot leaves. Hypotheses of synergism/antagonism between the studied compounds were also elucidated in order to justify the obtained results. In this specific sample type, carotenoids and cholesterol showed the greatest relationships with results from TAC assays, as well with induction points using Oxitest® equipment, while α-tocopherol and phytosterols showed negative correlations. Phenolic compounds did not have any influence on the system because the baking procedure at high temperature had severe impacts on them.

Development, characterization and chemometric analysis of a gluten-free food bar containing whole flour from a new cultivar of amaranth

Food bars are consumed heavily, especially because of their practicality; however they cannot be ingested by celiac patients and present low contents of essential nutrients. The goal of this study was the development and physical-chemical, nutritional and sensory evaluation of a gluten-free food bar containing amaranth and linseed. Gluten fractions were not detected in the food bar formulations. Crude protein and total lipid contents ranged from 68.32 to 76.60 and 74.56 to 82.06 g kg-1 of food, respectively. The polyunsaturated/saturated and n-6:n-3 fatty acid ratios ranged from 0.45:1 to 0.55:1 and 1.44:1 to 2.50:1, respectively. Calcium, magnesium, copper, iron, manganese and zinc were the principal minerals. Application of multivariate analysis enabled sample B to be distinguished according to its mineral and alfa-linolenic acid content. All food bar formulations had good sensory acceptance and high purchase intent.

Antioxidant Activity of Brazilian Bean Cultivars

This study quantified fatty acids and evaluated the proximate composition, antioxidant activity paired with Quencher procedure and total phenolic compounds in Brazilian bean cultivars. The samples showed high amounts of polyunsaturated fatty acids, such as linoleic acid (191.54 to 329.50 mg g-1 of total lipids) and α-linolenic acid (228.03 to 367.27 mg g-1 of total lipids). The obtained ratios between Omega 6 and 3 fatty acids were low, between 0.71 and 1.12. In relation to antioxidant activity assays, the cultivars showed the best results upon employing the 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) method (2401.34 to 4394.80 µmol Trolox equivalent g-1). The lowest results were observed in the ferric reducing antioxidant power (FRAP) assays, 530.93 to 1440.13 µmol Trolox equivalent g-1. The results from 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ABTS methods showed the greatest correlation between themselves (r = 0.619). High concentrations of total phenolic compounds were also detected in the studied cultivars, which varied from 81.85 to 173.65 mg gallic acid equivalent 100g-1.