Search

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.

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).

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. Cada matriz alimentar é única. Os antioxidantes endógenos de um produto de panificação não estudados podem mostrar diferentes respostas para atividade antioxidante total (TAA)/resistência a oxidação forçada (ROF) do que é esperado para outros alimentos reportados na literatura. Neste contexto, um design Box-Behnken e estudos de correlação foram aplicados para obter mais informações sobre como compostos antioxidantes específicos afetam o TAA/ROF em pães com sementes de chia e folhas de cenoura. Hipóteses de sinergismo/antagonismo entre os compostos estudados foram elucidadas para tentar justificar os resultados obtidos. Neste tipo específico de amostra, carotenóides e colesterol tiveram as maiores relações com resultados de ensaios de TAA, bem como com pontos de indução provenientes do equipamento Oxitest®, enquanto que α-tocoferol e fitosteróis mostraram correlações negativas. Compostos fenólicos não tiveram nenhuma influência no sistema porque o cozimento em alta temperatura das amostras destruiu grande parte desses analitos.

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.