112,277 research outputs found
Emprego da tecnologia supercrítica para a valorização do resíduo de semente de chia (Salvia hispanica)
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia de Alimentos, Florianópolis, 2014.A chia (Salvia hispanica) é uma planta cultivada nas Américas do Sul e Central, cuja semente é fonte de antioxidantes naturais e ácidos graxos essenciais. O presente estudo avaliou a obtenção de extratos de torta de chia, subproduto proveniente da extração do óleo de chia. Foram aplicadas as técnicas a baixa pressão como extração em Soxhlet (SOX), ultrassom (US) e maceração (MAC) utilizando etanol (EtOH), hexano (Hex) e acetato de etila (EtOAc) como solventes, a fim de comparar com o processo de extração supercrítica (ESC). As operações de ESC foram realizadas com pressões de 150 bar a 300 bar e temperaturas de 40 °C e 50 °C empregando o CO2 como solvente. Também foi realizada a aplicação de EtOH e EtOAc como cossolventes no processo de ESC em concentrações de 2,5 até 7,5 %. O processo de extração supercrítica sequencial (ESC-S) foi estudado, o qual possui duas etapas de extração, com uma despressurização rápida do sistema entre a primeira e a segunda etapa. A construção da curva cinética e modelagem matemática de processos de ESC e ESC-S foram executadas, além da estimativa de custos de manufatura da instalação de uma unidade industrial de ESC. Todos os extratos obtidos foram submetidos a análises de atividade antioxidante (método ABTS), teor de fenólicos totais (TFT), perfil de ácidos graxos e atividade antimicrobiana. Nas extrações a baixa pressão, os maiores rendimentos foram obtidos utilizando SOX com EtOH (15,4 ± 0,4 %). Nas ESC com CO2 puro, a pressão de 300 bar permitiu alcançar rendimentos de até 10,6 ± 0,2 %, na maior temperatura estudada. A utilização de cossolvente causou aumento no rendimento de extração (11,3 ± 0,1% utilizando EtOH a 7,5%). Os extratos obtidos em extrações a baixa pressão com EtOH e EtOAc obtiveram os melhores valores de TFT e atividade antioxidante. A utilização de cossolvente afetou positivamente os resultados de TFT e atividade antioxidante dos extratos de ESC. O perfil de ácidos graxos dos extratos confirmou altos teores de ácido linoleico e a-linolênico em todos os extratos testados. Extratos obtidos pelas diferentes técnicas mostraram atividade antimicrobiana contra B. cereus. A ESC-S com despressurização rápida teve efeito positivo com relação ao rendimento, onde foi atingido rendimento de 8,7 ± 0,2%, estatisticamente igual ao rendimento obtido em ESC na mesma condição, porém reduzindo o tempo de extração pela metade. A realização da segunda etapa de ESC-S utilizando EtOH 7,5% ocasionou um aumento no TFT dos extratos obtidos. O modelo que melhor se ajustou as curvas experimentais foi o modelo de Martínez et al. (2003). Segundo o modelo de Sovová (1994), para os processos de ESC e primeira etapa de ESC-S, o mecanismo de convecção foi mais representativo. Na segunda etapa de ESC-S o mecanismo de difusão também mostrou representatividade. A ESC-S quando realizada até a etapa de despressurização (ESC-Desp) mostrou ser um processo economicamente viável e lucrativo para aplicação em escala industrial, com valores de extrato competitivos com os valores de mercado, gerando extratos de alta qualidade em um menor tempo de processo.Abstract : Chia (Salvia hispanica) is a plant cultivated in South and Central America, whose the seed is a source of natural antioxidants and essential fatty acids. The present study evaluated the extracts attainment from chia seed cake, which is a byproduct from chia seed oil extraction process. It were applied low-pressure techniques, like Soxhlet extraction (SOX), ultrasound assisted extraction (US) and maceration (MAC) using ethanol (EtOH), hexane (Hex) and ethyl acetate (EtOAc) and as solvents with the objective of comparing with the high pressure process, performed by supercritical fluid extraction (SFE). SFE were performed at pressures from 150 to 300 bar and temperatures of 40 °C and 50 °C, using CO2 as solvent. It was also performed an application of EtOH and EtOAc as cosolvents on SFE process, using concentrations from 2.5 to 7.5%. A sequential supercritical fluid extraction (S-SFE) process was studied, wich includes two steps of extraction, with a fast depressurization of the system between the first and the second step of extraction. The kinetic extraction curves of SFE and S-SFE processes were built and mathematical models adjusted the experimental data. It were also performed an estimative of manufacturing costs from installing a supercritical fluid extraction industrial unit. All extracts was submitted to antioxidant analysis (ABTS method), total phenolics content (TPC), fatty acids profile and antimicrobial analysis. Among low-pressure extraction, the highest yield was achieved using SOX with EtOH (15.4 ± 0.4 %). Among the SFE assays using pure CO2, the pressure of 300 bar allowed to achieve yields up to 10.6 ± 0.2 %, in the highest tested temperature. The use of a cosolvent caused increase in yield (11.3 ± 0.1% using EtOH 7,5%). Extracts obtained by lowpressure techniques using EtOH and EtOAc showed the best values of TPC and antioxidant activity. The using of a cosolvent affected in a positive way the results of TPC and antioxidant activity of SFE extracts. The fatty acids profile of the extracts confirmed the high content of linoleic and a-linolenic acids in all tested extracts. Extracts obtained by different techniques showed antimicrobial activity against B. cereus. SSFE process with fast depressurization caused a positive effect in yield, achieving a yield of 8.7 ± 0.2%, statiscally equal to the yield obtained by SFE using the same condition, but reducing the extraction time by half. The performance of the S-SFE second step using EtOH 7.5% caused an increase in the TPC of the obtained extracts. Martínez et al (2003) was the model which best-adjusted experimental data. According to Sovová s model (1994), in S-SFE first step and SFE processes, the convection mechanism was more representative. In the S-SFE second step, the diffusion mechanism showed to be representative. S-SFE process, when realized until the depressurization step (SFE-Desp), showed to be an economically viable and profitable process on an industrial scale application, with values of extract competitive with market values, generating high quality extracts in a shorter process time
ChIA-PET2: A Versatile and Flexible Pipeline for ChIA-PET Data Analysis
No full textChIA-PET2 is a versatile and flexible pipeline for analyzing different types of ChIA-PET data from raw sequencing reads to chromatin loops. ChIA-PET2 integrates all steps required for ChIA-PET data analysis, including linker trimming, read alignment, duplicate removal, peak calling and chromatin loop calling. It supports different kinds of ChIA-PET data generated from different ChIA-PET protocols and also provides quality controls for different steps of ChIA-PET analysis. In addition, ChIA-PET2 can use phased genotype data to call allele-specific chromatin interactions. We applied ChIA-PET2 to different ChIA-PET datasets, demonstrating its significantly improved performance as well as its ability to easily process ChIA-PET raw data. ChIA-PET2 is available at https://github.com/GuipengLi/ChIA-PET2. © The Author(s) 2016.National Basic Research Program of China [2012CB316503]; National High Technology Research and Development Program of China [2012AA020401]; National Natural Science Foundation of China [91519326, 31361163004 and 31301044]; National Institutes of Health grants [HG001696, 5U01HG007919-02, 5U54HG00699604 and 5P50HG00773502]. National Basic Research Program of China [2012CB316503].School of Natural Sciences and Mathematic
Chemical composition of Brazilian chia seeds grown in different places
No full textThis study investigated and compared the occurrence and concentration of macronutrients, moisture, ash, dietary fiber, fatty acids, minerals, carotenoids, vitamins, flavonoids, phenolic compounds, antioxidant activity, phytate and tannin in Brazilian chia seeds grown in the states of Mato Grosso (MT) and Rio Grande do Sul (RS). High concentrations of lipids (31.2 g.100 g−1, on average), proteins (18.9 g.100 g−1, on average), dietary fiber (35.3 g.100 g−1, on average), vitamin E (8,203.6 μg.100 g−1, on average) were observed. Similar values for total phenolic compounds and phytic acid in chia seeds from both regions were observed. Chia grown in RS showed higher antioxidant activity than chia grown in MT, and the tannin concentrations were higher in chia seeds grown in Mato Grosso (19.08 ± 1.08 eq.catequina/g sample). In conclusion, Brazilian chia seeds showed high concentrations of lipids, proteins, total dietary fiber, minerals and vitamin E
Spectroscopic analysis of chia seeds
No full textChia seeds are becoming more and more popular in modern diets. In this contribution NIR and 2D-fluorescence spectroscopy were used to determine their nutritional values, mainly fat and protein content. 25 samples of chia seeds were analysed, whereof 9 samples were obtained from different regions in Kenya, 16 samples were purchased in stores in Germany and originated mostly from South America. For the purchased samples the nutritional information of the package was taken in addition to the values obtained for fat and protein, which were determined at the Hohenheim Core Facility. For the first time the NIR and fluorescence spectroscopy were used for the analysis of chia. For the spectral evaluation two different pre-processing methods were tested. Baseline correction with subsequent mean-centring lead to the best results for NIR spectra whereas SNV (standard normal variate transformation) was sufficient for the evaluation of fluorescence spectra. When combining NIR and fluorescence spectra, the fluorescence spectra were also multiplied with a factor to adjust the intensity levels. The best prediction results for the evaluation of the combined spectra were obtained for Kenyan samples with prediction errors below 0.2 g/100 g. For all other samples the absolute prediction error was 0.51 g/100 g for fat and 0.62 g/100 g for protein. It is possible to determine the amount of protein and fat of chia seeds by fluorescence and NIR spectroscopy. The combination of both methods is beneficial for the predictions. Chia seeds from Kenya had similar protein and lipid contents as South American seeds
Phenolics compounds, flavonoids and antioxidant activity of chia seed extracts (Salvia hispanica) obtained by different extraction conditions
No full textThis study aimed to chemically characterize the chia seed (Salvia hispanica), get chia seed
extracts at different concentrations of ethanol and temperature using a factorial design 22 with
triplicate at the central point and then analyze the extracts the content phenolics, flavonoids
and antioxidant activity in vitro. The results showed that the chia seed has a high content
of dietary fiber (374.4 g/kg), lipids (283.5 g/kg) and protein (231.7 g/kg). The same possess
antioxidant activity, and the extract with a higher antioxidant activity was obtained by the
method of stirring using temperatures of 600C and 80% ethanol concentrations. The content of
phenolic compounds was found to be 2,639 g of gallic acid equivalent/kg of dry sample. The
flavonoid content was 0.162 g equivalent of quercetin/kg dry sample. The IC50 found was of
3.841 mg/mL and FRAP 45.004 mmol trolox equivalent/ kg of dry sample
Propriedades físico-químicas e organolépticas da mucilagem da chia (Salvia hispanica L.): Physico-chemical and organoleptic properties of chia mucilage
No full textA Salvia hispânica L., conhecida popularmente como chia, ao entrar em contato com a água apresenta em sua composição um percentual de 5-6% (m/m) de mucilagem, que pode ser definida como uma substância translúcida, amorfa e polimérica, formada por unidades de monossacarídeos. A chia pode absorver até 12 vezes seu peso em água, o que contribui para o aumento de volume e viscosidade das sementes. Foram encontrados estudos utilizando a mucilagem da chia na área alimentícia, observando que além dessa mucilagem ter grande capacidade de retenção de água, ela age como espessante e estabilizante na formação de espumas. Neste presente trabalho, as sementes de chia foram colocadas em contato com a água destilada numa proporção de 1:10, 1:20, 1:30 e 1:40 (g de chia/g de água). Foram realizadas análises organolépticas como cor, odor e aspecto da mucilagem, assim como análises físico-quimicas como pH, densidade e viscosidade. Após estudo, observou-se que concentração com maior rendimento foi a de 1:30 (g de chia/g de água), sendo promissora em formulações alimentícias e cosméticas
Effect of dietary butter (CON), chia seed (CS) and pumpkin seed (PS) on FA profile (g /100 g FA total methyl ester) in sheep milk.
No full textEffect of dietary butter (CON), chia seed (CS) and pumpkin seed (PS) on FA profile (g /100 g FA total methyl ester) in sheep milk.</p
AcMNPV ChiA protein disrupts the peritrophic membrane and alters midgut physiology of Bombyx mori larvae
No full textAutographa californica multicapsid nucleopolyhedrovirus (AcMNPV) chitinase A (ChiA) is a protein which promotes the final liquefaction of infected host larvae. The potential of this viral molecule as a new tool for insect control is explored here. The ChiA gene was isolated from the AcMNPV genome by PCR and expressed in E coli. The recombinant protein, purified by affinity chromatography, showed both exo- and endo-chitinase activities and produced perforations on the peritrophic membrane (PM) of Bombyx mori larvae which increased in number and in size, in a dose-dependent manner. This structural alteration resulted into a significant increase of PM permeability to methylene blue and to the small neuropeptide proctolin. When the fifth instar larvae of B. mori were fed on a artificial diet supplemented with the recombinant ChiA, 100% mortality was observed at a dose of 1 mug/g of larval body weight (LW), while at sub-lethal doses of 0.56 mug/g LW, a reduced larval growth was recorded. These results indicate that AcMNPV-ChiA may offer interesting new opportunities for pest control. (C) 2004 Elsevier Ltd. All rights reserved
Yogurt Enriched with Chia Seeds: Physicochemical, Microbiological, and Sensory Changes during Storage
No full textThis study investigates the physicochemical, microbiological, and sensory properties of yogurt fortified with honey and chia seeds at concentrations of 5% and 10% (w/w) over a 21-day storage period at 4 ± 1 °C. The addition of chia seeds resulted in initial pH increases, with 5% and 10% chia seeds having pH values of 4.22 ± 0.02 and 4.31 ± 0.01, respectively, compared to 4.20 ± 0.01 for the control yogurt. During storage, the pH decreased by 0.17 units for the control yogurt and by 0.08 and 0.13 units for 5% and 10% chia seeds, respectively. The titratable acidity (TA) increased significantly, by 9.1% for the control yogurt and by 22.9% and 29.6% for the 5% and 10% yogurt, respectively. The protein content increased from 3.22 ± 0.03 g/100 g in the control sample to 3.92 ± 0.08 g/100 g and 4.59 ± 0.00 g/100 g for 5% and 10% chia seeds, respectively, without any significant changes during storage. The number of lactic acid bacteria (LAB) was highest in the control sample (9.005 ± 0.007 log CFU/g) and lowest in the 10% yogurt with chia seeds (8.495 ± 0.007 log CFU/g), with all samples remaining free of harmful microorganisms. The sensory evaluation showed that yogurt with 5% chia seeds received the highest overall acceptability scores, while yogurt with 10% chia seeds had poorer scores for taste and texture. Overall, fortification of yogurt with 5% chia seeds improves its nutritional value and sensory properties without compromising product safety or microbiological quality
Biochemical, nutraceutical and phytochemical characterization of chia and basil seeds: A comparative study
No full textChia and basil seeds have comparable nutritional profiles, bioactive components, and phytochemistry, which make it difficult for consumers and researchers to choose between the two. Thus, an in-depth study was conducted to compare the physiochemical, nutritional and bioactive profile of these seeds in order to obtain complete database regarding nutritional and phytochemical profiling of both seeds. The wonder seeds were analyzed for physico-chemical composition, fatty acid constituents, amino-acid profile and phytochemical screening. Fatty acid constituents were determined using GC-MS, while amino acids profile and identification and quantification of phytochemicals were performed using HPLC procedure. Physico-chemical evaluation of basil and chia seed revealed that basil was found superior to chia in terms of dietary fiber (40.85 g/100 g), fat content (33.10 g/100 g), vitamin A (1583 µg/100 g) and E (779 µg/100 g) while chia seed was rich in protein (21.54 g/100 g), iron (7.7mg/100 g), magnesium (335 mg/100 g) and phosphorus (860 mg/100 g). Amino acid profiling revealed the presence of high-quality protein in chia seeds comprising of almost all essential and non-essential amino acids in significant (p < .05) amounts as compared to basil seeds. Furthermore, higher proportion of α-linoleic acid (ALA) was detected in basil seeds (24.4g/100 g) as compared to chia seeds (5.25 g/100 g) as determined by GC-MS. Phytochemical screening showed that basil contained significantly (p < .05) higher amounts of total phenolic (17.66mgGAE/g of dry sample) and flavonoid content (0.57mgQE/100 g of dry sample) in comparison to chia seeds, which contributed to its higher anti-oxidant activity. Phenolic characterization revealed that basil seeds contained higher concentration of caffeic acid (4780.01 µg/g) followed by gallic acid (2330 µg/g). The inference drawn from the study concludes that both seeds can be put forth for enrichment of various food items or can be directly consumed as functional foods
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