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1.
Braz J Microbiol ; 54(2): 703-713, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36800074

RESUMO

Bacterial cellulose (BC) is a biopolymer principally synthetized by strains of the genus Komagataeibacter. However, high costs and low production yield make large-scale application difficult. The aim of this work was to evaluate the effects of successive batch culture before fermentation on the ability to increase the capacity of bacterial cellulose biosynthesis by a low-producing strain. The Komagataeibacter hansenii strain ATCC 23,769 was initially cultivated in fermentation broth for two periods of 35 or 56 days under static conditions. At the end of each period of time, they were transferred to new broth to be cultivated again (new batch culture cycle) for 35 or 56 days and carried out in parallel with a 10-day fermentation to determine the quantity of BC produced. As a result, a greater increase was observed after the end of the second and third batch cultures of 56 days (increases of 137% and 187% in relation to the nonbatch cultured strain, respectively). The produced samples presented higher crystallinity and thermal properties but lower water holding capacity. Through this work, it was concluded that the longer the batch culture time was, the greater the increase in the capacity of cellulose biosynthesis, which also depended on the number of successive batch culture cycles carried out.


Assuntos
Acetobacteraceae , Celulose , Técnicas de Cultura Celular por Lotes , Acetobacteraceae/genética , Biopolímeros
2.
Appl Biochem Biotechnol ; 194(11): 5017-5036, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35687307

RESUMO

Bacterial cellulose (BC) is a biopolymer mainly produced by acetic acid bacteria (AAB) that has several applications in the medical, pharmaceutical, and food industries. As other living organisms, AAB require sources of chemical elements and nutrients, which are essential for their multiplication and metabolite production. So, the knowledge of the nutritional needs of microorganisms that have important industrial applications is necessary for the nutrients to be supplied in the appropriate form and amount. Considering that the choice of different nutrients as nitrogen source can result in different metabolic effects, this work aimed to verify the effects of amino acid supplementation in the culture media for BC production by an AAB strain (Komagataeibacter intermedius V-05). For this, nineteen amino acids were tested, selected, and optimized through a Plackett and Burman factorial design and central composite design to determine the optimal concentrations of each required amino acid. Membranes produced under optimal conditions were characterized in relation to chemical structure and properties by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), infrared spectroscopy (FT-IR), and hydrophilic properties. Three amino acids had a significant positive effect and were required: aspartic acid (1.5 g L-1), phenylalanine (1.5 g L-1), and serine (3.0 g L-1). Conversely, all sulfur and positively charged amino acids had a negative effect and reduced the production yield. After optimization and validation steps, a production level of 3.02 g L-1 was achieved. Membranes produced from optimized media by this strain presented lower crystallinity index but greater thermal and hydrophilic properties than those produced from standard HS medium.


Assuntos
Acetobacteraceae , Celulose , Celulose/química , Espectroscopia de Infravermelho com Transformada de Fourier , Aminoácidos/metabolismo , Ácido Aspártico/metabolismo , Biopolímeros/metabolismo , Meios de Cultura/metabolismo , Suplementos Nutricionais , Enxofre , Nitrogênio/metabolismo , Fenilalanina , Serina/metabolismo , Preparações Farmacêuticas , Fermentação
3.
Food Res Int ; 148: 110629, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34507773

RESUMO

Prebiotics are compounds naturally present in some foods or can be synthesized by microorganisms and enzymes. Among the benefits associated with prebiotic consumption are the modulation of the intestinal microbiota that increase the production of short chain fatty acids and prevent the development of some disorders such as colon cancer, irritable bowel syndrome, diabetes, obesity, among others. Traditionally, prebiotics have been used in diverse food formulations to enhance their healthy potential or to improve their technological and sensory properties. However, different alternatives for the production of prebiotic products are being explored, such as edible coatings and films. Therefore, this review aims to highlight recent research on edible coatings and films incorporated with different prebiotics, the concept of prebiotics, the general characteristics of these materials, and the main production methods, as well as presenting the perspectives of uses in the food industry. Current works describe that polyols and oligosaccharides are the most employed prebiotics, and depending on their structure and concentration, they can also act as film plasticizer or reinforcement agent. The use of prebiotic in the coating can also improve probiotic bacteria survival making it possible to obtain fruits and vegetables with synbiotic properties. The most common method of production is casting, suggesting that other technologies such as extrusion can be explored aiming industrial scale. The use of film and coating carried of prebiotic is an emerging technology and there are still several possibilities for study to enable its use in the food industry. This review will be useful to detect the current situation, identify problems, verify new features, future trends and support new investigations and investments.


Assuntos
Filmes Comestíveis , Probióticos , Simbióticos , Oligossacarídeos , Prebióticos
4.
J Food Sci Technol ; 58(8): 3030-3038, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34294965

RESUMO

Flaxseed mucilage was extracted with distilled water, dried and used for film production with polyvinyl alcohol (PVA) (ratio 1:1) of different hydrolysis degrees (88.0 and 98.3%). The properties of the films were evaluated by determining the thickness, tensile measurements, moisture content, water vapor permeability, apparent opacity, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) analysis and thermogravimetric analysis. Flaxseed mucilage, when mixed with PVA, produces less resistant, less rigid, more-flexible films, has a higher thermal stability, and does not change the water vapor barrier properties compared with pure mucilage films. SEM revealed that films with mucilage and PVA mixtures formed a compact and homogeneous structure, corroborating the FTIR spectra that indicated a chemical interaction between these two biopolymers. In general, the degree of PVA hydrolysis did not influence the properties of the films when mixed with flaxseed mucilage extract. Therefore, films obtained from mixtures of flaxseed mucilage and PVA can be an interesting and advantageous alternative for producing bio-based packaging.

5.
Food Res Int ; 137: 109624, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33233212

RESUMO

This research aimed to evaluate the pretreatment of soybean with the carbohydrase multi-enzyme complex "Viscozyme L", during the extraction process; in order to improve the recovery of proteins and isoflavones in soybase, and reduce the loss of these compounds through the okara residue. Three concentrations of enzyme were studied at 50 °C, along with an experiment carried out without enzyme addition (control experiment). The results were also evaluated in relation to standard soybase processing. In comparison to the standard and control processes, the enzymatic pretreatment reduced up to 85% the total amount of okara residue. Due to the action of the multi-enzyme complex, protein and total isoflavone recovery increased from 42% to 83% and from 59% to 93%, respectively. The application of Viscozyme L also favored the conversion of conjugated forms of isoflavone to aglycone in the soybase, representing up to 50% of the total isoflavones. The enzymatic pretreatment of soybean with carbohydrase improved the nutritional quality of the soybase, while at the same time reducing residue generation; showing that the proposed food process can be considered environmentally friendly method.


Assuntos
Isoflavonas , Manipulação de Alimentos , Isoflavonas/análise , Glycine max
6.
Food Technol Biotechnol ; 58(1): 29-37, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32684785

RESUMO

Many fruits and vegetables contain compounds with antioxidant properties, but the processing and storage conditions of the food industry may damage these beneficial compounds and produce free radicals that are associated with oxidative stress. This study aims to evaluate in vitro the antioxidant capacity and prooxidant effects of juçara pulp fermented with Lactobacillus reuteri or Lactobacillus plantarum before and after spray-drying with maltodextrin, gum arabic or gelatin and stored at 25 °C for 90 days. The antioxidant capacity was assessed by measuring the ability to scavenge reactive oxygen species (ROS) in the neutrophil respiratory burst and free radical 2,2-diphenyl-1-picryl-hydrazyl (DPPH), and by determining the total phenolic content. The prooxidant effects were analyzed as free radical formation measured by electronic paramagnetic resonance (EPR). Fermentation by both bacteria increased the antioxidant activity, while the spray-drying process decreased the content of phenolic compounds (65-85%) and the DPPH scavenging ability, depending on the carrier usage. All of the samples inhibited ROS in the neutrophil burst, and the juçara pulp fermented by L. reuteri and dried with gum arabic exhibited the best performance. Spray-drying did not influence the intensity or type of free radicals detected by EPR. However, storage at room temperature decreased the antioxidant capacity and increased free radical formation.

7.
Food Technol Biotechnol ; 58(1): 84-90, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32684792

RESUMO

Soybean molasses is a by-product from the production of protein concentrate from soybean meal that predominantly contains sugars, with sucrose as the major component. In Brazil, soybean molasses is used for animal feed or it is discarded, although some industries use it to produce ethanol. This study aims to evaluate the parameters required for the acetic acid fermentation of soybean molasses, and characterise the resultant vinegar. To study the most suitable parameters for the acetic acid fermentation, vinegar was produced from the alcohol fermentation of soybean molasses through eight fermentation cycles: five for adaptation and three for production. The average acidity of the acetic acid fermentation product was 50.60 g/L, with an acetic acid fermentation yield, total yield of acetic acid in broth and productivity 65.01%, 92.76% and 0.033 g/(L·h), respectively. The vinegar produced from soybean molasses has an acidity of 5.07% (m/V), residual ethanol content 0.17% (m/V), sugars 7.86% (m/V), dry extract 14.67% (m/V), ash 2.27% (m/V) and a density of 1.023 g/cm3. The contents of total phenolics and isoflavones decreased after the alcohol and acetic acid fermentations. Moreover, the isoflavones profile of the fermented product comprised only three forms: daidzein, glycitin and genistin. According to our results, 3460 L of vinegar can be produced for every tonne of soy molasses, with an acetic acid concentration of 40 g/L, the minimum required by the legislation on vinegar production. Thus, these findings demonstrate that soy molasses represents a useful raw material for the production of vinegar.

8.
J Food Biochem ; 43(11): e13018, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31441957

RESUMO

Soybean consumption has been associated with health benefits. However, the effect of ultrasound (US) soybean pretreatment in terms of potential health benefits has not been investigated so far. Accordingly, the total phenolic content (TPC) and the total aglycone content (TAC) were optimized using the Box-Behnken design. Contrasting samples regarding isoflavones aglycones and TPCs were screened for their antioxidant and anti-inflammatory potentials using RAW 264.7 macrophages. US pretreated soybeans (55°C, 15 min, and 24 W/cm2 ) showed greater TPC and TAC compared to the control and this translated to higher antiradical activity and reduction of nuclear factor kappa B (NF-κB) activation. The concentration of genistein in treated soybeans increased by 95%. Furthermore, US pretreated soybeans rendered phenolic extracts that reduced the NF-κB activation by 86%. Therefore, this contribution demonstrates the beneficial effects of US pretreatment of soybeans, which provides a better feedstock for the functional food industry. PRACTICAL APPLICATIONS: Soybeans can be consumed as such or used as a feedstock to produce soy yogurt, fermented soymilk, tofu, and protein concentrate, among others. The greatest bioavailability of isoflavones compared to other flavonoids has recently been highlighted, and this has been explained by the relatively moderate lipophilicity of isoflavones as aglycones. The present contribution supports the use of US pretreatment of soybeans to obtain a feedstock with improved contents of isoflavones as aglycones. We have confirmed that phenolic extracts obtained from the US pretreated samples showed higher bioactivity as radical scavengers and by reducing the activation of nuclear factor kappa B (NF-κB) in a cell model, which is mediated by oxidative species. The clinical importance of NF-κB activation is derived mainly from its role in inflammatory responses. Therefore, our investigation may have a practical application in the procurement of soybean products and/or ingredients with improved functional properties related to their health benefits.


Assuntos
Antioxidantes/isolamento & purificação , Manipulação de Alimentos/métodos , Glycine max/química , Isoflavonas/isolamento & purificação , NF-kappa B/imunologia , Ultrassom/métodos , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Isoflavonas/química , Isoflavonas/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Células RAW 264.7 , Sementes/química
9.
J Food Sci Technol ; 56(3): 1380-1388, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30956317

RESUMO

The aim of this study was to evaluate the suitability of using chicken meat affected by wooden breast (WB) myopathy in the production of chicken sausages. Compare the technological and sensory properties of such sausages were compared with those produced from normal (N) breast meat. Three types of chicken sausages were elaborated: 100% containing N chicken meat, 100% of WB chicken meat and 50% N/50% of WB meat. The WB chicken meat presented higher values for pH, L*, moisture, cooking loss, shear force, hardness, chewiness, adhesiveness and gumminess; while WHC and protein content were higher for N chicken meat. N and WB chicken sausages presented similar values of WHC, a*, b* color values, protein content and TBARS. QDA indicated no sensory differences between the three sausage formulations, so did the acceptability and purchase intention. Therefore, WB chicken meat may be used to produce chicken sausages combined or not with N chicken meat. Further studies, however, may be required to investigate the nutritional value and digestibility of WB meat and derived products.

10.
Food Chem ; 271: 274-283, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30236677

RESUMO

The objective of this work was to evaluate the effects the solid-state fermentation parameters of defatted soybean flour (DSF) by Monascus purpureus or Aspergillus oryzae on the bioactive compounds. Central composite rotatable design, multi-response optimization, and Pearson's correlation were used. The fermentation parameters as initial pH (X1), DSF-to-water ratio (X2), and incubation temperature (X3) were taken as independent variables. The function responses were isoflavone content, total phenolic content (TPC), and antioxidant activity. All fermentation parameters affected the isoflavone content when fermented by Monascus purpureus, whereas the TPC or antioxidant activities remained almost unchanged. For the fermentation by Aspergillus oryzae, all the function responses were influenced by X2 and X3 and were independent of the X1. Estimated optimum conditions were found as x1 = 6.0, x2 = 1:1, and x3 = 30 °C for both fungi. Achieving suitable fermentation parameters is essential to increase bioactive compounds in the DSF that makes it promising for food industrial applications.


Assuntos
Antioxidantes/metabolismo , Aspergillus oryzae/fisiologia , Fermentação , Manipulação de Alimentos/métodos , Monascus/fisiologia , Farinha , Glycine max
11.
Braz. arch. biol. technol ; 62: e19180478, 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1019538

RESUMO

Abstract This work aimed to evaluate the enzymatic hydrolysis of okara protein concentrate with respect to degree of hydrolysis (DH) in order to obtain a protein hydrolysate with high antioxidant capacity and aglycones isoflavone content. A central composite rotatable design was carried out to evaluate the influence of temperature (40 to 70°C), enzyme:substrate ratio (0.5 to 5.0%, g/100g protein) and pH (7.0 to 9.0) on DH. The optimal condition was 55°C, pH 9 and enzyme:substrate ratio of 5.0%, resulting a DH value of 35.5%. After protein hydrolysis at optimal condition, the antioxidant capacities of hydrolysate increased from 58.29 to 383.49 μM Trolox equivalent/g solids (ABTS method) and 2.41 to 15.32 μM Trolox equivalent/g solids (FRAP method) when compared with protein concentrate. The higher radical scavenging ability of hydrolysate was due to great amount of hydrophobic amino acids (34.92 g/100g protein). Moreover, the protein hydrolysate obtained under optimal condition had 3 times higher aglycone isoflavone content than non-hydrolyzed sample. These results showed that protein hydrolysis of okara could be an alternative approach to increase antioxidant activity and enrich aglycones isoflavone in this byproduct generated from soymilk industry.


Assuntos
Peptídeos , Leite de Soja , Eletroforese , Proteína H do Complexo Glicina Descarboxilase , Isoflavonas , Projetos de Pesquisa
12.
Braz. arch. biol. technol ; 62: e19180119, 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1019542

RESUMO

Abstract The aim of this work was to study the myofibril proteins and collagen fraction changes in broiler chickens PSE (pale, soft, exudative) meat during ageing and their relationship to meat quality. The results presented an increase of myofibril proteins and collagen solubility promoted by the enhanced proteases activities during storage. Ultramicroscopically, the PSE meat samples revealed intracellularly a sarcomere super contraction and lacunas within the A and I bands while Z-lines appeared very dense and fragmented in comparison to normal samples. This observation was noticed already at 4h storage while extracellularly collagen fibrils decreased visually within the endomysium only after 24h of conditioning. These results influenced the quality as the PSE meat presented better functional properties at the first hours of conditioning before further proteins degradation by proteases. Thereafter, at the later ageing stage a further disintegration of the abnormal meat structure would affect the meat functional properties.


Assuntos
Qualidade dos Alimentos , Colágeno/química , Miofibrilas/química , Peptídeo Hidrolases , Galinhas
13.
Ciênc. rural (Online) ; 49(10): e20180743, 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1045246

RESUMO

ABSTRACT: This study aimed to evaluate the effect of different microwave-roasting timeson different sizes of soybean grains with black tegument to achieve the best crunchiness, flavor, and hardness. Black soybean dragées- containing a soybean core coated with layers of chocolate (dragée) - were manufactured, and their nutritional value, microbiological risk, acceptability, and consumer-purchase intentions were verified. Flavor and crunchiness of the roasted black soybeans wereonly affected by the roasting time in the microwave, whereas the hardness was only affected by grain size. The best core of the dragéewas obtainedusing grains ofsieve size 15 (large grains) roastedin the microwave for 11 min; this core presented higher frequencies for extremely crunchy notes (56%), toasted flavor (61%), and an instrumental hardness close to that of the existing commercial product (33.17 N). The manufactured dragées did not present resistant starch, anthocyanins, and microbiological risk, and they were sensorially accepted by the tasters (mean scores of 7.77 for texture and 8.36 for appearance on a scale of 1 to 9). Thus, roasted black soybean dragéeshave a high marketing potential from technological, nutritional, and sensorial points of view.


RESUMO: Este estudo objetivou avaliar o efeito do tempo de torra no micro-ondas para diferentes tamanhos de grãos de soja tipo alimento de tegumento preto, de forma a atingir a melhor crocância, sabor e dureza, e em seguida caracterizar o seu confeito, estruturado na forma de núcleo e camadas de cobertura de chocolate (drageados), em relação ao valor nutricional, risco microbiológico, aceitabilidade e intenção de compra pelos consumidores. O sabor e a crocância da soja preta torrada foram afetados somente pelo tempo de torra em micro-ondas, enquanto a dureza somente foi afetada pela dimensão dos grãos. O melhor núcleo (selecionado) foi obtido com os grãos de peneira 15 (grãos grandes), no tempo de 11 min de torra em micro-ondas, pois apresentou maior frequência para as notas de extremamente crocante (56%), sabor de torrado (61%), e uma dureza instrumental próxima ao produto comercial (33,17 N). As drágeas não apresentaram amido resistente, antocianinas e risco microbiológico, e foram sensorialmente aceitas pelos provadores (scores médios de 7,77 para textura e 8,36 para aparência, em uma escala de 1 a 9). Portanto, o drageado de soja preta torrada com chocolate é viável do ponto de vista tecnológico, nutricional e sensorial, com alto potencial de comercialização.

14.
Food Chem ; 269: 404-412, 2018 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-30100452

RESUMO

Ultrasound may convert conjugated isoflavones into their corresponding aglycones, the best form for absorption in the human body. However, ultrasound may also influence the activity of endogenous ß-glucosidase. Therefore, the present work evaluated the effects of soybean ultrasound pre-treatment by applying the Box-Behnken design prior to soaking, a step that is important for industries to prepare certain soy products. Furthermore, a multi-response optimisation is provided. The best conditions for soybean ultrasound pre-treatment were established as temperature, X1 = 55 °C; exposure time, X2 = 5 min and ultrasound intensity, X3 = 19.5 W cm-2. Under these conditions, soybeans with higher contents of aglycones were obtained and ß-glucosidase activity was kept as high as possible. A second experiment was conducted and confirmed that ultrasound pre-treatment results in a lower soaking time (2 h) to achieve the highest moisture content, lower hardness as well as increased content of aglycones.


Assuntos
Manipulação de Alimentos/métodos , Glycine max , Isoflavonas/análise , beta-Glucosidase/metabolismo , Humanos , Glycine max/química , Glycine max/enzimologia
15.
Foods ; 7(7)2018 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-30011817

RESUMO

Epicotyls from germinated soybeans (EGS) have great potential as sources of endogenous ß-glucosidase. Furthermore, this enzyme may improve the conversion of isoflavones into their corresponding aglycones. ß-Glucosidase may also increase the release of aglycones from the cell wall of the plant materials. Therefore, the aim of this work was to optimize both the extraction of ß-glucosidase from EGS and to further examine its application in defatted soybean cotyledon to improve the recovery of aglycones, which were evaluated by ultra-high performance liquid chromatography (UHPLC). A multistep optimization was carried out and the effects of temperature and pH were investigated by applying a central composite design. The linear effect of pH and the quadratic effect of pH and temperature were significant for the extraction of ß-glucosidase and recovery aglycones, respectively. Optimum extraction of ß-glucosidase from EGS occurred at 30 °C and pH 5.0. Furthermore, the maximum recovery of aglycones (98.7%), which occurred at 35 °C and pH 7.0⁻7.6 during 144 h of germination, increased 8.5 times with respect to the lowest concentration. The higher bioaccessibility of aglycones when compared with their conjugated counterparts is well substantiated. Therefore, the data provided in this contribution may be useful for enhancing the benefits of soybean, their products, and/or their processing by-products.

16.
J Food Sci Technol ; 55(4): 1508-1517, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29606765

RESUMO

The objective of this study was to optimize the extraction of protein by applying a multi-enzymatic pretreatment to okara, a byproduct from soymilk processing. The multi-enzyme complex Viscozyme, containing a variety of carbohydrases, was used to hydrolyze the okara cell walls and facilitate extraction of proteins. Enzyme-assisted extraction was carried out under different temperatures (37-53 °C), enzyme concentrations (1.5-4%) and pH values (5.5-6.5) according to a central composite rotatable design. After extraction, the protein was concentrated by isoelectric precipitation. The optimal conditions for maximum protein content and recovery in protein concentrate were 53 °C, pH 6.2 and 4% of enzyme concentration. Under these conditions, protein content of 56% (dry weight basis) and a recovery of 28% were obtained, representing an increase of 17 and 86%, respectively, compared to the sample with no enzymatic pretreatment. The multi-enzyme complex Viscozyme hydrolyzed the structural cell wall polysaccharides, improving extraction and obtaining protein concentrate from the okara. An electrophoretic profile of the protein concentrate showed two distinct bands, corresponding to the acidic and basic subunits of the protein glycinin. There were no limiting amino acids in the protein concentrate, which had a greater content of arginine.

17.
Braz. arch. biol. technol ; 61: e18180106, 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-974065

RESUMO

ABSTRACT The objective of this study was to determine the incidence of Pale, Soft, Exudative (PSE) meat and to characterize the Dark, Fim, Dry (DFD) meat as well as the Dead on Arrival (DOA) index in a commercial turkey slaughterhouse in southern Brazil during the summer and winter seasons. The journeys (n=64) were over a distance of 36 ± 20 km and took approximately 95 ± 20 min. Color (L*) and pH distribution of turkey breast meat (n=5,352) were evaluated from different farms (n=64) during the 2015-2016 years. The pH, water-holding capacity, color (L*, a*, b*) were used to establish cutoff values for DFD meat (L* < 44.0 and pH > 5.90) and presented correlation among them. The L* value was the highest during the summer (P<0.01), indicating the highest incidence of PSE meat (28.35 %), and lowest during winter, observing the highest incidence of DFD meat (10.3 %). Finally, the obtained summer DOA index was 0.23 % higher in relation to winter.

18.
Food Chem ; 229: 373-380, 2017 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-28372188

RESUMO

This study aimed to evaluate the isoflavone and total phenolic contents in kefir-fermented soymilk storage and after the in vitro digestive system simulation (DSS). Soymilk was fermented with kefir culture (0.02UC/L) at 25°C for 15h and stored at 4°C for 4days. After the fermentation and storage, the isoflavone and total phenolic contents were quantified by high performance liquid chromatography and spectrophotometry, respectively. The cell viability of lactic acid bacteria and yeast was evaluated. Fermentation promoted an increase of approximately 3log CFU/g cycles of the microorganisms and the storage process did not alter the aglycone isoflavones and total phenolic contents. The content of aglycone isoflavones increased 2-fold, and the total phenolic content increased 9-fold. Therefore, kefir-fermented soymilk is a good source of aglycone isoflavones and phenolics, since the content of these substances was increased significantly after the in vitro digestive system simulation of the product.


Assuntos
Sistema Digestório/química , Isoflavonas/química , Kefir/análise , Fenóis/química , Leite de Soja/química , Reatores Biológicos , Isoflavonas/análise , Fenóis/análise
19.
Food Chem ; 197(Pt A): 175-84, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-26616938

RESUMO

A simplex-centroid design comprising three solvents (water, ethanol and methanol) was used to optimise the extraction mixture for phenolics and antioxidant activities from defatted soy flour fermented with Monascus purpureus or Aspergillus oryzae. Total phenolics were more efficiently extracted using only water for both samples. The highest antioxidant activities by the DPPH and ABTS methods were obtained using extraction mixtures containing at least 75 wt% water. Specific water:ethanol:methanol ratios promoted the joint optimisation of the total phenolic and isoflavone contents as well as antioxidant activities: 0.5:0.375:0.125 (wt/wt/wt) and 0.5:0.3:0.2 (wt/wt/wt) from defatted soy flour fermented with M. purpureus or A. oryzae, respectively. However, a water:ethanol ratio of 0.5:0.5 (wt/wt) was deemed optimal because it is comprised of green solvents and yielded results that were greater than 90% of the multi-response maximum values. Both the solvents and the sample matrix strongly influenced the extractability of total phenolics and isoflavones.


Assuntos
Antioxidantes/análise , Fermentação , Farinha/análise , Glycine max/química , Polifenóis/análise , Solventes/química , Antioxidantes/farmacologia , Aspergillus oryzae/crescimento & desenvolvimento , Reatores Biológicos/microbiologia , Compostos de Bifenilo/química , Radicais Livres/química , Isoflavonas/análise , Monascus/crescimento & desenvolvimento , Oxirredução , Picratos/química
20.
Braz. arch. biol. technol ; 58(2): 272-277, Mar-Apr/2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-744304

RESUMO

The aim of this work was to evaluate pH values fall rate in chicken breast meat under commercial refrigeration processing conditions and the development of PSE (pale, soft, exudative) meat. Broiler breast samples from the Cobb breed, both genders, at 47 days of age (n = 100) were taken from refrigerated carcasses (RS) immersed in water and ice in a tank chilled at 0°C (±2). pH and temperature (T) values were recorded at several periods throughout refrigeration in comparison to samples left at room T as control (CS). The ultimate pH (pHu) value of 5.86 for RS carcasses were only reached at 11°C after 8.35 h post mortem (PM) while, for CS samples, pHu value was 5.94 at 22°C after 4.08 h PM. Thus, under commercial refrigeration conditions, the glycolysis rate was retarded by over 4.0 h PM and the breast meat color was affected. At 24.02 h PM, PSE meat incidence was 30% while for CS, meat remained dark and PSE meat was not detected. Results show retardation in the glycolysis rate and PSE meat development was promoted by the refrigeration treatment when compared with samples stored at processing room temperature.

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