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1.
Oncologist ; 29(3): e337-e344, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38071748

RESUMO

BACKGROUND: Liquid biopsy (LB) is a non-invasive tool to evaluate the heterogeneity of tumors. Since RAS mutations (RAS-mut) play a major role in resistance to antiepidermal growth factor receptor inhibitors (EGFR) monoclonal antibodies (Mabs), serial monitoring of RAS-mut with LB may be useful to guide treatment. The main aim of this study was to evaluate the prognostic value of the loss of RAS-mut (NeoRAS-wt) in LB, during the treatment of metastatic colorectal cancer (mCRC). METHODS: A retrospective study was conducted on patients with mCRC between January 2018 and December 2021. RAS-mut were examined in tissue biopsy, at mCRC diagnosis, and with LB, during treatment. RESULTS: Thirty-nine patients with RAS-mut mCRC were studied. LB was performed after a median of 3 lines (0-7) of systemic treatment including anti-vascular endothelial growth factor (anti-VEGF) Mabs. NeoRAS-wt was detected in 13 patients (33.3%); 9 (69.2%) of them received further treatment with anti-EGFR Mabs with a disease control rate of 44.4%. Median overall survival (OS), from the date of LB testing, was 20 months in the NeoRAS-wt group and 9 months in the persistent RAS-mut group (log-rank 2.985; P = .08), with a 12-month OS of 84.6% and 57.7%, respectively. NeoRAS-wt was identified as a predictor of survival (HR = 0.29; P = .007), with an 11-month improvement in median OS and a 71% decrease in risk of death, in heavily pretreated patients. CONCLUSIONS: In conclusion, monitoring clonal evolution in mCRC by LB may provide an additional treatment line for patients with NeoRAS-wt in advanced disease.


Assuntos
Antineoplásicos , Neoplasias do Colo , Neoplasias Colorretais , Neoplasias Retais , Humanos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Estudos Retrospectivos , Antineoplásicos/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Biópsia Líquida , Mutação
2.
Compr Rev Food Sci Food Saf ; 23(1): e13252, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38284602

RESUMO

Biosurfactants (surfactants synthesized by microorganisms) are produced by microorganisms and are suitable for use in different areas. Among biosurfactants, rhamnolipids are the most studied and popular, attracting scientists, and industries' interest. Due to their unique characteristics, the rhamnolipids have been used as synthetic surfactants' alternatives and explored in food applications. Besides the production challenges that need to be tackled to guarantee efficient production and low cost, their properties need to be adjusted to the final application, where the pH instability needs to be considered. Moreover, regulatory approval is needed to start being used in commercial applications. One characteristic of interest is their capacity to form oil-in-water nanosystems. Some of the most explored have been nanoemulsions, solid-lipid nanoparticles and nanostructured lipid carriers. This review presents an overview of the main properties of rhamnolipids, asserts the potential and efficiency of rhamnolipids to replace the synthetic surfactants in the development of nanosystems, and describes the rhamnolipids-based nanosystems used in food applications. It also discusses the main characteristics and methodologies used for their characterization and in the end, some of the main challenges are highlighted.


Assuntos
Glicolipídeos , Nanoestruturas , Glicolipídeos/química , Alimentos , Tensoativos/química
3.
Food Microbiol ; 109: 104134, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36309438

RESUMO

An enterocin whey solution, obtained by growing Enterococcus faecalis L2B21K3 and L3A21K6 in sweet whey - enterocin whey solution (EWS), was incorporated into gelatin/glycerol films that were tested for the control of Listeria monocytogenes. The films containing enterocins produced by either strain (EWS L2 and EWS K6 films) were shown to serve as a suitable matrix for bacteriocin release, preserve the anti-listerial activity for up to 90 days. When applied in cheese, EWS L2 and EWS K6 films were able to reduce L. monocytogenes contamination to undetected levels after 20 or 30 days, respectively, and prevented the migration of this pathogen from the films to cheese. The incorporation of EWS into films did not affect (p < 0.05) moisture content, solubility, permeability (water vapor and limonene), and elongation at break compared to control films (without EWS). However, thickness, swelling index and tensile strength were higher (p < 0.05) in EWS films. These results suggest that active EWS gelatin/glycerol films could be an effective, and safe application to control L. monocytogenes in cheese. In addition, the use of cheese whey as a culture medium for the production of the bacteriocins complemented with the incorporation in films formulation as a packaging material represents an alternative approach to reuse this by-product of cheese production.


Assuntos
Bacteriocinas , Queijo , Listeria monocytogenes , Soro do Leite , Gelatina , Glicerol/farmacologia , Microbiologia de Alimentos , Bacteriocinas/farmacologia
4.
Molecules ; 28(4)2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36838608

RESUMO

The growing need to expand the use of renewable energy sources in a sustainable manner, providing greater energy supply security and reducing the environmental impacts associated with fossil fuels, finds in the agricultural by-product bioethanol an economically viable alternative with significant expansion potential. In this regard, a dramatic boost in the efficiency of processes already in place is required, reducing costs, industrial waste, and our carbon footprint. Biofuels are one of the most promising alternatives to massively produce energy sustainably in a short-term period. Lignocellulosic biomass (LCB) is highly recalcitrant, and an effective pretreatment strategy should also minimize carbohydrate degradation by diminishing enzyme inhibitors and other products that are toxic to fermenting microorganisms. Ionic liquids (ILs) have been playing an important role in achieving cleaner processes as a result of their excellent physicochemical properties and outstanding performance in the dissolution and fractionation of lignocellulose. This review provides an analysis of recent advances in the production process of biofuels from LCB using ILs as pretreatment and highlighting techniques for optimizing and reducing process costs that should help to develop robust LCB conversion processes.


Assuntos
Líquidos Iônicos , Líquidos Iônicos/química , Etanol , Biocombustíveis , Lignina/química , Biomassa
5.
Appl Microbiol Biotechnol ; 106(22): 7477-7489, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36222896

RESUMO

The agro-industrial by-products corn steep liquor (CSL) and olive mill wastewater (OMW) were evaluated as low-cost substrates for rhamnolipid production by Burkholderia thailandensis E264. In a culture medium containing CSL (7.5% (v/v)) as sole substrate, B. thailandensis E264 produced 175 mg rhamnolipid/L, which is about 1.3 times the amount produced in the standard medium, which contains glycerol, peptone, and meat extract. When the CSL medium was supplemented with OMW (10% (v/v)), rhamnolipid production further increased up to 253 mg/L in flasks and 269 mg/L in a bioreactor. Rhamnolipids produced in CSL + OMW medium reduced the surface tension up to 27.1 mN/m, with a critical micelle concentration of 51 mg/L, better than the values obtained with the standard medium (28.9 mN/m and 58 mg/L, respectively). However, rhamnolipids produced in CSL + OMW medium displayed a weak emulsifying activity when compared to those produced in the other media. Whereas di-rhamnolipid congeners represented between 90 and 95% of rhamnolipids produced by B. thailandensis E264 in CSL and the standard medium, the relative abundance of mono-rhamnolipids increased up to 55% in the culture medium containing OMW. The difference in the rhamnolipid congeners produced in each medium explains their different surface-active properties. To the best of our knowledge, this is the first report of rhamnolipid production by B. thailandensis using a culture medium containing agro-industrial by-products as sole ingredients. Furthermore, rhamnolipids produced in the different media recovered around 60% of crude oil from contaminated sand, demonstrating its potential application in the petroleum industry and bioremediation. KEY POINTS: • B. thailandensis produced RL using agro-industrial by-products as sole substrates • Purified RL displayed excellent surface activity (minimum surface tension 27mN/m) • Crude RL (cell-free supernatant) recovered 60% of crude oil from contaminated sand.


Assuntos
Burkholderia , Petróleo , Análise Custo-Benefício , Areia , Glicolipídeos , Águas Residuárias , Tensoativos , Pseudomonas aeruginosa
6.
Int J Mol Sci ; 23(21)2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36362138

RESUMO

Xylooligosaccharides (XOS) are widely used in the food industry as prebiotic components. XOS with high purity are required for practical prebiotic function and other biological benefits, such as antioxidant and inflammatory properties. In this work, we immobilized the recombinant endo-1,4-ß-xylanase of Malbranchea pulchella (MpXyn10) in various chemical supports and evaluated its potential to produce xylooligosaccharides (XOS) from hydrothermal liquor of eucalyptus wood chips. Values >90% of immobilization yields were achieved from amino-activated supports for 120 min. The highest recovery values were found on Purolite (142%) and MANAE-MpXyn10 (137%) derivatives, which maintained more than 90% residual activity for 24 h at 70 °C, while the free-MpXyn10 maintained only 11%. In addition, active MpXyn10 derivatives were stable in the range of pH 4.0−6.0 and the presence of the furfural and HMF compounds. MpXyn10 derivatives were tested to produce XOS from xylan of various sources. Maximum values were observed for birchwood xylan at 8.6 mg mL−1 and wheat arabinoxylan at 8.9 mg mL−1, using Purolite-MpXyn10. Its derivative was also successfully applied in the hydrolysis of soluble xylan present in hydrothermal liquor, with 0.9 mg mL−1 of XOS after 3 h at 50 °C. This derivative maintained more than 80% XOS yield after six cycles of the assay. The results obtained provide a basis for the application of immobilized MpXyn10 to produce XOS with high purity and other high-value-added products in the lignocellulosic biorefinery field.


Assuntos
Eucalyptus , Xilanos , Madeira , Glucuronatos , Oligossacarídeos/química , Endo-1,4-beta-Xilanases , Prebióticos , Hidrólise
7.
Molecules ; 27(5)2022 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-35268769

RESUMO

"Flawless skin is the most universally desired human feature" is an iconic statement by Desmond Morris. Skin indicates one´s health and is so important that it affects a person's emotional and psychological behavior, these facts having propelled the development of the cosmetics industry. It is estimated that in 2023, this industry will achieve more than 800 billion dollars. This boost is due to the development of new cosmetic formulations based on nanotechnology. Nanocarriers have been able to solve problems related to active ingredients regarding their solubility, poor stability, and release. Even though nanocarriers have evident benefits, they also present some problems related to the high cost, low shelf life, and toxicity. Regulation and legislation are two controversial topics regarding the use of nanotechnology in the field of cosmetics. In this area, the U.S. FDA has taken the lead and recommended several biosafety studies and post-market safety evaluations. The lack of a global definition that identifies nanomaterials as a cosmetic ingredient is a hindrance to the development of global legislation. In the EU, the legislation regarding the biosafety of nanomaterials in cosmetics is stricter. "The cost is not the only important issue, safety and the application of alternative testing methods for toxicity are of crucial importance as well".


Assuntos
Cosméticos , Nanoestruturas , Composição de Medicamentos , Humanos , Nanotecnologia , Pele
8.
Europace ; 23(7): 1092-1099, 2021 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-33693816

RESUMO

AIMS: Vasovagal syncope (VVS) is the most common type of syncope and is usually considered a benign disorder. The potential for injury is worrisome but the likelihood is unknown. We aimed to determine the proportion of patients injured due to VVS. METHODS AND RESULTS: A systematic search of studies published until August 2020 was performed in multiple medical and nursing databases. Included studies had data on the proportion of patients with injury due to VVS prior to study enrolment. Random effects methods were used. Twenty-three studies having 3593 patients met inclusion criteria. Patients were diagnosed clinically with VVS, and 82% had >2 syncopal episodes before enrolment. Tilt test was positive in 60% and 14 studies reported comorbidities (32.6% hypertensive). The weighted mean injury rate was 33.5% [95% confidence interval (CI): 27.3-40.5%]. The likelihood of injury correlated with population age (r = 0.4, P = 0.05), but not with sex, positive tilt test, or hypertension. The injury rates were 25.7% (95% CI: 19.1-32.8%) in studies with younger patients (mean age ≤50 years, n = 1803) and 43.4% (95% CI: 34.9-52.3%) in studies with older patients (P = 0.002). Nine studies reported major injuries; with a weighted mean rate of major injuries of 13.9% (95% CI: 9.5-19.8%). CONCLUSION: Injuries due to syncope are frequent, occurring in 33% of patients with VVS. The risk of major injuries is substantial. Older patients are at higher risk. Clinicians should be aware of the risk of injuries when providing care and advice to patients with VVS.


Assuntos
Hipertensão , Síncope Vasovagal , Humanos , Pessoa de Meia-Idade , Síncope , Síncope Vasovagal/diagnóstico , Síncope Vasovagal/epidemiologia , Teste da Mesa Inclinada
9.
Crit Rev Food Sci Nutr ; 60(16): 2730-2741, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31433199

RESUMO

Background: Brewer's spent grain is one of the most abundant by-products of the brewing industry and is rich in various bioactive compounds (phenolic acids, insoluble dietary fiber and proteins). While at the present brewer's spent grain is mainly used as animal feed its rich nutritional content makes it an interesting alternative for food applications. Scope and approach: As the range of applications of the bioactive compounds extracted from by-products has been growing in recent years, there is the need to obtain and characterize these bioactive compounds. Extraction methods (supercritical carbon dioxide, autohydrolysis, alkaline hydrolysis, solvent extraction, ultrasound assisted extraction, dilute acid hydrolysis, enzymatic hydrolysis, microwave assisted extraction) have been developed and are always being subjected to new approaches to allow better extraction yields of the bioactive compounds. Key findings and conclusions: This review aims to provide a better understanding of the current advantages and limitations of brewer's spent grain extraction processes and to provide a background of brewer's spent grain composition and applications.HighlightsThe re-use of agro-industrial by-products can origin new added-value productsBSG is an agro-industrial by-product and is a source of various bioactive compoundsExtraction methods have been applied to extract these compounds from BSGIt is needed to find new techniques and new possible applications to the BSG.


Assuntos
Bebidas Alcoólicas , Fracionamento Químico/métodos , Grão Comestível/química , Ração Animal , Animais , Hidrólise
10.
Molecules ; 25(14)2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32679771

RESUMO

Cassava plays a key role in the food production and economies of several countries worldwide. Due to its starch content, alcoholic fermentation is a promising transformation process for adding value to cassava. However, most of the existing cassava beverages are from traditional origin, with the yields and quality often poorly known or controlled due to the use of artisanal production processes. This work aims at the application of easily implementable biotechnological tools for the production of cassava spirits, in order to add value to this raw material. Cassava flour was liquefied and saccharified using enzymatic cocktails, generating a fermentable broth with ~184 g L-1 of fermentable sugars. This was then fermented into an alcoholic product with ~10% ethanol by volume and distilled for spirit production. Cassava spirits with 40% ethanol by volume, with or without application of oak wood, were produced. For further valorization, volatile fractions of cassava spirits were characterized by gas chromatography-flame ionization detection (GC-FID) and GC-MS. These showed a predominance of yeast fermentation metabolites, complemented by wood extractives where oak chips were applied. Both produced spirits showed desirable sensory traits, receiving good acceptance by experienced tasters, demonstrating the feasibility of the proposed process to add value to cassava surplus.


Assuntos
Produtos Biológicos/química , Fenômenos Químicos , Destilação , Fermentação , Manihot/química , Biotecnologia , Etanol , Hidrólise
11.
Molecules ; 25(15)2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32731405

RESUMO

Increasing environmental and sustainability concerns, caused by current population growth, has promoted a raising utilization of renewable bio-resources for the production of materials and energy. Recently, nanocellulose (NC) has been receiving great attention due to its many attractive features such as non-toxic nature, biocompatibility, and biodegradability, associated with its mechanical properties and those related to its nanoscale, emerging as a promising material in many sectors, namely packaging, regenerative medicine, and electronics, among others. Nanofibers and nanocrystals, derived from cellulose sources, have been mainly produced by mechanical and chemical treatments; however, the use of cellulases to obtain NC attracted much attention due to their environmentally friendly character. This review presents an overview of general concepts in NC production. Especial emphasis is given to enzymatic hydrolysis processes using cellulases and the utilization of pulp and paper industry residues. Integrated process for the production of NC and other high-value products through enzymatic hydrolysis is also approached. Major challenges found in this context are discussed along with its properties, potential application, and future perspectives of the use of enzymatic hydrolysis as a pretreatment in the scale-up of NC production.


Assuntos
Celulases/química , Celulose/química , Nanofibras/química , Nanopartículas/química , Indústria Química
12.
Molecules ; 25(12)2020 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-32630539

RESUMO

In Europe, pine forests are one of the most extended forests formations, making pine residues and by-products an important source of compounds with high industrial interest as well as for bioenergy production. Moreover, the valorization of lumber industry residues is desirable from a circular economy perspective. Different extraction methods and solvents have been used, resulting in extracts with different constituents and consequently with different bioactivities. Recently, emerging and green technologies as ultrasounds, microwaves, supercritical fluids, pressurized liquids, and electric fields have appeared as promising tools for bioactive compounds extraction in alignment with the Green Chemistry principles. Pine extracts have attracted the researchers' attention because of the positive bioproperties, such as anti-inflammatory, antimicrobial, anti-neurodegenerative, antitumoral, cardioprotective, etc., and potential industrial applications as functional foods, food additives as preservatives, nutraceuticals, pharmaceuticals, and cosmetics. Phenolic compounds are responsible for many of these bioactivities. However, there is not much information in the literature about the individual phenolic compounds of extracts from the pine species. The present review is about the reutilization of residues and by-products from the pine species, using ecofriendly technologies to obtain added-value bioactive compounds for industrial applications.


Assuntos
Produtos Biológicos/metabolismo , Alimento Funcional , Química Verde , Valor Nutritivo , Fenóis/metabolismo , Pinus/química , Extratos Vegetais/metabolismo , Produtos Biológicos/isolamento & purificação , Suplementos Nutricionais , Fenóis/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Solventes/química
13.
Crit Rev Food Sci Nutr ; 58(11): 1864-1877, 2018 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-28362165

RESUMO

Nowadays, food and nutrition have a greater impact in people's concerns, with the awareness that nutrition have a direct impact in health and wellbeing. Probiotics have an important role in this topic and consumers are starting to really understand their potential in health, leading to an increasing interest of the companies to their commercial use in foods. However, there are several limitations to the use of probiotics in foods and beverages, being one of them their efficiency (directly associated to their survival rate) upon ingestion. This work is focused in microencapsulation techniques that have been used to increase probiotics efficiency. More specifically, this work reviews the most recent and relevant research about the production and coating techniques of probiotic-loaded microcapsules, providing an insight in the effect of these coatings in probiotics survival during the gastrointestinal phase. This review shows that coatings with the better performances in probiotics protection, against the harsh conditions of digestion, are chitosan, alginate, poly-L-lysine, and whey protein. Chitosan presented an interesting performance in probiotics protection being able to maintain the initial concentration of viable probiotics during a digestive test. The analyses of different works also showed that the utilization of several coatings does not guarantee a better protection in comparison with monocoated microcapsules.


Assuntos
Cápsulas/química , Excipientes/química , Probióticos , Alginatos/química , Quitosana/química , Composição de Medicamentos , Humanos , Viabilidade Microbiana , Polilisina/química , Polímeros/química , Proteínas do Soro do Leite/química
14.
Crit Rev Food Sci Nutr ; 57(7): 1377-1393, 2017 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-26065435

RESUMO

Whey proteins are widely used as nutritional and functional ingredients in formulated foods because they are relatively inexpensive, generally recognized as safe (GRAS) ingredient, and possess important biological, physical, and chemical functionalities. Denaturation and aggregation behavior of these proteins is of particular relevance toward manufacture of novel nanostructures with a number of potential uses. When these processes are properly engineered and controlled, whey proteins may be formed into nanohydrogels, nanofibrils, or nanotubes and be used as carrier of bioactive compounds. This review intends to discuss the latest understandings of nanoscale phenomena of whey protein denaturation and aggregation that may contribute for the design of protein nanostructures. Whey protein aggregation and gelation pathways under different processing and environmental conditions such as microwave heating, high voltage, and moderate electrical fields, high pressure, temperature, pH, and ionic strength were critically assessed. Moreover, several potential applications of nanohydrogels, nanofibrils, and nanotubes for controlled release of nutraceutical compounds (e.g. probiotics, vitamins, antioxidants, and peptides) were also included. Controlling the size of protein networks at nanoscale through application of different processing and environmental conditions can open perspectives for development of nanostructures with new or improved functionalities for incorporation and release of nutraceuticals in food matrices.


Assuntos
Suplementos Nutricionais/análise , Nanoestruturas/química , Proteínas do Soro do Leite/química , Fenômenos Químicos , Inocuidade dos Alimentos , Géis/química , Concentração de Íons de Hidrogênio , Nanotubos/química , Desnaturação Proteica , Domínios e Motivos de Interação entre Proteínas , Temperatura
15.
Crit Rev Biotechnol ; 36(2): 259-67, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-25519697

RESUMO

Currently, prebiotics are all carbohydrates of relatively short chain length. One important group is the fructooligosaccharides (FOS), a special kind of prebiotic associated to the selective stimulation of the activity of certain groups of colonic bacteria. They have a positive and beneficial effect on intestinal microbiota, reducing the incidence of gastrointestinal infections and also possessing a recognized bifidogenic effect. Traditionally, these prebiotic compounds have been obtained through extraction processes from some plants, as well as through enzymatic hydrolysis of sucrose. However, different fermentative methods have also been proposed for the production of FOS, such as solid-state fermentations utilizing various agro-industrial by-products. By optimizing the culture parameters, FOS yields and productivity can be improved. The use of immobilized enzymes and cells has also been proposed as being an effective and economic method for large-scale production of FOS. This article is an overview of the results considering recent studies on FOS biosynthesis, physicochemical properties, sources, biotechnological production and applications.


Assuntos
Biotecnologia , Oligossacarídeos , Prebióticos
16.
Mar Drugs ; 14(2)2016 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-26901207

RESUMO

Marine microorganisms possess unique metabolic and physiological features and are an important source of new biomolecules, such as biosurfactants. Some of these surface-active compounds synthesized by marine microorganisms exhibit antimicrobial, anti-adhesive and anti-biofilm activity against a broad spectrum of human pathogens (including multi-drug resistant pathogens), and could be used instead of existing drugs to treat infections caused by them. In other cases, these biosurfactants show anti-cancer activity, which could be envisaged as an alternative to conventional therapies. However, marine biosurfactants have not been widely explored, mainly due to the difficulties associated with the isolation and growth of their producing microorganisms. Culture-independent techniques (metagenomics) constitute a promising approach to study the genetic resources of otherwise inaccessible marine microorganisms without the requirement of culturing them, and can contribute to the discovery of novel biosurfactants with significant biological activities. This paper reviews the most relevant biosurfactants produced by marine microorganisms with potential therapeutic applications and discusses future perspectives and opportunities to discover novel molecules from marine environments.


Assuntos
Organismos Aquáticos/metabolismo , Descoberta de Drogas/métodos , Tensoativos/farmacologia , Animais , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Biofilmes/efeitos dos fármacos , Humanos , Metagenômica/métodos , Tensoativos/isolamento & purificação
17.
Compr Rev Food Sci Food Saf ; 15(5): 878-896, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33401801

RESUMO

Lactulose is a lactose-based carbohydrate with well-known prebiotic effect and recognized medical applications. Currently, the commercially available lactulose is chemically synthesized. Nevertheless, the process leads to low yields and high levels of by-products. Alternatively, lactulose can be produced by enzymatic synthesis, which provides a cleaner production under mild conditions. Two different enzymatic routes were reported for lactulose production. Lactulose can be obtained through hydrolysis and transfer reactions catalyzed by a glycosidase. Alternatively, lactulose can be produced by direct isomerization of lactose to lactulose catalyzed by cellobiose-2-epimerase. An interesting characteristic of lactulose is also its capacity to act as substrate in additional enzymatic synthesis which leads to the formation of attractive compounds, such as lactulose-based oligosaccharides and lactulose esters. Besides increasing the interest and potential of lactulose, these lactulose-based compounds can also offer new and promising functionalities and applications. Herein, we review the enzymes involved in the synthesis of lactulose, as well as the reaction conditions and yields. The potential of different enzymes is discussed and it is shown that reaction conditions and composition of products depend on the type of enzyme and its microbial source. The conversion of lactulose into lactulose-based compounds is also covered, describing in detail the biocatalysts involved, the reaction conditions used, and the potential of the final products obtained.

18.
Crit Rev Food Sci Nutr ; 55(10): 1444-55, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24915327

RESUMO

An increased commercial interest in fructo-oligosaccharides (FOS) has emerged in the last decade due to their prebiotic activity. At large scale, the FOS are produced by microbial enzymes from sucrose. A mixture of FOS and other saccharides is obtained in this process. The presence of such saccharides reduces the prebiotic, caloric, and cariogenic value of the final product. Therefore, many efforts have been conducted to obtain a product with increased FOS purity. This review comprises the most important technological and physicochemical aspects including FOS production and recovery processes; safety, dose and health claims concerning its intake; and commercially available FOS.


Assuntos
Frutose/biossíntese , Frutose/isolamento & purificação , Oligossacarídeos/biossíntese , Oligossacarídeos/isolamento & purificação , Frutose/administração & dosagem , Frutose/metabolismo , Frutose/farmacologia , Humanos , Oligossacarídeos/administração & dosagem , Oligossacarídeos/metabolismo , Oligossacarídeos/farmacologia , Prebióticos/análise , Sacarose/metabolismo
19.
Crit Rev Food Sci Nutr ; 55(5): 595-610, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24915370

RESUMO

Sugar esters are non-ionic surfactants that can be synthesized in a single enzymatic reaction step using lipases. The stability and efficiency of lipases under unusual conditions and using non-conventional media can be significantly improved through immobilization and protein engineering. Also, the development of de novo enzymes has seen a significant increase lately under the scope of the new field of synthetic biology. Depending on the esterification degree and the nature of fatty acid and/or sugar, a range of sugar esters can be synthesized. Due to their surface activity and emulsifying capacity, sugar esters are promising for applications in food industry.


Assuntos
Sacarose Alimentar/síntese química , Enzimas Imobilizadas/metabolismo , Indústria Alimentícia , Lipase/metabolismo , Tensoativos/síntese química , Carboidratos , Esterificação , Ésteres , Ácidos Graxos
20.
Microb Cell Fact ; 14: 14, 2015 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-25636532

RESUMO

BACKGROUND: Surface active compounds produced by microorganisms are attracting a pronounced interest due to their potential advantages over their synthetic counterparts, and to the fact that they could replace some of the synthetics in many environmental and industrial applications. RESULTS: Bioemulsifier production by a Paenibacillus sp. strain isolated from crude oil was studied. The bioemulsifier was produced using sucrose with and without adding hydrocarbons (paraffin or crude oil) under aerobic and anaerobic conditions at 40°C. It formed stable emulsions with several hydrocarbons and its emulsifying ability was not affected by exposure to high salinities (up to 300 g/l), high temperatures (100°C-121°C) or a wide range of pH values (2-13). In addition, it presented low toxicity and high biodegradability when compared with chemical surfactants. A preliminary chemical characterization by Fourier Transform Infrared Spectroscopy (FT-IR), proton and carbon nuclear magnetic resonance (1H NMR and 13C CP-MAS NMR) and size exclusion chromatography indicated that the bioemulsifier is a low molecular weight oligosaccharide-lipid complex. CONCLUSION: The production of a low molecular weight bioemulsifier by a novel Paenibacillus strain isolated from crude oil was reported. To the best of our knowledge, bioemulsifier production by Paenibacillus strains has not been previously reported. The features of this novel bioemulsifier make it an interesting biotechnological product for many environmental and industrial applications. Graphical Abstract Novel bioemulsifier from Paenibacillus sp.


Assuntos
Emulsificantes/metabolismo , Paenibacillus/metabolismo , Petróleo/metabolismo , Sacarose/metabolismo , Aerobiose , Anaerobiose , Biodegradação Ambiental , Cromatografia em Gel , Emulsificantes/química , Emulsificantes/farmacologia , Temperatura Alta , Concentração de Íons de Hidrogênio , Lipídeos/análise , Lipídeos/química , Espectroscopia de Ressonância Magnética , Peso Molecular , Oligossacarídeos/análise , Oligossacarídeos/química , Paenibacillus/classificação , Paenibacillus/genética , Petróleo/microbiologia , Filogenia , RNA Ribossômico 16S/genética , Salinidade , Espectroscopia de Infravermelho com Transformada de Fourier , Vibrio/efeitos dos fármacos , Vibrio/metabolismo
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