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1.
Foods ; 12(9)2023 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-37174463

RESUMO

The efficiency of natural olive pomace extracts for enhancing the quality of fresh-cut apples was compared with commercial ascorbic acid and two different packaging films (biodegradable polylactic acid (PLA) and oriented polypropylene (OPP)) were tested. The composition of atmosphere inside the packages, the physicochemical parameters (firmness, weight loss and color), the microbial load, total phenolic content and antioxidant activity of fresh-cut apples were evaluated throughout 12 days of storage at 4 °C. After 12 days of refrigerated storage, a significant decrease in O2 was promoted in PLA films, and the weight loss of the whole packaging was higher in PLA films (5.4%) than in OPP films (0.2%). Natural olive pomace extracts reduced the load of mesophilic bacteria (3.4 ± 0.1 log CFU/g and 2.4 ± 0.1 log CFU/g for OPP and PLA films, respectively) and filamentous fungi (3.3 ± 0.1 log CFU/g and 2.44 ± 0.05 log CFU/g for OPP and PLA films, respectively) growth in fresh-cut apples after five days of storage at 4 °C, and no detection of coliforms was verified throughout the 12 days of storage. In general, the olive pomace extract preserved or improved the total phenolic index and antioxidant potential of the fruit, without significant changes in their firmness. Moreover, this extract seemed to be more effective when combined with the biodegradable PLA film packaging. This work can contribute to the availability of effective natural food additives, the sustainability of the olive oil industries and the reduction of environmental impact. It can also be useful in meeting the food industries requirements to develop new functional food products.

2.
Foods ; 11(17)2022 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-36076767

RESUMO

Mango peel is rich in nutritional and functional compounds, such as carbohydrates, dietary fibers, proteins, and phenolic compounds, with high potential to be applied in the food industry. Most of the investigation about recovery of bioactive compounds from fruit bioproducts involves extraction techniques and further separation of target compounds. There is still a lack of information about the potential of membrane processes to recover the nutritive/functional compounds present in aqueous extracts of those bioproducts. This research is addressed to study the performance of ultrafiltration (UF), followed by nanofiltration (NF) of UF permeates, to fractionate the compounds present in aqueous extracts of mango peel. Both UF and NF concentration processes were carried up to a volume concentration factor of 2.0. Membranes with molecular weight cut-offs of 25 kDa and 130 Da were used in the UF and NF steps, respectively. UF and NF concentrates showed antioxidant activity, attributed to the presence of phenolic compounds, with rejections of about 75% and 98.8%, respectively. UF membranes totally rejected the higher molecular weight compounds, and NF membranes almost totally concentrated the fermentable monosaccharides and disaccharides. Therefore, it is envisaged that NF concentrates can be utilized by the food industry or for bioenergy production.

3.
Pharmaceuticals (Basel) ; 15(9)2022 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-36145383

RESUMO

The use of medicinal plants in a variety of health conditions remains essential for the discovery of new treatments. The present study aimed to investigate the bioactive properties of three native plants from Cabo Verde Islands, namely Artemisia gorgonum Webb, Sideroxylon marginatum (Decne. ex Webb) Cout., and Tamarix senegalensis DC., contributing to the characterization of less-known medicinal plants and their potential benefits for human health. Known compounds, such as kaempferol, quercetin, caffeyolquinic, and apigenin derivatives, among others, were detected in the plant species under study. Overall, all species demonstrated good antioxidant capacity, especially the ethanolic extracts of A. gorgonum (EC50 = 0.149 mg/mL) in TBARS assay. Moreover, the ethanolic extracts of the studied plants showed cytotoxic properties against tumor cells, and again the A. gorgonum extract proved to be the most effective in inhibiting tumor growth, mainly in the CaCO2 (GI50 = 17.3 µg/mL) and AGS (GI50 = 18.2 µg/mL) cell lines. Only the ethanolic extracts of T. senegalensis and S. marginatum demonstrated anti-inflammatory activity, albeit weak (EC50 = 35 and 43 µg/mL, respectively). The present study contributed to increased knowledge about the bioactive properties of these plants commonly used in traditional medicine, some of which was discussed for the first time, opening new perspectives for their use in a wider range of health conditions, especially in African countries, where access to modern health care is more limited.

4.
Foods ; 11(16)2022 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-36010421

RESUMO

Fresh-cut fruits and vegetables, as near-fresh foods, are a quick and easy solution to a healthy and balanced diet. The rapid degradation of nutritional and sensory quality during the processing and storage of a product is critical and plant-type-dependent. The introduction of disruptive technological solutions in fresh-cut processing, which could maintain fresh-like quality with less environmental impact, is an emerging research concept. The application of abiotic stress treatments (heat shock and UV-C) induces metabolic responses and microbial effects in plant tissues, potentially slowing down several quality senescence pathways. The previously selected combined and single effects of heat shock (100 °C/45 s; in the whole root) and UV-C (2.5 kJ/m2) treatments and two packaging conditions (oriented polypropylene (OPP) vs. micro-perforated OPP films) on controlling critical degradation pathways of fresh-cut carrots and on promoting bioactive and sensory quality during storage (5 °C, 14 days) were studied. Among the tested combinations, synergistic effects on the quality retention of fresh-cut carrots were only attained for applying heat shock associated with micro-perforated OPP film packaging. Its effects on reducing (3.3 Log10 CFU/g) the initial contamination and controlling microbiological spoilage (counts below the threshold limit of 7.5 Log10 CFU/g), increasing the bioactive content (38% and 72% in total phenolic content and chlorogenic acid, respectively), and preserving fresh quality attributes prove to be a viable alternative technology for shredded carrot processing.

5.
Bioengineering (Basel) ; 9(7)2022 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-35877362

RESUMO

Tomato pomace is rich in carotenoids (mainly lycopene), which are related to important bioactive properties. In general, carotenoids are known to react easily under environmental conditions, which may create a barrier in producing stable functional components for food. This work intended to evaluate the storage stability and in vitro release of lycopene from encapsulated tomato pomace extract, and its bioaccessibility when encapsulates were incorporated in yogurt. Microencapsulation assays were carried out with tomato pomace extract as the core material and arabic gum or inulin (10 and 20 wt%) as wall materials by spray drying (160 and 200 °C). The storage stability results indicate that lycopene degradation was highly influenced by the presence of oxygen and light, even when encapsulated. In vitro release studies revealed that 63% of encapsulated lycopene was released from the arabic gum particles in simulated gastric fluid, whereas for the inulin particles, the release was only around 13%. The feed composition with 20% inulin showed the best protective ability and the one that enabled releasing the bioactives preferentially in the intestine. The bioaccessibility of the microencapsulated lycopene added to yogurt increased during simulated gastrointestinal digestion as compared to the microencapsulated lycopene alone. We anticipate a high potential for the inulin microparticles containing lycopene to be used in functional food formulations.

6.
Foods ; 11(12)2022 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-35742002

RESUMO

The main objective of this study was to extend the shelf life of fresh red raspberry (Rubus idaeus. L. cv. 'Kweli') by using active film-pads inside commercial compostable packages. The pads were produced with chitosan (Ch) with the incorporation of green tea (GTE) and rosemary (RSME) ethanolic extracts as natural antifungal agents. Pads were placed on the bottom of commercial fruit trays underneath the fruits, and the trays were heat-sealed with a polyacid lactic (PLA) film. Preservation studies were carried out over 14 days of storage at refrigeration temperature (4 °C). Raspberry samples were periodically analyzed throughout storage, in terms of quality attributes (fungal decay, weight loss, firmness, surface color, pH, total soluble solids), total phenolic content and antioxidant activity. Gas composition inside the packages was also analyzed over time. From the packaging systems tested, the ones with active film-pads Ch + GTE and Ch + RSME were highly effective in reducing fungal growth and decay of raspberry during storage, showing only around 13% and 5% of spoiled fruits after 14 days, respectively, in contrast with the packages without pads (around 80% of spoiled fruits detected). In addition, fruits preserved using packages with Ch + RSME active film-pads showed lower mass loss (5.6%), decreased firmness (3.7%) and reduced antioxidant activity (around 9% and 15% for DPPH and FRAP methods, respectively). This sustainable packaging presents a potential strategy for the preservation of raspberries and other highly perishable small fruits.

7.
Food Sci Technol Int ; 28(5): 421-429, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34078129

RESUMO

In fresh-cut vegetables, plant tissues are often challenged by (a)biotic stresses that act in combination, and the response to combinatorial stresses differs from that triggered by each individually. Phenolic induction by wounding is a known response contributing to increase products phenolic content. Heat application is a promising treatment in minimal processing, and its interference on the wound-induced response is produce-dependent. In carrot, two-combined stress effects were evaluated: peel removal vs. shredding, and heat application (100 °C/45 s) vs. shredding, on changes in total phenolic content (TPC) during 10 days (5 °C). By applying the first stress combination, a decrease in TPC was verified on day 0 (∼50%), ascribed to the high phenolic content of peels. Recovery of initial fresh carrot levels was achieved after 7 days owing to phenolic biosynthesis induced by shredding. For the second combination, changes in TPC, phenylalanine-ammonia-lyase (PAL), and peroxidase (POD) activity of untreated (Ctr) and heat-treated (HS) peeled shredded carrot samples were evaluated during 10 days. The heat-shock did not suppress phenolic biosynthesis promoted by PAL, although there was a two-day delay in TPC increments. Notwithstanding, phenolic accumulation after 10 days exceeded raw material TPC content. Also, the decrease in POD activity (30%) could influence quality degradation during storage.


Assuntos
Daucus carota , Antioxidantes/metabolismo , Fenóis/análise , Fenilalanina Amônia-Liase , Verduras/metabolismo
8.
Foods ; 10(7)2021 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-34359524

RESUMO

This study aimed to develop edible monolayer emulsion-based barriers with polysaccharides as film-forming components (chitosan and sodium alginate), soy lecithin as a surfactant and olive oil as a hydrophobic barrier. Monolayer barriers in the form of films were prepared by casting filmogenic emulsions composed of 2% w/v chitosan (dissolved in lactic acid 1% v/v) or 1% w/v sodium alginate, with different lipid contents (25, 50 and 100% w/w biopolymer basis) and different surfactant concentrations (5, 10 and 25% w/w, lipid basis). Glycerol was used as a plasticizer (25 % w/w, biopolymer basis). After the emulsion drying process, the obtained stand-alone films were sprayed with a crosslinking solution, achieving an optimized crosslinker content of 3.2 mgCa2+/cm2 alginate film and 4 mg tripolyphosphate/cm2 chitosan film. The effect of oil and lecithin contents, as well the presence of crosslinking agents, on the film's water vapour permeability (WVP), water vapour sorption capacity, mechanical properties and colour parameters, was evaluated. The results have shown that the lowest WVP values were obtained with formulations containing 25% lipid and 25% surfactant for chitosan films, and 100% lipid and 25% surfactant for alginate films. The application of the crosslinking agents decreased even further the WVP, especially for chitosan films (by 30%). Crosslinking also increased films' resistance to deformation under tensile tests. Overall, the films developed present a good potential as polysaccharide-based barriers with increased resistance to water, which envisages the use of the designed formulations to produce either edible/biodegradable films or edible coatings.

9.
Foods ; 10(6)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34205876

RESUMO

Pineapple peel still contains an important amount of phenolic compounds and vitamins with valuable antioxidant activity. In this way, the aim of this study was the recovery of the bioactive compounds from pineapple peel using environmentally friendly and low-cost techniques, envisaging their application in food products. From the solid-liquid extraction conditions tested, the one delivering an extract with higher total phenolic content and antioxidant capacity was a single extraction step with a solvent-pineapple peel ratio of 1:1 (w/w) for 25 min at ambient temperature, using ethanol-water (80-20%) as a solvent. The resulting extract revealed a total phenolic content value of 11.10 ± 0.01 mg gallic acid equivalent (GAE)/g dry extract, antioxidant activity of 91.79 ± 1.98 µmol Trolox/g dry extract by the DPPH method, and 174.50 ± 9.98 µmol Trolox/g dry extract by the FRAP method. The antioxidant rich extract was subjected to stabilization by the spray drying process at 150 °C of inlet air temperature using maltodextrin (5% w/w) as an encapsulating agent. The results showed that the antioxidant capacity of the encapsulated compounds was maintained after encapsulation. The loaded microparticles obtained, which consist of a bioactive powder, present a great potential to be incorporated in food products or to produce bioactive packaging systems.

10.
Molecules ; 26(11)2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34072026

RESUMO

Pineapple is consumed on a large scale around the world due to its appreciated sensorial characteristics. The industry of minimally processed pineapple produces enormous quantities of by-products (30-50%) which are generally undervalued. The end-of-life of pineapple by-products (PBP) can be replaced by reuse and renewal flows in an integrated process to promote economic growth by reducing consumption of natural resources and diminishing food waste. In our study, pineapple shell (PS) and pineapple core (PC), vacuum-packed separately, were subjected to moderate hydrostatic pressure (225 MPa, 8.5 min) (MHP) as abiotic stress to increase bromelain activity and antioxidant capacity. Pressurized and raw PBP were lyophilized to produce a stable powder. The dehydrated samples were characterized by the following methodologies: chemical and physical characterization, total phenolic compounds (TPC), antioxidant capacity, bromelain activity, microbiology, and mycotoxins. Results demonstrated that PBP are naturally rich in carbohydrates (66-88%), insoluble (16-28%) and soluble (2-4%) fiber, and minerals (4-5%). MHP was demonstrated to be beneficial in improving TPC (2-4%), antioxidant activity (2-6%), and bromelain activity (6-32%) without affecting the nutritional value. Furthermore, microbial and mycotoxical analysis demonstrated that powdered PC is a safe by-product. PS application is possible but requires previous decontamination to reduce the microbiological load.


Assuntos
Ananas/química , Ananas/fisiologia , Antioxidantes/química , Alimento Funcional/análise , Benzotiazóis/química , Compostos de Bifenilo/química , Bromelaínas/análise , Carboidratos/química , Técnicas de Química Analítica , Cor , Fibras na Dieta , Embalagem de Alimentos , Conservação de Alimentos , Liofilização , Frutas/química , Micotoxinas/química , Valor Nutritivo , Fenol/química , Picratos/química , Pós , Pressão , Ácidos Sulfônicos/química , Água/química
11.
Foods ; 10(4)2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33805309

RESUMO

Fresh figs are very appreciated and have been associated with health benefits. However, these fruits are highly perishable. In this study, edible coatings were studied envisaging their positive effect in enhancing figs' shelf-life. Fig fruits cv. 'Pingo de mel' were harvested at commercial ripening stage and single emulsion-based coatings, composed of chitosan + olive oil and alginate + olive oil, were applied. After coatings application by dipping each fruit in the emulsion-based solutions at 4 °C and drying, the coated fruits were sprayed with crosslinking solutions (6% tripolyphosphate and 1% calcium chloride for chitosan and alginate-based coatings, respectively). Then, were maintained at 4 °C and analyzed after 1, 7, 14 and 19 days of storage. After each time interval, fruits were further maintained at 25 °C for 2 days. The results have shown that coatings were effective on delaying fungal decay and postharvest ripening indicators (respiration rate, mass loss, softening and total soluble solids/titratable acidity ratio). The results foresee a fruits' shelf life between 14 and 19 days under refrigeration at 4 °C that may be followed up to 2 days at ambient temperature, higher than that estimated for uncoated fruits (less than 14 days at 4 °C plus to 2 days at ambient temperature).

12.
Foods ; 9(12)2020 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-33256241

RESUMO

Dehydrated pineapple by-products enriched in bromelain using a hydrostatic pressure treatment (225 MPa, 8.5 min) were added in marinades to improve beef properties. The steaks from the silverside cut (2 ± 0.5 cm thickness and weight 270 ± 50 g), characterized as harder and cheaper, were immersed in marinades that were added to dehydrated and pressurized pineapple by-products that corresponded to a bromelain concentration of 0-20 mg tyrosine, 100 g-1 meat, and 0-24 h time, according to the central composite factorial design matrix. Samples were characterized in terms of marination yield, pH, color, and histology. Subsequently, samples were cooked in a water-bath (80 °C, 15 min), stabilized (4 °C, 24 h), and measured for cooking loss, pH, color, hardness, and histology. Marinades (12-24 h) and bromelain concentration (10-20 mg tyrosine.100 g-1 meat) reduced pH and hardness, increased marination yield, and resulted in a lighter color. Although refrigeration was not an optimal temperature for bromelain activity, meat hardness decreased (41%). Thus, the use of pineapple by-products in brine allowed for the valorization of lower commercial value steak cuts.

13.
Antioxidants (Basel) ; 9(8)2020 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-32722611

RESUMO

Alginate-based edible films containing natural antioxidants from pineapple peel were applied in the microbial spoilage control, color preservation, and barrier to lipid oxidation of beef steaks under storage at 4 °C for five days. Different stabilization methods of pineapple peel compounds were used before incorporation into alginate films, including extracted compounds with an hydroalcoholic solvent encapsulated in microparticles, microparticles produced by spray-drying pineapple peel juice, and particles obtained by milling freeze dried pineapple peel. Bioactive films exhibited higher antioxidant activity (between 0.15 µmol to 0.35 µmol FeSO4.7H2O/g dried film) than the alginate film without these compounds (0.02 µmol FeSO4.7H2O/g dried film). Results showed that control films without active compounds had no significant effect on decreasing the microbial load of aerobic mesophilic and Pseudomonas spp., while the films containing encapsulated hydroalcoholic extract showed a significant inhibitory effect on microbial growth of meat at two days of storage. Alginate films containing peel encapsulated extract were effective for maintaining the color hue and intensity of red beef meat samples. Pineapple peel antioxidants have the potential to retard lipid oxidation in meat samples, and the possibility of incorporation of a higher amount of pineapple peel bioactive compounds in the films should be investigated.

14.
Foods ; 9(6)2020 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-32498295

RESUMO

A pineapple peel hydroalcoholic extract rich in phenolic compounds, was stabilized by microencapsulation using spray drying technology, with maltodextrin, inulin, and arabic gum as wall materials. The influence of the type of wall material and drying temperature (150 and 190 °C) on the particles properties was studied. The particles presented a spherical shape with a diameter ranging from approximately 1.3 to 18.2 µm, the exception being the ones with inulin that showed a large degree of agglomeration. All powders produced presented an intermediate cohesiveness and a fair to good flowability according to Carr index and Hausner ratio, which envisages suitable handling properties at an industrial scale. The microencapsulation processes using maltodextrin and arabic gum at 150 °C were the ones that showed higher maintenance of the antioxidant activity of compounds present in the extract before encapsulation during spray drying. In addition, the microparticles obtained were quite efficient in stabilizing the encapsulated phenolic compounds, as their antioxidant activity did not change significantly during six months of storage at 5 °C.

15.
Molecules ; 24(22)2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31731614

RESUMO

In recent years, great interest has been focused on using natural antioxidants in food products, due to studies indicating possible adverse effects that may be related to the consumption of synthetic antioxidants. A variety of plant materials are known to be natural sources of antioxidants, such as herbs, spices, seeds, fruits and vegetables. The interest in these natural components is not only due to their biological value, but also to their economic impact, as most of them may be extracted from food by-products and under-exploited plant species. This article provides an overview of current knowledge on natural antioxidants: their sources, extraction methods and stabilization processes. In addition, recent studies on their applications in the food industry are also addressed; namely, as preservatives in different food products and in active films for packaging purposes and edible coatings.


Assuntos
Antioxidantes/química , Conservação de Alimentos , Frutas/química , Sementes/química , Especiarias , Verduras/química
16.
Int J Food Sci ; 2019: 8914852, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30805358

RESUMO

Carotenoids are a class of natural pigments found mainly in fruits and vegetables. Among them, ß-carotene is regarded the most potent precursor of vitamin A. However, it is susceptible to oxidation upon exposure to oxygen, light, and heat, which can result in loss of colour, antioxidant activity, and vitamin activity. Thus, the objective of this work was to study the microencapsulation process of ß-carotene by spray drying, using arabic gum as wall material, to protect it against adverse environmental conditions. This was carried out using the response surface methodology coupled to a central composite rotatable design, evaluating simultaneously the effect of drying air inlet temperature (110-200°C) and the wall material concentration (5-35%) on the drying yield, encapsulation efficiency, loading capacity, and antioxidant activity. In addition, morphology and particles size distribution were evaluated. Scanning electron microscopy images have shown that the particles were microcapsules with a smooth surface when produced at the higher drying temperatures tested, most of them having a diameter lower than 10 µm. The conditions that enabled obtaining simultaneously arabic gum microparticles with higher ß-carotene content, higher encapsulation efficiency, and higher drying yield were a wall material concentration of 11.9% and a drying inlet temperature of 173°C. The systematic approach used for the study of ß-carotene microencapsulation process by spray drying using arabic gum may be easily applied for other core and wall materials.

17.
Int J Biol Macromol ; 104(Pt A): 1099-1106, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28687391

RESUMO

The potential of a bacterial exopolysaccharide named FucoPol, produced by the bacterium Enterobacter A47, as encapsulation matrix was explored. Spherical capsules with a smooth surface were produced by spray drying. The obtained microcapsules had average diameters ranging from 0.5 to 26.7µm and presented thin walls (thickness from 222 to 1094nm). The capsules were loaded with two bioactive compounds: gallic acid (GA) and oregano essential oil (OEO). Both bioactive materials were encapsulated in FucoPol particles, retaining their antioxidant activity after the drying process. Release studies showed that GA release in simulated gastric and intestinal fluids was faster than that of OEO, envisaging that the latter had established stronger interactions with the polymer matrix. These results suggest that FucoPol has a good potential for use as encapsulating material of bioactive compounds for application in several areas, including food, cosmetic or pharmaceutical products.


Assuntos
Portadores de Fármacos/química , Fucose/química , Polissacarídeos Bacterianos/química , Antioxidantes/química , Cápsulas , Liberação Controlada de Fármacos , Enterobacter/química , Interações Hidrofóbicas e Hidrofílicas
18.
Int J Biol Macromol ; 84: 43-53, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26657585

RESUMO

The optimisation of an edible coating based on low acyl (L)/high acyl (H) gellan gum for ready-to-eat mango bars was performed through a central composite rotatable design (CCRD). The independent variables were the concentration of gellan (L/H90/10) and the concentration of Ca(2+) in the coating solution, as well as the storage time after coating application. The response variables studied were the coating thickness, mango bars firmness, syneresis, and colour alterations. Gellan concentration was the independent variable that most influenced the thickness of the coating. Syneresis was quite low for the conditions tested (<1.64%). Similarly, the colour alterations were low during the entire storage time (ΔE<5). Considering the model predictions, 1.0%wt L/H90/10 with addition of 6 mM Ca(2+) could represent the optimal coating formulation for the mango bars. The release of eight volatile compounds from the uncoated and coated mango bars with the selected formulation was analysed by Headspace - Solid Phase Micro Extraction-Gas Chromatography during 9 days of refrigerated storage. This work showed that the coating can improve mango bars sensory characteristics (appearance and firmness) and stability in terms of syneresis, colour and volatiles content during storage increasing the commercial value of the final product.


Assuntos
Materiais Revestidos Biocompatíveis , Mangifera , Polissacarídeos Bacterianos , Materiais Revestidos Biocompatíveis/química , Mangifera/química , Mangifera/ultraestrutura , Modelos Teóricos , Polissacarídeos Bacterianos/química , Compostos Orgânicos Voláteis
19.
J Food Sci ; 81(1): E65-75, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26613390

RESUMO

Carqueja (Pterospartum tridentatum) is an endemic species and various bioactive compounds have been identified in its aqueous extract. The aim of this study was to protect the natural antioxidants from the aqueous extract of carqueja by encapsulation in Ca-alginate microbeads and Ca-alginate microbeads containing 10% and 20% (w/v) of inulin. The microbeads produced by electrostatic extrusion technique had an average diameter from 625 µm to 830 µm depending on the portion of inulin. The sphericity factor of the hydrogel microbeads had values between 0.014 and 0.026, while freeze dried microbeads had irregular shape, especially those with no excipient. The reduction in microbeads size after freeze drying process (expressed as shrinkage factor) ranged from 0.338 (alginate microbeads with 20% (w/v) of inulin) to 0.523 (plain alginate microbeads). The expressed radical scavenging activity against ABTS and DPPH radicals was found to be between 30% and 40% for encapsulated extract, while the fresh extract showed around 47% and 57% of radical scavenging activity for ABTS and DPPH radicals, respectively. The correlation between antioxidant activity and the total phenolic content were found to be positive (in both assay methods, DPPH and ABTS), which indicate that the addition of inulin didn't have influence on antioxidant activity. The presence of inulin reduced stiffness of the hydrogel, and protected bead structure from collapse upon freeze-drying. Alginate-inulin beads are envisaged to be used for delivery of aqueous P. tridentatum extract in functional food products.


Assuntos
Alginatos , Antioxidantes/administração & dosagem , Cálcio , Portadores de Fármacos , Fabaceae/química , Inulina , Extratos Vegetais/administração & dosagem , Antioxidantes/análise , Antioxidantes/farmacologia , Benzotiazóis/metabolismo , Compostos de Bifenilo/metabolismo , Cápsulas , Liofilização , Alimento Funcional , Ácido Glucurônico , Ácidos Hexurônicos , Hidrogel de Polietilenoglicol-Dimetacrilato , Microesferas , Oxirredução , Fenóis/administração & dosagem , Fenóis/análise , Fenóis/farmacologia , Picratos/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ácidos Sulfônicos/metabolismo
20.
Food Sci Technol Int ; 21(2): 83-93, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24285830

RESUMO

Chitosan-based edible films were prepared and subjected to cross-linking reactions using sodium tripolyphosphate and/or to beeswax coating on both films interfaces. In addition, chitosan-beeswax emulsion-based films were produced. The goal of these modifications of the chitosan films was the improvement of their barrier to water vapor and to decrease their affinity to liquid water maintaining or improving the mechanical and optical properties of the original chitosan films. The cross-linking with tripolyphosphate decreased both the water vapor permeability and the water absorption capacity to about 55% and 50% of that of the original chitosan films, respectively. However, there was an increase in the films stiffness, revealed by the increased Young modulus from 42 kPa up to 336 kPa. The multilayered wax-chitosan-wax films exhibited a similar improvement of the barrier properties to water vapor, with the advantage of maintaining the mechanical properties of the original chitosan films. However, these wax-coated films showed a higher water absorption capacity, which is believed to be a consequence of water entry into small pores between the film and the wax layers. Regarding the film samples subjected to cross-linking and further coating with beeswax, a similar behavior as the uncoated cross-linked films was observed. The emulsion-based composite films were characterized by a substantial decrease of the water vapor permeability (40%), along with a decrease in their stiffness. Regarding the optical properties, all films presented a yellowish color with similar values of lightness, chroma, and hue.


Assuntos
Plásticos Biodegradáveis/química , Quitosana/química , Embalagem de Alimentos/métodos , Ceras/química , Humanos , Permeabilidade , Vapor , Água
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