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1.
This study aimed to investigate the partition behaviors of various polar anthocyanins in NaH2PO4/(NH4)2SO4-ethanol aqueous two-phase systems (ATPS) and to extract anthocyanins from Nitraria tangutorun Bobr. and Lycium ruthenicum Murr. Anthocyanins in Hibiscus sabdariffa L., Morus atropurpurea Roxb., N. tangutorun, and L. ruthenicum were profiled using HPLC-ESI-MS/MS and HPLC-DAD, and the partition behaviors of total anthocyanins and main anthocyanins were studied. The partition coefficient of anthocyanins increased with increased hydrophobicity, and low-polarity anthocyanins exhibited a higher preference for the top phase in NaH2PO4/(NH4)2SO4-ethanol ATPS. Additionally, the NaH2PO4-ethanol ATPS gave higher selectivity and total anthocyanin yield than the (NH4)2SO4-ethanol system. Extraction at 65 °C for 45 min and at 45.5 °C for 45 min using 28% NaH2PO4 and 26% ethanol (w/w) led to the recovery of 98.91 ± 0.03% of N. tangutorun anthocyanins (3.62 ± 0.05 mg/g) and 99.84 ± 0.01% of L. ruthenicum anthocyanins (13.16 ± 0.29 mg/g) from raw material; more than 70% of total sugars were removed in a single step. NaH2PO4-ethanol aqueous two-phase extraction is a promising method for extracting anthocyanins from N. tangutorun and L. ruthenicum.  相似文献   

2.
Antimicrobial activity is an attractive property for packaging materials which can extend the shelf life of products and provide microbial safety for consumers. The study aimed to analyze the physicochemical and antimicrobial properties of gelatin-based edible films containing trans-anethole as the active additive. Encapsulation with β-cyclodextrin was used as an effective way to introduce trans-anethole into gelatin matrix. The results showed that the trans-anethole/β-cyclodextrin inclusion complex could be evenly dispersed in the gelatin-based edible films with appropriate addition. The incorporation of trans-anethole conferred the edible films with good antimicrobial activity as expected, which increased with the content of trans-anethole increasing. Moreover, the addition of inclusion complex improved the tensile strength and surface hydrophobicity and reduced the moisture content of the edible films. It was interesting that the edible films presented great UV light barrier property and it was increased by the addition of inclusion complex. Overall, the antimicrobial gelatin-based edible films showed great potential as bioactive packaging materials to extend food shelf life.  相似文献   

3.
Silver (Ag) nanoparticles (NPs) were synthesised and characterised, and their antimicrobial activity against Escherichia coli, Staphylococcus aureus, Bacillus cereus, Pseudomonas fluorescens and microflora derived from raw chicken, beef or cooked ham was determined. Polyvinyl chloride (PVC) films or antimicrobial Ag/PVC nanocomposite films were manufactured via a solvent casting method and the mechanical and thermal properties of these materials determined. Manufactured antimicrobial Ag/PVC nanocomposite films were used to wrap chicken breast fillets, followed by modified atmosphere packaging (using conventional laminates and employing a gas mix of 60 % N2/40 % CO2), and compared against PVC control films. In general, Gram-negative bacteria were more sensitive to Ag NPs than Gram-positive bacteria and microflora isolated from meat products were more resistant than pure culture bacteria. However, the most sensitive bacteria to Ag NPs were Pseudomonas fluorescens. No significant differences (p?>?0.05) in tensile strength and elongation at break were observed, but glass transition temperatures (T g) of Ag/PVC nanocomposite films were lower (p?<?0.05) when compared to PVC control films. Results also indicated that antimicrobial Ag/PVC nanocomposite films significantly (p?<?0.05) extended the shelf-life of chicken breast fillets and reduced lipid oxidation of chicken breast fillets compared to PVC-wrapped equivalents. Overall, results indicated that antimicrobial Ag/PVC nanocomposite films can potentially be used as antimicrobial packaging for food packaging applications.  相似文献   

4.
This study aimed to develop and optimize a β-cyclodextrin (β-CD)-based technique for extracting anthocyanins from Lycium ruthenicum Murr. and to establish a ultra-high-performance liquid chromatography-diode array detector (UPLC-DAD) method for their analysis. β-CD solutions produced higher extraction yields of petunidin-3-O-(trans-p-coumaroyl)-rutinoside-5-O-glucoside and total anthocyanins from L. ruthenicum fruit than did pure water and aqueous hydroxypropyl-β-cyclodextrin (HPβ-CD) and ethanol and methanol solutions. Extraction at 50 °C for 30 min using 1.65% β-CD solution and a liquid/solid ratio of 15:1 produced the optimal extraction yield of L. ruthenicum anthocyanins. A UPLC-DAD method was developed for the determination of L. ruthenicum anthocyanins using an ethanol-based mobile phase, and the primary anthocyanins were identified using two-dimensional LC-MS/MS. Method validation showed that the developed method was accurate, stable, and reliable for the analysis of petunidin-3-O-(trans-p-coumaroyl)-rutinoside-5-O-glucoside and total anthocyanins from L. ruthenicum fruit. The present study showed that β-CD-based extraction coupled with UPLC-DAD analysis is an efficient and green method for the extraction and analysis of anthocyanins from L. ruthenicum fruit.  相似文献   

5.
Biodegradable films of chia by-products (mucilage and protein-rich fraction (PF)) incorporated with clove essential oil (CEO) were obtained and characterized. The effects of polymer concentration (PC; 1.0–3.0 %, w/v) and CEO concentration (0.1–1.0 %, v/v) were evaluated as well as the pH (7–10), using a 23 factorial design with four central points. The films exhibited moisture values between 11.6 and 52.1 % (d.b.), which decreased (p?<?0.05) with increasing PC and CEO. The thickness of the films increased (p?<?0.05) with increasing PC. PC and pH influenced (p?<?0.05) the lightness (L) and variation in color between red and green (a). The orientation of the color to yellow-blue hues (b) decreased significantly (p?<?0.05) with increasing PC. Transparency was significantly lower and higher (p?<?0.05) than PC and CEO, respectively. The film surface morphology was evaluated using atomic force miscrocope images, and thermogravimetric analysis (TGA) was performed to study the thermal stability of the films. The displacement and tensile strength were significantly lower (p?<?0.05) at higher concentrations of CEO, this variable being the only one with a significant effect. The chemical composition of the films was confirmed utilizing Fourier transform infrared (FTIR) spectroscopy. The proportion of CEO added to the films had a significant influence on antimicrobial activity, inhibiting the growth of both Escherichia coli and Staphylococcus aureus.  相似文献   

6.
Nisin (0.2 IU per cm2 films) containing biodegradable films were produced from pea protein isolate (PPI), whey protein isolate (WPI), and polylactic acid (PLA). Nisin was released over 4 h at 22 °C and 8 h at 4 °C. PPI released more nisin compared to other films suppressing the growth of Listeria monocytogenes (P?<?0.05) based upon diffusion into agar and liquid culture media. The population of bacteria after 48 h in liquid media was 6 CFU/mL (1 log10 increase) in PPI, 8.47 CFU/mL (3.47 log10 increase) in WPI and 9 CFU/mL (4 log10 increase) in PLA, which was significantly lower in protein based films compared to PLA (P?<?0.05). The inhibition zone in agar test was significantly higher (P?<?0.05) in PPI and WPI, compared to PLA film, which might be due to the higher hydration in protein based films. Fourier transform infrared spectroscopy (FTIR) showed that nisin altered the intensity of amide I peaks in protein based films suggesting that nisin can bind to the protein functional groups in PPI and WPI. Thermogram showed that nisin did not influence the glass transition and melting temperatures of the films. Nisin containing films exhibited significantly lower enthalpy compared to control films (P?<?0.05). PeakForce Quantitative Nano Mechanical Property Mapping (PeakForce QNM) was applied to extract material and mechanical properties in PPI, WPI and PLA films with and without nisin. Results showed significant reductions in material and mechanical properties of protein based films containing nisin compared to PLA films.  相似文献   

7.
The aim of the current research was to fabricate, characterize, and compare physical, mechanical, antimicrobial, antioxidant, and release properties of whey protein isolate (WPI)-based films containing free or nanoencapsulated thyme (Thymus vulgaris) extract (TE) at concentrations of 0, 5, 10, and 15% w/w of WPI. Nanoliposomes with an average size of 350 nm were prepared using thin-film hydration and sonication method. The data obtained from FTIR reflected the occurrence of some new interactions between WPI and nanoliposomes. XRD results approved the negative effect of free TE on the crystallinity of WPI. Besides, SEM images showed that free TE caused the cracks and holes in the WPI matrix to increase. However, the encapsulated TE did not show these negative effects. The nanoliposome incorporation improved the mechanical stiffness, leading to a decrease in the water vapor permeability (WVP). The possible antimicrobial activity of the films containing TE-loaded nanoliposomes against Staphylococcus aureus and Escherichia coli was decreased in comparison to the free TE-incorporated films, probably due to the inhibition effect of the encapsulation preventing the release of TE from the matrix. In addition, the antioxidant potential of the films containing TE-loaded nanoliposomes was lower than that of free TE-incorporated films. Release studies indicated that the migration of TE in ethanol 95% simulant decreased significantly by the nanoencapsulation of TE. However, the release rate increased by an increase in temperature in both types of active films. Therefore, this work showed that there is a potential for the production of antioxidant and antimicrobial controlled-release nanoactive WPI-TE films for use in food packaging and medical fields.  相似文献   

8.
Although the monkey orange (Strychnos spp.) tree fruit is widely distributed in Southern Africa and particularly in Zimbabwe, it is underutilized and little attention has been given to its potential commercialisation due to limited knowledge and information. Most of the fruits and their products are wasted because of limited harvest time, process control and storage conditions, leading to variability in shelf life and sensory quality, thereby impacting nutritional quality. Traditional processing techniques make insufficient use of this food resource within rural communities. This study aimed at identifying the existing bottlenecks by means of a survey among 102 smallholder farming respondents in the wet and dry regions of Zimbabwe. Results revealed that S. cocculoides and S. spinosa were used by 48% of respondents as a functional ingredient in porridge, by 25% in fermented mahewu drink and by 15% of respondents as a non-alcoholic juice. The fruits of S. innocua and S. madagascariensis are preferably processed into dried products. Taste, flavour and colour were the important quality characteristics for all processed products, and constraints to be solved are seed-flesh separation, long processing times, separation of juice and pulp during storage as well as pulp viscosity. Respondents reported monkey orange products to have health benefits for children and immune-compromised people, who, on regular consumption, have reportedly increased weight and resistance to disease. The positive perception about the processed products of Strychnos spp. offer a good opportunity to improve nutrition security by capitalizing on these not-yet-fully-exploited resources, but technological solutions to improve sensory quality and shelf life must be developed.  相似文献   

9.
Two ways of adding sorghum bran to tortillas were evaluated; adding to the corn flour before extrusion or after extrusion. The addition of sorghum bran increased the ferulic (FA), p-coumaric (p-CA), diferulic (di-FA) and triferulic (tri-FA) acids contents in corn flours and tortillas. Extrusion produced an increment of the free forms, and a part of the ferulic acid was degraded as a consequence of the extrusion conditions. Baking produced a reduction of bound and free forms of the phenolic acids in tortillas, however, high retention percentage of the phenolic acids was observed in flours and tortillas (83–90%). The antioxidant activity of flour and tortillas were correlated to the contents of the phenolic acids, especially with bound di-FA and tri-FA combined (r?=?0.92). Adding the sorghum bran before extrusion, produced flours with increased free phenolic acids content, and increased in vitro antioxidant activity.  相似文献   

10.
A new active packaging film based on murta leaf extract was elaborated. The extract was incorporated into a methylcellulose layer which was coated on a low-density polyethylene (LDPE) film. Its antioxidant effectivity, antimicrobial activity, and physicochemical properties were evaluated. The active film was able to keep its antimicrobial and antioxidant properties for at least 60 days. During this time, the growth of Listeria (L.) innocua was reduced by 2 log cycles and free radical formation could be inhibited by about 90 % for films stored under light and dark conditions. The active coating on the LDPE film did not affect the thermal and water vapor transmission properties; however, slight changes in the mechanical, color, and optical properties were observed. Finally, a sensory analysis showed that active coating did not change the flavor and odor properties of a fatty food packed inside the active material. This suggests that this active packaging film could be used to extend the shelf-life of packaged food.  相似文献   

11.
Black mulberry (Morus nigra L.) is one of the most important species of the genus Morus as its fruit contains substantial levels of anthocyanins and phenolic compounds which show a potentially positive effect on the human health. Nowadays, PLE is becoming a promising extraction technology. Therefore, the development of fast extraction methods of anthocyanins and phenolic compounds from mulberry pulp using pressurized-liquid extraction (PLE) has been studied in this paper. The operating conditions (solvent, temperature, pressure, purge time, pH, and flushing) were investigated by a Box–Behnken design. Analysis of the model clearly showed that the most influential factors were temperature and solvent composition. The optimum extraction conditions for anthocyanins were 47.2% methanol in water, a temperature of 75.5 °C, pressure of 200 atm, a purge time of 90 s, pH 3.01, and 50.2% for flushing. The best conditions for the extraction of phenolics were 74.6% methanol, 99.4 °C, 100 atm, 90 s purge, pH 7, and 100% flushing. The optimum extraction time was 10 min. The precision values of the methods were also evaluated and excellent results (RSD?<?5%) were obtained. The developed methods were successfully applied to several mulberry marmalade samples. The results using PLE were compared to those achieved by UAE methods. Similar extraction yields were obtained for anthocyanins by PLE and UAE under optimized conditions; however, PLE required less methanol consumption. Besides, PLE showed higher extraction efficiency for total phenolic compounds. From the results, it can be concluded that pressurized-liquid extraction can be considered as an efficient alternative and powerful tool for the extraction of bioactive compounds from mulberries.  相似文献   

12.
The ongoing demand for high-quality processed foods which would preserve their natural and fresh-like characteristics has awakened a growing interest in non-thermal technologies. Thanks to their ability to inactivate microorganisms under mild conditions, these technologies avoid drawbacks usually attributed to the use of thermal treatments, such as nutrient loss, off-flavors, and changes in the food’s physical and chemical properties. Saccharomyces cerevisiae (S. cerevisiae) mainly causes spoilage in liquid foods with high sugar content and low pH values. Thus, it is one of the most undesirable microorganisms in the food industry since its presence may lead to important economic losses. This review offers an exhaustive compilation and critical revision of research conducted in the field of S. cerevisiae inactivation in liquid media, emphasizing the use of non-thermal technologies, such as high pressure processing, high-power ultrasound, supercritical carbon dioxide, pulsed electric fields, and others. Likewise, using these technologies in combination (the hurdle approach) may enhance their individual effect and significantly reduce the treatment time needed to obtain a given level of S. cerevisiae inactivation. In general, non-thermal technologies are proving to be able to successfully inactivate S. cerevisiae in liquid media. However, the need for further investigation and complete industrial implementation is made evident throughout this review.  相似文献   

13.
To explore the use of starfish gelatin (SFG) films as a biodegradable material, SFG from starfish was extracted and used as a film material. In addition, to provide antimicrobial activity and enhanced flavor of SFG films, vanillin was incorporated. As the concentration of vanillin increased, the tensile strength of the films increased and water vapor permeability decreased. With regard to the structural characteristics of SFG films containing vanillin, the microstructure of the SFG films was not affected by the addition of vanillin. In addition, the SFG films containing vanillin exhibited antimicrobial activity against Listeria monocytogenes. As the application of the SFG films, crab sticks were packed with SFG films containing 0.05% vanillin. During storage, the populations of L. monocytogenes inoculated on crab sticks wrapped with SFG films containing vanillin were lower than those on the control sample, suggesting that SFG films containing vanillin can be useful in active food packaging.  相似文献   

14.
The aim of this study was to develop, characterize and evaluate in vitro the efficacy of active films, based on an inclusion complex formed by β-cyclodextrin, 2-nonanone and two polymer matrices (polylactic acid and low density polyethylene). The different films were characterized by scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), themogravimetric analysis (TGA), optical properties and antimicrobial activity against B. cinerea. The results showed important differences in the parameters evaluated where the level of agglomerates of additives was a key to explain these changes. Finally, microbiological analysis showed high effectiveness in reducing the Botrytis cinerea growth. The active films developed in this study were able to inhibit the growth of phytopathogenic fungus B. cinerea at different experimental conditions. The studied films have potential use for packaging fresh fruit susceptible to biological attack by this fungus.  相似文献   

15.
The influence of different washings, temperatures, and packagings on anthocyanins of minimally processed pomegranate seeds was evaluated. No differences were found in anthocyanin composition after washing with different solutions, although a slight decrease in pigments occurred. Storage in perforated polypropylene bags preserved pigments and a slight increase in most anthocyanins occurred. During storage in modified atmospheres, anthocyanins increased at 1°C, but decreased at 8 and 4°C. The delphinidin derivatives were the most sensitive while cyanidin and pelargonidin derivatives were stable and increased slightly. The 3,5-diglucosides were more stable than 3-glucosides. Compared with storage at 1°C for 7 days in perforated OPP bags, unperforated OPP bags maintained the pigments better. However, stored an additional 4 days at 4°C to simulate domestic storage, they were better preserved in perforated films.  相似文献   

16.
In this study, the effective variables involved in ultrasound-assisted extraction (UAE) of fenugreek (Trigonella foenum graecum) seeds polysaccharides (FSPs) were optimized through Box–Behnken response surface design. The maximum yield of FSPs was 33.49% under the modified optimum conditions of an ultrasound power of 120 W, an irradiation time of 22 min and a liquid-to-solid ratio (L/S) of 30:1 mL g?1. The predicted yield was in a very good agreement with the experimental yield of 33.41%. This value was higher than the FSPs yield obtained using conventional extraction (CE) method for 180 min at the same extraction temperature and L/S ratio. The primary chemical and structural characteristics were investigated by UV, FT-IR, and GC-MS. FSPs found to be a heteropolysaccharide consisted of galactose (38.18%), glucose (3.71%), mannose (46.13%), rhamnose (1.02%), and arabinose (0.83%). Furthermore, the FSPs exhibited considerable scavenging activity against 1,1-Diphenyl-2-Picrylhydrazyl free radicals and ferric reducing antioxidant power and reducing power, in a concentration-dependent mode in vitro. Our results suggested that UAE technique gave a higher yield of FSPs with a shorter extraction time than the CE and FSPs can also be used as promising resources of natural agent for functional foods and medicinal industries.  相似文献   

17.
A method to improve wood durability using natural extracts was evaluated. Wood deterioration is a condition caused by several abiotic and biotic factors including fungal contamination. To date, approaches aiming at the reduction of these contaminants mainly involve the use of chemicals agents. Natural products could represent an alternative strategy. Aqueous extracts of Punica granatum L. (pomegranate) peel and Melia azedarach L. barks were evaluated as antifungal agents to improve natural durability of beech wood and maritime pine. To evaluate the effect of treatments under simulated accelerated ageing of wood by natural conditions, impregnation and leaching tests were performed. Results demonstrated that samples impregnated with pomegranate or M. azedarach solutions notably increased the biological resistance of wood in a dose-dependent manner. These results were confirmed by the reduction in weight losses in treated samples even after 6 weeks of fungal exposure. Moreover, after leaching tests, 20 and 7% (w/v) of pomegranate and M. azedarach extract solutions were demonstrated as the better concentrations to enhance wood durability. Total phenol content and characterization of the phenolic compounds in both, natural extracts and wood samples were analyzed by Folin–Ciocalteu assay and HPLC-DAD. In conclusion, it was demonstrated that the present method can be considered as an effective treatment to increase wood durability while it proposes the valorization of natural extractives in wood industry.  相似文献   

18.
The aim of this study was to investigate the extrusion cooking behaviours of two wheat flour samples (W1DK, W2CH) in two different twin-screw extrusion systems, where the wheat flour samples were characterised by rapid visco analyser (RVA) measurements. A new method is proposed to model and compare the wheat flour extrusion behaviours in the two systems through the RVA measurements, an extrudate bulk density model and a melt viscosity calculation. A new method is suggested to calculate the melt viscosity in the extrusion process. The average viscosity value of the W1DK sample was 64% higher than that of the W2CH sample in the RVA measurements. The comparison results show that the high viscosity for W1DK obtained from the RVA corresponds to a high reduced melt viscosity (η r , (1/s)γ) for W1DK, i.e., η r ?=?0.25–2.61 (1/s)γ (η r ?=?0.042–0.082 (1/s)γ for W2CH), a high specific mechanical energy (SME) for W1DK, i.e., SME?=?8.16–11.28 kJ/kg (SME?=?5.57–9.99 kJ/kg for W2CH) and a low extrudate bulk density (ρ B ) for W1DK, i.e., ρ B ?=?185–488 g/L (1 g/L?=?1 kg/m3) (ρ B ?=?406–510 g/L for W2CH) in the two extrusion systems. The RVA viscosity and the calculated melt viscosity can be used to identify a recipe characteristic in terms of torque and extrudate bulk density in the two extrusion systems. A comparison has also been made for the bulk density model and response surface methodology in the extrudate bulk density prediction.  相似文献   

19.
This study aimed to investigate the cholinesterase (ChE) inhibitory and antioxidant activities of essential oil (EO) and ethanolic extract (EE) of two Lamiaceae medicinal plants from Algeria: Thymus algeriensis Boiss. & Reut. and Teucrieum polium subsp capitatum. The chemical composition of EOs analyzed by GC and GC–MS revealed the presence of carvacrol (43.2%), p-cymene (18.7%) and γ-terpinene (14.8%) as major compounds in T. algeriensis, while germacrene D (25.0%), bicyclogermacrene (10.4%), β-pinene (11.3%) and spathulenol (5.8%) were the most important components in T. polium oil. The best inhibitory activity on acetylcholinesterase (AChE) was exhibited by the EO of T. algeriensis. On the other hand, T. polium oil was more efficient against butyrylcholinesterase (BChE) than against AChE, whereas EEs showed weak or no inhibitory effect, particularly against AChE. Antioxidant activity was evaluated by β-carotene bleaching, ferric and cupric reducing powers and inhibition of ABTS?+, DPPH? and superoxide radicals. EOs showed different antioxidant trends depending on the assay used while ethanol extracts had high activity with all tests.  相似文献   

20.
Edible films derived from starch have been proposed as packaging materials. However, they may suffer physicochemical changes due to a variety of factors, such as pulsed light (PL) treatments. In this study, the effect of PL treatment as a crosslinking method on films made from cassava (Manihot esculenta C.) and taro (Colocasia esculenta L. Schott) starch, plasticized with glycerol was evaluated. The average molecular weight, contact angle, moisture content, X-ray diffraction pattern, color, and mechanical and microstructural properties were evaluated. Films subjected to PL showed deterioration compared with control films as demonstrated by an increase in the contact angle, surface roughness, and crystallinity, and a decrease in the tensile strength, transparency, and water content, independent of the amylose content of the starches evaluated. Finally, the surface properties of these materials are defined by intermolecular interactions such as van der Waals-type force interactions (hydrogen bond), new bonds (crosslinking) formed between the biopolymeric chains (starch), and by breakage of covalent bonds.  相似文献   

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