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1.
Food Chem ; 346: 128883, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33434864

RESUMO

Bacteriophages (phages) have been extensively utilized as antibacterial agents in the food industry because of their host-specificity. However, their application in polymer films has been limited because of the lack of a strong attachment method for phage to the surface. We developed an antibacterial film by covalently immobilizing Escherichia coli (E. coli)-specific phage T4 on a polycaprolactone (PCL) film. The chemical bond formation was confirmed by XPS analysis, and the covalent attachment of phage T4 effectively inhibited E. coli growth even after external stimulation of the film by sonication. When applied as a packaging film for raw beef inoculated with E. coli O157:H7, the chemically functionalized PCL film showed approximately 30-fold higher bacterial inhibitory effects than the film with physically adsorbed phage T4. These results indicate the promising application potential of chemically functionalized PCL film with phage T4 as an antibacterial food packaging material against the foodborne pathogen E. coli.


Assuntos
Bacteriófago T4/química , Escherichia coli O157/crescimento & desenvolvimento , Embalagem de Alimentos/métodos , Poliésteres/química , Animais , Bacteriófago T4/patogenicidade , Bovinos , Escherichia coli O157/virologia , Microbiologia de Alimentos , Embalagem de Alimentos/instrumentação , Carne/microbiologia
2.
Food Chem ; 343: 128430, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33406575

RESUMO

In this study, the influence of the concentration of flour from jabuticaba peel (FJP) and the concentration of glycerol (CG) on the physicochemical, barrier, mechanical, optical, spectroscopic and biodegradability properties of corn starch films was evaluated using response surface methodology. The increase in the concentrations of FJP and CG enhanced the thickness and permeability to water vapor, and made the films more hydrophilic. In addition to that, the interaction between the two variables caused reduction in the solubility of the films. High concentrations of FJP and CG reduced the maximum tensile strength, and increased CG increased the elongation and decreased the young's modulus of the films. Among the tests studied, the T1 film (15.80% FJP and 15.80% CG) was biodegradable, presenting the best mechanical and barrier properties such as low water vapor permeability, solubility and water holding capacity, showing great potential to be used as biodegradable packaging system.


Assuntos
Biopolímeros/química , Farinha/análise , Myrtaceae/metabolismo , Amido/química , Biopolímeros/metabolismo , Embalagem de Alimentos/métodos , Glicerol/química , Interações Hidrofóbicas e Hidrofílicas , Permeabilidade , Solubilidade , Resistência à Tração , Água/química
3.
Int J Food Microbiol ; 339: 109007, 2021 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33341684

RESUMO

Cast films obtained from polyvinyl alcohol (PVOH) blended with casein hydrolysates (HCas) in a weight ratio of 1:1 were employed to carry nisin-producing L. lactis and phytic acid in order to broaden the antimicrobial spectrum of L. lactis to Gram-positive and Gram-negative spoilage and pathogen bacteria. For this purpose, the effect of the antimicrobial activity of various film formulations and combinations of films on the growth of E. coli at 37 °C for 24 h was studied. The film system that showed antimicrobial activity against Gram-negative bacteria consisted of phytic acid and L. lactis incorporated in separate films. When the active agents were in the same film the viability of L. lactis decreased considerably and it did not exert antimicrobial activity against the bacterium. Therefore, the combination of L. lactis and phytic acid in separate films was chosen as the reliable system, and the effect of its activity on the growth of Gram-negative bacteria (E. coli, Salmonella enterica, and Pseudomonas fluorescens) and Gram-positive bacteria (Listeria monocytogenes) in liquid culture medium was tested at refrigeration temperature (4 °C), and with simulated breaks in the cold chain (14 °C and 24 °C). The survival of L. lactis in coexistence with these bacteria was also studied. The film system exerted an antimicrobial effect against the Gram-negative bacteria tested, and the activity depended on the bacteria and the temperature assayed. With regard to the antimicrobial activity against L. monocytogenes, phytic acid improved the antimicrobial capacity of L.lactis. The survival of L. lactis was maintained at 7-8 log (CFU/mL) culture in liquid medium throughout the storage period. The films developed were intended to be used as coatings in the design of a double-sided active bag for a non-fermented dairy product. The bags were filled with homemade preservative-free pastry cream, and the microbiological shelf life and evolution of pH of the packaged ready-to-eat food stored at 4 °C was studied for 20 days. The results showed a reduction in the growth of spoilage bacteria and therefore an increase in the shelf life of the packaged product. The films developed could be applied in the design of packages for perishable dairy foods in order to increase their microbiological shelf life.


Assuntos
Microbiologia de Alimentos/métodos , Embalagem de Alimentos/métodos , Bactérias Gram-Negativas/efeitos dos fármacos , Lactococcus lactis/metabolismo , Nisina/farmacologia , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Contagem de Colônia Microbiana , Bactérias Gram-Positivas/efeitos dos fármacos , Lactococcus lactis/crescimento & desenvolvimento , Nisina/metabolismo , Álcool de Polivinil/química , Refrigeração
4.
Food Chem ; 339: 127844, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32829243

RESUMO

Fat-filled milk powders (FMP) are inexpensive milk alternatives predominantly exported to developing countries to satisfy growing demands for dairy proteins. Harsh climatic and sanitary conditions, poor border controls and relatively long periods for distribution and storage enhance the inherent vulnerability of FMP to fraud and stability. Rapid, low-cost methods are needed for extensive routine authentication of FMP products. This study investigated, for the first time, the sample integrity and the quality dynamics of 7 Nigerian FMP brands stored for 7 weeks at 40 °C. The prominent melamine and urea absorption peaks were absent, but protein contents were below the permitted limit. The peak absorbance of the OH functional group increased while the tryptophan contents decreased with storage time. Multiclass analyses differentiated the fresh FMP brands from one another, and from those that were aged. Robust interval-PLS predictions obtained for storage time may be excellent indicators of FMP freshness and stability.


Assuntos
Embalagem de Alimentos/métodos , Leite/química , Animais , Cromatografia Gasosa , Cromatografia Líquida de Alta Pressão , Ácidos Graxos/análise , Microbiologia de Alimentos , Análise dos Mínimos Quadrados , Leite/microbiologia , Nigéria , Pós/química , Análise de Componente Principal , Salmonella/isolamento & purificação , Temperatura , Triazinas/análise , Ureia/análise
5.
Food Chem ; 334: 127487, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32688178

RESUMO

Biodegradable films poly(butylene adipate-co-butylene terephthalate) (PBAT)/poly(lactic acid) (PLA) incorporated with nano-polyhedral oligomeric silsesquioxane (POSS(epoxy)8) as a reactive compatibilizer were developed by melt processing. Structural, morphological, mechanical, and gas permeability properties of the films were determined. 1H NMR and GPC demonstrated that the POSS(epoxy)8 was chemically bound at the PBAT/PLA boundary phase via an epoxide ring opening reaction. SEM micrographs of impact fracture surfaces demonstrated the POSS(epoxy)8 improved interfacial adhesion between PBAT and PLA matrix. The mechanical properties of the PBAT/PLA films containing POSS(epoxy)8 were enhanced relative to pristine PBAT/PLA films. The water vapor, CO2 and O2 permeability of the PBAT/PLA films were improved by POSS(epoxy)8 addition. PBAT/PLA films containing POSS(epoxy)8 were shown to be superior to pristine PBAT/PLA films and polyethylene films in food storage tests. Results suggest that POSS(epoxy)8 addition during PBAT/PLA film production offers a simple strategy for the production of high performance biodegradable plastic packaging films.


Assuntos
Plásticos Biodegradáveis/química , Embalagem de Alimentos/métodos , Nanocompostos/química , Poliésteres/química , Dióxido de Carbono/química , Armazenamento de Alimentos/métodos , Oxigênio/química , Permeabilidade , Resistência à Tração
6.
Food Chem ; 334: 127605, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32738726

RESUMO

Chitosan (Ch) and zinc oxide nanoparticles loaded gallic-acid films, (Ch-ZnO@gal) have been prepared aiming for their exploitation as environmentally benign food packaging material. The chitosan films with varying quantities of zinc oxide nanoparticles loaded gallic-acid (ZnO@gal) content were synthesized in order to evaluate the effect of ZnO@gal on their optimum mechanical and biological potential. The characteristic results have shown that the incorporation of ZnO@gal into chitosan films remarkably enhanced the desired mechanical property of the chitosan films. Other noticeable physical properties such as oxygen and water vapor permeability (WVP), swelling, water solubility and UV-vis light transmittance have also been found to improve positively. SEM analysis of the films indicates a good material compatibility between chitosan and ZnO@gal matrices. Ch-ZnO@gal films possess significant antibacterial potential and strong antioxidant behavior compared to pristine chitosan. The overall results suggested that the prepared biocomposite chitosan films may be considered for active food packaging applications.


Assuntos
Quitosana/química , Embalagem de Alimentos/métodos , Ácido Gálico/química , Nanopartículas/química , Óxido de Zinco/química , Antibacterianos/química , Antioxidantes/química , Bacillus subtilis/efeitos dos fármacos , Materiais Biocompatíveis/química , Escherichia coli/efeitos dos fármacos , Embalagem de Alimentos/instrumentação , Permeabilidade , Solubilidade , Vapor , Resistência à Tração , Raios Ultravioleta , Óxido de Zinco/farmacologia
7.
Food Chem ; 337: 127751, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32777575

RESUMO

The type of container (airtight and pouches with different O2 permeability) and packing conditions (cover brine, air or N2 atmosphere) has been studied to preserve black ripe olives in acid medium for a year. Unlike the traditional sterilized product, these acidified olives only needed pasteurization to assure its microbial safety, the absence of acrylamide being an additional advantage. Surprisingly, an increase in the oxygen diffusion through the films (i) faded the black color of the olives, (ii) softened the fruit that lost around 33% of its initial firmness in only 6 months, and (iii) produced the lipid́s oxidation forming volatile compounds that transmitted an abnormal flavor which tasters identified as rancid. Therefore, ripe olives in acid medium must be packed in airtight containers such as glass jars, cans o metallic pouches with cover brine or N2 atmosphere. The addition of calcium is recommended to avoid olive softening.


Assuntos
Embalagem de Alimentos/métodos , Olea/química , Acrilamida/análise , Cor , Frutas/química , Concentração de Íons de Hidrogênio , Fenômenos Mecânicos , Oxirredução , Pasteurização , Paladar
8.
Food Chem ; 336: 127634, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32777654

RESUMO

Bilayer colorimetric films were developed for monitoring fish spoilage by using gelatin (GN) incorporated with ZnO nanoparticles as the upper layer (GN-ZnO), and gellan gum (GG) incorporated with mulberry anthocyanins (MBA) as the lower layer (GG-MBA). The color stability of the bilayer colorimetric films under visible and ultraviolet light was improved with the increase of ZnO nanoparticles content. Meanwhile, the bilayer films had good NH3 sensitivity. The limit of detection of the GG-MBA/GN-2.0% ZnO film to NH3 was 0.01 mM. The electrochemical writing ability of the bilayer films was also identified, indicating the feasibility of inks-free printing on biopolymer films. Finally, the GG-MBA/GN-2.0% ZnO film with an electrochemical writing pattern was used to monitor crucian spoilage. The GG-MBA/GN-2.0% ZnO film with electrochemical writing pattern showed visible color changes with the crucian spoilage. In conclusion, the bilayer colorimetric film was expected to be a good fish spoilage indicator in smart packaging.


Assuntos
Embalagem de Alimentos/métodos , Inocuidade dos Alimentos , Luz , Animais , Antocianinas/química , Cor , Produtos Pesqueiros/análise , Embalagem de Alimentos/instrumentação , Gelatina/química , Concentração de Íons de Hidrogênio , Nanopartículas Metálicas/química , Morus/química , Morus/metabolismo , Polissacarídeos Bacterianos/química , Resistência à Tração , Óxido de Zinco/química
9.
Food Chem ; 337: 127995, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32919274

RESUMO

A novel intelligent pH-responsive color indicator was prepared by adsorbing a natural naphthoquinone pigment, shikonin, onto cellulose paper. FTIR results indicated that shikonin was crosslinked with the cellulose of the indicator paper. The addition of shikonin increased antioxidant activity, thermal stability, and water resistance properties of the paper. The indicator changed the color from red to dark blue, depending on the pH of buffer solutions. Also, the indicator showed high stability after 4 months of storage and maintained high sensitivity to pH changes. This indicator was used to monitor fish and pork freshness during storage at room temperature, and the results showed a high correlation between the color change of the indicator and the pH change of the sample. The shikonin-adsorbed indicator with stable and sensitive color change depending on pH can be used in the intelligent food packaging applications to monitor the quality of packaged food in real-time.


Assuntos
Colorimetria/métodos , Produtos Pesqueiros/análise , Concentração de Íons de Hidrogênio , Naftoquinonas/química , Carne Vermelha/análise , Animais , Celulose/química , Embalagem de Alimentos/métodos , Suínos
10.
Food Chem ; 338: 128013, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33091995

RESUMO

Chitosan-procyanidin composite films (CS-PC films) with different mass ratios were prepared by solution casting method. Their structural, thermal, physical, and antioxidant properties, antibacterial activity and pH responsivity were determined. Compared with CS-control film, CS-PC films exhibited lower solubility and higher tensile strength. The antimicrobial properties against Escherichia coli and Aspergillus niger were improved by 20.0% and 30.4%, respectively. CS-PC films indicated good antioxidant activity through their DPPH and ABTS+ scavenging rates, which were 2.45 times higher than CS-control film. pH responsivity was represented by the outstanding changes in color, which were visible to the naked eye. Food packaging film with high antioxidant activity, bacteriostatic properties and pH responsivity was prepared by CS and PC. Compared with the initial properties of cheese, the characteristics of cheese packaged with CS-PC films were obviously better than those of the control groups.


Assuntos
Anti-Infecciosos/química , Antioxidantes/química , Biflavonoides/química , Catequina/química , Queijo/análise , Quitosana/química , Embalagem de Alimentos/métodos , Proantocianidinas/química , Anti-Infecciosos/farmacologia , Aspergillus niger/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Concentração de Íons de Hidrogênio
11.
Tex Med ; 116(8): 30-31, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32866272

RESUMO

IN TEXAS, COVID-19 outbreaks have been especially pronounced in three types of facilities: nursing homes, jails or prisons, and meatpacking plants. The Amarillo area has plenty of all three. But it was the meatpacking plants that drew national attention to Amarillo's COVID-19 problems. The city, which straddles Potter and Randall counties, has numerous plants that employ 12,000 to 15,000 people. In early April, Amarillo's two hospitals began filling up with COVID-19 patients who worked at a plant in neighboring Moore County. Two weeks later, workers from a plant in Potter County flooded in.


Assuntos
Infecções por Coronavirus , Transmissão de Doença Infecciosa/prevenção & controle , Embalagem de Alimentos , Controle de Infecções , Produtos da Carne/virologia , Pandemias , Pneumonia Viral , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Embalagem de Alimentos/métodos , Embalagem de Alimentos/normas , Humanos , Controle de Infecções/métodos , Controle de Infecções/organização & administração , Indústria de Embalagem de Carne/organização & administração , Pandemias/prevenção & controle , Pneumonia Viral/epidemiologia , Pneumonia Viral/prevenção & controle , Texas/epidemiologia
12.
J Food Sci ; 85(9): 2857-2865, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32812228

RESUMO

The present study was aimed to develop Manihot esculenta and Carrageenan bio-based composite active film functionalized with anise, caraway, and nutmeg essential oils (EOs) and to assess the shelf life of chicken nuggets wrapped with the developed film at refrigeration storage. Overall, the Minimum Inhibitory Concentration (MIC) values of the three EOs ranged from 0.4 to 0.8% v/v of which nutmeg EO was found most effective. Incorporation of EOs in the film resulted in significant (P ˂ 0.05) decrease in tensile strength and water activity while elongation at break was significantly (P ˂ 0.05) increased. No significant (P ˃ 0.05) changes in thickness and Water Vapor Transmission Rate (WVTR) were observed. Based on physicomechanical and sensory evaluation, films incorporated with 0.5, 1, and 1% concentration of anise, nutmeg, and caraway EO were selected. Chicken nuggets overwrapped with aforementioned films were stored aerobically at refrigeration temperature (4 ± 1 °C) to evaluate antimicrobial, antioxidant, and sensory characteristics. The result indicated that pH, peroxide, free fatty acid (FFA), and thiobarbituric acide (TBA) value of treatments were significantly (P ˂ 0.05) lower than controls however significantly (P < 0.05) higher DPPH activity was observed in all treatments. The total plate count, psychrophilic count and, yeast and mold count were also significantly (P ˂ 0.01) lower in treatment groups and were within the permissible limits. The treated samples were well acceptable during whole storage period of 15 days. The application of composite, active edible bio-based film was found proficient in confining product quality attributes throughout storage. PRACTICAL APPLICATION: The majority of films used for packaging of meat and meat products are derived from synthetic "plastic" materials. The demerits associated with plastics have eventually led to explore natural alternatives such as edible films. The composite-active bio-based films have a huge potential to be molded for specific film properties based on requirements of product-specific packaging conditions.


Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/análise , Filmes Comestíveis , Embalagem de Alimentos/instrumentação , Produtos da Carne/análise , Óleos Voláteis/análise , Polímeros/química , Animais , Antioxidantes/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Carragenina/química , Galinhas , Embalagem de Alimentos/métodos , Armazenamento de Alimentos , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Humanos , Manihot/química , Produtos da Carne/microbiologia , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia , Polímeros/síntese química , Refrigeração , Paladar
13.
Food Chem ; 332: 127375, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32622189

RESUMO

Biopolymer films based on chitosan/potato protein/linseed oil/ZnO NPs were developed to maintain the storage quality of raw meat. Results indicated that the incorporation of ZnO NPs could effectively improve the transparency and tensile strength of the films, while addition of linseed oil could make the composite film maintain good elastic property. Films blended with chitosan/potato protein/linseed oil/ZnO NPs (Fcpzl) exhibited an excellent moisture barrier capability. SEM showed that ZnO NPs could harmoniously exist in various polymers matrix. FTIR analysis demonstrated that different components were bound together by intramolecular and intermolecular interactions, among which hydrogen bonds were the main force. Raw meat samples were wrapped with different films to evaluate the preservative effect during 4 °C storage. Results indicated that Fcpzl possessed best protective effect of raw meat with excellent acceptable sensory properties during 7 days storage, which could reduce the speed of increasing pH and total bacterial counts.


Assuntos
Quitosana/química , Embalagem de Alimentos/métodos , Armazenamento de Alimentos/métodos , Óleo de Semente do Linho/química , Carne , Proteínas de Plantas/química , Óxido de Zinco/química , Qualidade dos Alimentos , Carne/microbiologia , Solanum tuberosum/química , Resistência à Tração
14.
Food Chem ; 333: 127537, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32683265

RESUMO

Antifungal bioplastic films were developed based on poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) blends as PLA60/PBAT40 (PLA/PBAT) and PBAT60/PLA40 (PBAT/PLA) with incorporated trans-cinnamaldehyde using cast-extrusion. Trans-cinnamaldehyde was more compatible in PLA which exhibited plasticization that increased molecular mobility, crystallinity, permeability but limited volatile release and reduced film strength. Interaction of trans-cinnamaldehyde modified CO functional groups of PLA and PBAT. Phase separation was higher in PBAT/PLA films due to less surface adhesion in PBAT networks. Higher release of trans-cinnamaldehyde enhanced bread crystallinity but gave lower rate of hardness increase due to plasticization of starch and protein and reduced lipid crystallinity. Increased bread hardness correlated with decreased water activity that was effectively prevented by higher release of trans-cinnamaldehyde. Films containing trans-cinnamaldehyde (2-10%) showed high antifungal efficacy against Penicillium sp. and Aspergillus niger but low effective against Rhizopus sp. Trans-cinnamaldehyde reduced bacterial and fungal growth in breads, extending shelf-life for 21 days.


Assuntos
Acroleína/análogos & derivados , Adipatos/química , Alcenos/química , Pão , Embalagem de Alimentos/métodos , Ácidos Ftálicos/química , Poliésteres/química , Acroleína/química , Antifúngicos/química , Pão/microbiologia , Permeabilidade , Amido/química
15.
Int J Food Microbiol ; 332: 108774, 2020 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-32634639

RESUMO

The effects of gamma irradiation (0.5, 1.0, 1.5 and 2.5 kGy doses) on Tuber aestivum packaged under modified atmosphere was evaluated. The respiration rate, microbial populations, sensory characteristics and content of bioactive compounds (total carbohydrates, chitins, ß-glucans, proteins, total phenols and sterols) were monitored from immediately after treatment up to day 42 of storage at 4 °C. All the irradiation treatments tested reduced the microbial groups studied by more than 3 log cfu/g. Increasing irradiation doses slowed down the subsequent microbial development throughout the conservation period for all the groups studied. The irradiation treatments did not negatively affect truffle sensory characteristics. Only a slight visible superficial yeast growth was detected at the end of the shelf-life in all doses applied. Total carbohydrate content, chitins, ß-glucans and proteins levels were not affected after irradiation. However, sterols, particularly stigmasterol, slightly decreased after irradiation, while levels of phenolic compounds doubled during storage. Gamma irradiation (2.5 kGy) could be used to extend the shelf-life of summer truffles packaged under modified atmosphere, since no remarkable reduction of bioactive compounds were noticed after 42 days of storage, and their sensory and microbial parameters were of higher quality than those of non-irradiated controls.


Assuntos
Ascomicetos/efeitos da radiação , Irradiação de Alimentos/métodos , Embalagem de Alimentos/métodos , Armazenamento de Alimentos , Compostos Fitoquímicos/efeitos da radiação , Ascomicetos/química , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Qualidade dos Alimentos , Raios gama , Compostos Fitoquímicos/análise
16.
Food Chem ; 329: 126989, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32502742

RESUMO

In this study, a polyethylene (PE) film coated with chitosan (CS) and gallic acid (GA) was prepared using plasma modification technology and applied for the preservation of tilapia fillets. Based on the analysis of surface morphology and surface functional groups, it was shown that plasma modification allowed CS and GA coating on PE. And GACS/PE demonstrated better antioxidant ability than CS/PE and GA/PE individually. The results of the tilapia freshness test showed that the total plate count showed that GACS/PE can inhibit 1.52 log CFU/g and delay the production of volatile basic nitrogen below 15 mg/100 g after 14 d of storage. Moreover, GA/PE (0.26 mg MDA/kg) and GACS/PE (0.24 mg MDA/kg) showed better thiobarbituric acid inhibitiry effect than control (0.30 mg MDA/kg) on day 14. These results indicate that these packaging films are efficient in extending the shelf life of tilapia fillets.


Assuntos
Quitosana/química , Embalagem de Alimentos/métodos , Conservação de Alimentos/métodos , Ácido Gálico/química , Polietileno/química , Tilápia , Animais
17.
Int J Food Microbiol ; 332: 108765, 2020 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-32593919

RESUMO

Carrot cellulose nano fibers (CNF) have been extracted from carrot pulp using acid hydrolysis process. The size of the CNF was in the range of 6.33-58.77 nm. Starch nano-composite films were manufactured using varying concentration of CNF (5%, 10%, 15%, 20%) and mechanical properties of the films were studied at relative humidity 50% and 75%. Nano-composite films were manufactured using Eucalyptus globulus leafs extract (1%, 2%, 3%, 4%). Physio-chemical properties, antioxidant, antimicrobial, morphological and crystalline properties of the films were studied. Nano-composite films with 4% Eucalyptus globulus leafs extract was best to provide better barrier, antioxidant properties to grapes when wrapped and stored at room temperature (25 ± 2)°C for 7 days and refrigerator temperature (4 ± 1)°C for 28 days. Wrapped grapes with NCC/Eucalyptus globulus leaf extract stored for 28 days either at 25 °C or 4 °C had bacterial surface loads reduced up to 5 orders of magnitude compared to non-wrapped samples and had 4 orders of magnitude less bacterial surface loads than at the beginning of the experiments. Wrapped grapes with NCC/Eucalyptus globulus leaf extract significantly reduced the growth of Escherichia coli, Listeria monocytogenes, Salmonella typhimurium and Penicillium spp. when the cells of these organisms were spiked onto grapes and the samples were stored either at (25 ± 2) °C or (4 ± 1) °C for 28 days. The results showed that nano-composite with 4% Eucalyptus globulus leafs extract films have immense potential as food packaging/wrapping material.


Assuntos
Eucalyptus/química , Embalagem de Alimentos/métodos , Amido/síntese química , Amido/farmacologia , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Celulose/análise , Celulose/química , Daucus carota/química , Nanoestruturas/química , Extratos Vegetais/química , Amido/química , Vitis/microbiologia
18.
J Food Sci ; 85(7): 1997-2003, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32572983

RESUMO

Designing modified atmosphere packages (MAPs) for fresh produce requires respiration rate (RR) data. A steady-state (SS) approach is widely used but is expensive, tedious, and time-consuming. Unsteady-state (USS) methods mitigate shortcomings of the SS approach, but comparisons between the two approaches have not been done to verify the design outcomes of MAPs, especially those with microperforations. RR measurement methods for grape tomatoes and blueberries were compared. Data were then used to design microperforated MAP packages to compare predicted design specifications created from RR data with observed shelf life. Results show that the USS method provides similar magnitudes of RR and predicts similar numbers of perforations as the SS method. Observations of packages produced using 100 µm perforations, using measured respiration data, suggest that both methods underestimated what might have been deemed correct by about one microperforation. PRACTICAL APPLICATION: Designing packaging for fresh produce requires the knowledge of produce respiration. Steady-state methods are conceptually simple, but time-consuming. Unsteady-state methods are rapid. This work compares methods on design of packages.


Assuntos
Mirtilos Azuis (Planta)/química , Embalagem de Alimentos/métodos , Lycopersicon esculentum/química , Vitis/química , Atmosfera , Mirtilos Azuis (Planta)/metabolismo , Frutas/química , Frutas/metabolismo , Lycopersicon esculentum/metabolismo , Vitis/metabolismo
19.
J Food Sci ; 85(7): 2153-2163, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32572986

RESUMO

The application of bacterial cellulose (BC) as a wrapping material for vacuum-packaged beef was studied and compared against unwrapped beef for up to 3 weeks. The impact of BC wrap on the weight loss, purge accumulation, and drip loss were assessed along with low-field nuclear magnetic resonance, physicochemical, microbiological, and sensorial evaluations. The BC wrap significantly (P < 0.05) reduced purge accumulation in vacuum packages which was confirmed by an increased swelling ratio and scanning electron microscopy images. Colorimetric measurements showed significantly (P < 0.05) increased redness and yellowness values in wrapped samples compared to unwrapped samples. BC wrap did not affect pH, tenderness, and odor of meat, but significantly (P < 0.05) increased lipid oxidation, and numbers of lactic acid bacteria and Brochothrix thermosphacta counts. This study shows that BC wrap has potential as a purge absorbent in vacuum packaged meat. PRACTICAL APPLICATION: Bacteria cellulose has good water holding capacity that can be utilized to absorb purge exudate from beef. It helps to improve the appearance and consequently consumer acceptance of vacuum packed beef.


Assuntos
Celulose/química , Embalagem de Alimentos/métodos , Conservação de Alimentos/métodos , Carne/análise , Adsorção , Animais , Bactérias/química , Bactérias/metabolismo , Bovinos , Cor , Microbiologia de Alimentos , Embalagem de Alimentos/instrumentação , Conservação de Alimentos/instrumentação , Humanos , Lactobacillales/crescimento & desenvolvimento , Carne/microbiologia , Paladar , Vácuo
20.
J Food Sci ; 85(4): 947-955, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32237089

RESUMO

Edible packaging films have been widely studied because of its safety, green, and effective characteristics. In this paper, chitosan (CH) edible films containing hexahydro-ß-acids (HBA) were prepared, and its physical and mechanical properties, bioactivity, and their impact on the shelf life of pork were investigated. The infrared spectra indicated that the molecular interaction between CH and HBA was observed. Scanning electron microscopy was used to analyze the surface morphology of the film, and light transmittance analysis displayed that the addition of HBA enhanced the film's UV blocking performance. Compared to the CH film, the tensile strength of CH-HBA film increased to 29.19 ± 0.45 MPa, and the scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) reached 1.40 ± 0.01 mg rutin/cm2 of the film. The antibacterial activity of the CH-HBA film on Escherichia coli (44825) and Staphylococcus aureus (26001) showed that the CH-HBA film is a feasible antibacterial package. Furthermore, compared to pork packaged in CH and polyethylene films, fresh pork packaged with CH-HBA films displayed prolongation of shelf life due to reduction in microbial proliferation, thiobarbituric values, pH, and total volatile base nitrogen contents during storage at 4 °C for 16 days. The freshness of pork was prolonged by 7-8 days when the dosage of HBA was increased to 0.3% from 0.1% (w/v). These results revealed that the CH-HBA film can effectively extend the shelf life of pork. PRACTICAL APPLICATION: This study effectively prolonged the shelf life of pork. A chitosan-edible film combined with hexahydro-ß-acids has a potential application value in replacing traditional packaged fresh meat.


Assuntos
Antibacterianos/farmacologia , Quitosana/farmacologia , Embalagem de Alimentos/instrumentação , Carne Vermelha/análise , Ácidos/análise , Ácidos/farmacologia , Animais , Antibacterianos/análise , Quitosana/análise , Filmes Comestíveis , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Embalagem de Alimentos/métodos , Armazenamento de Alimentos , Carne Vermelha/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Suínos , Resistência à Tração
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