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1.
J Sci Food Agric ; 102(2): 794-800, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34223648

RESUMO

BACKGROUND: Two edible coating (EC) emulsions based on potato starch (F6 and F10) alone or formulated with sodium benzoate (SB, 2% w/w) (F6/SB and F10/SB) were evaluated to maintain postharvest quality of cold-stored 'Fino' lemons and control sour rot on lemons artificially inoculated with Geotrichum citri-aurantii. Previous research showed the potential of these ECs to improve the storability of 'Orri' mandarins and reduce citrus green and blue molds caused by Penicillum digitatum and Penicillium italicum, respectively. RESULTS: The coatings F6/SB and F10/SB significantly reduced sour rot incidence and severity compared to uncoated control samples on lemons incubated at 28 °C for 4 and 7 days. The F6/SB coating reduced weight loss and gas exchange compared to uncoated fruit after 2 and 4 weeks of storage at 12 °C plus a shelf life of 1 week at 20 °C, without adversely affecting the lemon physicochemical quality. CONCLUSION: Overall, the F6/SB coating formulation, composed of pregelatinized potato starch, glyceryl monostearate, glycerol, emulsifiers and SB, with a total solid content of 5.5%, showed the best results in reducing citrus sour rot and maintaining the postharvest quality of cold-stored 'Fino' lemons. Therefore, it showed potential as a new cost-effective postharvest treatment suitable to be included in integrated disease management programs for citrus international markets with zero tolerance to chemical residues. © 2021 Society of Chemical Industry.


Assuntos
Citrus/microbiologia , Conservação de Alimentos/métodos , Fungicidas Industriais/química , Fungicidas Industriais/farmacologia , Geotrichum/efeitos dos fármacos , Doenças das Plantas/microbiologia , Amido/química , Amido/farmacologia , Citrus/química , Composição de Medicamentos , Armazenamento de Alimentos , Frutas/química , Frutas/microbiologia , Geotrichum/crescimento & desenvolvimento , Doenças das Plantas/prevenção & controle , Benzoato de Sódio/química , Solanum tuberosum/química
2.
Foods ; 10(9)2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34574225

RESUMO

The sulfur-containing salts, classified as food additives, sodium metabisulfite (SMBS), potassium metabisulfite (PMBS), aluminum sulfate (AlS), and aluminum potassium sulfate (AlPS), were evaluated for their activity against Monilinia fructicola, Rhizopus stolonifer, and Geotrichum candidum, the most economically important fungal pathogens causing postharvest disease of stone fruit. In in vitro tests with potato dextrose agar (PDA) Petri dishes amended with different concentrations of the salts (0, 10, 20, 30, 50, and 100 mM), SMBS and PMBS at all concentrations, AlS above 20 mM, and AlPS above 30 mM, completely inhibited the mycelial growth of the three fungi after incubation at 25 °C for up to 10 days. In in vivo primary screenings with artificially inoculated nectarines, aqueous solutions of the four salts reduced the incidence and severity of brown rot (BR) at concentrations of 10 and 50 mM, whereas only AlS and AlPS reduced Rhizopus rot (RR), and none of the salts was effective against sour rot (SR). Solutions at 100 mM were phytotoxic and injured the fruit peel. In small-scale trials, 1 min dip treatments at 20 °C in SMBS or PMBS at 10 mM significantly reduced the incidence and severity of BR after incubation at 20 °C for up to 8 days. Conversely, dips in AlS and AlPS reduced neither BR nor RR. Results highlight the potential of SMBS and PMBS as new nonpolluting tools for the integrated control of BR, but not RR and SR, on stone fruit.

3.
Int J Food Microbiol ; 330: 108713, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-32512363

RESUMO

Sodium metabisulfite (SMBS), potassium metabisulfite (PMBS), aluminum sulfate (AlS) and aluminum potassium sulfate (AlPS), common sulfur-containing salts used as food additives, were evaluated for their antifungal activity against Penicillium digitatum, Penicillium italicum and Geotrichum citri-aurantii, the most economically important pathogens causing postharvest diseases of citrus fruits. In vitro radial mycelial growth was measured on potato dextrose agar (PDA) Petri dishes amended with five different concentrations of the salts (10, 20, 30, 50, 100 mM) after 7 d of incubation at 25 °C. SMBS and PMBS at all concentrations, and AIS and AIPS above 20 mM, completely inhibited the growth of these fungi. The curative antifungal activity of the four salts to control citrus green (GM) and blue (BM) molds and sour rot (SR) was evaluated on 'Valencia' oranges artificially inoculated in rind wounds with P. digitatum, P. italicum and G. citri-aurantii, respectively. In vivo primary screenings showed no significant antifungal activity of AlS and AlPS to control the three diseases at any dose tested, but SMBS and PMBS reduced the incidence and severity of GM, BM and SR at various concentrations. Effective salts and concentrations were selected for in vivo dip treatments in small-scale trials. Dips at room temperature (20 °C) in SMBS and PMBS at 20 and 50 mM for 60 or 120 s significantly reduced the incidence and severity of GM and BM, with PMBS at 50 mM for 120 s the most effective treatment. Conversely, dips in SMBS and PMBS at 50 mM for 60 or 120 s did not reduce SR incidence and severity. SMBS and PMBS treatments are potentially new tools to be included in reduced-risk non-polluting strategies to control Penicillium diseases, but not SR, on citrus fruits.


Assuntos
Antifúngicos/farmacologia , Citrus/microbiologia , Aditivos Alimentares/farmacologia , Doenças das Plantas/prevenção & controle , Enxofre/farmacologia , Aditivos Alimentares/química , Conservação de Alimentos/métodos , Frutas/microbiologia , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Temperatura , Fatores de Tempo
4.
Int J Food Microbiol ; 301: 9-18, 2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31055161

RESUMO

A large amount of GRAS (generally recognized as safe) salts and concentrations were evaluated in in vitro tests (inhibition of mycelial growth on PDA dishes) against Lasiodiplodia theobromae, the causal agent of citrus Diplodia stem-end rot. Ammonium carbonate (AC, 0.2%), potassium sorbate (PS, 2.0%), potassium carbonate (PC, 0.2%), sodium methylparaben (SMP, 0.1%), sodium ethylparaben (SEP, 0.1%), sodium benzoate (SB, 2.0%), and potassium silicate (PSi, 2.0%) were selected as the most effective. Disease control ability of edible composite coatings formulated with hydroxypropyl methylcellulose (HPMC), beeswax (BW), and these selected antifungal GRAS salts was assessed in in vivo experiments with 'Ortanique' mandarins and 'Barnfield' oranges artificially inoculated with L. theobromae. Coatings containing 2% PS, 0.1% SEP, or 2% SB were the most effective reducing disease severity (up to 50% reduction) and were also applied to non-inoculated and cold-stored 'Barnfield' oranges to determine their effect on postharvest fruit quality. After periods of 21 and 42 d at 5 °C followed by 7 d of shelf life at 20 °C, coatings containing SEP and SB significantly reduced weight loss and did not adversely affect the physicochemical quality attributes (firmness, soluble solid content, titratable acidity, and ethanol and acetaldehyde content) and sensory flavor with respect to uncoated control fruit. Although the internal gas concentration (CO2 level) of coated fruit increased, the coatings did not induce off-flavors.


Assuntos
Ascomicetos/efeitos dos fármacos , Citrus/microbiologia , Microbiologia de Alimentos/métodos , Conservação de Alimentos/métodos , Derivados da Hipromelose/farmacologia , Sais/farmacologia , Antifúngicos/farmacologia , Frutas/microbiologia , Lipídeos/química , Lipídeos/farmacologia
5.
Crit Rev Food Sci Nutr ; 58(4): 662-679, 2018 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-27469103

RESUMO

Processing of fruits and vegetables generates physiological stresses in the still living cut tissue, leading to quality deterioration and shorter shelf life as compared with fresh intact produces. Several strategies can be implemented with the aim to reduce the rate of deterioration of fresh-cut commodities. Such strategies include low temperature maintenance from harvest to retail and the application of physical and chemical treatments such as modified atmosphere packaging (MAP) with low O2 and high CO2 levels and antioxidant dips. Other technologies such as edible coatings with natural additives, new generation of coatings using nanotechnological solutions such as nanoparticles, nanoencapsulation, and multilayered systems, and nonconventional atmospheres such as the use of pressurized inert/noble gases and high levels of O2 have gained a lot of interest as a possibility to extend the shelf life of minimally processed fruits and vegetables. However, the high perishability of these products challenges in many cases their marketability by not achieving sufficient shelf life to survive the distribution system, requiring the combination of treatments to assure safety and quality. This review reports the recent advances in the use of MAP, edible coatings, and the combined effect of both technologies to extend the shelf life of fresh-cut fruits and vegetables.


Assuntos
Embalagem de Alimentos/métodos , Conservação de Alimentos/métodos , Qualidade dos Alimentos , Frutas , Verduras , Atmosfera
6.
J Sci Food Agric ; 97(1): 252-260, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26997097

RESUMO

BACKGROUND: The greatest hurdle to the commercial marketing of fresh-cut fruits is related to their higher susceptibility to enzymatic browning, tissue softening, and microbial growth. The aim of this study was to test the efficacy of a pectin-based edible coating and low oxygen modified atmosphere packaging (MAP) to control enzymatic browning and reduce microbial growth of fresh-cut 'Rojo Brillante' persimmon. The survival of Escherichia coli, Salmonella enteritidis and Listeria monocytogenes artificially inoculated on fresh-cut fruit was also assessed. The pectin coating was amended with 500 IU mL-1 nisin (NI) as antimicrobial agent and 10 g kg-1 citric acid and 10 g kg-1 calcium chloride as anti-browning and firming agents, respectively. Persimmon slices were dipped in the coating or in water (control) and packed under 5 kPa O2 (MAP) or in ambient atmosphere for up to 9 days at 5 °C. Microbial growth, package gas composition, colour, firmness, polyphenol oxidase activity, visual quality and overall sensory flavour of persimmon slices were measured during storage. RESULTS: Coating application combined with active MAP significantly reduced the CO2 emission and O2 consumption in the package. The coating was effective in reducing browning and also inhibited the growth of mesophilic aerobic bacteria. Coating also reduced the populations of E. coli, S. enteritidis and L. monocytogenes. CONCLUSION: The combination of the pectin-based edible coating and active MAP proved to be the most effective treatment to maintain the sensory and microbiological quality of persimmon slices for more than 9 days of storage. © 2016 Society of Chemical Industry.


Assuntos
Anti-Infecciosos , Diospyros/microbiologia , Embalagem de Alimentos/instrumentação , Embalagem de Alimentos/métodos , Frutas/microbiologia , Pectinas , Cloreto de Cálcio , Dióxido de Carbono/análise , Escherichia coli/crescimento & desenvolvimento , Conservação de Alimentos/métodos , Qualidade dos Alimentos , Humanos , Listeria monocytogenes/crescimento & desenvolvimento , Reação de Maillard , Nisina , Oxigênio/análise , Salmonella enteritidis/crescimento & desenvolvimento , Sensação , Paladar
7.
Food Sci Technol Int ; 23(1): 3-16, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27251678

RESUMO

The combined effect of antibrowning dips and controlled atmosphere storage on fresh-cut "Rojo Brillante" persimmon quality was investigated. Persimmon slices were dipped in 10 g L-1 ascorbic acid, 10 g L-1 citric acid or water and were stored in different controlled atmospheres at 5 ℃. Controlled atmosphere conditions were 21 kPa O2 + 10 kPa CO2 (Atm-B), 21 kPa O2 + 20 kPa CO2 (Atm-C), 5 kPa O2 + 10 kPa CO2 (Atm-D) and 5 kPa O2 in the absence of CO2 (Atm-E). Air (Atm-A) was used as a control. Atmospheres with high CO2 concentrations induced darkening, associated with a flesh disorder known as "internal flesh browning". Only the samples placed in Atm-E, and treated with 10 g L-1 ascorbic acid or 10 g L-1 citric acid, controlled enzymatic browning, reduced firmness loss and prevented the "internal flesh browning" disorder. The maximum limit of marketability was achieved in the samples treated with 10 g L-1 citric acid and stored in Atm-E for nine storage days at 5 ℃. The total vitamin C, free radical scavenging activity, total phenolic content and total carotenoids of the fresh-cut "Rojo Brillante" persimmons were affected by maturity stage at harvest, whereas antibrowning dips and controlled atmosphere storage had no clear effect.


Assuntos
Diospyros/química , Manipulação de Alimentos , Conservação de Alimentos , Frutas/química , Reação de Maillard , Valor Nutritivo , Ácido Ascórbico/análise , Carotenoides/análise , Cor , Embalagem de Alimentos , Armazenamento de Alimentos , Fenóis/análise , Compostos Fitoquímicos/análise
8.
Food Sci Technol Int ; 22(7): 574-586, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26865077

RESUMO

To prevent enzymatic browning of fresh-cut 'Rojo Brillante' persimmon, different combinations of ascorbic acid (AA) and citric acid (CA) with calcium chloride (CaCl2) were tested in fruit harvested at two maturity stages (MS1 and MS2). Color, firmness, sensory quality, total vitamin C, radical scavenging activity, total phenolic content, and carotenoids were evaluated over nine days of storage at 5 ℃. Antibrowning dips reduced enzymatic browning if compared with the control samples. Selecting fruits with good firmness and the addition of 10 g/l CaCl2 help prevent loss of firmness of fresh-cut "Rojo Brillante" persimmons treated with acidic solutions as antibrowning agents to control enzymatic browning. The limit of marketability of the persimmon fruit processed at MS1 was significantly reduced by the burst of the disorder known as "flesh browning," and only the samples treated with 10 g/l CA + 10 g/l CaCl2 maintained a limit of marketability close to seven days. At MS2, all the antibrowning solutions allowed a limit of marketability of seven storage days at 5 ℃. Nutritional quality was not affected by either antibrowning dips or cutting processes, but MS at harvest was.


Assuntos
Cor , Diospyros/química , Frutas/química , Valor Nutritivo , Paladar , Ácido Ascórbico/análise , Carotenoides/análise , Aditivos Alimentares/química , Manipulação de Alimentos , Conservação de Alimentos , Armazenamento de Alimentos , Humanos , Reação de Maillard , Micronutrientes/análise , Fenóis/análise
9.
J Agric Food Chem ; 63(3): 761-8, 2015 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-25568930

RESUMO

To better understand the tolerance of strawberries (Fragaria vesca L.) to high CO2 in storage atmospheres, fermentation and cellular damage were investigated. Fruits were stored for 3 and 6 days at 0 °C in the presence of different CO2 levels (0, 20, or 40%) with 20% O2. Changes in pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) gene expression and in fermentative metabolites, as well as in bound water and malondialdehyde (MDA) concentrations, were analyzed. In strawberries stored without added CO2, up-regulation of PDC and ADH was not associated with an increase in fermentative metabolites. By contrast, moderate ethanol fermentation in fruits exposed to 20% CO2 seems to be essential to maintain fruit metabolism, reducing both lipid peroxidation and cellular water stress. However, if the CO2 concentration increases (40%), the excess acetaldehyde and ethanol produced were closely correlated with a decrease in bound water and production of MDA.


Assuntos
Dióxido de Carbono/administração & dosagem , Fermentação/efeitos dos fármacos , Conservação de Alimentos/métodos , Fragaria/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Acetaldeído/metabolismo , Álcool Desidrogenase/genética , Temperatura Baixa , Etanol/metabolismo , Frutas/metabolismo , Expressão Gênica , Malondialdeído/análise , Piruvato Descarboxilase/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Água/metabolismo
10.
Int J Food Microbiol ; 179: 72-9, 2014 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-24742996

RESUMO

Common food preservative agents were evaluated in in vitro tests for their antifungal activity against Monilinia fructicola, the most economically important pathogen causing postharvest disease of stone fruits. Radial mycelial growth was measured in Petri dishes of PDA amended with three different concentrations of the agents (0.01-0.2%, v/v) after 7 days of incubation at 25 °C. Thirteen out of fifteen agents tested completely inhibited the radial growth of the fungus at various concentrations. Among them, ammonium carbonate, ammonium bicarbonate and sodium bicarbonate were the most effective while sodium acetate and sodium formate were the least effective. The effective agents and concentrations were tested as ingredients of hydroxypropyl methylcellulose (HPMC)-lipid edible coatings against brown rot disease on plums previously inoculated with M. fructicola (curative activity). 'Friar' and 'Larry Ann' plums were inoculated with the pathogen, coated with stable edible coatings about 24h later, and incubated at 20 °C and 90% RH. Disease incidence (%) and severity (lesion diameter) were determined after 4, 6, and 8 days of incubation and the 'area under the disease progress stairs' (AUDPS) was calculated. Coatings containing bicarbonates and parabens significantly reduced brown rot incidence in plums, but potassium sorbate, used at 1.0% in the coating formulation, was the most effective agent with a reduction rate of 28.6%. All the tested coatings reduced disease severity to some extent, but coatings containing 0.1% sodium methylparaben or sodium ethylparaben or 0.2% ammonium carbonate or ammonium bicarbonate were superior to the rest, with reduction rates of 45-50%. Overall, the results showed that most of the agents tested in this study had significant antimicrobial activity against M. fructicola and the application of selected antifungal edible coatings is a promising alternative for the control of postharvest brown rot in plums.


Assuntos
Antifúngicos/farmacologia , Ascomicetos/efeitos dos fármacos , Conservantes de Alimentos/farmacologia , Conservantes de Alimentos/normas , Prunus/microbiologia , Ascomicetos/crescimento & desenvolvimento , Carbamatos/farmacologia , Derivados da Hipromelose , Lipídeos/farmacologia , Metilcelulose/análogos & derivados , Metilcelulose/farmacologia , Parabenos/farmacologia , Ácido Sórbico/farmacologia
11.
Int J Food Microbiol ; 166(3): 391-8, 2013 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-24026010

RESUMO

The antifungal activity of food additives or 'generally recognized as safe' (GRAS) compounds was tested in vitro against Botrytis cinerea and Alternaria alternata. Radial mycelial growth of each pathogen was measured in PDA Petri dishes amended with food preservatives at 0.2, 1.0, or 2.0% (v/v) after 3, 5, and 7 days of incubation at 25 °C. Selected additives and concentrations were tested as antifungal ingredients of hydroxypropyl methylcellulose (HPMC)-lipid edible coatings. The curative activity of stable coatings was tested in in vivo experiments. Cherry tomatoes were artificially inoculated with the pathogens, coated by immersion about 24 h later, and incubated at 20 °C and 90% RH. Disease incidence and severity (lesion diameter) were determined after 6, 10, and 15 days of incubation and the 'area under the disease progress stairs' (AUDPS) was calculated. In general, HPMC-lipid antifungal coatings controlled black spot caused by A. alternata more effectively than gray mold caused by B. cinerea. Overall, the best results for reduction of gray mold on cherry tomato fruit were obtained with coatings containing 2.0% of potassium carbonate, ammonium phosphate, potassium bicarbonate, or ammonium carbonate, while 2.0% sodium methylparaben, sodium ethylparaben, and sodium propylparaben were the best ingredients for coatings against black rot.


Assuntos
Alternaria/efeitos dos fármacos , Botrytis/efeitos dos fármacos , Aditivos Alimentares/farmacologia , Frutas/microbiologia , Solanum lycopersicum/microbiologia , Alternaria/crescimento & desenvolvimento , Antifúngicos/farmacologia , Botrytis/crescimento & desenvolvimento , Conservantes de Alimentos/química , Conservantes de Alimentos/farmacologia , Tempo
12.
J Sci Food Agric ; 92(4): 794-802, 2012 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-22052696

RESUMO

BACKGROUND: Citrus fruit represent an important source of vitamin C, as well as other bioactive compounds. Edible coatings have the potential to extend shelf life of citrus by providing a semi-permeable barrier to water and gases, which depends on coating composition, solid content (SC), and cultivar. However, little is known about the effect of coatings on citrus nutritional quality. This work studies the effect of coating composition and SC of hydroxypropyl methylcellulose (HPMC)-beeswax (BW)-shellac coatings on the physico-chemical, sensory and nutritional quality of 'Oronules' mandarins. Coatings prepared at the same lipid content differed in the BW:shellac ratio (1:3 and 3:1) and SC of the formulations (40 and 80 g kg⁻¹). RESULTS: The coating with 1:3 BW:shellac ratio and 80 g kg⁻¹ SC was the most effective controlling weight loss, although it was less effective than the commercial wax tested. Increasing SC had a greater effect than the BW:shellac ratio in fruit internal atmosphere and sensory quality, with the presence of off-flavour when coatings were applied at 80 g kg⁻¹ SC. Nutritional quality was not affected by the application of the different treatments. CONCLUSION: HPMC-lipid coatings have the potential to extend shelf life of 'Oronules' mandarins. However, care should be taken controlling formulation SC to avoid the build-up of off-flavour.


Assuntos
Citrus/química , Conservação de Alimentos/métodos , Frutas/química , Lipídeos/química , Metilcelulose/análogos & derivados , Antioxidantes/análise , Fenômenos Químicos , Feminino , Manipulação de Alimentos , Humanos , Derivados da Hipromelose , Masculino , Metilcelulose/química , Valor Nutritivo , Permeabilidade , Controle de Qualidade , Resinas Vegetais/química , Sensação , Espanha , Propriedades de Superfície , Paladar , Ceras/química
13.
Crit Rev Food Sci Nutr ; 51(9): 872-900, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21888536

RESUMO

The use of edible films and coatings is an environmentally friendly technology that offers substantial advantages for shelf-life increase of many food products including fruits and vegetables. The development of new natural edible films and coatings with the addition of antimicrobial compounds to preserve fresh and minimally processed fruits and vegetables is a technological challenge for the industry and a very active research field worldwide. Antimicrobial agents have been successfully added to edible composite films and coatings based on polysaccharides or proteins such as starch, cellulose derivatives, chitosan, alginate, fruit puree, whey protein isolated, soy protein, egg albumen, wheat gluten, or sodium caseinate. This paper reviews the development of edible films and coatings with antimicrobial activity, typically through the incorporation of antimicrobial food additives as ingredients, the effect of these edible films on the control of target microorganisms, the influence of antimicrobial agents on mechanical and barrier properties of stand-alone edible films, and the effect of the application of antimicrobial edible coatings on the quality of fresh and fresh-cut fruits and vegetables.


Assuntos
Anti-Infecciosos/farmacologia , Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Alginatos/química , Celulose/química , Quitosana/química , Manipulação de Alimentos , Embalagem de Alimentos/métodos , Frutas , Proteínas/química , Amido/química , Verduras
14.
J Food Sci ; 75(8): S418-26, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21535515

RESUMO

Edible composite coatings based on hydroxypropyl methylcellulose (HPMC), hydrophobic components (beeswax and shellac), and food preservatives with antifungal properties were evaluated on "Ortanique" mandarins during long-term cold storage. Selected food preservatives included potassium sorbate (PS), sodium benzoate (SB), sodium propionate (SP), and their mixtures. Intact mandarins or mandarins artificially inoculated with the pathogens Penicillium digitatum and Penicillium italicum, the causal agents of citrus postharvest green (GM) and blue (BM) molds, respectively, were coated and stored up to 8 wk at 5 °C + 1 wk of shelf-life at 20 °C. HPMC-lipid coatings containing food preservatives controlled better GM than BM on Ortanique mandarins. SB- and SB + SP-based coatings reduced the incidence of GM by about 35% after 4 wk at 5 °C. Among all coatings, only the SB-based coating reduced the incidence of GM (about 16%) after 6 wk at 5 °C. All coatings significantly reduced disease severity of both GM and BM after 6 wk at 5 °C. Analytical and sensory fruit quality was evaluated on intact mandarins. All coatings, especially the SB + SP-based coatings, were effective to control weight loss and maintain the firmness of coated mandarins. Internal gas concentration, juice ethanol and acetaldehyde content, sensory flavor, off-flavor, and fruit appearance were not adversely affected by the application of the antifungal coatings. Further studies should focus on the modification of some physical characteristics of the coatings to improve the gloss and visual aspect of treated mandarins.


Assuntos
Antifúngicos/farmacologia , Citrus/microbiologia , Conservantes de Alimentos/farmacologia , Frutas/microbiologia , Metilcelulose/análogos & derivados , Penicillium/efeitos dos fármacos , Ácidos Esteáricos/química , Adulto , Fenômenos Químicos , Feminino , Manipulação de Alimentos , Glicerol/química , Humanos , Derivados da Hipromelose , Masculino , Metilcelulose/química , Pessoa de Meia-Idade , Penicillium/crescimento & desenvolvimento , Penicillium/isolamento & purificação , Propionatos/farmacologia , Controle de Qualidade , Sensação , Benzoato de Sódio/farmacologia , Ácido Sórbico/farmacologia , Propriedades de Superfície , Temperatura
15.
J Agric Food Chem ; 57(7): 2770-7, 2009 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-19256514

RESUMO

Edible composite coatings based on hydroxypropyl methylcellulose (HPMC), lipid components (beeswax and shellac), and food preservatives with antifungal properties were evaluated in vivo on clementine mandarins cv. Clemenules, hybrid mandarins cv. Ortanique, and oranges cv. Valencia. Their curative and preventive activity against citrus postharvest green (GM) and blue molds (BM), caused by Penicillium digitatum (PD) or Penicillium italicum (PI), respectively, were determined. Fruits were artificially inoculated before or after the application of the coatings and incubated up to 7 days at 20 degrees C. Selected food preservatives included mineral salts, organic acid salts, parabens, and 2-deoxy-d-glucose. Inoculated but uncoated fruits were used as controls. For curative activity, HPMC-lipid edible composite coatings containing sodium benzoate (SB) were most effective in reducing the incidence and severity of GM on clementine mandarins cv. Clemenules (86 and 90%, respectively). On this cultivar, the reduction in GM incidence by the SB-based coating was twice that of potassium sorbate (PS)-based coating. On mandarins cv. Ortanique, PS- and SB-based coatings reduced the incidence of GM and BM by more than 40 and 21%, respectively. However, the HPMC-lipid coating containing a mixture of PS and sodium propionate (PS + SP) exhibited a synergistic effect in the reduction of the incidence of GM (78%) and BM (67%). Coatings with parabens modestly reduced disease incidence and severity. On oranges cv. Valencia, coatings with food preservatives better controlled BM than GM. Coatings containing SB + PS and SB + SP reduced the incidence and severity of BM by 85% and 95%, respectively. PS- and SB- based coatings controlled GM more effectively than coatings formulated with other food preservatives. In every cultivar, fruit coated before inoculation did not show any incidence or severity reduction of both GM and BM (preventive activity). In every test, the antifungal action of the coatings was fungistatic rather than fungicidal.


Assuntos
Citrus/microbiologia , Conservação de Alimentos/métodos , Frutas/microbiologia , Fungicidas Industriais/administração & dosagem , Metilcelulose/análogos & derivados , Derivados da Hipromelose , Penicillium/crescimento & desenvolvimento , Resinas Vegetais , Ceras
16.
J Agric Food Chem ; 56(23): 11270-8, 2008 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-19012404

RESUMO

New hydroxypropyl methylcellulose (HPMC)-lipid edible composite films containing low-toxicity chemicals with antifungal properties were developed. Tested chemicals were mainly salts of organic acids, salts of parabens, and mineral salts, classified as food additives or generally recognized as safe (GRAS) compounds. Selected films containing food preservatives were used for in vitro evaluation (disk diameter test) of their antifungal activity against Penicillium digitatum (PD) and Penicillium italicum (PI), the most important postharvest pathogens of fresh citrus fruit. Mechanical properties and oxygen (OP) and water vapor permeabilities (WVP) of selected films were also determined. Film disks containing parabens and their mixtures inhibited PD and PI to a higher extent than the other chemicals tested. Among all organic acid salts tested, potassium sorbate (PS) and sodium benzoate (SB) were the most effective salts in controlling both PD and PI. The use of mixtures of parabens or organic acid salts did not provide an additive or synergistic effect for mold inhibition when compared to the use of single chemicals. Barrier and mechanical properties of films were affected by the addition of food preservatives. Results showed that HPMC-lipid films containing an appropriate food additive should promise as potential commercial antifungal edible coatings for fresh citrus fruit.


Assuntos
Antifúngicos/farmacologia , Aditivos Alimentares/farmacologia , Conservantes de Alimentos/farmacologia , Lipídeos/farmacologia , Metilcelulose/análogos & derivados , Penicillium/efeitos dos fármacos , Antifúngicos/química , Aditivos Alimentares/química , Conservação de Alimentos/métodos , Conservantes de Alimentos/química , Derivados da Hipromelose , Lipídeos/química , Metilcelulose/química , Metilcelulose/farmacologia
17.
J Agric Food Chem ; 56(22): 10689-96, 2008 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-18950188

RESUMO

The objective of this work was to investigate the effect of fatty acid (FA) type and content on mechanical properties, water vapor permeability and oxygen permeability of hydroxypropyl methycellulose (HPMC)-beeswax (BW) stand-alone edible films. The effect of these films formed as coatings on the postharvest quality of 'Ortanique' mandarins was also studied. Selected FAs were stearic acid (SA), palmitic acid (PA), and oleic acid (OA), using BW/FA ratios of 1:0.5 and 1:0.2 (w/w). HPMCBW coatings reduced weight and firmness loss of 'Ortanique' mandarins, without compromising flavor quality compared to uncoated mandarins. Coatings containing OA provided the best weight loss control at both concentrations tested; however, when the BW/OA ratio was 1:0.5, the coatings increased fruit internal CO2, ethanol, and acetaldehyde contents of 'Ortanique' mandarins, therefore reducing flavor compared to the rest of the coatings studied. Although barrier and mechanical properties might be used to understand coating performance, differences observed between film oxygen permeability and coating permeability indicate that permeance should be measured on the coated fruit.


Assuntos
Citrus sinensis , Ácidos Graxos/análise , Embalagem de Alimentos/instrumentação , Frutas/química , Metilcelulose/análogos & derivados , Ceras , Conservação de Alimentos/métodos , Humanos , Derivados da Hipromelose , Ácido Oleico/análise , Ácido Oleico/química , Ácido Palmítico/análise , Ácido Palmítico/química , Controle de Qualidade , Sensação , Ácidos Esteáricos/análise , Ácidos Esteáricos/química
18.
J Agric Food Chem ; 56(20): 9502-9, 2008 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-18823125

RESUMO

The effect of the composition of hydroxypropyl methylcellulose (HPMC)-beeswax (BW) edible coatings on stand-alone film properties and on postharvest quality of coated 'Angeleno' plums was studied. Glycerol (G) and mannitol (M) were tested as plasticizers at two different plasticizer/HPMC ratios (100:1 and 300:1 molar basis). BW content was 20 or 40% (dry basis). An increase in G content increased film flexibility and vapor permeability (WVP), whereas an increase in M content enhanced film brittleness without affecting WVP. An increase in BW content reduced film flexibility and reduced WVP of only G-plasticized films. Coatings reduced plum softening and bleeding, but were not effective in reducing plum weight loss. At low plasticizer content, coatings reduced texture loss effectively. Low BW also lowered plum bleeding. Plasticizer type affected only ethanol and acetaldehyde contents without affecting the remaining quality parameters. Therefore, HPMC-BW coatings have the potential to extend the shelf life of plums. However, this effect depends on coating composition. Differences between coating and film performance indicate that data from stand-alone films may be used as a preliminary screening, but coating performance should be analyzed on coated fruit.


Assuntos
Conservação de Alimentos/métodos , Glicerol/química , Manitol/química , Metilcelulose/análogos & derivados , Prunus/química , Ceras/química , Acetaldeído/análise , Etanol/análise , Frutas/química , Derivados da Hipromelose , Metilcelulose/química , Permeabilidade
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