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1.
J Oleo Sci ; 69(9): 1031-1041, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32788512

RESUMO

To accelerate the fermentation rate and reduce the adverse effects of undesirable microorganism contamination on rice noodle quality, the pure inoculum fermentation method was used to produce fermented rice noodles. The results indicated that the pure inoculum fermented rice slurry required 10 h to reach a stable pH value. While, the pH value of the natural, pure and natural inoculum fermented rice slurries required 54, 18 and 20 h to stabilize, respectively. Free amino acids and lactic acid concentrations of the pure inoculum fermented rice slurry were higher than those of the natural and natural inoculum fermented rice slurries. The pure inoculum fermentation modified the proximate composition and lowered the pasting viscosities of the rice flour. The texture, cooking and eating qualities of the pure inoculum fermented rice noodles were similar to those of the natural fermented ones. In addition, the pure inoculum fermented rice noodles had higher relative contents of aldehydes than other fermented rice noodles and thus had a better flavor. Therefore, pure inoculum fermentation accelerated the fermentation rate and improved the rice noodle flavor while maintaining the texture, cooking and eating qualities of the rice noodles.


Assuntos
Fermentação , Manipulação de Alimentos/métodos , Qualidade dos Alimentos , Lactobacillus plantarum/metabolismo , Oryza/química , Oryza/microbiologia , Aldeídos/análise , Análise de Alimentos , Concentração de Íons de Hidrogênio , Paladar , Fatores de Tempo
2.
PLoS One ; 15(8): e0237265, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32841240

RESUMO

Roasting is the most common method of processing coffee. During roasting, aromatic compounds are generated due to various reactions, which are important for developing color, flavor and aroma. Acrylamide is an undesirable carcinogenic substance that is metabolically activated and formed during the coffee roasting process. Coffea arabica was first found in Ethiopia, and Ethiopia can produce a large volume of coffee. The major coffee-producing areas in Ethiopia are Hararghe, Sidama, Gimbi/Nekemte, Yergachefe and Limu. The primary purpose of this study was to quantify the acrylamide contents of brewed and roasted coffee collected from street coffee sellers and industrial processors found in Addis Ababa, Ethiopia, and optimize the roasting conditions for Sidama coffee. The acrylamide contents were determined by HPLC using a DAD at 210 nm, the antioxidant property were examined using a UV-spectrophotometer, and moisture and nutrient composition of coffee was determined using the method described by the AOAC (Association of Official Analytical Chemists). The roasting temperature and time were optimized based on the acrylamide content, nutritional composition and antioxidant property of the coffee using central composite design. The roasting temperature and time significantly affected (p<0.05) the acrylamide level, nutritional composition and antioxidant property of the coffee. The acrylamide contents of street and industrial processed powdered coffee were 346 ±19 to 701±38µg/kg and 442±14 to 906±7µg/kg, respectively. Brewed coffee from street vendors and industrial processing had acrylamide contents of 25±2 to 49±1µg/L and 63±2 to 89±4µg/L, respectively. The EC50 values for scavenging radicals for the optimized coffee ranged from 171±0 to 111±4 µg/L. The optimal roasting temperature and time were 190°C and 6 minutes, at this temperature and time the acrylamide content decreased, and the antioxidant and nutritional compositions of the coffee improved.


Assuntos
Acrilamida/análise , Antioxidantes/análise , Coffea/química , Café/química , Nutrientes/análise , Manipulação de Alimentos/métodos , Tecnologia de Alimentos/métodos , Temperatura Alta , Sementes/química
3.
PLoS One ; 15(6): e0235472, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32603372

RESUMO

Refrigerated ready-to-eat (RTE) dips often have pH and water activity combinations conducive to the proliferation of foodborne pathogens, including Listeria monocytogenes. This study conducted product assessments of five refrigerated RTE dips: baba ghanoush, guacamole, hummus, pesto, and tahini, along with individual dip components including avocado, basil, chickpeas, cilantro, eggplant, garlic, and jalapeno pepper. Dips and dip components were inoculated with 2 log CFU/g of L. monocytogenes and stored at 10°C for 28 days. The pathogen was enumerated throughout storage and growth rates were determined using the DMFit program to compute the time required for L. monocytogenes to achieve a 1 log CFU/g increase in population. Survival and growth rates varied significantly between the refrigerated RTE dips and dip components assessed in this study. For dips, L. monocytogenes progressively decreased in baba ghanoush, pesto, and tahini. In contrast, the pathogen proliferated in both hummus and guacamole and the highest growth rate was observed in guacamole (0.34±0.05 log CFU/g per day) resulting in a 1 log CFU/g increase in population in 7.8 days. L. monocytogenes proliferated in all dip components with the exception of eggplant and garlic. The pathogen achieved the highest growth rate in chickpeas (2.22±1.75 log CFU/g per day) resulting in a computed 1 log CFU/g increase in only 0.5 days. Results from this study can aid in understanding how L. monocytogenes behaves in refrigerated RTE dips and dip components and data can be utilized in understanding product formulations and in risk assessments.


Assuntos
Fast Foods/microbiologia , Listeria monocytogenes/crescimento & desenvolvimento , Cicer/microbiologia , Qualidade de Produtos para o Consumidor , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Conservação de Alimentos/métodos
4.
Food Chem ; 332: 127401, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32610261

RESUMO

Tofu gel was made by using citric acid (0.14%) in combination with varied volumetric ratios (e.g., 0-4%) of nano fish bone (NFB). The gel properties were investigated by colorimetry, penetration tests, scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. As the volumetric ratio increased from 0 to 3%, the soluble calcium concentrations of soymilk linearly increased from 1.78 to 6.42 mg/mL. Correspondently, yield, moisture and texture values of the tofu gel increased continuously (p < 0.05) while syneresis and whiteness decreased (p < 0.05). Furthermore, ionic bonds, hydrophobic interactions and hydrogen bonds increased by 140%, 40% and 10%, respectively. With the addition of NFB, the α-helices of the soybean proteins changed to ß-sheets and random coil structures. Additionally, the tofu gel network became more orderly and denser. The results confirmed that NFB can be utilized as a functional coagulant ingredient to improve the properties of acid-induced tofu gels.


Assuntos
Osso e Ossos/química , Ácido Cítrico/química , Peixes , Manipulação de Alimentos/métodos , Nanoestruturas/química , Alimentos de Soja/análise , Animais , Géis , Interações Hidrofóbicas e Hidrofílicas , Espectroscopia de Infravermelho com Transformada de Fourier
5.
Food Chem ; 332: 127399, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32645676

RESUMO

Different baking conditions were used in order to evaluate its effects on bread aspects. Doughs were baked at 160, 190 and 220 °C, during 9, 12, 15 and 20 min, and characterized in relation to color change, oxalate and mineral concentration, and protein digestibility. The higher the baking temperature and time, the higher the crust color change, the lower the oxalate concentration, and the higher the amount of some macro minerals. Protein digestibility may also be favored, however it does not follow a linear correlation. Although it is not possible to obtain a condition that favors the content of all minerals, protein digestibility and reduces oxalate content, the use of high temperatures and times is important as it can reduce oxalate and thereby prevent its associated problems. Understanding how to optimize it during baking could be used to produce breads with a higher mineral bioavailability, an important strategy for food industry and also when using alternative flours.


Assuntos
Pão/análise , Digestão , Manipulação de Alimentos/métodos , Minerais/análise , Oxalatos/análise , Proteínas de Plantas/química , Triticum/química , Farinha/análise , Temperatura Alta , Proteínas de Plantas/metabolismo
6.
Food Chem ; 332: 127391, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32603920

RESUMO

The objectives of the present work were to investigate the influence of Gum Arabic (GA) on the physicochemical properties and ultra-high temperature (UHT) processability of ß-lactoglobulin(ß-lg)-stabilized d-limonene emulsions. Moreover, we also wanted to evaluate the antimicrobial efficiency and mechanism of ß-lg-GA bilayer d-limonene emulsions. Physicochemically stable bilayer emulsions could be formed with an optimal concentration of GA (1.00 wt%), which showed a higher tolerance to both flocculation and coalescence, as well as better protective effects on d-limonene against UHT-treatment that up to 94.32% of d-limonene was retained in emulsions. Likewise, it is also noteworthy that no obvious difference in the minimal inhibitory concentration could be found between bilayer emulsions with or without UHT processing. Moreover, the antimicrobial effects of the bilayer emulsions with UHT treatment were shown to be dose-dependent, which was evidenced from the results of scanning electron microscopy and the determination of released cell constituents. Keywords: ß-lactoglobulin; gum arabic; d-limonene emulsion; physicochemical stability; UHT processability, antimicrobial efficiency.


Assuntos
Antibacterianos/química , Emulsões/química , Manipulação de Alimentos/métodos , Limoneno/química , Bicamadas Lipídicas/química , Antibacterianos/farmacologia , Elasticidade , Emulsões/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Goma Arábica/química , Temperatura Alta , Lactoglobulinas/química , Testes de Sensibilidade Microbiana , Viscosidade
7.
Food Chem ; 332: 127429, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32645678

RESUMO

Thermal processing is a traditional method for processing hawthorn into food or medicine. In this study, the compositions of free and bound phenolic compounds in raw hawthorn were analyzed by ultra-performance liquid chromatography quadrupole-time of flight mass spectrometry, and the effect of thermal processing on phenolics and antioxidant activity was determined. Among the phenolics identified in unheated hawthorn, 26 were soluble, while only 10 were insoluble-bound. Thermal processing caused a significant reduction in total soluble phenolics content, but an increase in total insoluble-bound phenolics (p < 0.05). Procyanidin B2 and epicatechin showed the largest decreases in content, and were not detected in well-cooked hawthorn. The antioxidant activity also clearly decreased, with the chlorogenic acid, procyanidin B2, hyperoside, and isoquercetin contents correlating significantly (p < 0.05) with antioxidant activity. In general, the effect of thermal processes on phenolics and antioxidant activity was dependent on the types of phenolics and processing conditions.


Assuntos
Antioxidantes/química , Crataegus/química , Manipulação de Alimentos/métodos , Fenóis/química , Extratos Vegetais/química , Antioxidantes/isolamento & purificação , Cromatografia Líquida , Temperatura Alta , Fenóis/isolamento & purificação , Extratos Vegetais/isolamento & purificação
8.
Food Chem ; 332: 127486, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32663756

RESUMO

Activated complex theory (ACT), apart from Van 't Hoff equation, has long been applying as an alternative tool to connect the kinetics (reaction rate constant, k) and thermodynamics parameters (including standard enthalpy of activation, △H++; standard entropy of activation, △S++; standard Gibbs free energy of activation, △G++). The study mainly focuses on ACT application in food systems, especially oil and fruit juice processing. Considering there are several improper calculations or mistakes often found in papers published recently in 2014-2019, three considerations are presented when applying the ACT, including 1) Understand that the reaction should be a single chemical elementary step; 2) Ensure that the units used should be consistent; 3) Effectively analyze the kinetics and thermodynamic parameters by choosing proper temperatures. This study is expected to further improve the understanding and correct application of this well-known theory in future work.


Assuntos
Manipulação de Alimentos/métodos , Tecnologia de Alimentos , Entropia , Tecnologia de Alimentos/métodos , Sucos de Frutas e Vegetais/análise , Cinética , Óleos/química , Temperatura , Termodinâmica
10.
Food Chem ; 333: 127442, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32673950

RESUMO

Betalains are violet-red, natural food grade pigments with health benefits; however, their stability limits its use in industrial food processing. This can be overcome by placing the betalains in lecithin nanoliposomes (NLs), which causes a 76% improvement of betalain colour and stability. Extended sonication time (8 min) lowered the zeta potential (-47.5 to -40.8), and particle size (74.23 to 55.35 nm). Zeta potential, particle size, and polydispersity index of Betalain NLs (BNLs) didn't change significantly during storage (40 days). Degradation in the colour of BNLs was observed only at 121 °C (20 min) while the native juice degraded at 100 °C (20 min). BNLs were incorporated in gummy candies (GuCa) to improve its colour stability. The betalain retention, colour, texture, antioxidant activity, and shelf-life of the GuCa during storage (5 °C, 28 days) demonstrated the efficacy of BNLs to be explored as a natural colourant for the food industry.


Assuntos
Betalaínas/química , Doces , Caryophyllales/química , Frutas/química , Lipossomos/química , Antioxidantes/química , Cor , Dieta Vegana , Manipulação de Alimentos/métodos , Armazenamento de Alimentos , Sucos de Frutas e Vegetais , Humanos , Nanoestruturas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Paladar , Temperatura
11.
Food Chem ; 333: 127423, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32659660

RESUMO

The aim of this work was to study the effect of thickness of samples, air velocity and infrared power on the drying kinetics and quality attributes of blanched eggplant slices during infrared drying. The drying experiments were made by Response Surface Methodology (RSM) based on a Box-Behnken design (BBD). Experiments were conducted at a thickness of 3, 5, and 7 mm, air velocity of 0.5, 1.25, and 2 m/s, as well as at infrared power 1000, 1500, and 2000 W. The drying time was affected by operating parameters. The drying processes increased total phenolic content and potassium content, significantly. The total color difference (ΔE) was in the range of 10.22-25.14. In the end, this process was optimized for reaching the best experimental condition.


Assuntos
Dessecação/métodos , Manipulação de Alimentos/métodos , Raios Infravermelhos , Solanum melongena/química , Fenóis/análise , Potássio/análise
12.
Food Chem ; 329: 127181, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32502743

RESUMO

The compounds that the wood releases to the wine and the oxygen transmission rate (OTR) of the barrel define the final wine. The new possibility of choosing the OTR of the barrel allows the winemaker to globally control the ageing process. The aim of this work was to study the volatile composition of woods classified according to their OTR, which are used to build barrels for wine ageing. The results showed that volatile composition differs depending on wood OTR and the temperature reached during toasting. On the toasted side of the stave in contact with the wine, low OTR wood had a statistically higher content in furan compounds (5-hydroxymethylfurfural, furfural and 5-methylfurfural), acetovanillone and phenolic aldehydes (vanillin and syringaldehyde), while 4-ethylguaiacol and trans-ß-methyl-γ-octalactone were significantly higher in staves with a high OTR. The same red wine aged first for three months in high and low oxygenation barrels presents different characteristics.


Assuntos
Manipulação de Alimentos/métodos , Oxigênio/química , Quercus/química , Compostos Orgânicos Voláteis/química , Vinho/análise , Benzaldeídos/química , Cromatografia Gasosa , Análise Discriminante , Furanos/química , Guaiacol/química , Temperatura , Madeira/química
13.
PLoS One ; 15(6): e0233239, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32516315

RESUMO

Foodborne contamination and associated illness in the United States is responsible for an estimated 48 million cases per year. Increased food demand, global commerce of perishable foods, and the growing threat of antibiotic resistance are driving factors elevating concern for food safety. Foodborne illness is often associated with fresh-cut, ready-to-eat produce commodities due to the perishable nature of the product and relatively minimal processing from farm to the consumer. The research presented here optimizes and evaluates the utility of microfluidic droplets, also termed ultra-miniaturized bioreactors, for rapid detection of viable Salmonella enterica ser. Typhimurium in a shredded lettuce wash water acquired from a major Mid-Atlantic produce processing facility (denoted as Producer) in the U.S. Using a fluorescently-labeled anti-S. Typhimurium antibody and relative fluorescence intensities, paired with in-droplet incubation, S. Typhimurium was detected and identified with 100% specificity in less than 5 h. In initial optimization experiments using S. Typhimurium-spiked sterile water, the relative fluorescence intensity of S. Typhimurium was approximately two times that of the observed relative intensities of five non-S. Typhimurium negative controls at 4-h incubation in droplets containing Rappaport-Vasiliadis (RV) broth at 37°C: relative fluorescence intensity for S. Typhimurium = 2.36 (95% CI: 2.15-2.58), Enterobacter aerogens 1.12 (95% CI: 1.09-1.16), Escherichia coli 700609 = 1.13 (95% CI: 1.09-1.17), E. coli 13706 1.13 (95% CI: 1.07-1.19), E. coli 700891 1.05 (95% CI: 1.03-1.07) and Citrobacter freundii 1.04 (95% CI: 1.03-1.05). S. Typhimurium- and E. aerogens-spiked shredded lettuce wash waters acquired from the Producer were then incubated 4 h in-droplet at 37°C with RV broth. The observed relative fluorescence of S. Typhimurium was significantly higher than that of E. aerogens, 1.56 (95% CI: 1.42-1.71) and 1.10 (95% CI: 1.08-1.12), respectively. While further optimization focusing on compatible concentration methodologies for highly-dilute produce water samples is needed, this application of droplet microfluidics shows great promise in dramatically shortening the time necessary-from days to hours-to confirm viable bacterial contamination in ready-to-eat produce wash waters used throughout the domestic and international food industry.


Assuntos
Microbiologia de Alimentos/métodos , Doenças Transmitidas por Alimentos/prevenção & controle , Técnicas Analíticas Microfluídicas/métodos , Cloro/análise , Citrobacter freundii , Contagem de Colônia Microbiana , Desinfetantes , Escherichia coli O157 , Contaminação de Alimentos/análise , Manipulação de Alimentos/métodos , Indústria de Processamento de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Microfluídica/métodos , Salmonella typhimurium
14.
Int J Food Microbiol ; 329: 108685, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32497791

RESUMO

Foodborne pathogens constitute a major food safety risk for cantaloupe, and pathogen biofilms formed are particularly difficult to remove. The goal of this study was to evaluate abrasive brushing in removing biofilms from cantaloupe surface using Listeria monocytogenes V7 and Salmonella enterica serovar Typhimurium ATCC 13311 as models. Cantaloupe rind pieces were inoculated and then subjected to 30 min or 24 h incubations. The incubated rind pieces were subject to different washing and/or brushing procedures and then the bacterial cells were enumerated. Cryo-SEM showed planktonic cells after 30 min incubation, whereas biofilms formed at rind surfaces after 24 h incubation. For L. monocytogenes 30 min incubation group, the log reductions were 1.4 for brushing, 2.1 for brushing with diatomaceous earth (DE), 2.8 for peroxyacetic acid (PAA) washing, 4.2 for brushing with PAA, and 4.0 for brushing with DE and PAA. In contrast, for the 24 h incubation group, the log reductions were 0.4 for brushing, 1.5 for brushing with DE, 1.1 for PAA washing, 1.6 for brushing with PAA, and 3.0 for brushing with DE and PAA. Similar results were observed for the S. Typhimurium group. These outcomes showed the pathogen-removal efficacy of brushing with DE (abrasive brushing) in the presence of biofilms, suggesting the potential application of abrasive brushing in cleaning cantaloupe for improved food safety.


Assuntos
Biofilmes , Cucumis melo/microbiologia , Manipulação de Alimentos/métodos , Microbiologia de Alimentos/métodos , Biofilmes/efeitos dos fármacos , Contagem de Colônia Microbiana , Qualidade de Produtos para o Consumidor , Listeria monocytogenes/efeitos dos fármacos , Ácido Peracético/farmacologia , Salmonella typhimurium/efeitos dos fármacos
15.
Food Chem ; 331: 127258, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32544652

RESUMO

Flavor stability is important for the quality of tea beverages. Baking is a typical processing technology to improve the flavor of tea leaves. In present study, seven raw tea materials, including steamed spring and autumn tea leaves, pan-fired spring tea leaves, and their corresponding baked tea leaves, were used to investigate the effect of baking on flavor stability of green tea beverages. The results showed that tea beverages prepared with baked tea had better flavor stability. The baking process obviously changed the concentrations of some important flavor substances, especially the aromatic pyrrole substances from 0 (unbaked) to 338.13 µg/L (baked) in tea beverages. Heat treatment had little influence on the flavor of tea beverages prepared from baked tea, but caused great changes in non-volatile and volatile components in those prepared from unbaked leaves. These results could help guide the processing of tea beverages which would improve their flavor quality stability.


Assuntos
Bebidas/análise , Manipulação de Alimentos/métodos , Chá/química , Catequina/análise , Cromatografia Líquida de Alta Pressão , Cor , Espectrometria de Massas , Folhas de Planta/química , Folhas de Planta/metabolismo , Polifenóis/análise , Análise de Componente Principal , Paladar , Chá/metabolismo , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química
16.
Food Chem ; 331: 127259, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32562977

RESUMO

Production of high-quality healthy foods through sustainable methodologies is an urgent necessity. High pressure homogenization (HPH) is an interesting alternative to obtain premium citrus juices, but its effects on bioactive compounds are unclear. There was studied the influence of HPH (150 MPa) and pasteurization (92 °C for 30 s and 85 °C for 15 s) processing on physicochemical properties and in vitro bioaccessibility of carotenoids and flavonoids in orange juices. Regarding fresh juice, physicochemical properties of samples remained unchanged although cloudiness was improved by homogenization. Pasteurization did not affect total carotenoids content and retinol activity equivalents (RAE) of juices whereas homogenization yielded a significant reduction (1.37 and 1.35-fold, respectively). Interestingly, particle size reduction from homogenization drastically enhanced (about 5-fold) bioaccessibility of carotenoids including hardly bioaccessible epoxycarotenoids, finding unaltered rates in pasteurized samples. Bioaccessibility of flavonoids was constant in all cases. Results can promote HPH as an efficient option to obtain health-enhanced foods.


Assuntos
Carotenoides/química , Citrus sinensis/química , Flavonoides/química , Manipulação de Alimentos/métodos , Sucos de Frutas e Vegetais/análise , Carotenoides/análise , Cromatografia Líquida de Alta Pressão , Citrus sinensis/metabolismo , Flavonoides/análise , Tamanho da Partícula , Pasteurização , Pressão
17.
Food Chem ; 331: 127262, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32563799

RESUMO

Stevioside is the main and the sweetest glycoside of stevia plant. It is attractive as a natural sweetener to diabetics and others on carbohydrate-controlled diets. This paper discusses the stability of stevioside under food processing conditions. It was found that stevioside was transformed not only to rubusoside, steviolbioside, steviol monoside and steviol but also to previously unknown stevioside α-anomer and rubusoside α-anomer. Those two identified stevioside transformation products are formed not only during the heating of acidic, neutral and alkaline stevioside standard solutions and stevia leaves suspensions in water and ethanol/water solvents but also during the processing of foods containing stevia. Apart from presenting the new compounds, the paper additionally shows that the recombination of sugar moiety with steviolbioside molecule in MS/ESI source can occur. The effect of molecule recombination in the MS source is known from the literature; however, it has not been reported previously in relation to stevioside derivatives.


Assuntos
Diterpenos de Caurano/química , Manipulação de Alimentos/métodos , Glucosídeos/química , Edulcorantes/química , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Hidrólise , Espectrometria de Massas por Ionização por Electrospray , Temperatura
18.
Int J Food Microbiol ; 331: 108694, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-32521373

RESUMO

This study evaluated if coatings with chitosan (Chi) and phenolic-rich extract from acerola (Malpighia emarginata D.C., PEA) or jabuticaba (Plinia jaboticaba (Vell.) Berg, PEJ) processing by-products are effective to control the development of rot caused by Lasiodiplodia pseudotheobromae, L. viticola, L. euphorbicola, L. theobromae and L. hormozganensis in papaya (Carica papaya L.) fruit. Effects of formulated coatings on some physicochemical parameters indicative of postharvest quality of papaya were investigated. Twenty-six different phenolics were found in PEA and PEJ, including flavonoids, stilbenes, tannins and phenolic acids. Chi (1-5 mg/mL), PEA and PEJ (25-100 mg/mL) separately caused mycelial growth inhibition on all isolates. Combinations of Chi (3 and 4 mg/mL) and PEA (50 and 75 mg/mL) or PEJ (75 and 100 mg/mL) had additive interactions. Coatings with Chi (4 mg/mL) and PEA (50 or 75 mg/mL) or PEA (75 or 100 mg/mL) inhibited rot development in papaya fruit infected with Lasiodiplodia isolates during 8 days of room temperature storage. Coatings with 4 mg/mL Chi and 75 mg/mL PEA or 100 mg/mL PEJ were the most effective to control rot development. These coatings did not affect negatively physicochemical parameters indicative of postharvest quality of papaya fruit during storage. Coatings with combined Chi and PEA or PEJ could be novel strategies to control postharvest rot caused by Lasiodiplodia in papaya fruit.


Assuntos
Carica/microbiologia , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Frutas/microbiologia , Malpighiaceae/química , Myrtaceae/química , Extratos Vegetais/farmacologia , Ascomicetos/efeitos dos fármacos , Quitosana/farmacologia , Fenóis/farmacologia
19.
Int J Food Microbiol ; 331: 108697, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-32563133

RESUMO

This research investigated the use of high-pressure processing (HPP) for inactivating vegetative pathogens and spoilage microbiota in fresh unfiltered coconut water (Cocos nucifera L) from nuts obtained from Florida and frozen CW from Brazil with pH >5.0 and storage at 4 °C. Additionally, CW was evaluated to determine if it supported the growth and toxin production of Clostridium botulinum with or without the use of HPP when stored at refrigeration temperatures. Samples of fresh unfiltered CW were inoculated to 5.5 to 6.5 logs/mL with multiple strain cocktails of E. coli O157:H7, Salmonella spp. and Listeria monocytogenes and HPP at 593 MPa for 3 min at 4 °C. HPP and inoculated non-HPP controls were stored at 4 °C for 54 and 75 days for Florida CW and Brazil CW, respectively. Results of analyses showed HPP samples with <1 CFU/mL and no detection (negative/25 mL) with enrichment procedures for the 3 inoculated pathogens for all analyses. The non-HPP control samples did not show growth of the pathogens but a gradual decrease in levels to ca. 3-Logs/mL by day 54 in the fresh Florida CW and similarly in frozen Brazil CW by Day 75. Microbial spoilage of uninoculated samples was evaluated for normal spoilage microbiota through 120 days storage at 4 °C. Microbial counts remained at ca. 2-logs with no detectable signs of spoilage for HPP samples through 120 d. The non-HPP control samples spoiled within 2 weeks of storage at 4 °C with gas production, cloudiness, and off-odors. To evaluate if CW supports the growth and toxin production of C. botulinum, samples of unfiltered and filtered (0.2 µm) CW were inoculated with either proteolytic or non-proteolytic C. botulinum spores at 2 log CFU/mL that were processed at 593 MPa for 3 min and stored at 4 °C and 10 °C for 45 days. Inoculated positive and non-inoculated negative controls were prepared and stored as the HPP treated and non-HPP samples. No growth of C. botulinum or toxin production was detected in either the unfiltered or filtered CW regardless if products were HPP treated or not. All inoculated samples with C. botulinum spores were enriched at Day-45 in PYGS media to determine the viability of the inoculated spores at the end of shelf-life and screened for C. botulinum toxins. In all samples, C. botulinum toxin Types A, B and E were detected indicating spores were viable throughout the storage. Type F toxin was not detected possibly due to inherent conditions in the samples that may affected toxin screening.


Assuntos
Fenômenos Fisiológicos Bacterianos , Cocos/microbiologia , Manipulação de Alimentos/métodos , Microbiologia de Alimentos/métodos , Sucos de Frutas e Vegetais/microbiologia , Alimentos Crus/microbiologia , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Brasil , Contagem de Colônia Microbiana , Temperatura
20.
Ecotoxicol Environ Saf ; 201: 110729, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32485491

RESUMO

The transformation of carbosulfan (CSN) in apples was investigated during oven-drying, microwave drying, and sun-drying. CSN transformed primarily into carbofuran (COA) during these drying processes. The conversion kinetics of CSN and COA was fitted by curve regression and mainly conformed to quadratic models (R2 = 0.70-0.97). Oven-drying promoted the transformation of CSN into COA. Microwave drying resulted in the highest scavenging capacity against CSN and COA (41%-100%). Moreover, a transformation mechanism was proposed on the basis of density functional theory (DFT) calculation. The COA originated from a series of chemical reactions involving hydroxyl substitution, cleavage, and oxidation; this result was further confirmed on the basis of molecular electrostatic potential (MEP) and molecular orbital theory. Furthermore, the toxicity and stability of CSN and COA were evaluated with the T.E.S.T. program. COA was less toxic than CSN to aquatic organisms but more toxic than CSN to rats. Therefore, COA production should be avoided during drying. Microwave drying was found to be the optimum choice for drying apples.


Assuntos
Carbamatos/metabolismo , Dessecação/métodos , Manipulação de Alimentos/métodos , Malus/química , Animais , Organismos Aquáticos/efeitos dos fármacos , Carbamatos/química , Carbamatos/toxicidade , Carbofurano/química , Carbofurano/metabolismo , Carbofurano/toxicidade , Dessecação/instrumentação , Manipulação de Alimentos/instrumentação , Depuradores de Radicais Livres/análise , Ratos
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