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1.
J Agric Food Chem ; 68(3): 712-726, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31891495

RESUMO

Lycopene, one of the most dominant carotenoids in a person's diet, is a well-known natural compound that has protective effects against chronic diseases. Industrial and domestic processing and storage conditions significantly influence retention and isomerization of lycopene; thus, in recent years, great attention has been given for their preservative effects of lycopene. This review highlights recent strategies that have been developed to preserve lycopene in processed products, especially in tomato pulp, puree, paste, and juice. The key factors influencing lycopene degradation and isomerization, such as ingredients and intensity of thermal treatments, are also discussed. Special attention was paid to the crystalline structures of lycopene which facilitate its resistance to degradation and isomerization. Emerging non-thermal processing methods, such as ultrasound and high-pressure processing (HPP), are critically evaluated for their preservation of thermo-labile compounds. Novel trends to improve lycopene stability by micro- and nanoencapsulation and addition of antioxidants are also included to examine their efficacy to protect against light, heat, oxygen, and other oxidative processes. Finally, recommended processing and storage conditions are discussed to provide strategies to retain the highest possible amount of bioactive lycopene until consumption.


Assuntos
Manipulação de Alimentos/métodos , Licopeno/química , Manipulação de Alimentos/instrumentação , Temperatura Alta , Isomerismo , Lycopersicon esculentum/química
2.
J Food Sci ; 85(2): 316-323, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31968398

RESUMO

This work proposes a novel approach based on the real-time monitoring of the fining process of apple juices by static multiple light scattering. The change in transmission was used to determine the fining effectiveness of three vegetable proteins, respectively, red lentil, green lentil, and green pea proteins. Further treatment with gelatin-bentonite was used as a control. The modified Gompertz function was applied to fit the transmission signals. According to (1) the rate of flocculation and (2) the rate of sedimentation, the best fining efficiency was achieved by red lentil, which was similar to that of gelatin-bentonite and higher than green lentil and green pea proteins. This ranking was obtained at any dose from 60 to 900 mg per liter of juice. The results suggest the use of red lentil as a potential fining agent for apple juices and highlight the advantages of using static multiple light scattering technique as a quality control tool for studying the kinetics of the fining process. PRACTICAL APPLICATION: The study proposed the use of vegetable proteins as fining agents for apple juices. Their efficiency was ably monitored in real time by static multiple light scattering.


Assuntos
Manipulação de Alimentos/métodos , Sucos de Frutas e Vegetais/análise , Malus/química , Proteínas de Vegetais Comestíveis/química , Manipulação de Alimentos/instrumentação , Lens (Planta)/química , Ervilhas/química
3.
Food Microbiol ; 87: 103367, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31948615

RESUMO

Listeria monocytogenes is an important foodborne pathogen, causative agent of listeriosis. The epidemiology and persistence of this bacterium in meat processing plants may be related to its serotype, so it is of utmost importance to carry out a correct differentiation of L. monocytogenes serotypes. The objective of this study was to develop a unique quadruplex real-time quantitative PCR (qPCR) method able to differentiate the four most predominant and worrying L. monocytogenes serotypes (1/2a, 1/2b, 1/2c and 4b) in isolates from meat processing plants and ready-to-eat (RTE) dry-cured meat products. The design of specific primers and probes was based on the lmo0737, lmo0308, ORFC (locus genomically equivalent to gltA-gltB) and ORF2110 genes. A qPCR based on a fragment of the 16S rRNA gene was used to ensure the amplification of Listeria spp. genomic DNA. The standard curves showed efficiency values ranging between 92.3% and 105.8% and, R2 values > 0.98. The specificity of the method was also confirmed by the comparison of the results with those obtained by a previously reported conventional multiplex PCR. In addition, none of the strains which were not ascribed to L. monocytogenes amplified any of the target genes related to the four major serotypes of this pathogenic species. The qPCR, therefore, provides a sensitive, specific and rapid tool for identifying the L. monocytogenes serotypes 1/2a, 1/2b, 1/2c and 4b. This method could be very useful for identifying sources of L. monocytogenes contamination in the meat industry or for epidemiological monitoring of persistent strains throughout the processing of RTE meat products.


Assuntos
Listeria monocytogenes/isolamento & purificação , Carne/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Primers do DNA/genética , DNA Bacteriano/genética , Contaminação de Alimentos/análise , Manipulação de Alimentos/instrumentação , Listeria monocytogenes/classificação , Listeria monocytogenes/genética , Produtos da Carne/microbiologia , RNA Ribossômico 16S/genética , Sorogrupo
4.
J Sci Food Agric ; 100(4): 1653-1661, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31802493

RESUMO

BACKGROUND: The consumption of pesticide-contaminated sour cherries as fruit or juice has become a major health concern, and so the search for alternative processing technologies, such as pulsed electric fields (PEF), ozone (O), and ultrasonication (US) has intensified. The objectives of this experimental study of sour cherry juice were fourfold: (1) to quantify the removal efficiency of new processing technologies (PEF, O, US), and their combinations, for the pesticides chlorpyrifos ethyl, τ-fluvalinate, cyprodinil, pyraclostrobin, and malathion; (2) to detect their impact on physical, bioactive, and sensory properties; (3) to determine their microbial inactivation levels for Escherichia coli O157:H7, Bacillus cereus, Pseudomonas syringae subs. Syringae, and Penicillum expansum; and (4) to jointly optimize multiple responses of physical, quality, and sensory properties, pesticides, and microbial inactivation. RESULTS: Except for all the O treatments, the physical, bioactive and sensory properties of sour cherry juice were not adversely affected by the treatments. The joint optimization suggested PEF1 (24.7 kV cm-1 for 327 µs), PEF2 (24.7 kV cm-1 for 655 µs), PEF2 + O + US, US, and PEF2 + O as the five best treatments. PEF2 + O + US best achieved both pesticide removal and microbial inactivation. CONCLUSION: PEF2 + O + US provided promising reductions in pesticide and microbial loads. © 2019 Society of Chemical Industry.


Assuntos
Manipulação de Alimentos/métodos , Sucos de Frutas e Vegetais/microbiologia , Praguicidas/química , Prunus avium/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Contagem de Colônia Microbiana , Contaminação de Alimentos/análise , Manipulação de Alimentos/instrumentação , Sucos de Frutas e Vegetais/análise , Viabilidade Microbiana , Praguicidas/isolamento & purificação , Prunus avium/química , Controle de Qualidade
5.
Int J Food Microbiol ; 313: 108381, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31670167

RESUMO

As a raw agricultural commodity, wheat is exposed to microbial contamination; therefore, enteric pathogens may be among its microbiota creating a food safety risk in milled products. This research evaluates (1) the effectiveness of organic acids dissolved in saline solutions to reduce the counts of pathogenic microorganisms in soft and hard wheat, and also investigates the effect of seasonal temperature on (2) survivability of pathogens in wheat kernels and on (3) pathogen inactivation during tempering with saline organic acid solutions. Wheat samples were inoculated with cocktails of either 5 serovars of Salmonella enterica, 5 E. coli O157:H7 or 6 non-O157 Shiga toxin-producing E. coli (STEC) strains to achieve a concentration of ~7 log CFU/g. Inoculated samples were allowed to stand for 7-days at temperatures (2.0, 10.8, 24.2, 32 °C) corresponding to those experienced during winter, spring/fall, and summer (average and maximum) in the main wheat growing regions in the state of Nebraska, USA. Besides water, solutions containing acid (acetic or lactic 2.5% or 5.0% v/v) and NaCl (~26% w/v) were used for tempering the wheat to 15.0% (soft) and 15.5% (hard) moisture at the different seasonal temperatures. The survival of pathogenic microorganisms throughout the resting period, and before and after tempering was analyzed by plating samples on injury-recovery media. The survival rate of pathogenic microorganisms on wheat kernels was higher at temperatures experienced during the winter (2.0 °C) and spring/fall (10.8 °C) months. Regardless of tempering temperature, the initial pathogen load was reduced significantly by all solutions when compared to the control tempered with water (P ≤ .05). The combination of lactic acid (5.0%) and NaCl was the most effective treatment against Salmonella enterica, E. coli O157:H7 and non-O157 STEC, with average reduction values of 1.8, 1.8 and 1.6 log CFU/g for soft wheat and 2.6, 2.4 and 2.4 log CFU/g for hard wheat, respectively. Implementation of organic acids and NaCl in tempering water may have the potential to reduce the risk of pathogen contamination in milled products.


Assuntos
Ácidos/farmacologia , Manipulação de Alimentos/métodos , Cloreto de Sódio/farmacologia , Triticum/microbiologia , Ácidos/química , Contagem de Colônia Microbiana , Escherichia coli O157/efeitos dos fármacos , Escherichia coli O157/crescimento & desenvolvimento , Manipulação de Alimentos/instrumentação , Microbiologia de Alimentos , Inocuidade dos Alimentos , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/crescimento & desenvolvimento , Estações do Ano , Temperatura
6.
J Sci Food Agric ; 100(1): 16-24, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31328265

RESUMO

Pulsed electric field (PEF) treatment consists of exposing food to electrical fields between electrodes within a treatment chamber, which can improve the preservation of fresh-like products such as milk. Although several studies support the use of PEF technology to process milk at low temperature, these studies reported microbial reductions of around 3 log10 cycles and also indicated a limited impact of PEF on some endogenous and microbial enzymes. This scenario indicates that increasing the impact of PEF on both enzymes and microorganisms remains a major challenge for this technology in milk processing. More recently, combining PEF with mild heating (below pasteurization condition) has been explored as an alternative processing technology to enhance the safety and to preserve the quality of fresh milk and milk products. Mild heating with PEF enhanced the safety of milk and derived products (3 log10 -6 log10 cycles reduction on microbial load and drastic impact on the activity enzymes related to quality decay). Moreover, with this approach, there was minimal impact on enzymes of technological and safety relevance, proteins, milk fat globules, and nutrients (particularly for vitamins) and improvements in the shelf-life of milk and selected derived products were obtained. Finally, further experiments should consider the use of milk processed by PEF with mild heating on cheese-making. The combined approach of PEF with mild heating to process milk and derived products is very promising. The characteristics of current PEF systems (which is being used at an industrial level in several countries) and their use in the liquid food industry, particularly for milk and some milk products, could advance towards this strategy. © 2019 Society of Chemical Industry.


Assuntos
Manipulação de Alimentos/métodos , Leite/química , Animais , Bovinos , Manipulação de Alimentos/instrumentação
7.
J Sci Food Agric ; 100(1): 74-80, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31435945

RESUMO

BACKGROUND: Infrared (IR)-assisted spouted bed drying (SBD) has emerged as a potential alternative to the traditional hot air drying for heat sensitive components. The aim of this study was to investigate effect of IR-assisted SBD and application of cold press (CP), solvent extraction (SE) and ultrasound assisted extraction (UAE) on the quality of flaxseed oil. SBD and IR-assisted SBD were performed at air temperatures of 40, 60, 80 °C and their effects on the drying rate, fatty acids composition and oil peroxide and acid values were evaluated. Quality of oil extracted from the dried flaxseeds by CP, SE and UAE methods was then evaluated. RESULTS: Increasing air temperature in the presence of IR increased the drying rate. The peroxide values (PVs) of IR-SBD samples were higher than those of SBD at the same temperature. IR treatment did not notably change the composition of fatty acids in flaxseed oil, except in linoleic acid content. UAE gave higher extraction yield than CP and SE methods. UAE yielded an oil with higher percentage of saturated fatty acids, whereas the percentage of omega-3 and omega-6 fatty acids was higher in the CP method. The oil extracted by CP exhibited lower levels of PV (0.516 meq O2 /kg oil) and acid value (1.36%), as compared to oils extracted by SE and UAE methods. CONCLUSION: Both UAE and conventional methods did not significantly influence the composition of fatty acids in the extracted oils. Nonetheless, the CP method yielded an oil with a high percentage of omega-3 and omega-6 fatty acids. © 2019 Society of Chemical Industry.


Assuntos
Linho/química , Manipulação de Alimentos/métodos , Óleo de Semente do Linho/química , Ácidos Graxos/química , Manipulação de Alimentos/instrumentação , Raios Infravermelhos , Óleo de Semente do Linho/isolamento & purificação , Sementes/química , Temperatura , Ultrassom
8.
J Sci Food Agric ; 100(1): 102-109, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31436308

RESUMO

BACKGROUND: The combination of sugar osmotic dehydration and microwave vacuum drying is an effective method for the dehydration of blackberries, the retention of their antioxidant properties, and the extension of their shelf life. Mass transfer during the osmotic dehydration of blackberries in sugar solution was investigated together with its influence on microwave vacuum drying characteristics, and the retention rate of anthocyanins in dried frozen blackberries. RESULTS: The concentrations of the osmotic solutions that were tested contained 40%, 50%, and 60% sugar, and the osmotic solution temperatures were 30 °C, 40 °C, and 50 °C. The solution-to-blackberry mass ratio was 10:1 (w/w) and the process duration varied from 0 to 5 h. A two-parameter mathematical model was used to describe mass transfer in the osmotic dehydration of blackberry samples and estimate moisture loss and solid gain in the final equilibrium. The results showed that the dehydration rate and solid gain rate of the blackberries increased with an increase in osmotic concentration, osmotic time, and the temperature of the solution under certain experimental conditions. The effective diffusivity of moisture and solute were estimated using the analytical solution of Fick's second law of diffusion. The moisture and effective diffusivities of sugar in the above osmotic dehydration conditions were in the range of 1.77 × 10-9 -2.10 × 10-9 and 1.36 × 10-9 -1.60 × 10-9 m2 .s-1 , respectively. CONCLUSION: The pretreatment of sugar osmosis greatly reduced the microwave vacuum drying time in the latter part of the dehydration period and increased anthocyanin retention. © 2019 Society of Chemical Industry.


Assuntos
Antocianinas/química , Dessecação/métodos , Manipulação de Alimentos/métodos , Rubus/química , Dessecação/instrumentação , Manipulação de Alimentos/instrumentação , Frutas/química , Micro-Ondas , Osmose , Temperatura , Vácuo , Água/análise
9.
J Sci Food Agric ; 100(1): 168-176, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31471909

RESUMO

BACKGROUND: Removing excessive naturally occurring fluoride from tea and/or infusions is difficult because the process has low efficiency and causes secondary pollution. In this study, a novel electrodialysis (ED) technology was developed. We examined the effect of crucial parameters (electrolyte concentration, operation voltage, ED duration and initial concentration of the tea infusion) on defluoridation performance using a highly efficient ion-exchange membrane with five-compartment cells. RESULTS: The most effective ED system results were obtained at an electrolyte concentration of 10 g kg-1 and operating voltage of 20 V. Moreover, the fluoride removal capacity (10.70-66.93%) was highly dependent on the ED duration (1-15 min) and initial concentration of the tea infusion (0.5-10 g kg-1 ). The longer the ED duration and the lower the initial concentration, the higher was the defluoridation performance. During ED, limited loss of the main inclusions (total polyphenols, catechins, caffeine and selected ions) was observed. Furthermore, the D201 anion resin-filled ED stack (0.5-5 g) and improvement of concentrate compartment electrolyte (≥5 times the dilute compartment electrolyte) in the ED system enhanced the defluoridation rate significantly. CONCLUSION: ED is a potentially effective method that can be used for defluoridation in the deep processing of tea products. © 2019 Society of Chemical Industry.


Assuntos
Diálise/métodos , Fluoretos/química , Manipulação de Alimentos/métodos , Chá/química , Diálise/instrumentação , Fluoretos/isolamento & purificação , Manipulação de Alimentos/instrumentação
10.
J Sci Food Agric ; 100(2): 560-569, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31588555

RESUMO

BACKGROUND: Preprocessing technologies of fresh tea leaves have a great influence on tea quality. A multifunctional preprocessing device for tea raw materials has been designed and utilized as a novel item of equipment to synchronously meet the process needs of spreading of green tea, withering of black tea and shaking of oolong tea. RESULTS: The preprocessing parameters of fresh tea leaves for spreading of green tea, withering of black tea and shaking of oolong tea were optimized by orthogonal experiments. Sensory assessment combined with statistical tools was employed as an analytical method to evaluate the pretreatment effect of processing different sorts of tea. The range analysis and variance analysis of tea sensory evaluation combined with chemical components (total polyphenols, free amino acids and soluble sugar) showed that A3 B2 C3 (70%, 25 °C, 8 h), A1 B3 C1 (60%, 28 °C, 18 h) and A1 B1 C3 (5 min, 20 °C, discontinuous leaf turning c) were considered to be the optimum schemes for the best pretreatment conditions of the above three major processing types of tea, respectively. The verification experiment of the proposed schemes was performed with satisfactory performance. CONCLUSION: This study demonstrated that a multifunctional preprocessing device for fresh tea leaves can be successfully applied to simultaneously estimate spreading of green tea, withering of black tea and shaking of oolong tea. © 2019 Society of Chemical Industry.


Assuntos
Camellia sinensis/química , Manipulação de Alimentos/instrumentação , Folhas de Planta/química , Chá/química , Aminoácidos/análise , Humanos , Polifenóis/análise , Paladar
11.
J Sci Food Agric ; 100(2): 764-774, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31605372

RESUMO

BACKGROUND: Air classification was used to fractionate canola meal (CM). The effect of combinations of air classification conditions, including rotor speed ranging from 300 to 1200 rpm, air stream rate from 700 to 860 cfpm, and secondary air from 0 to 30%, on particle size and nutritive composition was investigated. Response surface methodology was used to develop response surface equations to estimate these effects. RESULTS: Protein concentration increased in almost all the fine fractions. Effects of both secondary air and rotor speed of the air classifier were significant at P ≤ 0.1 and P ≤ 0.01, respectively. Almost all the fine fractions contained more oil. Rotor speed, air stream rate, and their interaction were significant at P ≤ 0.01. Both acid detergent fiber (ADF) and neutral detergent fiber (NDF) were shifted to the coarse fractions during the air classification. The rotor speed was significant for both ADF and NDF at P ≤ 0.01. CONCLUSIONS: Protein shifted to the fine fractions. The highest protein concentration in the fine CM fraction was estimated to be 404.2 g kg-1 , demonstrating an enhancement of 10.7%. ADF and NDF shifted to the coarse CM fractions and were respectively estimated to be 294.8 and 332 g kg-1 , which were increased by 52.7% and 43.7%. Oil shifted to the fine fractions. The highest concentration was predicted to be 59.7 g kg-1 , increased by 45.6%. Fine or coarse fraction yields were estimated to be 35-50%, indicating that they are acceptable for an industrial manufacture. © 2019 Society of Chemical Industry.


Assuntos
Brassica napus/química , Gorduras/análise , Manipulação de Alimentos/métodos , Fibras na Dieta/análise , Manipulação de Alimentos/instrumentação , Valor Nutritivo , Tamanho da Partícula
12.
J Sci Food Agric ; 100(2): 794-802, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31612484

RESUMO

BACKGROUND: Low-sodium sausages were manufactured using sodium substitution and biopolymer encapsulation. A diet comprising 10% treatment sausages (six treatment groups: C (100% NaCl), T1 (55% sodium substitute + 45% saltwort salt), T2 (55% sodium substitute + 45% saltwort salt with chitosan), T3 (55% sodium substitute + 45% saltwort salt with cellulose), T4 (55% sodium substitute + 45% saltwort salt with dextrin), and T5 (55% sodium substitute + 45% saltwort salt with pectin)) was added to a 90% commercial mouse diet for 4 weeks. RESULTS: Subacute toxicity, hematology, liver function, and organ weight tests in low-sodium sausage groups showed results similar to those of the control group, and all toxicity test levels were within normal ranges. CONCLUSIONS: All low-sodium sausage types tested are suggested to be safe in terms of subacute toxicity. Moreover, low-sodium sausages can be manufactured by biopolymer encapsulation of saltwort using pectin, chitosan, cellulose, and dextrin without toxicity. © 2019 Society of Chemical Industry.


Assuntos
Biopolímeros/análise , Aditivos Alimentares/análise , Manipulação de Alimentos/métodos , Produtos da Carne/análise , Salsola/química , Sódio/análise , Animais , Biopolímeros/metabolismo , Biopolímeros/toxicidade , Celulose/análise , Celulose/metabolismo , Celulose/toxicidade , Quitosana/análise , Quitosana/metabolismo , Quitosana/toxicidade , Feminino , Aditivos Alimentares/metabolismo , Aditivos Alimentares/toxicidade , Manipulação de Alimentos/instrumentação , Masculino , Produtos da Carne/toxicidade , Camundongos , Camundongos Endogâmicos ICR , Salsola/metabolismo , Salsola/toxicidade , Sódio/metabolismo , Sódio/toxicidade , Suínos
13.
J Dairy Sci ; 103(1): 201-209, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31677839

RESUMO

Concentrating milk by reverse osmosis (RO) has the potential to increase cheese yield but is known to impair cheese-making properties. The main compositional differences between ultrafiltration (UF) and RO concentrates are the high lactose and mineral contents of the latter. The objective of this work was to determine the distinct effects of high lactose and high minerals on the cheese-making properties of RO concentrate, by supplementing UF concentrate with lactose. The soluble colloidal equilibria of concentrates were studied as well as several other properties: rennet gelation behavior, cheese mass balance, composition, and microstructure. Rennet coagulation time was longer and gel firming rate was lower for RO concentrate than for UF concentrate. Lactose was mainly responsible for these differences. Lactose in RO concentrate was also responsible for the 7% increase of moisture-adjusted cheese yield, relative to UF concentrate. Compared with cheese made from UF concentrate, cheese made from RO concentrate showed higher moisture content, which could not be attributed to lactose but to the high mineral concentration. This study showed the potential of using RO instead of UF concentrate to maximize cheese yield. The approach is, however, limited to applications where post-acidification can be controlled, and will require appropriate strategies to reduce the negative effects of high mineral content in RO concentrate.


Assuntos
Queijo/análise , Manipulação de Alimentos/instrumentação , Lactose/análise , Minerais/análise , Osmose , Ultrafiltração/instrumentação
14.
Food Chem ; 311: 125932, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31862565

RESUMO

The present study investigated the changes in structural and emulsifying properties of lotus seed protein isolates (LSPIs) under different microwave-vacuum (MV) treatments. A decrease of fluorescence peak intensity with blue-shift of the fluorescence emission maximum indicated that MV treatment induced unfolding of LSPIs so that more hydrophobic residues were exposed. Raman spectra showed that the ordered secondary structures (α-helix, ß-sheet) gradually converted into ß-turns and random coils during 50-150 W MV treatment. Particle size distribution and atomic force microscope revealed that the amounts of small subunits increased when the LSPIs were modified by 50-100 W MV treatment. Emulsions prepared by 100-W-MV-LSPIs exhibited the optimal emulsifying ability with the smallest oil droplet sizes. Confocal laser scanning microscopy and analytical centrifugal analyzer further proved 50-100 W MV-treatment enhanced the flocculation and creaming stability. Our findings provide a certain theoretical foundation to apply MV technology for developing desirable LSPIs-stabilized emulsions.


Assuntos
Manipulação de Alimentos/métodos , Lotus/química , Proteínas de Plantas/química , Emulsões/química , Manipulação de Alimentos/instrumentação , Interações Hidrofóbicas e Hidrofílicas , Micro-Ondas , Tamanho da Partícula , Conformação Proteica em alfa-Hélice , Sementes/química , Vácuo
15.
Food Chem ; 311: 125911, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31869650

RESUMO

Milk allergenic proteins are the main reason of cow's milk allergy. The most common method for removing milk allergenic proteins is enzymatic hydrolysis. However, the direct application of protease to hydrolyze allergens will lead to the introduction of new allergenic proteins. An ideal strategy for removing milk allergenic proteins without introducing new allergenic proteins is immobilization of protease. Herein, we established a simple method to synthesize a novel papain-Cu3(PO4)2·3H2O-magnetic nanoflowers (PCMNs). The PCMNs demonstrated 1556% higher activity than the free alkaline papain. Moreover, the PCMNs could hydrolyze most of allergenic proteins in cow's milk, generating low-sensitive milk. In cycle analysis, the PCMNs also exhibited good reusability and were easily separated from the product.


Assuntos
Manipulação de Alimentos/métodos , Proteínas do Leite/química , Leite/química , Papaína/química , Alérgenos/química , Alérgenos/imunologia , Animais , Catálise , Bovinos , Manipulação de Alimentos/instrumentação , Hidrólise , Fenômenos Magnéticos , Leite/imunologia , Proteínas do Leite/imunologia
16.
J Food Sci ; 85(1): 132-142, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31880332

RESUMO

Curcuma longa is a rhizome used for the extraction of curcumin, a yellow colorant that only represents 3 wt% of the dried rhizome. To increase the possibility of using the entire rhizome as a food colorant, in the present investigation, the effect of ultra-fine friction grinding (supermasscolloider) to obtain turmeric suspensions was evaluated. To achieve this goal, two distances between the grinding stones or Gap were evaluated (G of -1 and -1.5), and the obtained suspensions were characterized by infrared spectroscopy and through the determination of curcumin content, color, particle size, sedimentation index, serum cloudiness, and microstructure. The results establish that a lower G contributes to an increase in the release of curcumin in the suspension up to 21%, which is related to a greater tendency for yellow coloration, observed in the increase of the * b coordinate of color (from 61.588 to 66.497). Additionally, it was found that a lower G generates smaller particle sizes, which is related to a lower turbidity. PRACTICAL APPLICATION: This research shows that ultra-fine friction grinding (UFFG) has great potential for the development of turmeric suspensions. The results have applications in the food industry sector, because UFFG could be used to produce different types of vegetable suspensions.


Assuntos
Curcuma/química , Manipulação de Alimentos/métodos , Extratos Vegetais/química , Curcumina/química , Curcumina/isolamento & purificação , Manipulação de Alimentos/instrumentação , Tamanho da Partícula , Extratos Vegetais/isolamento & purificação , Rizoma/química
17.
J Food Sci ; 84(12): 3565-3572, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31750950

RESUMO

We investigated the influence of both the clarification by ultrafiltration membranes with 100 or 18 kDa molar weight cut-off (MWCO) and subsequent storage on phenolic properties and color of mulberry juice (MJ). Results showed that clarification by the ultrafiltration membrane with 100 kDa MWCO elevated levels of total polyphenols (↑11.4%), total monomeric anthocyanins (↑87.7%), phenolic acids and flavonoids (↑10-64%), thus leading to enhanced antioxidant activity (↑twofolds) and α-glucosidase inhibitory rate (↑23.3%), as well as redness (↑37.9%), which were sharply decreased in the clarified MJ by the ultrafiltration membrane with 18 kDa MWCO. MJ pretreated by the membrane with 100 kDa MWCO exhibited better storage stability than the other two juices. Hence, the ultrafiltration membrane with 100 kDa MWCO has great potential in juice clarification for purpose of enrichment of phenolic compounds, and enhancement of bioactive activities and storage stability. PRACTICAL APPLICATION: Mulberry juice has many health benefits related to phenolic compounds. Clarification is necessary to obtain a bright, clear juice and improves juice taste, thus making a favorable first impression on consumer. Ultrafiltration membrane with 100 kDa MWCO is recommended in mulberry juice processing, since it helps to enrich phenolic compounds, and enhance bioactive activities and sensory quality of mulberry juice.


Assuntos
Manipulação de Alimentos/métodos , Sucos de Frutas e Vegetais/análise , Morus/química , Compostos Fitoquímicos/química , Antocianinas/química , Antioxidantes/química , Cor , Flavonoides/análise , Manipulação de Alimentos/instrumentação , Armazenamento de Alimentos , Frutas/química , Membranas Artificiais , Fenóis/química , Polifenóis/análise , Paladar , Ultrafiltração
18.
J Food Sci ; 84(10): 2932-2943, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31524954

RESUMO

The microbiota of traditional dry-cured sausages and industrial environment was assessed to characterize the diversity of coagulase-negative staphylococci (CNS), and establish potential relationships with hygiene level or technological characteristics. Eight processing units from South Portugal were audited according to a checklist of requirements. Environmental and products' samples at different production stages were evaluated regarding hygiene and safety criteria. CNS were recovered, characterized, and their potential use as starters evaluated. Low genetic diversity was observed for Staphylococcus xylosus, whereas Staphylococcus equorum showed diverse genetic profiles. Staphylococcus xylosus predominated in products with a long period of cold smoking, Staphylococcus saprophyticus in products with a long period of hot smoking, Staphylococcus epidermidis in products with a short period of cold smoking, and S. equorum in nonsmoked products. Most S. xylosus were resistant to tetracycline, whereas S. equorum were susceptible. Antibioresistance restricted the selection of starters due to safety recommendations. PRACTICAL APPLICATION: The present manuscript highlighted a few staphylococci strains that could potentially be used as starter cultures in fermented meat products. These selected strains do not show resistance to antimicrobials, exhibit adequate technological features, and are well adapted to the industrial environments of meat processing industries using different processing technologies. Therefore, the selected strains ready to be used in the manufacturing of traditional fermented meat products to ensure safety, standardize product properties, and shorten ripening.


Assuntos
Biodiversidade , Produtos da Carne/microbiologia , Staphylococcus/isolamento & purificação , Animais , Antibacterianos/farmacologia , Fermentação , Manipulação de Alimentos/instrumentação , Microbiologia de Alimentos , Filogenia , Portugal , Staphylococcus/classificação , Staphylococcus/efeitos dos fármacos , Staphylococcus/genética , Suínos
19.
mSphere ; 4(4)2019 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-31391275

RESUMO

Listeria monocytogenes is frequently found in foods and processing facilities, where it can persist, creating concerns for the food industry. Its ability to survive under a wide range of environmental conditions enhances the potential for cross-contamination of the final food products, leading to possible outbreaks of listeriosis. In this study, whole-genome sequencing (WGS) was applied as a tool to characterize and track 100 L. monocytogenes isolates collected from three food processing environments. These WGS data from environmental and food isolates were analyzed to (i) assess the genomic diversity of L. monocytogenes, (ii) identify possible source(s) of contamination, cross-contamination routes, and persistence, (iii) detect absence/presence of antimicrobial resistance-encoding genes, (iv) assess virulence genotypes, and (v) explore in vivo pathogenicity of selected L. monocytogenes isolates carrying different virulence genotypes. The predominant L. monocytogenes sublineages (SLs) identified were SL101 (21%), SL9 (17%), SL121 (12%), and SL5 (12%). Benzalkonium chloride (BC) tolerance-encoding genes were found in 62% of these isolates, a value that increased to 73% among putative persistent subgroups. The most prevalent gene was emrC followed by bcrABC, qacH-Tn6188, and qacC. The L. monocytogenes major virulence factor inlA was truncated in 31% of the isolates, and only one environmental isolate (L. monocytogenes CFS086) harbored all major virulence factors, including Listeria pathogenicity island 4 (LIPI-4), which has been shown to confer hypervirulence. A zebrafish embryo infection model showed a low (3%) embryo survival rate for all putatively hypervirulent L. monocytogenes isolates assayed. Higher embryo survival rates were observed following infection with unknown virulence potential (20%) and putatively hypovirulent (53 to 83%) L. monocytogenes isolates showing predicted pathogenic phenotypes inferred from virulence genotypes.IMPORTANCE This study extends current understanding of the genetic diversity among L. monocytogenes from various food products and food processing environments. Application of WGS-based strategies facilitated tracking of this pathogen of importance to human health along the production chain while providing insights into the pathogenic potential for some of the L. monocytogenes isolates recovered. These analyses enabled the grouping of selected isolates into three putative virulence categories according to their genotypes along with informing selection for phenotypic assessment of their pathogenicity using the zebrafish embryo infection model. It has also facilitated the identification of those isolates with genes conferring tolerance to commercially used biocides. Findings from this study highlight the potential for the application of WGS as a proactive tool to support food safety controls as applied to L. monocytogenes.


Assuntos
Microbiologia de Alimentos , Genótipo , Listeria monocytogenes/genética , Sequenciamento Completo do Genoma , Animais , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana , Manipulação de Alimentos/instrumentação , Variação Genética , Genoma Bacteriano , Listeria monocytogenes/patogenicidade , Listeriose/microbiologia , Fatores de Virulência/genética , Peixe-Zebra
20.
J Food Sci ; 84(9): 2528-2536, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31433070

RESUMO

Wheat flour may be thermally processed to improve microbiological safety; however, come-up time for thermal processing of wheat flour is long due to its low thermal conductivity. In the present study, a novel radiofrequency (RF)-assisted thermal processing approach was investigated for reducing the come-up time of soft wheat flour (SWF) and for improving microbiological safety. The temperature and time combinations of 80 °C for 7 and 10 hr, 90 °C for 2 and 3 hr, and 100 °C for 0.75 and 1 hr for RF-assisted thermal processing were selected to achieve a minimum of a 7-log reduction in Salmonella spp. The quality and functional properties of RF-assisted thermally processed SWF was evaluated by solvent retention capacity (SRC), swelling power, sodium dodecyl sulfate sedimentation tests, and rapid-visco-analyzer test, and the values were compared with the untreated (unpasteurized) and commercially pasteurized SWF. All the SRC attributes at 80 °C for 7 hr, 90 °C for 2 hr and 100 °C for 0.75 hr were not significantly different from that of the unpasteurized SWF. The optimum RF-assisted thermal processing conditions of 80 °C for 7 hr and 90 °C for 2 hr were recommended for pasteurization of SWF without any compromise in the quality and functionality. PRACTICAL APPLICATION: Thermal processing of low-moisture foods such as flours and powders through traditional methods is not practical due to extremely long come-up times. Novel radiofrequency-assisted thermal processing is poised to reduce the processing time 89 times for 100 °C. The processing parameters determined in this study will enhance the microbiological safety of wheat flour without compromising the quality and functionality.


Assuntos
Farinha/análise , Manipulação de Alimentos/métodos , Triticum/química , Farinha/microbiologia , Manipulação de Alimentos/instrumentação , Temperatura Alta , Pasteurização , Pós/química , Ondas de Rádio , Salmonella/crescimento & desenvolvimento , Salmonella/efeitos da radiação , Condutividade Térmica , Triticum/microbiologia
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