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1.
J Food Sci ; 89(4): 1988-2000, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38372192

RESUMO

Romaine lettuce outer leaves, as opposed to the more commonly marketed heart, are typically discarded and present an opportunity for upcycling as dried powders. Duquesne Romaine lettuce was evaluated to quantify and compare quality attributes of fresh outer and heart leaves, dried powders following hot air drying, and dried powders following an infrared (IR) blanching pretreatment before drying. Attributes measured for fresh leaves included moisture, water activity (Aw), color, total soluble phenolics (TSP), and antioxidant capacity (AC). Drying kinetics and time/energy saving through IR blanching were evaluated. Attributes measured for dried powders included moisture, Aw, color, true density, water vapor isotherms, TSP, AC, cadmium (Cd) content, and pesticide residues. TSP, AC, Cd, and pesticide residues were higher, whereas moisture content and Aw were lower in fresh outer versus heart leaves. Hot air drying reduced TSP and AC to 63.6% and 35.2% of fresh values, respectively, whereas IR blanching further reduced TSP and AC to 37.3% and 25.4% in outer leave powders. On the other hand, TSP and AC increased 237% and 151%, respectively, for unblanched heart powders. Higher increase of TSP than AC in heart leaf powder may indicate synthesis of phenolic compounds activated by abiotic stresses such as cutting and high temperatures at the initial drying stage. IR blanching resulted in significant time/energy savings for drying of outer leaves. Microbial loads were substantially reduced during drying, although microbial population on outer leaves were more resistant. Safe to eat outer leaf Romaine lettuce powders can be produced, assuming appropriate agricultural practices.


Assuntos
Lactuca , Resíduos de Praguicidas , Cádmio/análise , Resíduos de Praguicidas/análise , Antioxidantes/química , Dessecação/métodos , Folhas de Planta/química
2.
Foods ; 11(2)2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-35053909

RESUMO

Olive pomace (OP) is a valuable food byproduct that contains natural phenolic compounds with health benefits related to their antioxidant activities. Few investigations have been conducted on OP from the United States while many studies on European OP have been reported. OP of Arbequina, the most common cultivar from California, was collected and extracted by water, 70% methanol and 70% ethanol, followed by purification using macroporous absorbing resin. Results showed that the extractable total phenolic content (TPC) was 36-43 mg gallic acid equivalents (GAE)/g in pitted, drum-dried defatted olive pomace (DOP), with major contributions from hydroxytyrosol, oleuropein, rutin, verbascoside, 4-hydroxyphenyl acetic acid, hydroxytyrosol-glucoside and tyrosol-glucoside. Macroporous resin purification increased TPC by 4.6 times the ethanol crude extracts of DOP, while removing 37.33% total sugar. The antioxidant activities increased 3.7 times Trolox equivalents (TrE) by DPPH and 4.7 times TrE by ferric reducing antioxidant power (FRAP) in the resin purified extracts compared to the ethanol crude extracts. This study provided a new understanding of the extraction of the bioactive compounds from OP which could lead to practical applications as natural antioxidants, preservatives and antimicrobials in clean-label foods in the US.

3.
J Food Sci ; 86(11): 4865-4876, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34642970

RESUMO

Olive pomace (OP) is the main by-product of olive oil extraction. After pit and skin removal, OP pulp has high concentrations of dietary fiber and phenolics with high antioxidant capacity. This study evaluated mice health benefits of drum-dried pitted OP pulp obtained after first and second oil extraction. Fresh OP was steam blanched, then pits and skins separated in a pulper/finisher, and pulp drum-dried and milled. OP was characterized by proximate analysis, total soluble phenolics (TSP), individual phenolics, and dietary fiber. Drum-dried pitted OP from first and second extraction was formulated at 10% and 20% in a high fat mice diet. Low fat (5%) and high fat (18%) control diets were also used for comparison. First extraction OP had higher TSP than OP from second extraction. Hydroxytyrosol was the main phenolic in OP. Mice weight gain was lower for the four OP diets compared to high and low-fat control diets. Fecal protein was high for all OP diets, indicating poor protein retention in mice, possibly by phenolics binding of protein and enzymes. Liver weight and adipose tissue were lower in mice consuming the four high fat OP diets compared to high fat control diet. Also, there was no effect on blood glucose by OP in diets. Mice gut microbiota analysis indicated that Actinobacteria decreased in the OP diets compared to the two control diets while Bacteroidetes increased, indicating a positive correlation with reduced body fat and weight. Drum-dried pitted OP is a novel agricultural by-product with its bioactive compounds having the potential to be incorporated in feeds and foods providing health benefits. PRACTICAL APPLICATION: Drum-dried pitted olive pomace can be produced from first or second olive oil extraction byproducts to be used as a shelf-stable healthy food or feed supplement.


Assuntos
Olea , Animais , Antioxidantes , Fibras na Dieta/análise , Camundongos , Azeite de Oliva , Fenóis/análise
4.
Heliyon ; 7(5): e06874, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34027147

RESUMO

Healthful tasty high protein, vegetable, gluten-free snacks are needed for all as well as those sensitive to gluten for in between meals and for after school events. Peanut meal a low value farm by-product was used to increase protein content and to add value for growers. Bile acid binding okra with cholesterol lowering potential and jalapeno, turmeric and ginger with healthy phytonutrients were included to increase vegetable consumption. The objective was to have healthy tasty snacks with ≥24% protein content. Gluten-free, whole grain, high protein, Sorghum-Peanut meal-Okra (SPO) and SPO-Jalapeno, SPO-Turmeric root and SPO-Ginger root snacks were sensory evaluated by 73 volunteers. Physical testing of the snacks included water activity, true and bulk density, texture and proximate analyses. Taste and Odor of the SPO and SPO-Jalapeno snacks were similar and significantly (p ≤ 0.05) higher than SPO-Turmeric root and SPO-Ginger root. Acceptability of SPO and SPO-Jalapeno snacks were both 88%; this value is quite desirable. Acceptability of SPO-Turmeric and SPO-Ginger were only 56 and 51% respectively. Turmeric and ginger have been reported with many health benefits; however these snacks were not preferred by the tasters. Water activity (Aw) of the snacks tested was SPO (0.42) < SPO-Turmeric (0.52) < SPO-Jalapeno (0.54) < SPO-Ginger (0.62). Water activity indicates that all the snacks were crispy and had longer shelf life. Expansion of these snacks was SPO-Ginger root 84%, SPO-Turmeric root 76%, SPO-Jalapeno 42% and SPO only 14%. Data suggest snacks containing spices were fluffy and would give good presentation in packaging. The objective of attaining protein level was clearly attained, as values ranged 24-26%. These snacks are easy to make in house kitchens or by food companies. These healthy snacks offer a gluten-free, high protein, tasty choice for all, including vegetarians and individuals hypersensitive to gluten.

5.
ACS Omega ; 4(21): 19172-19176, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31763540

RESUMO

The effects of cellulose nanocrystals (CNCs) (12, 24, and 36% w/w) on the microstructure and mechanical and thermal properties of canola protein isolate films were evaluated. The incorporation of cellulose nanocrystals led to homogeneous films, and new Fourier transform infrared peaks appeared at 1055 cm-1, indicating the presence and the interaction of CNCs with proteins and glycerol. The addition of CNCs also improved the thermal stability of the films, since higher temperatures were required for their thermal decomposition. In addition, CNC addition resulted in an increase in tensile strength and a decrease in elongation at break values due to strong interactions between the OH groups in proteins, glycerol, and CNCs.

6.
Foods ; 8(11)2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31752409

RESUMO

Whole grain quinoa and wheat, high-protein vegetable flatbreads were evaluated by tasters and a physical analysis was conducted. The objective was to produce nutritious, tasty gluten-free (quinoa) as well as gluten-containing (wheat) flatbreads. Flatbreads were Quinoa Peanut Oilcake Broccoli (QPCBROC), Wheat Peanut Oilcake Broccoli (WPCBROC), Quinoa Peanut Oilcake Beets (QPCBEET) and Wheat Peanut Oilcake Beets (WPCBEET). Peanut Oilcake would increase protein and add value to this farm byproduct. Bile acid binding broccoli and beets with cholesterol-lowering potential were used. Tasters preferred QPCBROC flatbreads for all sensory parameters. Acceptance of flatbreads was QPCBROC (83%), WPCBROC (70%), QPCBEET (78%) and WPCBEET (69%); these values were statistically similar. The objective of ≥25% protein content was exceeded by 5-8% and that of ≥70% acceptance was adequately achieved. These flatbreads were low in fat (5-6%) and contained essential minerals (4%) with only ≤1% added salt. Porosity and expansion data suggest that these flatbreads would take up relatively little shelf space. These flatbreads require only three ingredients and can be made in a household kitchen or by commercial production. These flatbreads offer a nutritious, tasty choice for all, and quinoa flatbreads offer an option for gluten-sensitive individuals.

7.
Polymers (Basel) ; 11(8)2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31370362

RESUMO

This paper provides proof of concept that activated carbon (AC) may be readily produced using limited conversion methods and resources from sawdust of massaranduba (Manilkara huberi) wood, thereby obtaining value-added products. Sawdust was sieved and heat-treated in an oxygen-free muffle furnace at 500 °C to produce charcoal. The charcoal was activated in a tubular electric furnace at 850 °C while being purged with CO2 gas. Microstructural, thermal and physical properties of the three components: sawdust, charcoal and AC were compared by means of field emission scanning electron microscopy (FESEM), X-ray diffractometry (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), density and water adsorption/desorption measurements. The resulting AC had a large surface area as measured by Brunauer-Emmett-Teller (BET) comparable to other such values found in the literature. The large surface area was due to pore development at the microstructural level as shown by FESEM. XRD illustrated that sawdust had a semi-crystalline structure whereas charcoal and AC evidenced mostly amorphous structures. TGA and DSC showed that AC had high reactivity to moisture compared to sawdust and charcoal.

8.
J Food Sci ; 84(3): 412-420, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30730569

RESUMO

This study investigated drum-drying's ability to produce dried food-grade olive pomace as a potential food ingredient that is more nutritionally dense than its freeze-dried and hot-air dried counterparts. The pits and skin were removed from fresh olive pomace, and the remaining pulp was dried to <5% moisture through freeze-drying, hot-air drying, and drum-drying at two rotational speeds. The drying treatments had no significant (P ≤ 0.05) effect on the olive pomace's fat or dietary fiber contents but did increase the L* , a* , and b* color parameter values. Although all the drying treatments significantly (P ≤ 0.05) decreased the fresh olive pomace's antioxidant capacity, drum-drying preserved the olive pomace's antioxidant capacity significantly (P ≤ 0.05) better than freeze-drying and hot-air drying. The drum-dried samples had concentrations of caffeic acid and verbascoside that were significantly (P ≤ 0.05) higher than the other dried pomace samples and were not significantly (P ≤ 0.05) different from the fresh pomace. The drum-dried olive pomace contained concentrations of hydroxytyrosol, tyrosol, vanillic acid, luteolin-7-glucoside, and rutin that were not significantly (P ≤ 0.05) different from the dried sample with the highest concentration of each respective phenolic compound. No oleuropein was found in the fresh or dried olive pomace. The results of this study show that drum-drying is an energy efficient method for converting olive pomace into a stable food-grade supplement that preserves its high phenolic, antioxidant, and dietary fiber contents to potentially benefit human health when incorporated into food or supplement products. PRACTICAL APPLICATION: Pitting and drying converts the olive pomace into a stable form that is free of physical hazards and could be incorporated into food products to increase their nutritional quality through olive pomaces' high fiber, antioxidant, and phenolic contents. Drum-drying allows food-grade olive pomace to retain higher amounts of beneficial soluble phenolics and a higher antioxidant capacity than conventional drying methods, thus furthering olive pomace's potential valorization as a food ingredient.


Assuntos
Antioxidantes/química , Manipulação de Alimentos/métodos , Olea/química , Fenol/química , Extratos Vegetais/química , Resíduos/análise , Antioxidantes/isolamento & purificação , Fenol/isolamento & purificação , Extratos Vegetais/isolamento & purificação
9.
J Food Sci ; 83(4): 984-991, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29577286

RESUMO

Carvacrol is a volatile monoterpenic phenol and main component of oregano essential oil that shows nonspecific antimicrobial activity against foodborne pathogenic bacteria. Fish-skin gelatin (FSG) nanofibers encapsulating carvacrol (15%, 20%, 25%, and 30%, w/w FSG) were successfully prepared via solution blow-spinning (SBS) technique using lecithin (2.475% wb) as the surfactant. FSG emulsions with lower carvacrol ratios (5% and 10%) showed higher values in particle size and surface tension as well as lower values in viscosity and modulus, which led to failure of maintaining nanofibers shape. The formed carvacrol-FSG nanofibers showed round and smooth morphologies with average fiber diameters ranging from 103.2 to 138.1 nm as the carvacrol ratio increased from 15% to 30%. Carvacrol was evenly dispersed within the interior of nanofiber matrix. All carvacrol-FSG nanofibers showed inhibitive effects against the growth of Escherichia coli, Salmonella enterica, and Listeria monocytogenes. Moreover, nanofibers with lower carvacrol ratios showed bigger inhibition zones for E. coli and L. monocytogenes (20 mm compared with 12.5 mm for lowest to highest carvacrol ratios, respectively). Nanofibers stored at 20 °C (51% RH) showed better retention (40% to 60%) for carvacrol during the first 4 weeks of storage, while nanofibers stored at 2 °C (70% RH) showed better retention (10% to 30%) at the end of storage. PRACTICAL APPLICATION: Results obtained in the study may help with antimicrobial carvacrol addition levels for gelatin fiber preparation using solution blow spinning (SBS) method. SBS gelatin fibers with added antimicrobials have potential applications for food packaging and medical wound dressing.


Assuntos
Bactérias/efeitos dos fármacos , Proteínas de Peixes/farmacologia , Conservação de Alimentos/métodos , Gelatina/farmacologia , Monoterpenos/farmacologia , Nanofibras , Óleos Voláteis/farmacologia , Animais , Antibacterianos/farmacologia , Cimenos , Escherichia coli/efeitos dos fármacos , Peixes , Microbiologia de Alimentos , Embalagem de Alimentos/métodos , Doenças Transmitidas por Alimentos/microbiologia , Humanos , Listeria monocytogenes/efeitos dos fármacos , Monoterpenos/administração & dosagem , Óleos Voláteis/administração & dosagem , Origanum/química , Extratos Vegetais/farmacologia , Salmonella enterica/efeitos dos fármacos , Pele , Soluções/química , Viscosidade
10.
Int J Mol Sci ; 19(2)2018 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-29470390

RESUMO

Cinnamaldehyde, a natural preservative that can non-specifically deactivate foodborne pathogens, was successfully incorporated into fish skin gelatin (FSG) solutions and blow spun into uniform nanofibers. The effects of cinnamaldehyde ratios (5-30%, w/w FSG) on physicochemical properties of fiber-forming emulsions (FFEs) and their nanofibers were investigated. Higher ratios resulted in higher values in particle size and viscosity of FFEs, as well as higher values in diameter of nanofibers. Loss of cinnamaldehyde was observed during solution blow spinning (SBS) process and cinnamaldehyde was mainly located on the surface of resultant nanofibers. Nanofibers all showed antibacterial activity by direct diffusion and vapor release against Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes. Inhibition zones increased as cinnamaldehyde ratio increased. Nanofibers showed larger inhibition effects than films prepared by casting method when S. typhimurium was exposed to the released cinnamaldehyde vapor, although films had higher remaining cinnamaldehyde than nanofibers after preparation. Lower temperature was favorable for cinnamaldehyde retention, and nanofibers added with 10% cinnamaldehyde ratio showed the highest retention over eight-weeks of storage. Results suggest that FSG nanofibers can be prepared by SBS as carriers for antimicrobials.


Assuntos
Acroleína/análogos & derivados , Gelatina/química , Nanofibras/química , Nanotecnologia/métodos , Pele/química , Acroleína/química , Animais , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Emulsões , Peixes , Nanofibras/ultraestrutura , Tamanho da Partícula , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Tensão Superficial , Viscosidade
11.
J Food Sci ; 82(6): 1402-1411, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28471491

RESUMO

The primary advantage of nanofibers over larger diameter fibers is the larger surface area to volume ratio. This study evaluated solution blow spinning (SBS) processing conditions for obtaining food-grade gelatin nanofibers from mammalian and fishery byproducts, such as pork skin gelatins (PGs) and high molecular weight fish skin gelatin (HMWFG). HMWFG had a highest intact collagen structure compared to PGs. PGs with different Bloom values, solution viscosities, and surface tensions were compared with HMWFG for their ability to produce nanofibers through SBS. Only HMWFG fibers were obtained irrespective of processing conditions, which looked like fluffy cotton candy. HMWFG nanofibers had round morphologies with a narrower diameter distribution and lower average fiber diameter (AFD) under medium gelatin concentrations, medium air pressures, and medium feed rates. The highest glass transition temperature (Tg ) values were obtained at medium concentrations, medium air pressure, and either high or low feed rate. The thinnest HMWFG nanofibers with an AFD of 80.1 nm and the highest Tg value of 59.0 °C could be formed by combining a concentration of 17.6% (w/v), an air pressure of 0.379 MPa, and a feed rate of 0.06 mL/min from the response surface analysis. HMWFG Brunauer, Emmett, and Teller surface area increased from 221 to 237 m2 /g, indicating their potential applicability for active compound carrier.


Assuntos
Manipulação de Alimentos , Gelatina/química , Nanofibras/química , Animais , Peixes , Fenômenos Mecânicos , Reologia , Pele , Soluções , Suínos , Viscosidade
12.
Compr Rev Food Sci Food Saf ; 16(5): 1151-1169, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33371612

RESUMO

Food packaging materials are traditionally expected to contain foodstuffs and protect them from deteriorating agents. Although petroleum-derived polymers have been widely used for this purpose, the rising concern with their nonrenewable and/or nonbiodegradable nature paves the route for the development of greener alternatives, including polysaccharides and polypeptides. The use of these food-grade biomacromolecules, in addition to fruits and vegetables, provides edible packaging with suitable physical-mechanical properties as well as unique sensory and nutritional characteristics. This text reviews the chronological development pathway of films based on fruit and vegetable purees, pomaces, and extracts. Recent advances are extensively reviewed with an emphasis on the role that each film component plays in the resulting materials, whose production methods are examined from a technical standpoint and essential properties are compiled and contrasted to their conventional, synthetic counterparts. Finally, this comprehensive review discusses advantages and limitations of edible films based on fruits and vegetables.

13.
J Food Sci ; 81(12): N3015-N3025, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27861896

RESUMO

Zein fibers were successfully fabricated via solution blow spinning (SBS) using acetic acid as solvent. Surface tension, viscosity and modulus of zein solutions were respectively determined by force tensiometer and rheometer. Increases of these properties were observed with an increase of concentration from 20% to 35% (w/w). The fabrication conditions of zein fibers were initially investigated as a function of zein concentration (25% to 35% w/w), feed rate (0.04 to 0.1 mL/min) and air pressure (0.28 to 0.62 MPa). The average fiber diameter (AFD) ranged from 174 to 9595 nm based on scanning electron microscopy (SEM). A Box-Behnken experimental design (BBD) was further performed to identify and quantify the significance of above parameters. The statistical analysis showed that the linear coefficient of concentration, the quadratic term of concentration as well as the interaction between concentration and air pressure were demonstrated statistically significant. Optimal conditions, with an AFD of 138 nm, could be obtained in the SBS of zein fibers by combining a concentration of 23% (w/w), a feed rate of 0.04 mL/min and an air pressure of 0.38 MPa. The moisture sorption capacity of fibers increased slightly as AFD decreased from ∼550 to ∼200 nm, with an increase of BET surface area from 116.5 to 140.0 m2 /g.


Assuntos
Manipulação de Alimentos , Zeína/química , Anti-Infecciosos/química , Antioxidantes/química , Preparações de Ação Retardada/química , Fenômenos Mecânicos , Microscopia Eletrônica de Varredura , Reologia , Soluções , Viscosidade
14.
Heliyon ; 2(12): e00213, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28054034

RESUMO

Sensory evaluation of quinoa gluten-free whole grain low fat and salt snacks was conducted. The snacks were Quinoa, Quinoa-Cayenne Pepper, Quinoa-Ginger and Quinoa-Turmeric. Cayenne pepper, ginger and turmeric are common spices that contain health promoting nutrients. Cayenne pepper has been associated with enhancing heat production. Ginger has been reported to improve blood flow and prevent joint pains. Turmeric has been observed to have wound healing potential. All the snacks contained 6% corn oil and 2% salt. Snack dough was prepared using 120 mL water for 100 g dry ingredients. About 20 g of snack dough was placed on center of preheated KrumKake Express Baker and cooked for 2 min. Seventy in-house volunteers judged Color/Appearance of Quinoa, Quinoa-Cayenne Pepper and Quinoa-Ginger snacks significantly (p ≤ 0.05) higher than Quinoa-Turmeric snacks. Odor/Aroma of Quinoa-Ginger snacks was significantly higher than other snacks tested. Texture/Mouth-feel of Quinoa-Cayenne Pepper, Quinoa-Ginger and Quinoa-Turmeric snacks was similar and significantly higher than Quinoa snacks. Taste/Flavor and Acceptance was similar in four kinds of snacks tested. Water activity of all the snacks tested ranged from 0.41-0.55 suggesting that these snacks were crispy with good antimicrobial stability. These snacks would be quite filling due to their expansion of 2.6-3.1 times due to high porosity. Acceptance of snacks tested was Quinoa 79%, Quinoa-Cayenne Pepper 77%, Quinoa-Ginger 73% and Quinoa-Turmeric 70%. These snacks contained only 3-4 ingredients and could be made in any house kitchen or commercial production. Acceptance of 70-79% is very desirable. These healthy nutritious gluten-free quinoa snacks offer choice for all including vegetarians and individuals hypersensitive to gluten.

15.
Bioresour Technol ; 177: 58-65, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25479394

RESUMO

Apple, grape, olive, and tomato pomaces as well as almond and walnut shells were torrefied at different temperatures and times in a muffle furnace. The fiber content and thermal stability of the raw byproducts were examined and the moisture and ash contents, elemental composition, and gross calorific values of the raw and torrefied samples were characterized. Response surface methodology and a central composite design were used to examine the effects of temperature and time on mass and energy yields of the torrefied byproducts. Raw apple pomace had the highest hemicellulose content, whereas raw grape pomace had the highest lignin content. Raw tomato pomace had the highest gross calorific value because of its high carbon content. Temperature had a larger effect on mass and energy yields than time. Grape pomace generally had the highest mass and energy yields. Also, energy yields of the byproducts could be predicted from mass loss values.


Assuntos
Biotecnologia/métodos , Nozes/química , Resíduos , Elementos Químicos , Temperatura , Termogravimetria
16.
J Food Sci ; 79(5): M903-10, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24749789

RESUMO

UNLABELLED: Thyme essential oil (TEO) and apple skin polyphenols (ASP) are natural compounds considered as generally recognized as safe by FDA, with biological effects against bacteria and fungi. This work aimed to evaluate physical and antimicrobial properties of açaí edible films formulated with TEO and ASP at 3% and 6% (w/w) individually or combined at 3% (w/w) each. Physical properties studied include mechanical resistance, water vapor permeability (WVP), color, and thermal resistance. Antimicrobial activity against Listeria monocytogenes was determined using the overlay diffusion test. Addition of ASP resulted in improved mechanical properties. TEO at 6% (w/w) resulted in increased elongation. ASP films had significant higher WVP than control film. ASP films were lighter and had more red color than other films. Incorporation of ASP resulted in improved film thermal stability, whereas TEO caused rapid thermal decomposition. Presence of clusters was observed on the surface of films. Addition of ASP resulted in a smoother surface, whereas addition of TEO led to the formation of crater-like pits on the film surface. Açaí edible film incorporated with 6% (w/w) TEO presented the highest antimicrobial activity. However, both antimicrobials are necessary in the açaí films in order to obtain edible films with suitable physical-mechanical properties. The results of the present study showed that TEO and ASP can be used to prepare açaí edible films with adequate physical-mechanical properties and antimicrobial activity for food applications by direct contact. PRACTICAL APPLICATION: Developed açaí edible films presented antimicrobial activity against L. monocytogenes and good physical-mechanical properties, showing the potential use of açaí edible films in food preservation.


Assuntos
Antibacterianos/farmacologia , Euterpe , Conservação de Alimentos/métodos , Listeria monocytogenes/efeitos dos fármacos , Óleos Voláteis/farmacologia , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Embalagem de Alimentos/métodos , Malus/química , Permeabilidade , Extratos Vegetais/química , Thymus (Planta)/química
17.
J Agric Food Chem ; 62(4): 984-90, 2014 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-24405047

RESUMO

Increasing strawberry consumption has led to a growing safety concern because they are not washed after harvest. An antimicrobial edible coating could be an effective postharvest technique to ensure microbial safety and, at the same time, retain overall quality of the fruits. Response surface methodology was used to optimize the antimicrobial activity against Escherichia coli O157:H7 and Botrytis cinerea and several physical properties (turbidity, viscosity, and whitish index) of an alginate coating. A full factorial design was used to select the concentrations of carvacrol and methyl cinnamate on the basis of their effect against E. coli and B. cinerea. A central composite design was then performed to evaluate the effects/interactions of the two antimicrobials on the coating characteristics. The results from analysis of variance showed the significant fitting of all responses to the quadratic model. To attain the desirable responses, the optimal concentrations were 0.98% (w/w) carvacrol and 1.45% (w/w) methyl cinnamate.


Assuntos
Alginatos/química , Anti-Infecciosos , Cinamatos/farmacologia , Embalagem de Alimentos/instrumentação , Fragaria/microbiologia , Monoterpenos/farmacologia , Botrytis/efeitos dos fármacos , Fenômenos Químicos , Cimenos , Escherichia coli O157/efeitos dos fármacos , Frutas , Ácido Glucurônico/química , Ácidos Hexurônicos/química
18.
J Food Sci ; 77(9): E215-23, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22900795

RESUMO

Cold- and warm-water fish gelatin granules were exposed to ultraviolet-B radiation for doses up to 29.7 J/cm(2). Solutions and films were prepared from the granules. Gel electrophoresis and refractive index were used to examine changes in molecular weight of the samples. Also, the gel strength and rheological properties of the solutions as well as the tensile and water vapor barrier properties of the films were characterized. SDS-PAGE and refractive index results indicated cross-linking of gelatin chains after exposure to radiation. Interestingly, UV-B treated samples displayed higher gel strengths, with cold- and warm-water fish gelatin having gel strength increases from 1.39 to 2.11 N and from 7.15 to 8.34 N, respectively. In addition, both gelatin samples exhibited an increase in viscosity for higher UV doses. For gelatin films, the cold-water fish gelatin samples made from irradiated granules showed greater tensile strength. In comparison, the warm-water gelatin films made from irradiated granules had lower tensile strength, but better water vapor barrier properties. This might be due to the UV induced cross-linking in warm-water gelatin that disrupted helical structures.


Assuntos
Gelatina/química , Géis/química , Raios Ultravioleta , Água/química , Animais , Eletroforese em Gel de Poliacrilamida , Peixes , Tecnologia de Alimentos/métodos , Peso Molecular , Permeabilidade , Reologia , Vapor , Temperatura , Resistência à Tração , Viscosidade
19.
J Agric Food Chem ; 60(32): 7799-804, 2012 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-22831761

RESUMO

The addition of plant essential oils to edible films and coatings has been shown to protect against bacterial pathogens and spoilage while also enhancing sensory properties of foods. This study evaluated the effect of adding 0.5 and 0.75% carvacrol (active ingredient of oregano oil) to apple- and tomato-based film-forming solutions and 0.5 and 0.75% cinnamaldehyde (active ingredient of cinnamon oil) to apple-based film-forming solutions on sensory properties of cooked chicken wrapped with these films. Paired preference tests indicated no difference between baked chicken wrapped with tomato and apple films containing 0.5% carvacrol and cinnamaldehyde compared to chicken wrapped with tomato or apple films without the plant antimicrobials. The taste panel indicated a higher preference for carvacrol-containing tomato-coated chicken over the corresponding apple coating. There was also a higher preference for cinnamaldehyde-containing apple films over corresponding carvacrol-containing wrapping. Films containing antibacterial active compounds derived from essential oils can be used to protect raw chicken pieces against bacterial contamination without adversely affecting preferences of wrapped chicken pieces after baking.


Assuntos
Anti-Infecciosos , Galinhas , Embalagem de Alimentos/instrumentação , Carne , Sensação , Acroleína/administração & dosagem , Acroleína/análogos & derivados , Acroleína/química , Animais , Cimenos , Preferências Alimentares , Conservação de Alimentos/métodos , Frutas , Humanos , Solanum lycopersicum , Malus , Monoterpenos/administração & dosagem , Monoterpenos/química
20.
J Sci Food Agric ; 92(11): 2341-8, 2012 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-22419219

RESUMO

BACKGROUND: The effect of ultraviolet-B (UV-B) light as a postharvest treatment to enhance the antioxidant content of carrots and fresh-cut carrot products was evaluated. Four levels of UV-B dose ranging from 1.3 to 12 kJ m⁻² were applied to whole, baby and various styles of cut carrots, and the changes in antioxidant capacity, total soluble phenolics and phenylalanine ammonia-lyase (PAL, EC 4.3.1.24) activity were measured after a 3 day incubation period at 15 °C and 45% relative humidity. RESULTS: Both cutting style and dose level were factors in determining carrot responses to UV-B treatment. Antioxidant capacity increased significantly (1.4-6.6-fold). Total soluble phenolic results correlated directly with those of antioxidant capacity (R² = 0.953), indicating that the enhancements achieved were due to an increase in phenolic content. High-performance liquid chromatography analysis revealed that 5-O-caffeoylquinic acid (5-CQA) was the primary phenolic responsible for this increase. Higher PAL activity was also observed in UV-B-treated samples, indicating that the increase in 5-CQA was a biological response to UV-B exposure. CONCLUSION: UV-B treatment has the potential to increase the nutritional value of carrots and offers an exciting opportunity to increase consumer accessibility to dietary choices that are rich in antioxidants.


Assuntos
Antioxidantes/análise , Daucus carota/química , Daucus carota/efeitos da radiação , Irradiação de Alimentos , Raízes de Plantas/química , Raízes de Plantas/efeitos da radiação , Raios Ultravioleta , Antioxidantes/química , Ácido Clorogênico/análogos & derivados , Ácido Clorogênico/análise , Ácido Clorogênico/química , Cromatografia Líquida de Alta Pressão , Daucus carota/enzimologia , Relação Dose-Resposta à Radiação , Manipulação de Alimentos , Embalagem de Alimentos , Fenóis/análise , Fenóis/química , Fenilalanina Amônia-Liase/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/enzimologia , Ácido Quínico/análogos & derivados , Ácido Quínico/análise , Ácido Quínico/química , Solubilidade , Fatores de Tempo
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