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This study aimed to produce soluble potato starch ultrafine fibers for the encapsulation of pinhao coat extract (PCE), evaluating their relative crystallinity (RC), thermal stability, antioxidant activity, antimicrobial activity against Escherichia coli and Staphylococcus aureus, as well as in vitro biological digestion. In the simulation of in vitro biological digestion, the phenolic compounds release profile was also evaluated. The ultrafine fibers were produced by electrospinning, based on a polymeric solution composed of soluble potato starch (50% w/v) and formic acid. Then, PCE was incorporated at various concentrations (0.5%, 1.0%, and 1.5%, w/w, dry basis). The endothermic event of free PCE was not observed in the ultrafine fibers, which suggests its encapsulation. The RC decreased according to the increase in PCE concentration in the ultrafine fibers. The PCE resisted thermal treatments when encapsulated into the ultrafine fibers (100 and 180°C), and the ultrafine fibers with 1% PCE presented the highest amount of preserved phenolic compounds. Regarding antioxidant activity, the free PCE presented 85% of DPPH inhibition and the ultrafine fibers had 18% inhibition, not differing among the PCE concentrations (p

Clove (Syzygium aromaticum, L.) essential oil is known for its antimicrobial activity against several pathogenic bacteria. Encapsulation of clove oil was proposed as a mean to disguise its strong odor that limits its uses in food industry. Thus, the aim of this study was extraction, encapsulation and assessment of the antimicrobial and antioxidant potential of clove essential oil. The essential oil showed high DPPH scavenging capacity and low hydroxyl radical inhibition. Clove essential oil showed in vitro inhibitory and bactericidal effect against S. aureus, E. coli, L. monocytogenes and S. Typhimurium. In addition, in situ antimicrobial activity of clove oil against S. aureus was superior to nitrite. The essential oil particles encapsulated with sodium alginate and emulsifiers, showed high encapsulation efficiency, low antioxidant activity and strong antimicrobial inhibition. Similar bacterial growth was observed in meat-like products after addition of either particles or nitrite.

The food industry is looking for strategies to prevent microbial growth in order to ensure food safety and shelf life. However, the use of synthetic preservatives, such as nitrate and nitrite in meat products, entails risks to human health. An alternative is the utilization of essential oils, widely known for their antimicrobial properties. This work aimed the antimicrobial potential of a bioactive coating based on chitosan incorporated with clove essential oil in in hamburger-like meat product. Through the analysis of antimicrobial activity by diffusion in agar and broth, there was an action against Gram-positive and Gram-negative bacteria. Regarding Staphylococcus aureus and Escherichia coli, the minimum inhibitory concentration (MIC) was 3.74 mg/mL and the minimum bactericidal concentration (MBC) was 374.33 mg/mL for both. In the micro atmospheric diffusion test, CEO reduced by up to 70 and 76% of the E. coli and S. aureus bacteria development, respectively. CEO was applied as an active component in chitosan-based coatings in hamburger-like meat, in which it was able to promote the control of microbial proliferation of Total Coliforms, Coliforms at 45 ⁰C and Coagulase-Positive Staphylococcus throughout 7 days of storage under refrigeration. It is concluded that the bioactive coating based on chitosan incorporated with clove essential oil promotes microbiological control in hamburger-like meat product. La industria alimentaria busca estrategias que eviten el crecimiento microbiano para garantizar la seguridad y la vida útil de los alimentos. Sin embargo, el uso de conservantes sintéticos como el nitrato y el nitrito en productos cárnicos presenta riesgos para la salud humana. Una alternativa es utilizar aceites esenciales, que son ampliamente conocidos por sus propiedades antimicrobianas. Este trabajo tuvo como objetivo evaluar el potencial antimicrobiano de un recubrimiento bioactivo a base de quitosano incorporado al aceite esencial de clavo en un producto cárnico análogo a la hamburguesa. Al analizar la actividad antimicrobiana por difusión en agar y caldo, se encontró acción frente a bacterias Gram positivas y Gram negativas. En cuanto a Staphylococcus aureus y Escherichia coli, la concentración mínima inhibitoria (MIC) fue de 3,74 mg/mL y la concentración bactericida mínima (CBM) fue de 374,33 mg/mL para ambos. En la prueba de difusión en micro-atmósfera, el aceite esencial de clavo (AEC) redujo el desarrollo de las bacterias E. coli y S. aureus hasta en un 70 y 76%, respectivamente. AEC se aplicó como componente activo en recubrimientos a base de quitosano en un producto cárnico similar a una hamburguesa, que pudo controlar la proliferación microbiana de Coliformes Totales, Coliformes a 45 °C y Estafilococos Coagulasa Positivos durante 7 días de almacenamiento refrigerado. Se concluye que el recubrimiento bioactivo a base de quitosano incorporado al aceite esencial de clavo promueve el control microbiológico en productos cárnicos tipo hamburguesa. A indústria alimentícia busca por estratégias que previnam o crescimento microbiano, a fim de garantir a segurança e a vida útil dos alimentos. No entanto, o uso de conservantes sintéticos, como nitrato e nitrito em produtos cárneos, acarreta riscos à saúde humana. Uma alternativa é a utilização de óleos essenciais, os quais são amplamente conhecidos por suas propriedades antimicrobianas. Este trabalho teve como objetivo avaliar o potencial antimicrobiano de um revestimento bioativo à base de quitosana incorporado ao óleo essencial de cravo-da-índia em um produto cárneo análogo a hambúrguer. Por meio da análise da atividade antimicrobiana por difusão em ágar e caldo, houve ação contra bactérias Gram-positivas e Gram-negativas. Em relação a Staphylococcus aureus e Escherichia coli, a concentração inibitória mínima (CIM) foi de 3,74 mg/mL e a concentração bactericida mínima (CBM) foi de 374,33 mg/mL para ambos. No teste de difusão em micro-atmosfera, o óleo essencial de cravo-da-índia (OEC) reduziu em até 70 e 76% o desenvolvimento das bactérias E. coli e S. aureus, respectivamente. O OEC foi aplicado como um componente ativo em revestimentos à base de quitosana em produto carne análogo a hambúrguer, no qual foi capaz de promover o controle da proliferação microbiana de Coliformes Totais, Coliformes a 45 ⁰C e Staphylococcus Coagulase-Positivo ao longo de 7 dias de armazenamento sob refrigeração. Conclui-se que o revestimento bioativo à base de quitosana incorporado ao óleo essencial de cravo-da-índia promove o controle microbiológico em produtos cárneos do tipo hambúrguer.

The need for biodegradable and innovative nanomaterials in the food packaging industry motivates the conduction of studies on the production and characterization of new nanomaterials. The aim of this study was to evaluate the encapsulation efficiency (EE), thermal resistance, and antioxidant and antimicrobial activities of carvacrol encapsulated in potato starch nanofibers. The nanofibers possessed low EE (26%–33%) and high thermal resistance, showing residual carvacrol quantities after exposure to high temperatures. They also showed reduced but stable inhibition of DPPH oxidation compared with free carvacrol (20%, 33%, and 52% for the nanofibers with 20%, 30%, and 40% carvacrol, respectively) and OH inhibition varying from 4% to 18% for the nanofibers in general. Moderate antimicrobial activity (0.98 mg/ml) was found for all nanofibers throughout minimal inhibitory concentration (MIC) values. Our findings highlight the potential of starch/carvacrol nanofibers for application in the food sector as an antimicrobial and antioxidant agent. PRACTICAL APPLICATIONS: The nanomaterial developed in this study can be applied in the elaboration of active food packages, which can act as antioxidants and/or antimicrobial agents. The end use includes packages that undergo high temperatures in their production. In addition, the packages containing the starch/carvacrol nanofibers can preserve several types of food products.

Compounds present in broccoli are vulnerable to the digestive process, and encapsulation becomes an alternative for their preservation. The encapsulation of broccoli extract, by electrospraying, was performed with the purpose of evaluating the effect of in vitro simulated digestion on individual compounds and antioxidant and antihyperglycemic potentials. Each digestion fraction was evaluated by chromatography, as well as for antioxidant activity and antihyperglycemic potential. The encapsulated extract showed high encapsulation efficiency and spherical morphology. Losses in the levels of phenolic compounds and glucosinolates were found in both extracts, considering the fractions submitted to digestion. The digestion promoted an increase in the inhibition of hydroxyl, nitric oxide and α-amylase, as well as a decrease in the inhibition of α-glucosidase in both extracts, when compared to undigested fractions. Thus, the digestion affects the compounds content in both encapsulated and unencapsulated extracts. However, they still promote the control of oxidative processes and hyperglycemia.

Synthetic preservatives are widely present in processed foods, but most of them have carcinogenic potential, requiring the development of new natural alternatives such as fruit extracts, for microbial control. The objective of the study was to evaluate the chemical characterization, antioxidant, and antimicrobial activity of the sugar apple pulp (Annona squamosa L.). Physicochemical characteristics were evaluated, an extract was prepared, and its antioxidant activity by DPPH method and antimicrobial by disk diffusion. Minimal inhibitory concentration and minimum bactericidal concentration against strains of Salmonella typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus were evaluated. The physicochemical analysis revealed that sugar apple pulp had 75.0% moisture, 3.0% ash, 4.0% protein, 0.2% lipids, 3.3% fibers, and 14.5% carbohydrates. The antioxidant activity of the extract by the DPPH method was 20.6%. The pulp extract from the sugar apple had inhibition zone for Staphylococcus aureus, satisfactory inhibitory effect against Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, and Salmonella Typhimurium, but did not present a bactericidal effect. Sugar apple pulp presents adequate levels of nutrients and potential for food application due to its microbiological activity and antioxidant properties.

Background Thyme essential oil (TEO) is an excellent natural substitute for synthetic compounds to maintain the quality and safety of food products. It acts as an antioxidant agent. We aimed to nanoencapsulate TEO at concentrations of 1%, 3%, and 5% (v/w, dry basis) in electrospun nanofibers made of starch (50% w/v) and formic acid (75% v/v). The rheological parameters of the fiber-forming solutions were measured, and various physical and chemical properties of the nanofibers were analyzed. Results The starch/TEO nanofibers presented homogeneous morphology. The starch nanofibers showed high encapsulation efficiency (EE, 99.1% to 99.8%), which, along with the Fourier transform infra-red (FTIR) spectrum and thermogravimetric analysis (TGA) analysis, indicate strong protection of the phenolic compounds of TEO. Nanofibers with 5% TEO retained up to 50% of the phenolic compounds after exposure to thermal treatment. The antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals of the starch/TEO nanofibers varied from 11.1% to 14.2% and the inhibition values (29.8%, P ≤ 0.05) against hydroxyl radicals were the same for free TEO and the nanofibers. Conclusion Owing to these properties, electrospun starch/TEO nanofibers can be applied in food products or food packaging.

Synthetic preservatives can have harmful effects on the body, so plant essential oils appear to be an attractive natural alternative. However, the use of essential oils is limited due to the low stability and possible negative effects on the sensory properties of food. Oil encapsulation was suggested as a way to overcome these drawbacks. The objective of this study was to encapsulate thyme essential oil and to evaluate its antioxidant and antimicrobial potential in vitro and in situ in of hamburger-like meat products. The casein-maltodextrin capsules produced by spray-drying were assessed for encapsulation efficiency, thermal stability, chemical compounds and morphology. Antioxidant activity was evaluated by DPPH, hydroxyl and nitric oxide methods, while antimicrobial activity was evaluated in vitro against four bacteria and in situ in hamburger-like products. The capsule showed high encapsulation efficiency and thermal stability, and spherical and irregular morphology. The casein-maltodextrin encapsulated essential oil showed antioxidant and antimicrobial activity against Staphylococcus aureus, Escherichia coli, Listeria monocytogenes and Salmonella Typhimurium tested in vitro and against thermotolerants coliforms and Escherichia coli in situ, showing potential for application as a natural preservative in food.

Reactive oxygen species and development of hyperglycemia underlie the most prevalent non-communicable chronic human diseases. Thus, the use of natural products, including essential oils, to control these processes has been the subject of many studies. This study aimed to elucidate the chemical composition of essential oils of clove, thyme, oregano, and sweet orange, characterize their antioxidant activity toward 2,2-diphenyl-1-picrylhydrazyl, hydroxyl, and nitric oxide radicals, and assess their antihyperglycemic potential, inhibiting the digestive enzymes α-amylase and α-glucosidase in vitro. The major compounds found in clove, thyme, oregano, and sweet orange essential oils were eugenol, thymol, 4-terpineol, and d -limonene, respectively. The clove essential oil shower a higher percentage of inhibition of hydroxyl radicals and nitric oxide, while the thyme essential oil displayed greater antioxidant activity toward the radical 2,2-Diphenyl-1-picrylhydrazyl compared with the other oils assessed in this study. In assays of inhibition of digestive enzymes related to development of hyperglycemia, thyme essential oil showed the greatest capacity to inhibit α-amylase, while sweet orange essential oil displayed the most potent inhibition of α-glucosidase. These results demonstrate the potential for use of these essential oils to prevent and/or treat diseases arising from oxidative stress, such as diabetes mellitus.

The objective of this study was to evaluate the in vitro susceptibility of fungi to starch/carvacrol nanofibers produced by electrospinning. The nanofibers were incorporated into bread dough or used in the development of active packages to minimize bread spoilage. In agar diffusion and micro-atmosphere assays, the nanofibers with 30 % or 40 % carvacrol presented inhibition zones with low growth and were effective inhibiting both the fungi evaluated in this work. The MICs for nanofibers with 30 % carvacrol were 0.098 and 9.8 mg/mL against Penicillium sp. and Aspergillus flavus, respectively; for the 40 % nanofibers, the MIC was 19.6 mg/mL against Aspergillus flavus. As for MFC, only the 30 % nanofibers exerted fungicidal effect. The treatments administered directly to the bread dough had low colony-forming unit. For bioactive packages, nonwovens with 30 % carvacrol were effective in preventing bread spoilage. Thus, nanofibers are a good alternative to chemical additives or bioactive packages in food industry.

Starch is considered an important ingredient in the preparation of safe food. Current study investigates the physicochemical, morphological, thermal and pasting properties of rice starches, subjected to HMT at 13 g/100 g moisture, at different treatment times (10, 30 and 60 min), directly in the grain paddy rice and in the isolated starch. HMT reduced extraction yield of rice starch with increasing HMT time. The HMT starches had lower gelatinisation enthalpy when compared to native starch. HMT in grain reduced extraction yield of starch by the alkaline method with increasing time of exposure to high temperatures, altering the structure of starch-protein. The HMT in grains decreases the setback of the isolated starches, due to amylose-lipid complexation induced by high temperatures applied on modification. The hydrothermal treatment increased the mechanical and thermal stability of rice starches and promoted the strengthening of links, forming a more stable structure.

Acetylation and oxidation are chemical modifications which alter the properties of starch. The degree of modification of acetylated and oxidized starches is dependent on the catalyst and active chlorine concentrations, respectively. The objective of this study was to evaluate the effect of acetylation and oxidation on the structural, morphological, physical–chemical, thermal and pasting properties of barley starch. Barley starches were acetylated at different catalyst levels (11%, 17%, and 23% of NaOH solution) and oxidized at different sodium hypochlorite concentrations (1.0%, 1.5%, and 2.0% of active chlorine). Fourier-transformed infrared spectroscopy (FTIR), X-ray diffractograms, thermal, morphological, and pasting properties, swelling power and solubility of starches were evaluated. The degree of substitution (DS) of the acetylated starches increased with the rise in catalyst concentration. The percentage of carbonyl (CO) and carboxyl (COOH) groups in oxidized starches also increased with the rise of active chlorine level. The presence of hydrophobic acetyl groups, carbonyl and carboxyl groups caused a partial disorganization and depolymerization of starch granules. The structural, morphological and functional changes in acetylated and oxidized starches varied according to reaction conditions. Acetylation makes barley starch more hydrophobic by the insertion of acetyl groups. Also the oxidation promotes low retrogradation and viscosity. All these characteristics are important for biodegradable film production.