Showing papers by "Amparo Chiralt published in 2011"
TL;DR: In this paper, the use of essential oils as natural antimicrobial and antioxidant compounds to obtain bioactive films or coatings is discussed, and the advantages and limitations are also reviewed.
Abstract: Antimicrobial and antioxidant properties of essential oils have previously been extensively reviewed. The mechanisms of action of essential oils have not been clearly identified but they seem to be related with their hydrophobic nature. Applying these natural compounds in the food industry could be a potential alternative, but its application costs and other problems, such as their intense aroma and potential toxicity, limit their use in the area of food preservation. An interesting strategy to reduce doses of essential oils while maintaining their effectiveness could be the incorporation of these natural compounds into edible/biodegradable films. This review discusses the use of essential oils as natural antimicrobial and antioxidant compounds to obtain bioactive films or coatings. The advantages and limitations are also reviewed.
376 citations
TL;DR: In this paper, the authors applied biodegradable coatings based on HPMC or CH with and without bergamot essential oil to table grapes, cv. Muscatel, in order to find environmentally friendly, healthy treatments with which to better preserve fresh fruit quality and safety during postharvest cold storage.
307 citations
TL;DR: In this article, the antimicrobial films were prepared by incorporating different concentrations of bergamot (BO), lemon (LO) and tea tree (TTO) essential oils (EO), into chitosan (CH) and hydroxypropylmethylcellulose (HPMC) films.
140 citations
TL;DR: In this article, film-forming dispersions and films, prepared by incorporating different concentrations of bergamot (BO), lemon (LO) and tea tree (TTO) essential oils into hydroxyproplymethylcellulose (HPMC) and chitosan (CH) were obtained and their physico-chemical properties were characterized.
136 citations
TL;DR: In this article, the authors applied HPMC to table grapes, cv. Muscatel, in order to improve quality and shelf life during storage, while taking advantage of the beneficial health properties of propolis.
111 citations
TL;DR: In this article, the effect of the homogenization conditions of the film-forming emulsions and lipid self-association on the physical properties of sodium caseinate films containing oleic and stearic acids was studied.
101 citations
TL;DR: In this article, a cross-linking effect in the film matrices containing ascorbic or citric acid was detected through the analysis of the film microstructure, mechanical behaviour and barrier properties to oxygen and water vapour.
96 citations
TL;DR: In this paper, a chitosan matrix containing different concentrations of bergamot oil (BO) was obtained and the migration of limonene, the major oil component, to five liquid food simulants (aqueous solutions with 0, 10, 50% and 95% of ethanol and isooctane) was studied at 20°C.
93 citations
TL;DR: Ferulic acid was more efficient at reducing oxygen and n-hexanal permeability than α-tocopherol as mentioned in this paper, which is decisive in the prevention of the oxidation of foods containing lipids.
84 citations
TL;DR: In this article, the impact of the properties of the FFD on the casted films, the water vapour permeability, mechanical properties and microstructure of the dry films were evaluated.
62 citations
TL;DR: In this article, high molecular weight chitosan with sunflower oil was used to make hamburger films, which increased the metmyoglobin (MtMb) content of coated hamburgers during cold storage.
Abstract: Edible films were prepared by combining high molecular weight chitosan with sunflower oil. Films were obtained by casting and were applied to the surface of pork meat hamburgers. Chitosan-based films increased the metmyoglobin (MtMb) content of coated hamburgers during cold storage, especially when using lactic acid as a solvent. The incorporation of sunflower oil to the chitosan matrix led to a reduction in MtMb content of hamburgers as compared to samples coated with pure chitosan films. Chitosan films led to a reduction in the microbial counts of samples during storage. However, it is important to modulate the oxygen permeability of films in order to avoid undesirable effects (MtMb formation).
TL;DR: Different isotonic solutions containing antibrowning compounds (EDTA, 4-hexylresorcinol, citrate and ascorbate), combined or not with calcium lactate, were applied to minimally processed (MP) pear samples (cv. Blanquilla) by using the vacuum impregnation (VI) technique in order to reduce enzymatic browning.
Abstract: Different isotonic solutions containing antibrowning compounds (EDTA, 4-hexylresorcinol, citrate and ascorbate), combined or not with calcium lactate, were applied to minimally processed (MP) pear samples (cv. Blanquilla) by using the vacuum impregnation (VI) technique in order to reduce enzymatic browning. Vacuum impregnated samples were packaged and colour, mechanical properties, development of respiration gases and volatiles in the package headspace and microbial counts were monitored throughout storage at 4 °C. VI treatments with ascorbate solutions and calcium lactate were the most effective to extending the shelf life of MP pear. These treatments caused fewer changes in colour, mechanical properties and volatile composition and slowed microbial growth. Calcium lactate led to a better preservation in terms of mechanical parameters but had minor effects on colour development during cold storage.
TL;DR: In this paper, the glass transition temperatures (T g ) of different noni powders and maltodextrin in DE 9-12 were obtained using differential scanning calorimetry (DSC).
TL;DR: In this article, high molecular weight chitosan (CH) and methylcellulose (MC) composite films were obtained by mixing different ratios (0:1, 0.5:1.5, 1.0: 1.5 and 1:0) of the biopolymers in two solvent conditions (0.95 and 6.85mmol of ions per g polymer).
Abstract: Edible films based on high molecular weight chitosan (CH) and methylcellulose (MC) were obtained by mixing different ratios (0:1, 0.5:1.5, 1.0:1.0, 1.5:0.5 and 1:0) of the biopolymers in two solvent conditions (0.95 and 6.85 mmol of ions per g polymer). In order to characterize the dry films, water sorption isotherms, water vapour permeability and film microstructure were evaluated. Water vapour permeability of CH-MC composite films was significantly affected by both the CH-MC ratio and the ionic concentration in the matrix. This can be attributed to the influence of ions on polymer chain packaging during the film formation and their role in the water uptake capacity of the films which affects the water transport properties.
TL;DR: In this article, the influence of basil essential oil, its content and homogenization treatment on the physical properties of chitosan-based edible films was studied, without (H1) and with (H2) microfluidization (MF).
Abstract: This work studies the influence of basil essential oil, its content and the homogenization treatment on the physical properties of chitosan-based edible films. Two homogenization treatments were applied, without (H1) and with (H2) microfluidization (MF). Composite films were softer, less rigid and more stretchable than pure CH films. MF intensified these changes. H2 films showed microcracks due to the weak interactions between chitosan and oil, which affected their mechanical behaviour. In pure chitosan films, MF significantly increased water vapour permeability. Homogenization treatment greatly affected this property. Gloss was reduced by the essential oil addition, whereas MF tended to yield glossier films.
TL;DR: This paper reviews the latest published studies and issued patents on the use of antioxidants agents in foodstuffs, and the properties of the most commonly used antioxidants as well as natural antioxidants are revised.
Abstract: The application of antioxidant ingredients is one of the most common ways to delay and prevent the detrimental effect of oxygen in foods. Some of the most widely used and studied antioxidants are carboxylic acids, tocopherols and thiol-containing compounds. However, consumer trends towards healthier and safer foods, together with the increasing concern for the potential toxicity of some antioxidants are leading research efforts towards the use of antioxidants obtained from natural sources, such as plant phenols, essential oils and chitosan. This paper reviews the latest published studies and issued patents on the use of antioxidants agents in foodstuffs. The properties of the most commonly used antioxidants as well as natural antioxidants are revised. Moreover, examples of recent patents on the application of antioxidants to different foodstuffs (meat, fish, vegetables, fruits and beverages) are given.
TL;DR: The effect of dairy proteins, especially β-casein, on the phase transitions of polysaccharides should be considered for controlling the Maillard reaction, as well as physical and chemical changes that occur during processing and storage of food systems.
TL;DR: Chitosan films enriched with basil (B) or thyme (T) essential oils (EO) were prepared by means of two homogenization treatments, without (H1) and with (H2) microfluidization as mentioned in this paper.
Abstract: Chitosan films enriched with basil (B) or thyme (T) essential oils (EO) were prepared by means of two homogenization treatments, without (H1) and with (H2) microfluidization. H2 treatment led to a significant decrease in the average particle size and the type of EO significantly affected d43 values (p
12 May 2011
TL;DR: In this paper, Kent et al. analyzed the influence of pretratamiento of the escaldado de mango on the deshidratation osmotica of agua and perdida de agua with presion atmosferica.
Abstract: Los tratamientos combinados como el escaldado, deshidratacion osmotica a presion atmosferica (OD) y deshidratacion osmotica con pulso de vacio (PVOD) se emplean en el procesamiento de frutas para mejorar su calidad (sensorial y nutricional). El escaldado reduce la actividad enzimatica y en algunos casos mejora el color en las frutas. La reduccion de la actividad de agua mediante el proceso de deshidratacion osmotica con la aplicacion de disoluciones concentradas de sal o azucar, a baja temperatura, permite reducir el contenido de agua congelable de frutas procesadas minimamente, para mejorar su conservacion en congelacion. En este se analizo la influencia del pretratamiento del escaldado de mango (var. Kent) sobre la cinetica de deshidratacion osmotica a presion atmosferica y con pulso de vacio. Los tratamientos se realizaron a 30oC con una disolucion de sacarosa concentrada a 59.3°Brix. Para cada tiempo del proceso (hasta 5 h) las muestras se analizaron en su variacion de peso y volumen, contenido de humedad, concentracion de solidos solubles y actividad de agua. La cinetica de las ganancias netas de soluto y agua se analizaron en terminos de la composicion de la fase liquida de la fruta (FLM: agua mas solidos solubles). Los tratamientos PVOD mostraron cineticas mas rapidas en ganancias de soluto y perdida de agua, y valores ligeramente mas altos de difusividad efectiva (D ) e en la FLM, especialmente en los pretratamientos de escaldado. En los tratamientos OD los cambios de volumen fueron explicados en terminos de la FLM. Los tratamientos PVOD presentaron una desviacion de la variacion de volumen frente a OD debido a la impregnacion deformacion durante el pulso de vacio.trabajo se analizo la influencia del pretratamiento del escaldado de mango (var. Kent) sobre la cinetica de deshidratacion osmotica a presion atmosferica y con pulso de vacio. Los tratamientos se realizaron a 30oC con una disolucion de sacarosa concentrada a 59.3°Brix. Para cada tiempo del proceso (hasta 5 h) las muestras se analizaron en su variacion de peso y volumen, contenido de humedad, concentracion de solidos solubles y actividad de agua. La cinetica de las ganancias netas de soluto y agua se analizaron en terminos de la composicion de la fase liquida de la fruta (FLM: agua mas solidos solubles). Los tratamientos PVOD mostraron cineticas mas rapidas en ganancias de soluto y perdida de agua, y valores ligeramente mas altos de difusividad efectiva (D ) e en la FLM, especialmente en los pretratamientos de escaldado. En los tratamientos OD los cambios de volumen fueron explicados en terminos de la FLM. Los tratamientos PVOD presentaron una desviacion de la variacion de volumen frente a OD debido a la impregnacion deformacion durante el pulso de vacio.
TL;DR: In this article, the effect of osmotic pretreatments was analyzed as a way to optimize the quality loss of pear slices (cv Blanquilla) during dried and/or rehydration processes.
Abstract: The effect of osmotic pretreatments was analyzed as a way to optimize the quality loss of pear slices (cv. Blanquilla) during dried and/or rehydration processes. Pear slices, osmotically pretreated and non-treated were dried at 45C, until about 10% final moisture, and rehydrated at 45, 55 and 65C in water. The rehydration kinetics of air-dried pear slices were analyzed by means of Peleg and Fick's models. Kinetics parameters obtained for both models can adequately predict the sample's behavior during rehydration process. Osmotic treatment seemed to slow down the kinetics of dried pear rehydration in terms of water gain and solute loss, with no significant effect on the final solute concentration of the fruit liquid phase. This could be related with the greater viscosity of the fruit liquid phase associated with the sugar gain during the osmotic step and the total loss of this sugar during rehydration.
PRACTICAL APPLICATIONS
Rehydration is a complex process and its main purpose consists of restoring the properties of the dry raw material. The capacity of the dry material to be rehydrated depends on certain intrinsic properties of the vegetal tissue and also, on how the rehydration process is carried out (process conditions) and on the previous pretreatments applied to the product. These pretreatments are usually used to obtain a better quality of the final product (i.e., better preserved from undesirable changes) and in this sense, applying an osmotic dehydration step prior to the rehydration process could be interesting. Thus, the process optimization of pretreated products, rehydrated under several conditions and pretreatments, is a desirable and useful tool to reformulate and obtain high-quality products.