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Mahfoudhi N.,High Institute of Food Industry | Mahfoudhi N.,University of Salerno | Hamdi S.,High Institute of Food Industry
Journal of Food Processing and Preservation | Year: 2015

The purpose of this study was to evaluate almond gum as an encapsulation material for β-carotene in comparison with gum arabic and to assess the functionality of the obtained powders applying them in cake as colorant. β-carotene gum powders were prepared by freeze-drying, then the kinetic degradation as well as the surface color changes of the powders, during a storage period of 70 days, under three relative humidities (RHs): 10, 45 and 80% were studied. The degradation rate of β-carotene and the decrease in the red color were described using a first-order kinetic model. The rate of degradation of β-carotene as well as that of the red color increased as increasing RH until a value at which the samples collapsed (80% RH). Results showed that microencapsulation with almond gum offered greater protection to β-carotene compared to gum arabic, and it was observed that the powders were able to color the studied food system (cake) in a homogenous manner. Practical Applications: In recent years, a growing interest was observed for new sources of biopolymers to be used in the food industry. In this work, a novel gum exudate, almond gum from Prunus dulcis, is compared with the well-established gum arabic, an exudate from Acacia senegal trees, in terms of their encapsulation abilities. Almond gum is a gum copiously exuded from the trunk, branches and fruits of P.dulcis trees, after mechanical injury and/or infection by microorganisms. It has been proved in the present study that almond gum could be used successfully as a wall material to encapsulate β-carotene by freeze-drying. Moreover, the results suggest that almond gum could be explored as a novel and potential natural wall material for use in encapsulation of active ingredients to substitute many other wall materials which are not all the time evident. © 2015 Wiley Periodicals, Inc. Source


Mahfoudhi N.,High Institute of Food Industry | Mahfoudhi N.,University of Salerno | Chouaibi M.,High Institute of Food Industry | Hamdi S.,High Institute of Food Industry
Food Science and Technology International | Year: 2014

The use of coatings is a technique used to increase postharvest life of the fruit. Almond gum exudate was used, in comparison with gum arabic, at concentrations of 10% as a novel edible coating, to preserve the quality parameters of tomato (Solanumlycopersicum). Fruits were harvested at the mature-green stage of ripening. Results showed that the coatings delayed significantly (p < 0.05) the changes in color, weight loss, firmness, titratable acidity, ascorbic acid content, soluble solids concentration, and decay percentage compared to uncoated control fruits. Sensory evaluation proved the efficacy of 10% almond gum and gum arabic coatings to maintain the overall quality of tomato fruits during storage period (20 days). In addition, the difference between gum arabic and almond gum coatings was not significant (p > 0.05) except for pulp color. Therefore, we can suggest the use of almond gum exudate as a novel edible coating extends the shelf-life of tomato fruits on postharvest. © 2012 The Author(s). Source


Mahfoudhi N.,High Institute of Food Industry | Hamdi S.,High Institute of Food Industry
Journal of Food Processing and Preservation | Year: 2015

Almond gum and gum arabic were used as edible coatings for sweet cherries in order to delay their ripening during postharvest storage at 2C and 90-95% relative humidity for 15 days. Coating of sweet cherries with 10% almond gum or gum arabic has been found to enhance their shelf life and postharvest quality. Fruits coated with almond gum or gum arabic showed a significant decrease in respiration rate as well as ethylene production. Moreover, coatings were able to delay changes in weight, firmness, titratable acidity, soluble solids concentration and color development compared with uncoated control fruit. The results suggested that by using almond gum as an edible coating, we can delay the ripening process and increase the shelf life of sweet cherries stored at 2C for 15 days without any spoilage and off-flavor. Practical Applications: Edible coatings could be an effective tool for delaying the ripening process of fruits and vegetables during the postharvest storage period. The effectiveness of almond gum from Prunus dulcis as a novel edible coating, in comparison with gum arabic, was studied in sweet cherries in order to maintain parameters related to quality during postharvest storage. The results showed that almond gum was able to slow down the gas exchange by reducing the CO2 concentration of coated sweet cherries, which reduced their ethylene production. As a result, the evolution of parameters related to the quality of sweet cherries was significantly delayed. Moreover, the results suggested that almond gum could be explored as a novel and potential natural edible coating to substitute the synthetic forms of fruit and vegetable packaging. © 2015 Wiley Periodicals, Inc. Source


Mahfoudhi N.,High Institute of Food Industry | Sessa M.,University of Salerno | Ferrari G.,University of Salerno | Hamdi S.,High Institute of Food Industry | Donsi F.,University of Salerno
Food Science and Technology International | Year: 2015

Almond gum contains an arabinogalactan-type polysaccharide, which plays an important role in defining its interfacial and rheological properties. In this study, rheological and interfacial properties of almond gum and gum arabic aqueous dispersions were comparatively investigated. The interfacial tension of almond gum and gum arabic aqueous dispersions was measured using the pendant drop method in hexadecane. The asymptotic interfacial tension values for almond gum were significantly lower than the corresponding values measured for gum arabic, especially at high concentration. Rheological properties were characterized by steady and oscillatory tests using a coaxial geometry. Almond gum flow curves exhibited a shear thinning non-Newtonian behavior with a tendency to a Newtonian plateau at low shear rate, while gum arabic flow curves exhibited such behavior only at high shear rate. The influence of temperature (5-50 °C) on the flow curves was studied at 4% (m/m) gum concentration and the Newtonian viscosities at infinite and at zero shear rate, for gum arabic and almond gum, respectively, were accurately fitted by an Arrhenius-type equation. The dynamic properties of the two gum dispersions were also studied. Both gum dispersions exhibited viscoelastic properties, with the viscous component being predominant in a wider range of concentrations for almond gum, while for gum arabic the elastic component being higher than the elastic one especially at higher concentrations. The rheological and interfacial tension properties of almond gum suggest that it may represent a possible substitute of gum arabic in different food applications. © The Author(s) 2015 Reprints and permissions:. Source


Mahfoudhi N.,High Institute of Food Industry | Sessa M.,University of Salerno | Chouaibi M.,High Institute of Food Industry | Ferrari G.,University of Salerno | And 2 more authors.
Food Hydrocolloids | Year: 2014

The emulsifying properties of almond gum from Prunus dulcis were assessed in comparison with gum arabic from Acacia senegal.Interfacial properties were preliminary evaluated by pendant drop method, while emulsifying ability was quantified in terms of mean droplet size of O/W emulsions prepared at different intensity levels of high pressure homogenization as well as of stability of resulting optimized emulsions.Response surface methodology (RSM) was used to determine the optimum emulsification conditions for minimum mean emulsion droplet size. Homogenization pressure (100-300MPa), number of passes (1-10 passes) and gum concentration (5, 7.5 and 10% w/w) were the factors investigated. Experiments were designed according to a three-level, three-variable Box-Behnken design (BBD), and a second-order polynomial model was developed for the response variable using multiple linear regression analysis, which resulted to be very accurate both for almond gum (R2=0.979) and for gum arabic (R2=0.993).Results showed that almond gum exhibited good emulsifying abilities, yet different from gum arabic. The measured interfacial properties of almond gum showed slower dynamics of adsorption and reorganization at the oil-water interface. Coherently, the optimum emulsification conditions determined by RSM required for almond gum a lower emulsifier concentration (5.7%) than for gum arabic (8.4%), but the use of gum arabic allowed for a smaller mean droplet size at lower intensity of high pressure homogenization treatment. Remarkably, the stability of 10% oil emulsions using almond gum as emulsifier was comparable to those using gum arabic, for gum concentrations in excess of 5%. © 2013. Source

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