Setareh Hosseinzadeh; Aram Bostan; Mohammad Hossein Hadad Khodaparast; Mohebbat Mohebbi
Abstract
Introduction : Flavors play an important role in consumer satisfaction and influence further consumption of foods. Most available aroma compounds are produced via chemical synthesis or extraction. Foodstuffs containing synthetic flavor in many cases are avoided, because the consumers suspect that these ...
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Introduction : Flavors play an important role in consumer satisfaction and influence further consumption of foods. Most available aroma compounds are produced via chemical synthesis or extraction. Foodstuffs containing synthetic flavor in many cases are avoided, because the consumers suspect that these compounds are toxic or harmful to their health. Recently, the market of flavors is focused in using aromatic materials arriving from natural sources to replace the use of synthetic flavors gradually (Badee, et al., 2012).Flavorsare indispensable ingredients of food preparations, and usually they are in liquid form that makes their handling and incorporating into food more difficult. Furthemore, many flavorcomponents exhibit considerable sensitivity to oxygen, light, and heat. In response to these difficulties, dried flavors have been developed. The objective of this work was to study the influence of different wall material concentration on the emulsion and spray dried flavor powder characteristics.Materials&methods: Spearmint oil was obtained by clevenger distillation method and modified starch was obtained from National Starch&Chemical Limited company (England).Different concentration of modified starch solutions (10, 20 & 30% w/w) were prepared by dispersing the solids in deionized water and heating at 40 ⁰C over a steam bath to facilitate solubilization. Thesolutions were allowed to cool to room temperature before storing at 4°C overnight. The spearmint oil (2.5 % w/w) was added to the solution and was homogenized vigorously (15000 rpm for 10 min.) with an Ultra Turrax homogenizer (T25, IKA, Germany) at ambient temperature. The emulsions were then further emulsified using Ultrasounds (20kHz, 1 min) (Jafari, et al., 2007).The obtained emulsion was spray dried in a BUCHI 190 Spray Dryer (Swiss) with an evaporation rate of 600 lit/1 hour, equipped with a pressurized nozzle operating at 4bar pressure. Feed ismetered into the dryer by a peristaltic pump. Powder was collected at the bottom of dryer cyclone and kept inair tight containers at -18⁰C until analyzed.The particle size of emulsion droplets and spray dried powder were determined using dynamic laser light scattering (Analysette22, Fritsch company, Germany).Encapsulation Efficiency was defined as the percentage of Menthol ad d-limonene thatwere entrapped inside the microcapsules to the total loaded to the emulsion. . Theequations was as follows:Encapsulation Efficiency=(Menthol or Limonene in Microcapsul(ppm))/(Menthol or Limonene in Emulsion(ppm))×100%The powders were attached to SEM stubs using double adhesivetape, coated with 3–5 mA gold/palladium under vacuum,and examined with a scanning electron microscope (S360 model, Oxford , England).Results&disscussion: Emulsion particle size were found to be in the range of 1.8 to 3.3 μm and wall material concentration had significant effect on it ( p
Setareh Hosseinzadeh; Mohammad Hossein Hadad Khodaparast; Aram Bostan; Mohebbat Mohebbi
Abstract
Introduction: Flavor plays a pivotal role in consumer satisfaction and further consumption of foods. Most available aroma compounds are synthetic and most of consumers tend to avoid them as they are of the idea that the chemical flavors are toxic or detrimental to their health. Recently, the market of ...
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Introduction: Flavor plays a pivotal role in consumer satisfaction and further consumption of foods. Most available aroma compounds are synthetic and most of consumers tend to avoid them as they are of the idea that the chemical flavors are toxic or detrimental to their health. Recently, the market of flavors from natural sources is shifting its focus on application rather than synthetic flavors (Badee et al, 2012). Essential oils consist of sensitive compounds against environmental effects. Microencapsulation is one of the methods which increases the stability of essential oils and flavors during storage and transportation. Different methods which may be used for microencapsulation include spray drying, spray-cooling, spray-chilling, coaservation, extrusion, fluidized bed method (KashappaGoud et al, 2003). However, spray drying method is preferred due to its high speed, high reliability, high flexibility and its being economical and the fact that it can be easily implemented in industry (KashappaGoud et al, 2003). Spray drying of essential oils requires homogenizer, spray dryer and chemical materials used for walls such as some types of emulsifiers and ingredients including maltodextrin, dried corn syrup, gum Arabic, gelatin and milk protein (Adamiec&Kalemba, 2004; Badee et al, 2012). Arabic gum (acacia gum) is a biopolymer which is derived from internal sap of acacia tree. It consists of a heteropolysaccharide complex with highly ramified structure (Phisut, 2012). It is an effective emulsifier for flavor emulsions thanks to its high water solubility, low solution viscosity, good surface activity, and ability to form a protective film around emulsion droplets (Chanamai&Mcclements, 2001). Maltodextrins are products of starch hydrolysis, consisting of D-glucose units linked mainly by α(1→4) glycosidic bonds. They are described by their dextrose equivalence (DE) which is inversely related to their average molecular weight. The greater the DE is, the shorter the glucose chains are and the more water they absorb (Phisut, 2012). Materials and method: Spearmint oil was produced by clevenger distillation from spearmint leaves (Mohal Khan et al, 2012). Malthodextrin with DE=18-20 from Xiwang Starch Co. Ltd., China, has a sweet taste and it is used in combination with emulsifiers, creates the walls and covers and causes thermal resistance and resistance to browning. Solubility in water=min 98%, moisture=4.5-6%, pH=4.5-6.5 and ash=max 0.1%. Arabic gum was prepared from Slandwide Corporation Co., Philippines, which is used as an emulsifier, stabilizer and the cover (moisture = max 10%, ash=max4% and pH =4-5).In making an emulsion, deionized double distilled water was used.A Solution of maltodextrin/arabic gum (1:1) in ratios of 10%, 20% and 30% in deionized water were prepared at 45°C and 1200 rpm for 1h (by Stirrer IKA). The solution was kept in cool room temperature at 4°C overnight (Badee et al, 2012; Baranauskiene et al, 2007). Then, 2.5% spearmint oil was added to an aqueous and homogenized (15000 rpm for 10 min) solution with an Ultra Turrax (model T25 digital, IKA Co, Germany) (Badee et al, 2012; Baranauskiene et al, 2007; Baranauskiene&Venskutonis, 2009; Frascareli et al, 2012). Then sonificasion (model ,HD3200, BANDELINE Co, Germany) for 1 minute by amplitude control 100%, frequency 20 kHz at 45 °C. The emulsion was spray dried in a BUCHI B-190 spray dryer (Badee et al, 2012; Baranauskiene et al, 2007; Baranauskiene&Venskutonis, 2009) where the inlet temperature was 180 °C, outlet temperature 60°C, pump speed 10 ml/min, air flow 600 l/h and pressure 4 bar. The powder was stored at -18°C until tested.Results and Discussion: The results of this research showed that during microencapsulation of spearmint oil at the fixed rate of 2.5%, wall concentration were effective in the stability of emulsions and in keeping menthol and d-limonene in microcapsule during drying and storage. By increasing wall material from 10% to 30% the most stability in emulsion was obtained and more half life and less release in microcapsules was achieved. Also, temperature plays an important role in protecting the volatile components, so that the microcapsules stored at 4°C had about half life which was 80 days more than the the samples stored at 25°C.
