The concentration of lycopene and β-carotene in the tomato pomace extract was quantified by HPLC, using an UltiMate-3000 HPLC system (Dionex, Germering, Germany, 2007) equipped with an oven at 30 ◦ C. Carotenoid separation, identification, and quantification were performed using a reversed phase C18 5 µm, 120 Å (4.6 × 150 mm) column by a gradient elution of acetonitrile:water:tetraethylammonioum (900:100:1) as solvent A and ethyl acetate as solvent B. The elution started with a mixture of 75% solvent A and 25% solvent B. After 10.5 min, solvent A was decreased to 59% and, after 20.0 min, to 0%. At 21 min, solvent A returned to the initial condition (75%), remaining constant up to 31 min. The flow rate was 1 mL.min −1 , and the running time was 31 min. The injection volume of the samples was 20 µL. The identification of carotenoids was based on their retention time of a peak compared with the carotenoids’ standards. Calibration curves were carried out using standard lycopene and β-carotene withdifferent concentrations (1–10 mg.L −1 ), using a 1:1 ACN:DCM solution as the solvent. Detection was carried out with a DAD-3000 diode array detector with a wavelength of 475 and 472 nm for lycopene and 440 nm for β-carotene. The amount of β-carotene and lycopene in the samples was expressed as mg.g extract −1 .
Carotenoids are a class of natural pigments found mainly in fruits and vegetables. Among them, 𝛽-carotene is regarded the most potent precursor of vitamin A. However, it is susceptible to oxidation upon exposure to oxygen, light, and heat, which can result in loss of colour, antioxidant activity, and vitamin activity. Thus, the objective of this work was to study the microencapsulationprocessof 𝛽-carotene byspraydrying, using arabic gum as wall material, to protect it against adverse environmental conditions. This was carried out using the response surface methodology coupled to a central composite rotatable design, evaluating simultaneously the effect ofdrying air inlet temperature (110-200 ∘ C) and the wall material concentration (5-35%) on the drying yield, encapsulation efficiency, loading capacity, and antioxidant activity. In addition, morphology and particles size distribution were evaluated. Scanning electron microscopy images have shown that the particles were microcapsules with a smooth surface when produced at the higher drying temperatures tested, most of them having a diameter lower than 10 𝜇m. The conditions that enabled obtaining simultaneously arabic gum microparticles with higher 𝛽-carotene content, higher encapsulation efficiency, and higher drying yield were a wall material concentration of 11.9% and a drying inlet temperature of 173 ∘ C. The systematic approach used for the study of 𝛽-carotene microencapsulationprocessbyspraydrying using arabic gum may be easily applied for other core and wall materials.
Food emulsions play an important role in product development and formulation, as well as to encapsulation of food additives. Conventional methods for emulsion production may present some drawbacks, such as the use of high shear stress, high energy demanding and polydisperse droplet size distribution. In this sense, membrane emulsification emerges as an alternative method to overcome all this issues and to produce fine and stable emulsions. Linseed oil has been widely studied in the last years, due to its nutritional composition, being the richest ω-3 vegetable source and for that reason it was used as the raw material for emulsion production. Premix and direct (cross flow) membrane emulsification were carried out using three different membrane materials: polissulphone, cellulose ester and α-alumina membrane. For premix membrane emulsification (PME) the variables transmembrane pressure, membrane material, surfactant type and membrane mean pore size were evaluated. The membrane mean pore size was the crucial factor to achieve emulsions by PME, once it was not possible to achieve stable emulsion with mean pore sizes lower than 0.8 μm. For direct membrane emulsification, transmembrane pressure, surfactant concentration and cross flow velocity were evaluated by means of a experimental design. The evaluated responses were stability, droplet size and distribution and dispersed phase flux. For all the variables studied, only dispersed phase flux showed to have significant influence of pressure. Comparing both methods of membrane emulsification, premix showed to be more suitable in terms of emulsion production throughput and droplet size correlation with membrane pore size, however, in terms of stability, direct membrane emulsification showed much better results. Encapsulation of linseed oil byspraydrying was promoted using the optimum point of the performed experimental design and the droplets size distribution has considerably changed with the addition of the wall material to the emulsion.
units linked mainly by glycosidic bonds, obtained by acid or enzyme hydrolysis of some starches (corn, rice, potato, starch, or wheat). Variations in DE values result in powders withdifferent physico-chemical properties, such bulk density, water absorption, water solubility, hygroscopicity, and porosity . Among other characteristics, maltodextrins have high solubility in water, low viscosity even at high solid content, neutral flavor, and colorless solutions, and they are readily available [22,23]. This wall material has been mostly used in products that are difficult to dry, with the purpose of decreasing stickiness and agglomeration problems during storage . Inulin is a reserve polysaccharide produced by many plants and is often extracted industrially from chicory. It is a polymer of fructose units linked with a terminal glucose unit at the end of the chain. It is referred as presenting functional activities, such as improvement of calcium bioavailability, and biological effects like anticytotoxic and immunomodulatory properties [25,26]. In addition, it behaves as a prebiotic, stimulating the activity of colon-beneficial microflora . Since its release takes place only in the intestine, this polymer can be used for the protection of the bioactive compounds susceptible to degradation along the human digestive tract. Arabic gum is a complex heteropolysaccharide with a highly-branched structure, consisting of D-glucuronic acid, L-rhamnose, D-galactose, and L-arabinose, including approximately 2% protein. It has been used as wall material in spraydrying due to its good emulsification properties, high solubility, and low viscosity in aqueous solutions. In addition, it provides good retention of volatile substances and confers effective protection against oxidation [22,28]. These three biopolymers were selected to be used in the present work due to their functional properties, in addition to their technological characteristics.
Spherical and irregularly shaped microparticles were obtained (results not shown). Aggregation of the microparticles was observed, a phenomenon possibly due to drop(s) coalescence during dryingprocess. Clumping results from the formation of a liquid bridge between wet particles and occurs if evaporation capacity of the fluidized bed is low (Ronsse et al. 2009) or when ethanol is used as solvent, which has been shown to favor aggregate formation (Yoo et al. 2011). Different microparticles shapes suggest heterogeneous distribution of their components (Burki et al. 2011). The observed tendency of microparticles to wrinkle and form folds and cavities could be a consequence of contraction force and viscosity increase during the drop(s) dryingprocess (Foster and Laetherman, 1995 in: Raffin et al. 2006). Moreover, hollow sphere morphology suggests a quick dryingprocesswith high temperature, close to or above solvent boiling point, which produces vapor inside the particle generating an empty core (Dobry et al. 2009).
CARNEIRO, H. C. F.; TONON, R. V.; GROSSO, C. R. F.; HUBINGER, M. D. Encapsulation efficiency and oxidative stability of flaxseed oil microencapsulated byspraydrying using different combinations of wall materials. Journal of Food Engineering, v. 115, n. 4, p. 443-451, 2013. http://dx.doi.org/10.1016/j.jfoodeng.2012.03.033. COSTA, S. S.; MACHADO, B. A. S.; MARTINS, A. R.; BAGNARA, F.; RAGADALLI, S. A.; ALVES, A. R. C. Dryingbyspraydrying in the food industry: micro-encapsulation, process parameters and main carriers used. African Journal of Food Science, v. 9, n. 9, p. 462-470, 2015. http://dx.doi.org/10.5897/AJFS2015.1279. DENARDIN, C. C.; SILVA, L. P. Estrutura dos grânulos de amido e sua relação com propriedades físico-químicas. Ciência Rural, v. 39, n. 3, p. 945-954, 2009. http://dx.doi.org/10.1590/S0103- 84782009005000003.
The percentage of maltodextrin influenced the product final moisture, showing a linear relationship with the increase in percentage of maltodextrin since the soursop pulp powder with 45% of maltodextrin had the highest moisture values. Although the powders differ statistically, the average moisture values are much lower than the maximum value established by law, which is 25% of moisture for dry or dehydrated fruit products. Mata et al. (2005), investigating soursoup powder obtained by the freeze-drying (lyophilization) process, found moisture values of 2.1%, which is above the result found in the present study. Therefore, this difference can be due to the different dehydration processes used.
The purpose of the present work was to study alternatives to the traditional air dryingof pears and to analyse their effect on the reduction ofdrying time and on the chemical and physical properties of the dried pears. The pears were dried in three differentdrying systems beyond the traditional open-air drying: (i) solar stove (length=3.2 m, with=1.9 m, height=2m in the center and 1.3 at the sides) with convective air drying promoted by a fan. The structure is aluminium and is completely enclosed in 3 mm greenhouse glass. A hygrometer was placed inside the stove to register the temperature and relative humidity at 10 minutes intervals; (ii) solar dryer with natural ventilation and with dimension structure of 990×595×375 mm enclosed with glass. The system is equipped with two trays at 5 cm and
ABSTRACT - The guava is one of the most popular tropical fruits, being highly accepted all over Brazil. Many food products can be made from the fruit, such as jams, jellies, liquors and many types of juice. Given the above, the objective of this research was to characterise atomised guava pulp as to its physicochemical composition, and assess its hygroscopic behaviour by means of adsorption isotherms employing different mathematical models. The physicochemical analyses, carried out on both the whole guava pulp and on the atomised guava powder, were: moisture; pH; acidity; soluble solids and ascorbic acid, giving the following results respectively: 88.57-5.69 %; 3.76-3.88, 0.43-0.24 mg 100 g -1 ; 8.43 to
Abstract: Microencapsulation is a processof entrapment, packaging or immobilizing an active (core) material, which can be in the state of solid, liquid or gas, within a more stable, protective secondary (wall) material that can be released at controlled rates under specific conditions. There are several microencapsulation techniques such as: spraydrying, spray cooling/chilling, freeze drying, extrusion, fluidized bed coating, coacervation, liposome entrapment, coextrusion, interfacial polymerization, radical polymerization, molecular inclusion in cyclodextrins, etc.
Table 1 shows the swelling degree of the samples containing the crosslinking agent. It has been reported in the literature that the swelling ability ofspray-dried chitosan is higher than that of pure chitosan. When the chitosan is crosslinked, the swelling ability of the samples is reduced and the matrices more rigid. Ionic interactions between the negative charges of the crosslinker (TPP) and positively charged groups of chitosan are the main interactions occurring within the network. The swelling capacity ofspray-dried chitosan micros- pheres crosslinked withdifferent volumes of TPP solution was pH- -dependent. At pH 1.2, the samples swelled very quickly, leading to fast dissolution of the samples after 1 h. However, swelling at pH 6.8 was slower. At pH 6.8, as the volume of added TPP solution increased, the swelling capacity ofspray-dried chitosan microspheres decreased considerably (Table 1). These results suggest that a more tightly crosslinked chitosan matrix does not swell (lower water uptake) as much as a loosely crosslinked chitosan matrix. With a lower volume of TPP, the chitosan network is loose and has a high hydrodynamic free volume to accommodate more of the solvent molecules, thereby inducing chitosan–TPP matrix swelling. 19-21
Dyster drying processes have produced a large amount of cooking soup byproducts. On this study, oyster cooking soup byproduct was concentrated and spray-dried after enzymatic hydrolysis to produce seasoning powder. Response surface methodology (RSM) was performed on the basis of single-factor studies to optimize the feeding temperature, hot air temperature, atomization pressure, and total solid content of oyster drying. Results revealed the following optimized parameters of this process: feeding temperature of 60 °C, total solid content of 30%, hot air temperature of 197 °C, and atomization pressure of 92 MPa. Under these conditions, the oyster powder yield was 63.7% ± 0.7% and the moisture content was 4.1% ± 0.1%. Dur pilot trial also obtained 63.1% yield and 4.0% moisture content. The enzyme hydrolysis of cooking soup byproduct further enhanced the antioxidant activity of the produced oyster seasoning powder to some extent. Spraydryingprocess optimized by RSM can provide a reference for high-valued applications of oyster cooking soup byproducts.
extract concentration in the solution to be dried was positive for increasing the S, representing an advantage for the process, increasing the productivity by increasing the concentration of product. Furthermore, the quadratic effect of inlet air temperature was negative, contributing to the decrease of the percentage of soluble solids. Higher concentrations of coffee leaf extract in the solution to be dried may have aided in the process, causing an easier release of the powder. With opposite effect, high inlet air temperatures may have caused rigid crusts in powder particles by rapidly removed from the surface, making the output of the nuclei thus damaging the solubility of the material. In spraydrying using maltodextrin as carrier of salvia tea (ŞAHIN-NADEEM et al., 2013) and watermelon juice (QuEK; CHoK; SWEDLuND, 2007), negative effect was also observed for the inlet air temperature on the percentage of soluble solids. those authors argue that, by increasing temperature, the agglomeration of the particles is reduced, with consequently reduced S. Based on that study, higher inlet air temperatures lead to obtaining a material with higher moisture content by crust formation on the surface of the particle. the formation of the crust and highest moisture content are two factors pointed out by several authors (QuEK; CHoK; SWEDLuND, 2007; toNoN et al., 2009; VARDIN; YASAR, 2012) as responsible for decreased S.
Yacon root is a functional food which contains antioxidants and prebiotics compounds. This study aimed to evaluate the physical, chemical and prebiotic characteristics of a yacon extract powder obtained by ultrafiltration (UF) with membranes of 10 and 30 kDa and encapsulation of the resulting permeate byspraydrying. Drying air temperatures of 140 and 160 ºC and concentrations of gum arabic of 10 and 15% were tested. The samples had solubility values greater than 90% while the hygroscopicity decreased with increasing gum concentration and drying temperature. Electron microscopy showed a strong tendency to agglomeration of smaller particles around the larger ones, mainly at a temperature of 140 ºC. Regarding color, the parameter L* showed that drying at 160 ºC produced darker samples and the parameters a* and b* indicated that all samples were greenish yellow. The concentration of inulin decreased during drying, whereas the levels of glucose and fructose increased due to the thermolysis reaction, which led to degradation of inulin chains at drying temperature. The permeates and retentates from the UF membranes had prebiotic activity, while only the encapsulated product from UF-30 membrane, metabolized by Lactobacillus acidophilus LA-5 ® , presented activity scores without significant difference to that of glucose.
The Pterodon emarginatus presents some pharmacological properties that may be related to the presence of vouacapanes. The purpose of this work is to reach a standardized dry extract of the P. emarginatus fruit. The powder, ethanolic extract and dry extract showed the presence of vouacapanes and lupeol confirmed by IR and GC-MS. The dryingprocess (spraydrying) using the colloidal silicon dioxide showed to prevent the thermal degradation and increased approximately twice the terpenes content. The scanning electron microscopy (SEM) showed irregular and spherical particles. The analytical method by spectrophotometry for the quantification of total terpenes was validated and showed to be selective, linear, precise, accurate and robust. In the antinociceptive activity test (capsaicin), the pre-treatment with the dried extract reduced the reactivity time in 50.9%. The results may suggest that the technological processes employed to transform the P. emarginatus fruits in standardized dried extract were adequate to maintain quality chemistry and antinociceptive activity described for the fruits. This work represents the first description of the obtaining of the standardized dried extract of P. emarginatus and also the identification of lupeol in the fruits of this medicinal plant.
final product differentiates according to its physicochemical or nutritional properties and microstructures (Caparino et al., 2012). The hot air drying technique is the most frequently used technique to produce dehydrated vegetables and fruits. In this technique, the need for elevated temperatures or lengthy drying durations may provoke severe harm to flavor, color, and nutrients of the product and it may also reduce rehydration capacity and bulk density of the dried fruit (Qing-guo et al., 2006). Microwave dryers are focused on water molecules and they transform electromagnetic energy into kinetic energy. Accordingly, heat is yielded inside the product and so energy transfer cannot be changed due to the obstacles to the transfer. By using this technique, it is possible to penetrate into the material and heat is produced in the total volume of the material. Thus, energy saving and increased drying rate are achieved (Motevali et al., 2011). Besides, there are some disadvantages of this technique, such as the overheating of the surface and textural damage to the product (Botha et al., 2012). Dryingby freezing technique enables an output product of high quality. The chemical, biological and physical properties of a product bear only minor changes. On the other hand, it is time-consuming and expensive. In this technique, the raw material which is in the drying chamber should go through the phase of long-lasting storage and pre-freezing, nevertheless, the high temperature of the heating plate hastens the sublimation period (Nawirska et al., 2009).
suitable properties as emulsion stabilizers. Starch phosphates could probably improve oil retention in blends with emulsifying starches. Surface oil contents of microencapsulated products ranged from 1.02 to 1.60 % of total solids. Surface oil was higher in phosphorylated taro and rice starches than in other modified starches. Succinylated waxy corn starch had the lowest values of surface oil. The high displayed stability may be attributed to good surface-active properties (ROMÁN-GUERRERO et al., 2009) of starch derivatives which possess hydrophobic groups that are accessible in short timescale, which enable them to adhere and spread out at the interface, thereby protecting newly formed droplets from aggregating or coalescing through steric stabilization and electrostatic stabilization mechanisms (DICKINSON, 2003). According to Risch and Reineccius (1988), this parameter is strongly associated with the emulsion droplet size, and low surface oil content is very important for providing storage stability to flavorings subject to oxidative
By the initial classification of the seed lots (Table 2), it is possible to note that for both cultivars, the 5.5mm sieve presented a low germination percentage, even though they seemed feasible after the tetrazolium test. Such seeds did not reach the minimum percentage required for the commercialization of soybean seeds in Brazil, which is 80% (Brasil, 2005). Although the studies performed so far have presented conflicting results regarding the relation between seeds size and physiological quality, unfavorable climate conditions of the seeds production region during the harvest of 2011/2012 need to be considered. Thus, the seeds from the 5.5 mm sieve may present bigger problems during the maturation and reserves accumulation, causing a reduction in their physiological quality.