Characterization of new sources of derivative starches as wall materials of essential oil by spray drying

Starch derivatives of taro (Colocasia esculenta L. Schott) and rice were characterized as wall materials of orange oil (d-limonene) by spray drying. Native starches were initially hydrolyzed with HCl and then esterified. Succinylated starches were modified using a conventional method in a slurry and were extruded; whereas, the phosphorylated starches were modified using the extrusion process. Viscosity and solubility of starches reduced after acid hydrolysis, derivatization, and extrusion. The particle size of the wall materials ranged between 20.05 and 31.81 µm. The encapsulation efficiency of the phosphorylated taro, rice, and waxy corn starches was 96.9, 96.8 and 97.1% respectively, and 98.6, 98.1, and 98.8% for succynilated taro, rice, and waxy corn starches, respectively. Starch derivatives of taro and rice could potentially be used as wall materials of orange oil d-limonene.

Use of the spray chilling method to deliver hydrophobic components: physical characterization of microparticles

Food industry has been developing products to meet the demands of increasing number of consumers who are concerned with their health and who seek food products that satisfy their needs. Therefore, the development of processed foods that contain functional components has become important for this industry. Microencapsulation can be used to reduce the effects of processing on functional components and preserve their bioactivity. The present study investigated the production of lipid microparticles containing phytosterols by spray chilling. The matrices comprised mixtures of stearic acid and hydrogenated vegetable fat, and the ratio of the matrix components to phytosterols was defined by an experimental design using the mean diameters of the microparticles as the response variable. The melting point of the matrices ranged from 44.5 and 53.4 ºC. The process yield was melting point dependent; the particles that exhibited lower melting point had greater losses than those with higher melting point. The microparticles' mean diameters ranged from 13.8 and 32.2 µm and were influenced by the amount of phytosterols and stearic acid. The microparticles exhibited spherical shape and typical polydispersity of atomized products. From a technological and practical (handling, yield, and agglomeration) points of view, lipid microparticles with higher melting point proved promising as phytosterol carriers.

Influence of spray drying operating conditions on microencapsulated rosemary essential oil properties

Spray drying is an important method used by the food industry in the production of microencapsulated flavors to improve handling and dispersion properties. The objective of this study was to evaluate the influence of the process conditions on the properties of rosemary essential oil microencapsulated by spray drying using gum Arabic as encapsulant. The effects of the wall material concentration (10-30%), inlet air temperature (135-195 ºC), and feed flow rate (0.5-1.0 L.h-1) on the moisture content, hygroscopicity, wettability, solubility, bulk and tapped densities, particle density, flowability, and cohesiveness were evaluated using a 2³ central composite rotational experimental design. Moisture content, hygroscopicity and wettability were significantly affected by the three factors analyzed. Bulk density was positively influenced by the wall material concentration and negatively by the inlet air temperature. Particle density was influenced by the wall material concentration and the inlet air temperature variables, both in a negative manner. As for the solubility, tapped density, flowability, and cohesiveness, the models did not fit the data well. The results indicated that moderate wall material concentration (24%), low inlet air temperature (135 ºC), and moderate feed flow rate (0.7 L.h-1) are the best spray drying conditions.

Evaluation of iron bioavailability in a mixture of cereals, seeds, and grains ("Human Ration")

Iron bioavailability was evaluated in three mixtures of cereals, seeds, and grains ("Human Ration"): light, regular, and homemade provided to rats. The animals received an iron depletion diet for 21 days, followed by a repletion diet containing 12 mg·kg-1 of iron for 14 days. The hemoglobin regeneration efficiency and the relative biological value did not differ between the light mixture and control group. The iron bioavailability of the light mixture of cereals, seeds, and grains and the control group were 99.99±27.62 and 80.02±36.63, respectively, while the regular and homemade mixtures of cereals, seeds, and grains showed lower iron bioavailability, 50.12±35.53 and 66.66±15.44, respectively; the iron content of the diet with light cereal mixture light was statistically similar to that of the control (ferrous sulfate 99.99±27.62). The high content of tannin (202.81±19.53 mg·100-1) in the diet with the regular cereal mixture may have contributed to its low iron bioavailability. The higher intake of soluble fiber by the animals fed the light mixture (21.15±0.92 g) was moderately correlated (r=0.5712, p=0.0018) with the concentration of propionate in the caecal bulk (65.49±11.08 µmol/g). The short chain fatty acids produced by soluble fiber fermentation, associated with the low-content of tannin may have improved iron solubility and absorption in the light cereal mixture diet. The iron bioavailability in the light mixture of cereals, seeds, and grains was similar to that of ferrous sulfate.

Stability of porridge pre-mixture made with Brazil nut flour and green banana flour with and without milk powder

The mixture of Brazil nut flour and green banana flour can improve the nutritional value of school meals, allowing for the use of regional ingredients derived from family agriculture. This study aimed to assess the stability of porridge pre-mixtures made with Brazil nut flour and green banana flour during six months of storage. Two types of pre-mixture were evaluated: with and without milk powder. These mixtures were packed in polyethylene/metallized polyester film, vacuum-sealed, and stored at room temperature. The products were evaluated for physicochemical composition, and every 30 days for moisture content, water activity, titratable acidity, pH, peroxide value and acidity of the lipid phase, total and thermotolerant coliforms, yeasts and molds, and sensory acceptance. There was no difference between the mixtures for the parameters evaluated. Moisture content, water activity, acidity of the lipid phase, and the yeast and mold count increased with storage time. The growth of yeasts and molds was more pronounced after 90 days of storage, when water activity reached the limit of 0.60. Although both products had good sensory acceptance throughout the period of study, it is recommended that the shelf life does not exceed 90 days.

Study of the physicochemical characteristics of soursop powder obtained by spray-drying

This study aimed at contributing to the development of new foodstuffs made by soursop pulp powder obtained by spraydrying. Different concentrations of maltodextrin DE 20 (15, 30, and 45%) were added to commercial soursop pulp, which was dehydrated afterwards. The following analyses were carried out: water activity, moisture, pH, soluble solids, acidity, ascorbic acid, hygroscopicity, degree of caking, and rehydration time. The results obtained for the three powder treatments (15, 30 and 45% of maltodextrin) were, respectectively: water activity (0.19a±0.00; 0.20a±0.00; 0.18a±0.01); moisture (1.17c±0.12; 1.47b±0.05; 1.82a±0.06); pH (3.75a±0.05; 3.73a±0.06; 3.70a±0.03); soluble solids (89.67a±0.00; 89.84a±0.00; 90.00a±0.06); acidity (3.01a±0.02; 1.91b±0.03; 1.24c±0.03); ascorbic acid (18.90a±0.00; 14.48b±0.00; 11.26b±0.78); hygroscopicity (5.93a±0.40; 3.82b±0.16; 3.28b±0.38); degree of caking (78.36a±2.86; 35.38b±6.07; 24.77b4.89), and rehydration time (02.03a±0.46; 01.16ab±0.50; 0.59b±0.30). The soursop powders with 30 and 45% of maltodextrin had few significant differences in terms of physicochemical and hygroscopic characteristics, which allow us to consider the percentage of 30% of maltodextrin, in this study, as the best percentage for soursop pulp atomization.

Preparation and Investigation of Bio-coal Mixture Fuels Used in Large Diesel Engines

Coal slurry was of vital interest during the last century due to its potential as an alternative fuel where liquid fuels were necessary. Recently, environmental impacts of the traditional fuels, similarities of bio-coal to that of coal, and huge bio-coal supply has attracted the attention to prepare bio-coal slurries as a new fuel. Rudolf Diesel who invented the diesel engine on 1895 was of the opinion that diesel engines are capable to use different kinds of fuels due to the special design. He tried some kind of vegetable oil to operate on his IC engine. Recently, due to high energy density and more environmentally friendly fuel, researchers believe that bio-coal slurries could act as a new alternative fuel in large diesel engines. Loads of research on different kinds of bio-coal slurry were done by the other researchers worldwide and a lot of progress to boost slurry’s quality were achieved recently. The present study aims to achieve the ideal condition of different factors affecting on the quality of bio-coal slurry. One charcoal sample and two kinds of torrefied wood were used to investigate and compare the reaction of various factors. The results show a great gap between the quality of slurries made of different samples and more researches are necessary to fully understand the impact of the different parameter and improving the quality.

An HPLC method for simultaneous determination of residual benomyl and MBC on apple foliage without cleanup

A simple High Performance Liquid Chromatograph (HPLC) method has been developed to identify benamyl (methyl 1- (butylcarbamoyl)-2-benzimidazole carbamate) and MBC (methyl 2-benzimidazole carbamat~ residues on apple leaves without cleanup. Sample leaves are freeze dried in a Mason jar and residues are then extracted by tumbling them in chloroform containing 5,000 microgram per milliliter of n-propyl isocyanate (PIC) at 10 C. To the extract, n-butyl isocyanate (BIC) was added at 5,000 microgram per milliliter and 20 microliter of this mixture injected onto the HPLC system. Separation is accomplished by the use of a Brownlee LiChrosorb silica gel column with a guard column and' operated with a mixed mobile phase consisting of chloroform and hexane (4:1) saturated with water. MBC, a degradation product of benomyl is identified if present as methyl l-(npropyl carbamoyl)-2-benzimidazole carbamate (MBC-n-PIC). Both benomyl and MBC-n-PIC can be detected with aKUltraviolet (UV) detector (280nm) at a concentration as low as 0.2 microgram per milliliter in apple leaves. The fate of benomyl on apple foliage after spray application of benomyl (Ben late 50 per cent wettable powder) was investigated by the method thus described. Benomyl quickly dissipated during the first 3-7 days, but the dissipatio'n sltowed down thereafter. In contrast, the concentration of MBC in leaves gradually increased after repeated applications of Benlate.

Probe-level linear model fitting and mixture modeling results in high accuracy detection of differential gene expression

Affiliation: Institut de recherche en immunologie et en cancérologie, Université de Montréal

Spray Pyrolysed Zinc Oxide Thin Films : Effects of Doping and Ion Beam Irradiation

In recent years scientists have made rapid and significant advances in the field of semiconductor physics. One of the most important fields of current interest in materials science is the fundamental aspects and applications of conducting transparent oxide thin films (TCO). The characteristic properties of such coatings are low electrical resistivity and high transparency in the visible region. The first semitransparent and electrically conducting CdO film was reported as early as in 1907 [1]. Though early work on these films was performed out of purely scientific interest, substantial technological advances in such films were made after 1940. The technological interest in the study of transparent semiconducting films was generated mainly due to the potential applications of these materials both in industry and research. Such films demonstrated their utility as transparent electrical heaters for windscreens in the aircraft industry. However, during the last decade, these conducting transparent films have been widely used in a variety of other applications such as gas sensors [2], solar cells [3], heat reflectors [4], light emitting devices [5] and laser damage resistant coatings in high power laser technology [6]. Just a few materials dominate the current TCO industry and the two dominant markets for TCO’s are in architectural applications and flat panel displays. The architectural use of TCO is for energy efficient windows. Fluorine doped tin oxide (FTO), deposited using a pyrolysis process is the TCO usually finds maximum application. SnO2 also finds application ad coatings for windows, which are efficient in preventing radiative heat loss, due to low emissivity (0.16). Pyrolitic tin oxide is used in PV modules, touch screens and plasma displays. However indium tin oxide (ITO) is mostly used in the majority of flat panel display (FPD) applications. In FPDs, the basic function of ITO is as transparent electrodes. The volume of FPD’s produced, and hence the volume of ITO coatings produced, continues to grow rapidly. But the current increase in the cost of indium and the scarcity of this material created the difficulty in obtaining low cost TCOs. Hence search for alternative TCO materials has been a topic of active research for the last few decades. This resulted in the development of binary materials like ZnO, SnO2, CdO and ternary materials like II Zn2SnO4, CdSb2O6:Y, ZnSO3, GaInO3 etc. The use of multicomponent oxide materials makes it possible to have TCO films suitable for specialized applications because by altering their chemical compositions, one can control the electrical, optical, chemical and physical properties. But the advantages of using binary materials are the easiness to control the chemical compositions and depositions conditions. Recently, there were reports claiming the deposition of CdO:In films with a resistivity of the order of 10-5 ohm cm for flat panel displays and solar cells. However they find limited use because of Cd-Toxicity. In this regard, ZnO films developed in 1980s, are very useful as these use Zn, an abundant, inexpensive and nontoxic material. Resistivity of this material is still not very low, but can be reduced through doping with group-III elements like In, Al or Ga or with F [6]. Hence there is a great interest in ZnO as an alternative of ITO. In the present study, we prepared and characterized transparent and conducting ZnO thin films, using a cost effective technique viz Chemical Spray Pyrolysis (CSP). This technique is also suitable for large area film deposition. It involves spraying a solution, (usually aqueous) containing soluble salts of the constituents of the desired compound, onto a heated substrate.

Fabrication and Characterization of Spray Pyrolysed Cadmium Sulphide Homojunction Solar Cells

The study on the fabrication and characterization of spray pyrolysed cadmium sulphide homojunction solar cells. As an alternative to the conventional energy source, the PV technology has to be improved. Study about the factors affecting the performance of the existing solar cells and this will result in the enhancement of efficiency of the cells. At the same time it is equally important to have R&D works on developing new photovoltaic devices and processes which are less expensive for large scale production. CdS is an important binary compound semiconductor, which is very useful in the field of photovoltaics. It is very easy to prepare large area CdS thin films. In order to fabricate thin film homojunction cadmium sulphide cells, prepared and characterized SnO2 thin film as the lower electrode, p-CdS as the active layer and n-CdS as window layer. Cadmium material used for the fabrication of homojunction solar cells is highly toxic. The major damage due to continued exposure to low levels of cadmium are on the kidneys, lungs and bones. The real advantage of spray pyrolysis process is that there is no emission of any toxic gases during the deposition. Very low concentration of the chemicals is needed in this process. The risk involved from this material is very low, though they are toxic. On large scale usage it may become necessary that the cells after their life, should be bought back by the companies to retrieve chemicals like cadmium. This will reduce environmental problem and also the material wastage

Direction Dependent Transmission Characteristics of Dye Mixture Doped Polymer Optical Fibre Preforms

The direction dependant wavelength selective transmission mechanism in poly (methyl methacrylate)(PMMA) rods doped with C 540 dye and C 540:Rh.B dye mixture as a combination has been investigated. When a polished slice of pure C 540 doped polymer rod was used side by side with a C540:Rh B doped rod with acceptor concentration [A] = 7x10-4 m/l , we could notice more than 100% change in the transmitted intensity along opposite directions at the C 540, Rh B emission and the excitation wavelengths . A blue high bright LED emitting at a peak wavelength 465nm was used as the excitation source.

Direction Dependent Transmission Characteristics of Dye Mixture Doped Polymer Optical Fibre Preforms

The direction dependant wavelength selective transmission mechanism in poly (methyl methacrylate)(PMMA) rods doped with C 540 dye and C 540:Rh.B dye mixture as a combination has been investigated. When a polished slice of pure C 540 doped polymer rod was used side by side with a C540:Rh B doped rod with acceptor concentration [A] = 7x10-4 m/l , we could notice more than 100% change in the transmitted intensity along opposite directions at the C 540, Rh B emission and the excitation wavelengths . A blue high bright LED emitting at a peak wavelength 465nm was used as the excitation source.