Study of the flash drying of the residue from soymilk processing - "okara"

The objective of this research project was to study the drying of soymilk residue in a pneumatic flash dryer, using response Surface Methodology (RSM), and to evaluate the quality of the dried residue. Soymilk residue, also known as okara, was provided by a Brazilian soymilk factory. RSM showed that for a 120 second drying cycle, the lower the residue moisture contents (y) obtained, the higher the recirculation rates (x1), regardless of the air drying temperature (x2), and it could be expressed by the equation y = 7.072 - 7.92x1, with R² = 92,92%. It is possible to obtain okara with 10% of moisture (dwb) under the condition x1=1.25, equivalent to RR = 61%, with air drying temperatures ranging from 252 °C to 308 °C. The dried okara obtained through Central Compound Rotational Design (CCRD) presented a centesimal composition similar to the okara dried in a tray dryer, known as the original okara. There were significant variations (p < 0.05) in the Emulsifying Capacity (EC), Emulsion Stability (ES) and Protein Solubility (PS) between the dehydrated residues obtained. It was concluded that the flash drying of okara is technically feasible and that the physicochemical composition of the residue was not altered; on the contrary, the process promoted a positive effect on the technological functional properties.

Sensory acceptability and physical stability evaluation of a prebiotic soy-based dessert developed with passion fruit juice

The aim of this study was to use a factorial design approach for developing a palatable and stable soy-based dessert with the addition of Soy Protein (SP), oligofructose, and Passion Fruit Juice (PFJ). Panelists (n = 50) used a seven-point hedonic scale to assess the overall liking, degree of liking of creaminess, taste, and color of the desserts. In addition, the samples were submitted to a preference ranking test in order to evaluate the products' preference. Water Holding Capacity (WHC) and backscattering (BS) measures were also determined to assess the physical stability of the trials. Sample F3 (35% PFJ and 2% SP) was the only one that presented a WHC index of 94.8%; moreover, none of the developed samples had synerisis after 72 hours of storage indicating adequate physical stability of the emulsion process. Samples F2 (25% PFJ, and 3.0% SP), F4 (35% PFJ, and 3.0% SP), and F5 (30% PFJ, and 2.5% SP) presented mean hedonic scores above 'slightly liked' for all sensory attributes. The acceptance index of samples varied from 62.50 to 88% showing the great sensory potential of such products.

The effect of sodium reduction and the use of herbs and spices on the quality and safety of bologna sausage

In this study, the replacement of 50% NaCl by KCl in Bologna sausage with the addition of herbs and spice blends (coriander, onion, white pepper, cardamom, and Jamaican pepper) was evaluated. The formulations tested showed a significant reduction in the sodium content with no major alterations in the emulsion stability, texture, and microbiological characteristics. The use of 50% KCl caused a reduction in the sensory quality leading to a significant decrease in the consumers' purchase intention. The formulations with the addition of herbs and spice blends presented better results in the sensory evaluation indicating that this strategy can reduce the negative effects resulting from the use of KCl.

Physical, chemical, technological and sensory characteristics of Frankfurter type sausage containing okara flour

The addition of okara flour to an emulsified meat product (Frankfurter type sausage) was evaluated based on the physical, chemical, technological, and sensory characteristics of the final product. Okara, residue from soymilk production, was provided by two soymilk producing companies whose production systems were based on the hot disintegration of the decorticated (company B) or undecorticated (company A) soybeans. The okara was dehydrated using a flash dryer and then ground into flour (>420 µm). However, The okara flours A and B showed approximately the same amount of protein (35 and 40 g.100 g-1 dwb). However, the okara flour A presented higher values (p < 0.05) for all technological functional properties studied (emulsification capacity, emulsion stability, protein solubility, and water hold capacity) than those of okara flour B. The A and B okara flours were used in a frankfurter sausage formulation as substitution of 1.5% and 4% of meat. The results showed that the sausages containing okara flours A and B, as well as the control sausage, were accepted by the sensory panel. Moreover, there were no significant differences (p < 0.05) in the physical (color, objective texture, and emulsion stability) and chemical (pH and proximate composition) measurements of the sausages with and without the okara flour.

Chemical constituents and technological functional properties of acerola (Malpighia emarginata DC.) waste flour

Acerola is a fruit that can be consumed in the form of juice and pulp. However, during its processing, a large amount of waste is generated (seed and bagasse). Adding value to these by-products is of great interest, since their use can enrich foods with nutrients and fiber. In this study, we performed phytochemical screening, determined the proximate and mineral composition, bioactive compounds and the technological functional properties of acerola seed flour and acerola bagasse flour. Seeds were dried in a ventilated oven at ± 45 °C and the bagasse was lyophilized. Samples were ground, stored in flasks protected from light. Phytochemical screening revealed metabolites of nutritional and pharmacological interest and no potentially toxic substances in the flours. Seed flour and bagasse flour showed high levels (g 100 g- 1 of dry matter - DM) of soluble fiber: 4.76 and 8.74; insoluble fiber: 75.76 and 28.58, and phenolic compounds: 4.73 and 10.82, respectively. The flours also showed high absorption of water, oil and emulsion stability, presenting potential for inclusion in meat products and bakery products.

Particle size and cholesterol content of a mayonnaise formulated by OSA-modified potato starch

Egg yolk was partially replaced (0, 25, 50, 75, and 100%) with octenyl succinic anhydride (OSA)-modified potato starch in a reduced-fat mayonnaise formulation to curtail the problems associated with high cholesterol and induced allergic reactions. The physicochemical properties included parameters such as: pH, fat content, and emulsion stability of the formulations analyzed. The samples with 75% and 100% egg yolk substitute showed the maximum emulsion stability (>95% after two of months storage), and they were selected according to cholesterol content, particle size distributions, dynamic rheological properties, microstructure, and sensory characteristic. A significant reduction (84-97%) in the cholesterol content was observed in the selected samples. Particle size analysis showed that by increasing the amount of OSA starch, the oil droplets with the peak size of 70 µm engulfed by this compound became larger. The rheological tests elucidated that in the absence of egg yolk, OSA starch may not result in a final product with consistent texture and that the best ratio of the two emulsifiers (OSA starch/egg yolk) to produce stable reduced-fat, low cholesterol mayonnaise is 75/25. The microscopic images confirmed the formation of a stable cohesive layer of starch surrounding the oil droplets emulsified in the samples selected.

Developing novel one-step processes for obtaining food-grade O/W emulsions from pressurized fluid extracts: processes description, state of the art and perspectives

Abstract In this work, a novel on-line process for production of food-grade emulsions containing oily extracts, i.e. oil-in-water (O/W) emulsions, in only one step is presented. This process has been called ESFE, Emulsions from Supercritical Fluid Extraction. With this process, emulsions containing supercritical fluid extracts can be obtained directly from plant materials. The aim in the conception of this process is to propose a new rapid way to obtain emulsions from supercritical fluid extracts. Nowadays the conventional emulsion formulation method is a two-step procedure, i.e. first supercritical fluid extraction for obtaining an extract; secondly emulsion formulation using another device. Other variation of the process was tested and successfully validated originating a new acronymed process: EPFE (Emulsions from Pressurized Fluid Extractions). Both processes exploit the supercritical CO2-essential oils miscibility, in addition, EPFE process exploits the emulsification properties of saponin-rich pressurized aqueous plant extracts. The feasibility of this latter process was demonstrated using Pfaffia glomerata roots as source of saponin-rich extract, water as extracting solvent and clove essential oil, directly extracted using supercritical CO2, as a model dispersed phase. In addition, examples of pressurized fluid-based coupled processes applied for adding value to food bioactive compounds developed in the past five years are reviewed.

Rheological properties of oil-in-water emulsions prepared with oil and protein isolates from sesame (Sesamum Indicum)

In this study, food emulsions of oil in water from sesame (Sesamum indicum) protein isolates and their oil were formulated and standardised. The effect of the concentrations of sesame (Sesamum indicum) protein isolates and base oil and the speed of the emulsification process for the food emulsion stability was studied. The protein isolates were achieved from the defatted sesame flour (DSF), obtaining a percentage of 80% ± 0.05% of protein. Emulsions were formulated through a factorial design 23. The rheological behaviour of sesame (Sesamum indicum) protein isolates-stabilised emulsions and microstructural composition were investigated. Stable emulsions with suitable rheological properties and microstructure were formulated at a concentration of 10% sesame oil and different concentrations of protein isolates, between 1.5% and 2.5%, with the best droplet distribution characteristics being shown for the 2.5% sesame protein isolates. The emulsions showed a non-Newtonian fluid behaviour, adjusting the Sisko model.

Lactose intolerance and cow's milk protein allergy

Abstract Adverse reactions to food intake have very diverse etiology and symptomatology. Regarding milk, its food allergy is presented as lactose intolerance, the sugar in milk, or allergy to milk protein. Despite having different symptomatology, confusions among allergic conditions to dairy and its mediators are common. Milk protein allergy originates from protein components present in milk, causing reactions to either the protein fractions in emulsion (caseins) or in whey (milk albumin). The allergic reaction is type IV mediated by T lymphocytes. The allergic reaction produces severe cellular damage and it triggers physical, mental and emotional symptomatology that may vary in time, intensity and severity. Lactose intolerance is originated by total or partial absence of the enzyme that digests this disaccharide. Lactose intolerance can be primary or congenital and secondary; the former being more rare and severe, the latter being more common. Lactase deficiency can be diagnosed by symptoms associated with cramping and diarrhea. Thus, the objective of this study was to conduct a review of available literature on cow’s milk protein allergy and lactose intolerance.

From protein structure to function with bioinformatics

It has long been known that amino acids are the building blocks for proteins and govern their folding into specific three-dimensional structures. However, the details of this process are still unknown and represent one of the main problems in structural bioinformatics, which is a highly active research area with the focus on the prediction of three-dimensional structure and its relationship to protein function. The protein structure prediction procedure encompasses several different steps from searches and analyses of sequences and structures, through sequence alignment to the creation of the structural model. Careful evaluation and analysis ultimately results in a hypothetical structure, which can be used to study biological phenomena in, for example, research at the molecular level, biotechnology and especially in drug discovery and development. In this thesis, the structures of five proteins were modeled with templatebased methods, which use proteins with known structures (templates) to model related or structurally similar proteins. The resulting models were an important asset for the interpretation and explanation of biological phenomena, such as amino acids and interaction networks that are essential for the function and/or ligand specificity of the studied proteins. The five proteins represent different case studies with their own challenges like varying template availability, which resulted in a different structure prediction process. This thesis presents the techniques and considerations, which should be taken into account in the modeling procedure to overcome limitations and produce a hypothetical and reliable three-dimensional structure. As each project shows, the reliability is highly dependent on the extensive incorporation of experimental data or known literature and, although experimental verification of in silico results is always desirable to increase the reliability, the presented projects show that also the experimental studies can greatly benefit from structural models. With the help of in silico studies, the experiments can be targeted and precisely designed, thereby saving both money and time. As the programs used in structural bioinformatics are constantly improved and the range of templates increases through structural genomics efforts, the mutual benefits between in silico and experimental studies become even more prominent. Hence, reliable models for protein three-dimensional structures achieved through careful planning and thoughtful executions are, and will continue to be, valuable and indispensable sources for structural information to be combined with functional data.

Partial characterization of genes from the embryonic axis of Melanoxylon brauna Schott. (Leguminosae-Caesalpinioideae) seeds

The objective of this study was to partially characterize some genes involved in the desiccation tolerance of the embryonic axis of Melanoxylon brauna seeds subjected, or not, to oven fast-drying. Seeds were initially dried rapidly in an oven at 40 ºC, 50 ºC, 60 ºC, 70 ºC, and 80 °C, for 24, 48 and 72 h and then subjected to germination tests and moisture content determination. Degenerate primers were designed for 19 genes. The CDNA was used as a template for PCR amplifications using the degenerate primers, and the PCR products obtained were purified, cloned and sequenced. The seeds showed a gradual reduction in percent germination with increasing temperature and drying time. Nucleotide sequences of the cloned fragments related to genes CAT1, SPS1, Abi5, Transk and PM25 were obtained. The similarity analysis with the sequences deposited in databases revealed similarities with genes CAT1, SPS1, Transk and PM25 from other plant species. The nucleotide sequences obtained from the respective genes will be used for designing specific primers for gene expression analyses during seed germination in order to understand the causes for loss of physiological quality of Melanoxylon brauna seeds.

Aikaerotteisesti fluoresenssia mittaavan reaaliaikaisen PCR-laitteen kehitys

Kvantitatiivinen reaaliaikainen polymeraasiketjureaktio (engl. polymerase chain reaction, PCR) on osoittautunut käyttäjäystävällisimmäksi menetelmäksi nukleiinihapposekvenssien kvantitoimisessa. Tätä menetelmää voidaan herkistää pienempien DNA-pitoisuuksien havaitsemiseen käyttämällä hyväksi aikaerotteista fluorometriaa (engl. time-resolved fluorometry, TRF) ja luminoivia lantanidileimoja, joiden fluoresenssin pitkän eliniän ansiosta emission mittaus voidaan suorittaa vasta hetki virittävän valopulssin jälkeen, jolloin lyhytikäinen taustasäteily ehtii sammua. Tuloksena saadaan korkea signaali-taustasuhde. Tämän diplomityön tarkoituksena oli rakentaa TRF:än pystyvä reaaliaikainen PCR-laite, sillä tällaista laitetta ei ole markkinoilla tarjolla. Laite rakennettiin kehittämällä lämpökierrätin ja yhdistämällä se valmiiseen TRF:än kykenevään mittapäähän. Mittapään ja lämpökierrättimen hallitsemiseksi kehitettiin myös tietokoneohjelma. Valon tuottamiseksi ja mittaamiseksi haluttiin käyttää edullisia komponentteja, joten työssä käytettiin valmiin mittapään optiikkaa, jossa viritys tapahtuu hohtodiodilla (engl. light-emitting diode, LED) ja lantanidileiman emission mittaus fotodiodilla (engl. photodiode, PD) tai valomonistinputkella (engl. photomultiplier tube, PMT). Myös mittapään suorituskykyä tutkittiin. Työtä varten kehitettiin lämpökierrätin, joka koostui Peltier-elementillä lämmitettävästä PCR-putkitelineestä ja lämpökannesta. Mittalaitteen suorituskyvyn tutkimiseen käytettiin kelaattikomplementaatioon perustuvaa PCR-tuotteen havaitsemismenetelmää. Kelaattikomplementaatio perustuu kahteen erilliseen oligonukleotidimolekyyliin, joista toiseen on sidottu lantanidi-ioni ja toiseen valoa absorboiva ligandirakenne, jotka yhdessä muodostavat fluoresoivan kokonaisuuden. Kehitetyn lämpökierrättimen todettiin olevan tarpeeksi tarkka sekä tehokas ja sen lämmitys- ja jäähdytysnopeuden maksimeiksi saatiin 2,6 °C/sekunti. Detektorina käytetyn PD:n ei todettu olevan tarpeeksi herkkä emission havainnoimiseksi ja se korvattiin laitteessa PMT:llä. Käytetyllä PCR-määrityksellä kynnyssykleiksi (engl. threshold cycle, Ct) sekä kehitetylle että referenssilaitteelle saatiin 28,4 käyttämällä samaa 100 000 kopion DNA:n aloitusmäärää. Työssä osoitettiin, että on mahdollista kehittää edullisia komponentteja käyttävä, TRF:än pystyvä, reaaliaikainen PCR-laite, joka kykenee vastaavaan Ct-arvoon kuin vertailulaite. PD:n herkkyys ei kuitenkaan riittänyt. Tulokset olivat lupaavia, sillä LED- ja PD-teknologiat kehittyvät ja markkinoille on tullut myös muita komponentteja, joiden avulla on tulevaisuudessa mahdollista kehittää vielä herkempi laite.

Emerging markets and the international financial architecture: a blueprint for reform

If emerging markets are to achieve their objective of joining the ranks of industrialized, developed countries, they must use their economic and political influence to support radical change in the international financial system. This working paper recommends John Maynard Keynes's "clearing union" as a blueprint for reform of the international financial architecture that could address emerging market grievances more effectively than current approaches. Keynes's proposal for the postwar international system sought to remedy some of the same problems currently facing emerging market economies. It was based on the idea that financial stability was predicated on a balance between imports and exports over time, with any divergence from balance providing automatic financing of the debit countries by the creditor countries via a global clearinghouse or settlement system for trade and payments on current account. This eliminated national currency payments for imports and exports; countries received credits or debits in a notional unit of account fixed to national currency. Since the unit of account could not be traded, bought, or sold, it would not be an international reserve currency. The credits with the clearinghouse could only be used to offset debits by buying imports, and if not used for this purpose they would eventually be extinguished; hence the burden of adjustment would be shared equally - credit generated by surpluses would have to be used to buy imports from the countries with debit balances. Emerging market economies could improve upon current schemes for regionally governed financial institutions by using this proposal as a template for the creation of regional clearing unions using a notional unit of account.

Metal oxides prepared through the nanocasting approach-mechanistic study, surface interactions and applications in separation

Mesoporous metal oxides are nowadays widely used in various technological applications, for instance in catalysis, biomolecular separations and drug delivery. A popular technique used to synthesize mesoporous metal oxides is the nanocasting process. Mesoporous metal oxide replicas are obtained from the impregnation of a porous template with a metal oxide precursor followed by thermal treatment and removal of the template by etching in NaOH or HF solutions. In a similar manner to the traditional casting wherein the product inherits the features of the mold, the metal oxide replicas are supposed to have an inverse structure of the starting porous template. This is however not the case, as broken or deformed particles and other structural defects have all been experienced during nanocasting experiments. Although the nanocasting technique is widely used, not all the processing steps are well understood. Questions over the fidelity of replication and morphology control are yet to be adequately answered. This work therefore attempts to answer some of these questions by elucidating the nanocasting process, pin pointing the crucial steps involved and how to harness this knowledge in making wholesome replicas which are a true replication of the starting templates. The rich surface chemistry of mesoporous metal oxides is an important reason why they are widely used in applications such as catalysis, biomolecular separation, etc. At times the surface is modified or functionalized with organic species for stability or for a particular application. In this work, nanocast metal oxides (TiO2, ZrO2 and SnO2) and SiO2 were modified with amino-containing molecules using four different approaches, namely (a) covalent bonding of 3-aminopropyltriethoxysilane (APTES), (b) adsorption of 2-aminoethyl dihydrogen phosphate (AEDP), (c) surface polymerization of aziridine and (d) adsorption of poly(ethylenimine) (PEI) through electrostatic interactions. Afterwards, the hydrolytic stability of each functionalization was investigated at pH 2 and 10 by zeta potential measurements. The modifications were successful except for the AEDP approach which was unable to produce efficient amino-modification on any of the metal oxides used. The APTES, aziridine and PEI amino-modifications were fairly stable at pH 10 for all the metal oxides tested while only AZ and PEI modified-SnO2 were stable at pH 2 after 40 h. Furthermore, the functionalized metal oxides (SiO2, Mn2O3, ZrO2 and SnO2) were packed into columns for capillary liquid chromatography (CLC) and capillary electrochromatography (CEC). Among the functionalized metal oxides, aziridinefunctionalized SiO2, (SiO2-AZ) showed good chemical stability, and was the most useful packing material in both CLC and CEC. Lastly, nanocast metal oxides were synthesized for phosphopeptide enrichment which is a technique used to enrich phosphorylated proteins in biological samples prior to mass spectrometry analysis. By using the nanocasting technique to prepare the metal oxides, the surface area was controlled within a range of 42-75 m2/g thereby enabling an objective comparison of the metal oxides. The binding characteristics of these metal oxides were compared by using samples with different levels of complexity such as synthetic peptides and cell lysates. The results show that nanocast TiO2, ZrO2, Fe2O3 and In2O3 have comparable binding characteristics. Furthermore, In2O3 which is a novel material in phosphopeptide enrichment applications performed comparably with standard TiO2 which is the benchmark for such phosphopeptide enrichment procedures. The performance of the metal oxides was explained by ranking the metal oxides according to their isoelectric points and acidity. Overall, the clarification of the nanocasting process provided in this work will aid the synthesis of metal oxides with true fidelity of replication. Also, the different applications of the metal oxides based on their surface interactions and binding characteristics show the versatility of metal oxide materials. Some of these results can form the basis from which further applications and protocols can be developed.

Incidence of resistance to benzimidazole fungicides in a field population of Venturia inaequalis /

The allele-specific polymerase chain reaction (PCR) was used to screen for the presence of benomyl resistance, and to characterize their levels and frequencies in field populations of Venturia inaequalis during two seasons. Three hundred isolates of V. inaequalis were collected each season from infected leaves of MalusX domestica. Borkh c.v. Mcintosh. The trees used were sprayed in the year prior to collection with five applications of benomyl, its homologue Azindoyle, or water. Monoconidial isolates of V. inaequalis were grown on 2% potato dextrose agar (PDA) for four weeks. Each isolate was taken from a single lesion from a single leaf. Total genomic DNA was extracted from the four week old colonies of V. inaequalis, prepared and used as a template in PCR reactions. PCR reactions were achieved by utilizing allele-specific primers. Each primer was designed to amplify fragments from a specific allele. Primer Vin was specific for mutations conferring the ben^^"^ phenotype. It was expected to amplify a 171 bp. DNA fragment from the ben^"^ alleles only. Primers BenHR and BenMR were specific for mutations conferring the ben"" and ben'^'' phenotypes, respectively. They were expected to amplify 172 bp. and 165 bp. DNA fragments from the ben"" and ben"^" alleles, respectively. Of the 953 isolates tested, 414 (69.9%) were benomyl sensitive (ben^) and 179 (30.1%) were benomyl resistant. All the benomyl resistant alleles were ben^"", since neither the ben"" nor the ben"" alleles were detected. Frequencies of benomyl resistance were 23%, 24%, and 23% for the 1997 collections, and were 46%, 26% and 38% for the 1998 collections for benomyl, Azindoyle and water treatments, respectively. Growth assay was performed to evaluate the applicability of using PCR in monitoring benomyl resistance in fungal field populations. Tests were performed on 14 isolates representing the two phenotypes (ben^ and ben^"'' alleles) characterized by PCR. Results of those tests were in agreement with PCR results. Enzyme digestion was also used to evaluate the accuracy and reliability of PCR products. The mutation associated with the ben^"'' phenotype creates a unique site for the endonuclease enzyme Bsh^236^ allowing the use of enzyme digestion. Isolates characterized by PCR as ben^'^'^ alleles had this restriction site for the SsA7l2361 enzyme. The most time consuming aspect of this study was growing fungal isolates on culture media for DNA extraction. In addition, the risk of contamination or losing the fungus during growth processes was relatively high. A technique for extracting DNA directly from lesions on leaves has been used (Luck and Gillings 1 995). In order to apply this technique in experiments designed to monitor fungicide resistance, a lesion has to be homogeneous for fungicide sensitivity. For this purpose, PCR protocol was used to determine lesion homogeneity. One hundred monoconidial isolates of V. inaequalis from 10 lesions (10-conidia/ lesion) were tested for their phenotypes with respect to benomyl sensitivity. Conidia of six lesions were homogeneous, while conidia of the remaining lesions were mixtures of ben^ and ben^ phenotypes. Neither the ben" nor the ben' phenotype was detected.