A liquid foaming technology was developed to produce bio-foams for packaging applications. Liquid foaming consists in the transformation of a liquid foamed solution into a porous solid polymer through liquid removal. Five bio-based liquid foaming formulations systems were explored in this research: starch-PVA-calcium sulfate, starch-gelatine, gelatine hydrogel, gelatinecomposites and hydrogel alternatives to gelatine. Gelatine hydrogel-composite foams secondary materials included bio-mass powders from agriculture waste, expanded vermiculite particles, silica aero-gel powders and honeycomb sandwich panels. The hydrogel foams alternative to gelatine were based on agar and gellan gum as main biopolymers. The feasibility of each formulation system was explored, and the key parameters of formulation and process conditions were identified. The role of different formulation (e.g. biopolymer content, gelatine strength, surfactant type and content, among others) and processing (e.g. expansion ratio, processing temperature and drying process, among others) factors on foaming and drying behaviour of the liquid foam, and the impact on foam structure and properties (density, drying shrinkage and mechanical, thermal and acoustic properties) of the solid foams were investigated. Hydrogel-foams with comparable densities and thermal conductivity to conventional polymeric foams were produced. Gelatine foams made with both surfactants "A" and C2 exhibited desirable properties for being a strong alternative to conventional plastic foams. Low densities (< 20 kg/m3), thermal conductivity (≈0.039 W/k·m), and relatively low shrinkage level were achieved. Production upscale research would need to consider drying process optimization for drying time reduction and drying shrinkage minimization.

Submitted by Juliana Aparecida Marques Eburneo null (julianaeburneo@gmail.com) on 2017-03-27T19:09:19Z No. of bitstreams: 1 Dissertação Final Versão Impressão.pdf: 1337107 bytes, checksum: a68b8582ead29404b314742e523864b0 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-03-29T19:40:50Z (GMT) No. of bitstreams: 1 eburneo_jam_me_bot.pdf: 1337107 bytes, checksum: a68b8582ead29404b314742e523864b0 (MD5) / Made available in DSpace on 2017-03-29T19:40:50Z (GMT). No. of bitstreams: 1 eburneo_jam_me_bot.pdf: 1337107 bytes, checksum: a68b8582ead29404b314742e523864b0 (MD5) Previous issue date: 2017-01-30 / A batata é a hortaliça com maior área cultivada no Brasil, sendo que sua produção se concentra nos estados da região sul e sudeste. Na cultura da batata o manejo inadequado da adubação nitrogenada pode causar crescimento exagerado da parte aérea, reduzir a qualidade de tubérculos e aumentar o custo de produção. Além disso, as condições de cultivo também podem influenciar as características do amido, principal carboidrato de reserva da batata, o que pode levar a interferências na aplicabilidade deste pelas indústrias alimentícias. Frente ao exposto, este trabalho teve por objetivo caracterizar amidos extraídos de batata cv Ágata cultivada sob diferentes doses de adubação nitrogenada e avaliar a possível interferência desta prática sobre a morfologia e distribuição de tamanho dos grânulos de amido, teor de amilose, teores de fósforo, cálcio, potássio e magnésio, composição físico-química, propriedades de pasta e térmicas; parâmetros estes determinantes para o estabelecimento das potencialidades de aplicabilidades do amido pelas indústrias. Para o alcance deste objetivo foram utilizados tubérculos de batata resultantes da colheita de ensaio experimental com adubação nitrogenada instalado em propriedade rural na região da cidade de Avaré, estado de São Paulo. Após o cultivo de 117 dias, as batatas foram colhidas, lavadas e processadas para a extração e análise do amido. Os resultados obtidos mostram que o amido de batata extraído de plantas cultivadas sem a aplicação de adubo nitrogenado apresentou grânulos redondos e ovalados, com predomínio de diâmetro maior na faixa de 26 a 50μm, padrão de difração de raio X do tipo B, 22,16% de cristalinidade relativa, elevada pureza, presença de 1090 ppm de fósforo, 893 ppm de potássio, 200 ppm de cálcio e 88 ppm de magnésio. Temperatura de pasta de 67,94°C, pico de viscosidade de 796,88 RVU, quebra de viscosidade de 622,03 RVU, viscosidade final de 236,28 RVU e tendência a retrogradação de 65,76 RVU. A gelatinização iniciou em 65,85°C, com pico em 68,03°C e final em 70,79°C, com variação de entalpia de 9,92 J g-1. A análise dos dados mostrou interferência da adubação nitrogenada sobre as características do amido de batata cv Ágata, sendo que o incremento nas doses de nitrogênio levou a obtenção de amidos com menor cristalinidade relativa, menores teores de fósforo, cálcio e magnésio, menor resistência à temperatura e agitação e menores temperaturas de gelatinização. Estes resultados indicam que o manejo cultural pode afetar importantes propriedades determinantes de aplicabilidade do amido de batata. / Potato is a vegetable with the largest cultivated area in Brazil and its production is concentrated in the states of the southeast region. In potato cultivation nitrogen fertilization management can cause overgrown growth, reduce the quality of tubers and increase the cost of production. In addition, the cultivation conditions may also influence the characteristics of the starch, main reserve carbohydrate of the potato, which can lead to interference in applicability of starch by industries. In view of the above, the objective of this work was to characterize starches extracted from Ágata cultivar cultivated under different rates of nitrogen fertilization, and to evaluate possible interference on morphology and size distribution of starch granules, amylose content, phosphorus, calcium, potassium and magnesium, physical-chemical composition, pasting and thermal properties, important characteristics for establishing the potential of starch application by industries. In order to reach this objective was analyzed tubers obtained from experimental area in the region of the Avaré city, state of São Paulo. After cultivation of 117 days potatoes were harvested, washed and processed for extraction and analysis of the starches. The results obtained show that potato starch extracted from plants cultivated without a nitrogen fertilizer application showed round and oval granules, with a larger diameter in the range of 26 to 50μm, pattern type B of X-ray diffraction, 22,16% of relative crystalline, high purity, presence of 1090 ppm of phosphorus, 893 ppm of potassium, 200 ppm of calcium and 88 ppm of magnesium. The pasting temperature was 67.94°C, viscosity peak was 796.88 RVU, viscosity breakdown was 622.03 RVU, final viscosity was 236.28 RVU and seatback was 65.76 RVU. The gelatinization of starch granules started at 65.85°C, with peak at 68.03°C, and final at 70.79°C, with enthalpy variation of 9.92 J g-1. The analysis of the data showed the interference of nitrogen fertilization on the characteristics of Ágata potato starch. The increase in nitrogen rates led to the obtaining of starches with lower relative crystalline, lower phosphorus, calcium and magnesium contents, lower resistance to temperature and agitation and lower gelatinization temperatures. These results indicate that cultural management can affect important determining properties of potato starch application, which is of great interest to the food industry.

Os filmes de quitosana/amido são utilizados para preparação de sistemas biocompatíveis de liberação controlada, materiais de revestimento e filmes comestíveis. As propriedades reológicas, térmicas, mecânicas, de taxa de transmissão de vapor de água (WVP) e solubilidade foram avaliadas em função das mudanças estruturais do amido (gelatinizado ou oxidado), da adição de polióis (etilenoglicol, glicerol e sorbitol) e da razão amilose/amilopectina (73% e 100% amilopectina). Os ensaios de reologia mostraram que as blendas formadas por quitosana e amido (100% amilopectina) tiveram interações mais fortes quando comparadas com as blendas de quitosana/amido (73% amilopectina), tanto na forma oxidada quanto na forma gelatinizada. Os polióis causam mudanças nas redes tridimensionais formadas entre a quitosana e o amido, tanto quando se usa amido gelatinizado como quando se usa o amido oxidado. Os valores de G´ encontrados para as blendas preparadas com amido oxidado foram em todos os casos menores em relação às blendas preparadas com amido gelatinizado, indicando diferenças na estrutura do gel formado e também na organização dos seus componentes. Essas mudanças foram resultantes da associação que ocorre entre a quitosana e o amido oxidado que é diferente daquela que ocorre entre quitosana e amido gelatinizado. A oxidação do amido A termogravimetria mostrou que a razão amilose/amilopectina não influencia o perfil de perda de massa e a oxidação amido aumenta a quantidade de água nos filmes e também diminui a estabilidade térmica observada por Tonset. O glicerol é o poliol que provoca maiores mudanças no comportamento de perda de massa dos filmes, pois é observada a decomposição de parte do glicerol que não está interagindo com a quitosana e o amido. O DSC mostrou que a presença de amilose nas blendas provoca uma interação mais forte da água com os polissacarídeos. Para todos os filmes com amido gelatinizado, a adição de polióis aumenta a temperatura de pico endotérmico e esta é quase sempre maior quando o glicerol é adicionado e que a oxidação do amido provoca um aumento nos valores de pico endotérmico, sugerindo que mais água está interagindo com os polímeros. A adição dos polióis aumenta os valores de espessura dos filmes, pelo aumento do volume livre do sistema, tanto nos filmes preparados com amido gelatinizado, quanto no oxidado. A presença de amilose nos filmes aumenta os valores de WVP e de solubilidade, provavelmente porque a presença de amilose auxilia no aumento da difusão de moléculas de água pelo e facilita a entrada de água e sua posterior solubilização. A adição dos polióis diminui os valores de WVP nos filmes de quitosana e amido gelatinizado. A oxidação do amido interfere mais nos valores de WVP para os filmes de quitosana/amido (100% amilopectina), sugerindo maior difusão das moléculas de água pelo filme. A oxidação aumenta os valores de solubilidade, pois as interações ocorrem em menor quantidade entre a quitosana e o amido, o que acaba facilitando o processo de solubilização. A adição dos polióis provoca um aumento na solubilidade de todos os filmes. Os ensaios preliminares de tração por DMA indicaram que os filmes de quitosana/amido gelatinizado e os filmes de quitosana/amido oxidado são rígidos e quebradiços e com a adição dos polióis ocorre um aumento na flexibilidade. Estudos preliminares destes filmes como suportes para liberação controlada de ciprofloxacina mostraram que estes são promissores para esta aplicação. / Chitosan/starch association represents an interesting alternative to the preparation of biocompatible drug delivery systems, packing materials and edible films. Changes in rheological, thermal and mechanical properties, water vapor permeability and solubility of chitosan/starch films were evaluated varying the starch structure form (gelatinized or oxidized), poliol addition (ethyleneglycol, glycerol and sorbitol) and amylose/amylopectin ratio (73% and 100% amylopectin). Rheological measurements showed that chitosan/starch (100% amylopectin) blends had stronger interaction compared to chitosan/starch (73% amylopectin) blends, both in gelatinized and oxidized starch form. Polyols cause changes in chitosan/starch three-dimensional networks due to reduction in polymer-polymer chain bonding that reflect in rheological properties. G´ modulus value decreases with starch oxidation, indicating variation in gel structure and also in organization of polymeric components, due to differences in association between chitosan and gelatinized or oxidized starch. Thermogravimetric curves showed that amylose/amylopectin ratio does not influence the weight loss behavior and starch oxidation increases the amount of water and decrease thermal stability of films, as observed by Tonset. Glycerol causes changes in weight loss behavior due to the presence of glycerol that not interact with chitosan and starch. DSC results suggest that amylose presence promotes a higher water interaction with polysaccharides. Polyol addition shift the endothermic peak associated to free water for higher temperatures, suggesting interaction between biopolymers and polyols. Also, polyol increases thickness values in all films as increase the free volume of the system. Amylose presence increases WVP and solubility values, suggesting the formation of low dense structure, which increases the water molecules diffusion and facilitates the dissolution of films in water. Polyols presence decrease WVP values in chitosan/gelatinized starch films. Starch oxidation affected the WVP values in chitosan/starch (100% amylopectin) films, suggesting low compact structure that allows the water molecule diffusion in the films. Starch oxidation increases solubility values as lower interaction between chitosan and oxidized starch, which facilitates the solubility process. Polyols addition causes an increase in solubility in all films. Preliminary mechanical tests performed by DMA indicated that chitosan/starch (gelatinized or oxidized) films are rigid and brittle and polyol addition increases the flexibility. In vitro ciprofloxacin drug delivery behavior showed that films are promising for this application.

Doctor of Philosophy / In this thesis, a set of wheat varieties (Triticum aestivum L.) produced by the Value Added Wheat Cooperative Research Centre with lower swelling power as compared to commercial Australian wheat varieties were studied to enhance our understanding of the role of amylose in starch functionality. These starches originated from a heterogeneous genetic background and had a narrow range of elevated amylose content (35 to 43%) linked with diverse functional properties. Small-angle X-ray scattering together with complementary techniques of differential scanning calorimetry and X-ray diffraction have been employed to investigate the features of starch granular structure at the nanometer scale. Starch chemical structure was characterized in terms of amylose content and amylopectin chain length distribution. Starch functionality was studied by a series of swelling, pasting and enzymic digestion methods. This study showed that swelling power of flour is a simple test that reflects a number of industrially relevant characteristics of starch, and therefore can be used as an indicator of amylose content and pasting properties of starch. In contrast to waxy starches and starches with normal amylose content, wheat starches with increased amylose content displayed characteristic pasting properties that featured decreasing peak, breakdown and final viscosities with increasing amylose contents. Existence of a threshold value in amylose content, above which final viscosity of starch paste does not further increase with increasing amylose content, was proposed. Variability in amylopectin chain length distribution was shown to have an additional effect on the swelling and pasting properties of the starches. On the molecular level, increased amylose content was correlated with increased repeat spacing of the lamellae present in the semicrystalline growth rings. In agreement with current understanding of starch synthesis, amylose was shown to accumulate in both crystalline and amorphous parts of the lamella. Using waxy starch as a distinctive comparison with the other samples confirmed general trend of increasing amylose content being linked with the accumulation of defects within crystalline lamellae. Amylose content was shown to directly influence the architecture of semicrystalline lamellae, whereas thermodynamic and functional properties were proposed to be brought about by the interplay of amylose content and amylopectin architecture. Subjecting starch granules with varying amylose content to pancreatic α-amylase showed differences in their digestion patterns. Pancreatic α-amylase preferentially attacked amorphous regions of waxy starch granules, whereas these regions for initial preferential hydrolysis gradually diminished with increasing amylose content. Observed variations in the extent of enzymic digestion were concluded to be primarily determined by the level of swelling of amorphous growth rings, which can also explain observed morphologies of partly digested granules with varying amylose content. It was confirmed that access to the granular components is not a function of the extent of crystallinity but rather the spatial positioning of the crystalline regions within the granule. Digestion kinetics is governed by factors intrinsic to starch granules, whereas influence of enzyme type was shown to be critical in determining the absolute rate of hydrolysis. Wheat starches with increased amylose content offer the potential to be used as slow digestible starch, mostly in their granular form or when complexed with lipids. Differences among varieties largely diminished when starches were gelatinized or allowed to retrograde demonstrating the importance of granular structure on starch hydrolysis. Wheat varieties used in this study displayed widely differing pasting properties in a Rapid Visco Analyser (RVA) and textural characteristics of the respective retrograded starch gels. Varietal differences in starch chemical composition among wheat varieties were shown to have significant effect on the extent of the response of starch viscoelastic characteristics to the addition of monopalmitin. Amylose content was positively correlated with the increase in final viscosity, which was attributed to the presence of more amylose in non-aggregated state contributing to higher apparent viscosity of the starch paste. Comparison of stored gels obtained from amylose-rich starches with gel prepared from waxy wheat varieties confirmed the critical role of amylose on the formation of starch network and thus providing the strength of the gel. Lack of correlation between textural properties of stored gels with amylose content or rheological characteristics measured by the RVA indicated that subtle differences in starch structure may have far-reaching consequences in relation to the strength of the gels, although these differences may have only limited effect on pasting properties in the RVA Viscoelastic properties of starch paste prepared from commercial wheat starch were significantly altered depending on the chain length and saturation of the fatty acid of the monoglyceride added during repeated heating and cooling in the Rapid Visco Analyser. Varying effects of different monoglycerides on the paste viscosity were attributed to different complexation abilities of these lipids with starch. It was proposed that stability and structure of the starch-lipid complexes formed affect the viscosity trace of the paste subjected to multiple heating and cooling. Our study indicated that differing monoglycerides in combination with the number of heat-cool cycles can be used to induce form I or form II starch-lipid complexes and thus manipulate paste rheology, gel structure and resistant starch content.

Urban forests grow in stressful environments that can have negativerepercussions on tree energy reserves. The goal of this research was to evaluate theimpact of exogenously applied carbohydrates on growth and vitality of live oaks(Quercus virginiana P. Miller). An initial study focused on carbohydrate partitioningrevealed that annual mean glucose concentration in leaf tissues (49.55 mg·g-1 DW) wasalmost double that in twigs, trunks, or roots. Starch concentrations in roots and trunks(38.98 and 38.22 mg·g-1 DW of glucose, respectively) were higher during the dormantseason and approximately three times the concentrations found in other tissues. Aninvestigation of the effects of exogenous soil applications of glucose and starch on soilmicrobial activity revealed no significant differences using recoverable viable microbes.However, soil respiration was significantly increased (P<0.05) by glucose a week afterapplication, while higher starch concentrations (120 g·L-1) significantly increased(P<0.05) soil respiration after the fourth week. Although tree soil drenched withcarbohydrates in a different study showed significantly (P<0.05) greener leaf color, higher chlorophyll fluorescence, and increased soil respiration at higher concentrationsof starch (120 g·L-1), no significant differences were observed in photosynthesis or trunk,canopy, or root growth. Analysis of 13C signatures was unable to detect uptake ofexogenous carbohydrates. For trunk-injected trees with glucose and sucrose, trunkgrowth was significantly (P<0.05) increased by carbohydrate supplementation.Differences were also found in twig glucose content, root starch content, and chlorophyllfluorescence among overall concentration means. A study to compare field diagnostictools with carbohydrate laboratory analysis established that a portable blood glucosemeter can be used to measure glucose content in trees. However, ohmmeter,refractometer, chlorophyll fluorescence spectrometer, and iodine staining results did notcorrelate well with laboratory analysis of carbohydrate concentrations. Results fromthese studies reveal that soil applied carbohydrates can greatly increase soil microbialactivity, provide evidence that trunk-injected carbohydrates may improve growth andvitality of live oaks, and provide a new field diagnostic tool to increase the efficiency ofmeasuring carbohydrates in trees.

The environmental menace associated with the existing eco-unfriendly conventional plastics prompted the exploration of natural polymers such as starch for the development of biodegradable plastics. These efforts have seen starch used in various ways, one of which is in the processing of thermoplastic starch (TPS). Thermoplastic starch (also known as plasticized starch) is the product of the interaction between starch and a plasticizer in the presence of thermomechanical energy. While starch blends with conventional plastics only yield products that biofragment, thermoplastic starch (TPS) offers a completely biodegradable option. However, it is limited in application due to its weak mechanical strength and poor moisture resistance. To this end, the objective of this study was to determine the effects of incorporating polycaprolactone (PCL) and flax fiber into glycerol-plasticized pea starch. The effects of processing moisture content on the physical properties of glycerol-plasticized pea starch were also evaluated. The physical properties investigated included morphology, tensile properties, moisture absorption, and thermal properties.<p> Accordingly, two thermoplastic pea starch mixtures containing 9.3 and 20% processing moisture contents were prepared while maintaining starch (pea starch) and glycerol in ratio 7:3 by weight (dry basis). Polycaprolactone was then compounded at 0, 10, 20, 30, and 40% by weight in the solid phase with the TPS mixtures to determine the effects of processing moisture content and PCL incorporation on the physical properties of glycerol-plasticized pea starch. This experiment was structured as a 2 x 5 factorial completely randomized design at 5% level of significance. Subsequently, PCL and flax fiber were compounded with the TPS mixture containing 20% processing moisture to determine the effects of PCL (0, 20, and 40% wt) and flax fiber (0, 5, 10, and 15% wt) incorporation on the physical properties of glycerol-plasticized pea starch. This was structured as a 3 x 4 factorial completely randomized design at 5% level of significance. All the samples were compressed at 140°C for 45 min under 25000-kg load. The compression-molded samples were characterized using scanning electron microscopy (SEM), tensile test, moisture absorption test, and differential scanning calorimetry (DSC) techniques.<p> The tensile fracture surfaces showed a moisture-induced fundamental morphological difference between the two TPSs. The TPS prepared at 20% processing moisture content revealed complete starch gelatinization, thus, exhibiting a rather continuous phase whereas the TPS prepared at 9.3% processing moisture content revealed instances of ungelatinized and partly gelatinized pea starch granules. Consequently, the tensile strength, yield strength, Youngs modulus, and elongation at break increased by 208.6, 602.6, 208.5, and 292.0%, respectively at 20% processing moisture content. The incorporation of PCL reduced the degree of starch gelatinization by interfering with moisture migration during compression molding due to its (PCL) hydrophobicity. At both processing moisture levels of 9.3 and 20%, PCL incorporation had significant impacts on the tensile properties of the plasticized pea starch. Flax fiber incorporation also increased the tensile strength, yield strength, and Youngs modulus while concomitantly reducing the elongation at break of the plasticized pea starch. In the TPS/PCL/flax fiber ternary composites, both PCL and flax fiber improved the tensile strength by acting as independent reinforcing materials as no PCL-fiber interfacial bonding was observed. Maximum tensile strength of 11.55 MPa was reached at 10% flax fiber and 40% PCL reinforcement. While the PCL-TPS interfacial interaction was poor, some degree of TPS-flax fiber interfacial bonding was noticed due to their chemical similarity.<p> TPS prepared at 20% moisture showed more moisture affinity than that prepared at 9.3% moisture. The moisture absorption of TPS dropped progressively with the addition of hydrophobic PCL. Fiber incorporation also reduced moisture absorption by the plasticized pea starch. PCL-fiber incorporation also yielded improved moisture resistance vis-à-vis pure TPS. Finally, the TPS processed at 9.3% moisture exhibited higher thermal stability than that processed at 20%. Individual components of the composites retained their respective thermal properties, thus, implying thermodynamic immiscibility.

The effects of feed processing, pea cultivar and their interaction on the nutritional value of field pea (Pisum sativum L.) for poultry were evaluated in regard to its apparent metabolizable energy (AMEn), apparent protein digestibility (APD), and rate and extent of starch digestion. Amino acid sparing as affected by the rate of starch digestion was studied in laying hens and broiler chickens. Also, the effects of feeding a slowly digested starch (SDS) from pea on performance and metabolism of broiler–breeder pullets were investigated. The first objective of this research was to evaluate the effects of screen–hole size, cold pelleting, and pre–pelleting conditioning temperature on nutrient digestibility of pea. There was no interaction between dietary treatments on all studied parameters. Small hammer–mill screen–hole size (3.2–mm) increased AMEn, APD, and extent of starch digestion values compared with coarse screen–hole size (6.4–mm). The AMEn and extent of protein digestion were not affected by cold pelleting, but the site of protein digestion was affected. In contrast, cold pelleting increased the rate and extent of starch digestion. Pre–pelleting conditioning temperature affected AMEn of pea in a quadratic fashion but had no positive effect on starch digestibility. The 70°C of pre–pelleting conditioning temperature maximized pea AMEn. Increasing pre–pelleting conditioning temperature decreased APD in a linear fashion. The second objective of this research was to study the effects of feed processing, pea cultivar and their interaction on AMEn, APD, and rate and extent of starch digestion. In vitro and in vivo experiments were conducted. An in vitro procedure simulating the gastric and small intestine conditions of chickens was developed to predict the rate and extent of starch digestion as affected by pea cultivar and sieve–hole size (0.5–, 1.0–, 2.0–mm). The rate and extent of starch digestion of cereal grain samples (barley, corn, and wheat) was also compared to pea starch. No interactions were found between pea cultivar and sieve–hole size on the kinetics of starch digestion. Pea cultivar affected the rate and extent of starch digestion. The small sieve–hole size in the in vitro assay resulted in a higher rate and extent of starch digestion. Pea starch was slowly digested in comparison with cereal grains. The in vivo experiment confirmed that fine grinding and pelleting improves AMEn and APD. Cultivar effects on AMEn and APD were observed, but no interaction was found between pea cultivar and feed processing. The third objective of this research was to investigate whether feeding SDS from pea would have sparing effect on amino acid utilization in chickens. In the first experiment, the effects of three levels of pea inclusion 0, 150, 300 g/kg on the response of laying hens to three levels of lysine intake (700, 780, and 860 mg per day) were evaluated using performance and production criteria. This experiment revealed that pea inclusion up to 300 g/kg in laying hen diets was well tolerated by laying hens and improved energy retention as indicated by increased body weight and egg weight. However, this experiment did not confirm the hypothesis that SDS from pea spared amino acids for laying hens. The second experiment investigated the interaction between SDS derived from pea and amino acid levels on the performance and carcass quality of broiler chickens. Six levels of pea inclusion (0, 150, 300, 450, 600, and 750 g/kg) and two levels of amino acids (100 and 85% of Ross × Ross 308 requirement) were examined in a broiler trial (0 – 35 d). The maximum level of pea inclusion recommended in diets increased with broiler age, but the effect of SDS from pea on amino acid sparing could not be confirmed. In the third experiment, the effects of feeding SDS from pea on growth performance and metabolism of broiler breeder pullets were investigated. Body weight and uniformity of pullets fed pea–based diet were similar to that of a wheat–based diet. Target body weight and uniformity of pullets were not affected by feeding a diet containing 890 g/kg of pea. Mean blood glucose levels and relative liver weight were markedly lower in broiler pullets fed pea–based diet compared with those fed a wheat–based diet. In conclusion, feed processing independently had a significant effect on the availability of pea nutrients. Pea is a good source of both energy and protein and that it can be partially or completely included to replace wheat and soybean meal in poultry diets. However, the effect of SDS on amino acid sparing could not be confirmed. Further research is needed to examine other feed processing techniques, pea cultivars, level of inclusion, and to understand other metabolism responses to feeding SDS from pea.

No description available.

The environmental menace associated with the existing eco-unfriendly conventional plastics prompted the exploration of natural polymers such as starch for the development of biodegradable plastics. These efforts have seen starch used in various ways, one of which is in the processing of thermoplastic starch (TPS). Thermoplastic starch (also known as plasticized starch) is the product of the interaction between starch and a plasticizer in the presence of thermomechanical energy. While starch blends with conventional plastics only yield products that biofragment, thermoplastic starch (TPS) offers a completely biodegradable option. However, it is limited in application due to its weak mechanical strength and poor moisture resistance. To this end, the objective of this study was to determine the effects of incorporating polycaprolactone (PCL) and flax fiber into glycerol-plasticized pea starch. The effects of processing moisture content on the physical properties of glycerol-plasticized pea starch were also evaluated. The physical properties investigated included morphology, tensile properties, moisture absorption, and thermal properties.<p> Accordingly, two thermoplastic pea starch mixtures containing 9.3 and 20% processing moisture contents were prepared while maintaining starch (pea starch) and glycerol in ratio 7:3 by weight (dry basis). Polycaprolactone was then compounded at 0, 10, 20, 30, and 40% by weight in the solid phase with the TPS mixtures to determine the effects of processing moisture content and PCL incorporation on the physical properties of glycerol-plasticized pea starch. This experiment was structured as a 2 x 5 factorial completely randomized design at 5% level of significance. Subsequently, PCL and flax fiber were compounded with the TPS mixture containing 20% processing moisture to determine the effects of PCL (0, 20, and 40% wt) and flax fiber (0, 5, 10, and 15% wt) incorporation on the physical properties of glycerol-plasticized pea starch. This was structured as a 3 x 4 factorial completely randomized design at 5% level of significance. All the samples were compressed at 140°C for 45 min under 25000-kg load. The compression-molded samples were characterized using scanning electron microscopy (SEM), tensile test, moisture absorption test, and differential scanning calorimetry (DSC) techniques.<p> The tensile fracture surfaces showed a moisture-induced fundamental morphological difference between the two TPSs. The TPS prepared at 20% processing moisture content revealed complete starch gelatinization, thus, exhibiting a rather continuous phase whereas the TPS prepared at 9.3% processing moisture content revealed instances of ungelatinized and partly gelatinized pea starch granules. Consequently, the tensile strength, yield strength, Youngs modulus, and elongation at break increased by 208.6, 602.6, 208.5, and 292.0%, respectively at 20% processing moisture content. The incorporation of PCL reduced the degree of starch gelatinization by interfering with moisture migration during compression molding due to its (PCL) hydrophobicity. At both processing moisture levels of 9.3 and 20%, PCL incorporation had significant impacts on the tensile properties of the plasticized pea starch. Flax fiber incorporation also increased the tensile strength, yield strength, and Youngs modulus while concomitantly reducing the elongation at break of the plasticized pea starch. In the TPS/PCL/flax fiber ternary composites, both PCL and flax fiber improved the tensile strength by acting as independent reinforcing materials as no PCL-fiber interfacial bonding was observed. Maximum tensile strength of 11.55 MPa was reached at 10% flax fiber and 40% PCL reinforcement. While the PCL-TPS interfacial interaction was poor, some degree of TPS-flax fiber interfacial bonding was noticed due to their chemical similarity.<p> TPS prepared at 20% moisture showed more moisture affinity than that prepared at 9.3% moisture. The moisture absorption of TPS dropped progressively with the addition of hydrophobic PCL. Fiber incorporation also reduced moisture absorption by the plasticized pea starch. PCL-fiber incorporation also yielded improved moisture resistance vis-à-vis pure TPS. Finally, the TPS processed at 9.3% moisture exhibited higher thermal stability than that processed at 20%. Individual components of the composites retained their respective thermal properties, thus, implying thermodynamic immiscibility.

No description available.