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Pilot Scale Wheat Germ Stabilization In A Spouted BedOymak, Mert Mehmet 01 May 2006 (has links) (PDF)
ABSTRACT
PILOT SCALE WHEAT GERM STABILIZATION IN A SPOUTED BED
OYMAK, Mert Mehmet
M.S., Department of Chemical Engineering
Supervisor: Prof. Dr. N. Suzan KINCAL
Co-Supervisor: Dr. Cevdet Ö / ZTiN
April 2006, 97 pages
Wheat germ, a nutritionally rich by product of wheat milling, has poor
storage stability due to its content of essential fatty acids along with oxidative
enzymes. A pilot scale conventional spouted bed was designed and constructed as a
high temperature & / #8211 / short time treatment unit to bring about drying and roasting
effects. By facilitating the use of high temperature inlet air, yet maintaining the bed
solids at a temperature below the degradation temperature, spouted bed dryers
achieve thermal efficiencies unachievable by other dryers.
The inlet diameter, diameter of the column and the angle of the cone were 6.2
cm, 16 cm and 65° / respectively. Thermocouples were placed on the inlet, exit and
discharge gate of the column. Temperature profiles were recorded during drying,
roasting and cooling of wheat germ. The drying temperatures ranged between 201
and 243° / C, operation times between 6.5 and 12 minutes, and air flow rate between 55
and 65 m3/h. It was seen that the degree of roasting was closely related to the exit
temperature of the air. The exit air temperature range was determined as 155-160° / C.
Sensory evaluation tests were carried out. Wheat germ processed at 60 m3/h & / #8211 / 209° / C for 12 min and 55 m3/h & / #8211 / 216° / C for 7 min were selected as the samples for
storage studies, on the basis of the results of sensory evaluation tests. Reproducibility
runs were carried out for the selected conditions. The bed height increase study was
carried out at 60 m3/h & / #8211 / 240 to 243° / C. The processed and raw wheat germ was stored
in paper pouches at 40° / C, to estimate the shelf life on the basis of earlier studies.
Peroxide values of both raw and processed samples were followed during the
storage period. The initial peroxide values of raw germ, processed samples, and
reproducibility samples were 1.1 meq peroxide / kg oil. The peroxide value
formation data were found to follow zero order rate kinetics. Comparison of the
peroxide value changes in the processed and raw samples indicated that in the
studied range of 55-60 m3/h & / #8211 / 209-216° / C & / #8211 / 7-12 min, about 8& / #8211 / 10 fold increase in the
shelf life due to stabilization was achieved. The color parameters of each run were
determined using the CIELAB (L*, a*, b*) system. Total color difference (& / #8710 / E*)
values due to processing were calculated using L*, a* and b* values, to be between
2.3 and 58.6.
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Lietuvoje gaminamų fermentinių sūrių ir sūrio produktų riebalų kokybės rodiklių įvertinimas / Evaluation of fat quality indicators in Lithuania fermented cheeses and cheese productsSasnauskaitė, Aistė 18 June 2013 (has links)
Darbo tikslas - įvertinti Lietuvoje gaminamų fermentinių sūrių ir sūrio produktų riebalų kokybės rodiklius.
Darbo uždaviniai: 1. Fermentinių sūrių ir sūrio produktų riebalų rūgščių nustatymas dujų chromatografijos metodu; 2. Fermentinių sūrių ir sūrio produktų riebalų kokybės rodiklių analizė ir nustatymo metodų įsisavinimas; 3. Fermentinių sūrių ir sūrio produktų riebalų peroksidų skaičiaus nustatymas ir duomenų statistinis apdorojimas; 4. Fermentinių sūrių ir sūrio produktų rūgštingumo skaičiaus nustatymas ir duomenų statistinis apdorojimas; 5. Fermentinių sūrių ir sūrio produktų juslinių savybių įvertinimas, taikant juslinių savybių profilius.
Tirti Lietuvoje pagaminti sūriai: fermentiniai kieti; fermentiniai puskiečiai; sūrio produktai; lydyti sūriai. Tyrimas atliktas Lietuvos sveikatos mokslų universiteto Lietuvos veterinarijos akademijos Maisto saugos ir gyvūnų katedroje ir Kauno technologijos universiteto Maisto instituto Chemijos laboratorijoje. Riebalų rūgštys buvo nustatytos dujų chromatografijos metodu, peroksidų skaičius, riebalų rūgštingumas nustatytas titruojant, aktyvusis rūgštingumas nustatytas potenciometru „CyberScan pH510“. Juslinė analizė fermentinių kietų, fermentinių puskiečių sūrių ir sūrio produktų atlikta taikant juslinių savybių profilius.
Išvados: 1. Fermentiniuose kietuose sūriuose buvo nustatytas didesnis sočiųjų riebalų rūgščių kiekis, lyginant su fermentiniais puskiečiais sūriais, sūrio produktais ir lydytais sūriais (p<0,05 visais atvejais)... [toliau žr. visą tekstą] / The aim of the work – evaluate fat quality indicators in Lithuania fermented cheeses and cheese products.
Objectives: 1. Determination of fatty acids in fermented cheeses and cheese products by gas chromatography method; 2. Analysis of fat quality indicators and uptake of detection methods in fermented cheeses and cheese products; 3. Determination of the peroxide value and statistical processing of data in fermented cheeses and cheese products; 4. Determination of the acidity and statistical processing of data in fermented cheeses and cheese products; 5. Sensory properties of fermented cheeses and cheese products.
Investigated Lithuania cheeses: fermented hard, fermented semi-hard, cheese products and processed cheeses. Analysis of fatty acids in the Lithuanian cheeses and their products was carried out of Lithuania Health Science University Veterinary Academy of Food and Animal Safety department and Kaunas University of Technology, Institute of Food Chemistry Laboratory. Fatty acids were determined by gas chromatography, peroxide and fat acidity were determined by titration, active acidity was determined by potentiometer „CyberScan pH510“. Organoleptic analysis was performed in fermented hard cheeses, fermented semi-hard cheeses and cheese products.
Conclusions: 1. The higher amount of saturated fatty acids were found in hard cheeses compared to the semi-hard cheese, cheese products and processed cheese (p <0.05 in all cases). Polyunsaturated fatty acids have been found... [to full text]
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Evaluation of oxidized rendered protein meals in pet foodsGray, Morgan January 1900 (has links)
Master of Science / Grain Science and Industry / Greg Aldrich / Rendered protein meal is an important source of dietary protein and fat in pet food. However, fats in rendered meals can oxidize rapidly if not protected. The most common measurement of oxidation is the peroxide value (PV), but the analysis is highly variable. Additionally, the incorporation of oxidized protein further shortens its shelf life. Therefore, our objectives were to evaluate methods to measure fat quality in rendered protein meals and to determine the effect of increasingly oxidized protein meals on the shelf life of extruded pet foods. In Experiment 1, samples of five chicken byproduct meals (CBPM) from each of three locations and five beef meat and bone meals (BMBM) from each of two locations were analyzed for PV, anisidine value (AV), and thiobarbituric acid reactive substances (TBARS). The PV varied by method and location (P < 0.05). The alternative oxidation analytical methods, AV and TBARS, were not strongly correlated to PV (R² > 0.01). In Experiment 2, one metric ton of each unpreserved CBPM and unpreserved BMBM were collected and left unpreserved (U) or preserved with either ethoxyquin (E) or mixed tocopherols (T). These were held at ambient conditions (25°C, 51% RH) and monitored for PV and AV until values plateaued (41 and 63 days for CBPM and BMBM, respectively). Each “aged” meal was then incorporated into a model extruded cat food diet (~30% protein). Samples of kibble for each treatment were collected and stored at an elevated temperature and humidity (40°C, 70% RH) for 18 weeks and an ambient temperature and humidity (~22°C, 45% RH) for 12 months. The initial reduction (P < 0.05) in PV of the U (highly oxidized) BMBM and CBPM after processing suggests oxidation levels were diluted by food production. The oxidized meal led to a shorter shelf life (P < 0.05) in the finished food by PV analysis; but, sensory analysis by quick assessment did not completely corroborate these findings. These results suggest that PV doesn’t fully describe rendered protein meal stability or have a direct impact on shelf life for consumers; but may have a negative impact on pets due to oxidized lipid consumption.
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Charakterizace a hodnocení stability olejů z plodů rakytníku / Characterization and evaluation of stability of oils from sea buckthorn berriesMichalíková, Adéla January 2017 (has links)
This diploma thesis deals with characterization of sea buckthorn oil. The sea buckthorn oil is frequently used as a food supplement and in dermatology. The first part summarizes the literature on sea buckthorn oil and its biological effects. In the experimental part, the thesis deals with the comparison of three commercially available preparates of sea buckthorn oils. We employed the basic characteristics of these oils, including the determination of peroxide value, iodine value, saponification value and acid value using titration methods. Spectroscopic measurements were used to further characterize the oils. The comparised sea buckthorn oil samples differed strongly in the peroxide value and in the stability during storage. In this respect, the oil from Relikt - Art Engel company had significantly lower value (2,95 mekv/kg) compared to other two oil samples studied from Elith Phito and Virde companies with peroxide values 12,68 and 8,97 mekv/kg. This value was also much less prone to increase during storage. A similar difference was also found in spectral and colorimetric characteristics of the oil samples, where this oil displayed much less optical density then the other two samples. This might be a result of different technology used for production of oils, or it may reflect some adulteration,...
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Efeito da dieta contendo alta inclusão de soja extrusada e fonte orgânica de selênio sobre a composição, teor de CLA, perfil de ácidos graxos e estabilidade oxidativa do leite de vacas holandesas / Effect of extruded soybean diet and organic selenium on milk composition, CLA content, fatty acid profiles and oxidative stability of milkPaschoal, Juliana Jorge 20 April 2007 (has links)
A formulação de dietas para ruminantes pode alterar o perfil de ácidos do leite, potencializando o valor nutritivo e nutracêutico do mesmo. Estas alterações podem, no entanto, aumentar a susceptibilidade do leite à oxidação, perdendo qualidade em sabor e tempo de prateleira. O objetivo deste trabalho consistiu em avaliar o efeito do fornecimento de dieta com alto teor de soja integral extrusada, associada ou não à suplementação com selênio orgânico, sobre a produção, a composição, a concentração de CLA, o perfil de ácidos graxos e a estabilidade oxidativa do leite. Vinte e quatro vacas holandesas foram agrupadas em três blocos, de acordo com o número de lactações e alimentadas com dieta total contendo 56% de volumoso e 44% de concentrado. Os animais foram distribuídos aleatoriamente nos seguintes tratamentos: A) dieta controle, B) dieta contendo 21% de soja extrusada e C) dieta contendo 21% de soja extrusada + 5 mg de selênio orgânico. As dietas foram balanceadas para obtenção dos mesmos níveis de energia e proteína. O fornecimento de soja extrusada não afetou o consumo de matéria seca, o peso vivo dos animais e a produção de leite. As vacas alimentadas com soja extrusada produziram leite com menor (P<0,01) porcentagem de gordura, menor (P<0,01) concentração de ácidos graxos de cadeias curta e média e maior (P<0,01) concentração de ácidos graxos de cadeia longa, quando comparadas às vacas alimentadas com a dieta controle. Com relação ao teor de saturação, produziram leite com menor (P<0,01) concentração de ácidos graxos saturados e maior (P<0,01) concentração de ácidos graxos poliinsaturados e de ácido linoléico conjugado (CLA). A concentração de colesterol total foi maior (P<0,01) no soro sanguíneo das vacas alimentadas com soja extrusada, quando comparado ao controle. A suplementação com selênio aumentou (P<0,05) significativamente a concentração do mineral no leite e retardou a oxidação do mesmo, avaliada pelo índice de peróxido (P<0,01). O fornecimento da dieta contendo 21% de soja alterou o perfil de ácidos graxos do leite, diminuindo a concentração de ácidos graxos saturados e aumentando a concentração de ácidos graxos poliinsaturados e ácido linoléico conjugado, no entanto, produziu um leite mais susceptível à oxidação. O enriquecimento do leite com selênio conseguiu minimizar este efeito influenciando positivamente a estabilidade do leite. / The manipulation of ruminant diet can modify the fatty acid profiles increasing its nutritive and therapeutic value. However, this change in fatty acid composition can increase milk oxidation and can affect its flavor and shelf life. The objective of this study was to evaluate the effect of extruded soybean diet and organic selenium supplementation on milk composition, CLA content, fatty acid profiles and oxidative stability of milk. Twenty four Holstein cows were grouped into three blocks according to number of parturition and were fed diets containing 56% forage and 44% concentrate. The animals were allocated to three treatments: A) control diet, B) 21% extruded soybean diet and C) 21% extruded soybean diet + 5 mg of organic selenium. The diets were formulated to provide the same energy and protein levels. The extruded soybean did not affect the dry matter intake, body weight and milk production. The cows fed extruded soybean diet produced milk with lower (P<0,01) concentration of fat, lower (P<0,01) concentration of short and medium chain fatty acids and higher (P<0,01) concentration of long chain fatty acids when compared to control group. Regarding to saturation level, those animals produced milk with lower (P<0,01) concentration of saturated fatty acids and higher (P<0,01) concentration of polyunsaturated fatty acids and CLA content. The serum concentration of cholesterol was higher (P<0,01) for treatments containing extruded soybean when compared to control. The organic selenium supplementation increased (P<0,05) milk selenium concentration and delayed milk oxidation measured by peroxide value (P<0,01). The inclusion of 21% of extruded soybean in dairy cattle diet resulted in production of milk fat with modified fatty acid profile with lower concentration of saturated fatty acids and higher concentration of polyunsaturated fatty acids and CLA content. However the milk fat was more susceptible to oxidation. The organic selenium supplementation was efficient to overcome this problem and therefore could maintain the stability of milk.
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Efeito da dieta contendo alta inclusão de soja extrusada e fonte orgânica de selênio sobre a composição, teor de CLA, perfil de ácidos graxos e estabilidade oxidativa do leite de vacas holandesas / Effect of extruded soybean diet and organic selenium on milk composition, CLA content, fatty acid profiles and oxidative stability of milkJuliana Jorge Paschoal 20 April 2007 (has links)
A formulação de dietas para ruminantes pode alterar o perfil de ácidos do leite, potencializando o valor nutritivo e nutracêutico do mesmo. Estas alterações podem, no entanto, aumentar a susceptibilidade do leite à oxidação, perdendo qualidade em sabor e tempo de prateleira. O objetivo deste trabalho consistiu em avaliar o efeito do fornecimento de dieta com alto teor de soja integral extrusada, associada ou não à suplementação com selênio orgânico, sobre a produção, a composição, a concentração de CLA, o perfil de ácidos graxos e a estabilidade oxidativa do leite. Vinte e quatro vacas holandesas foram agrupadas em três blocos, de acordo com o número de lactações e alimentadas com dieta total contendo 56% de volumoso e 44% de concentrado. Os animais foram distribuídos aleatoriamente nos seguintes tratamentos: A) dieta controle, B) dieta contendo 21% de soja extrusada e C) dieta contendo 21% de soja extrusada + 5 mg de selênio orgânico. As dietas foram balanceadas para obtenção dos mesmos níveis de energia e proteína. O fornecimento de soja extrusada não afetou o consumo de matéria seca, o peso vivo dos animais e a produção de leite. As vacas alimentadas com soja extrusada produziram leite com menor (P<0,01) porcentagem de gordura, menor (P<0,01) concentração de ácidos graxos de cadeias curta e média e maior (P<0,01) concentração de ácidos graxos de cadeia longa, quando comparadas às vacas alimentadas com a dieta controle. Com relação ao teor de saturação, produziram leite com menor (P<0,01) concentração de ácidos graxos saturados e maior (P<0,01) concentração de ácidos graxos poliinsaturados e de ácido linoléico conjugado (CLA). A concentração de colesterol total foi maior (P<0,01) no soro sanguíneo das vacas alimentadas com soja extrusada, quando comparado ao controle. A suplementação com selênio aumentou (P<0,05) significativamente a concentração do mineral no leite e retardou a oxidação do mesmo, avaliada pelo índice de peróxido (P<0,01). O fornecimento da dieta contendo 21% de soja alterou o perfil de ácidos graxos do leite, diminuindo a concentração de ácidos graxos saturados e aumentando a concentração de ácidos graxos poliinsaturados e ácido linoléico conjugado, no entanto, produziu um leite mais susceptível à oxidação. O enriquecimento do leite com selênio conseguiu minimizar este efeito influenciando positivamente a estabilidade do leite. / The manipulation of ruminant diet can modify the fatty acid profiles increasing its nutritive and therapeutic value. However, this change in fatty acid composition can increase milk oxidation and can affect its flavor and shelf life. The objective of this study was to evaluate the effect of extruded soybean diet and organic selenium supplementation on milk composition, CLA content, fatty acid profiles and oxidative stability of milk. Twenty four Holstein cows were grouped into three blocks according to number of parturition and were fed diets containing 56% forage and 44% concentrate. The animals were allocated to three treatments: A) control diet, B) 21% extruded soybean diet and C) 21% extruded soybean diet + 5 mg of organic selenium. The diets were formulated to provide the same energy and protein levels. The extruded soybean did not affect the dry matter intake, body weight and milk production. The cows fed extruded soybean diet produced milk with lower (P<0,01) concentration of fat, lower (P<0,01) concentration of short and medium chain fatty acids and higher (P<0,01) concentration of long chain fatty acids when compared to control group. Regarding to saturation level, those animals produced milk with lower (P<0,01) concentration of saturated fatty acids and higher (P<0,01) concentration of polyunsaturated fatty acids and CLA content. The serum concentration of cholesterol was higher (P<0,01) for treatments containing extruded soybean when compared to control. The organic selenium supplementation increased (P<0,05) milk selenium concentration and delayed milk oxidation measured by peroxide value (P<0,01). The inclusion of 21% of extruded soybean in dairy cattle diet resulted in production of milk fat with modified fatty acid profile with lower concentration of saturated fatty acids and higher concentration of polyunsaturated fatty acids and CLA content. However the milk fat was more susceptible to oxidation. The organic selenium supplementation was efficient to overcome this problem and therefore could maintain the stability of milk.
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Antioxidant Activity of Ampelopsis Grossedentata Crude Extract and its Major Component DihydromyricetinYe, Liyun 25 August 2011 (has links)
Oxidation limits the shelf life of many food products. Adding antioxidants to foods is the most common way to solve this problem. Reports on safety issues of synthetic food additives have raised consumer interest in "all natural" foods, without added antioxidants or with synthetic replaced with natural antioxidants. The natural antioxidants now in use are much more expensive and less potent than the synthetic antioxidants. Thus, effective and economical natural antioxidants are of great interest to researchers. Teng Cha is a type of herbal tea found in China that has reported high levels of antioxidants. Antioxidant activity of Teng Cha extract and its major component dihydromyricetin has been reported, but no studies have provided clear evidence for the antioxidant effectiveness of Tech Cha extracts. The goal of this study was to measure the antioxidant activity of Teng Cha extract and dihydromyricetin (DHM), a major component of Tech Cha extract. The DPPH assay was conducted and antioxidant activities of the crude extract and dihydromyricetin were evaluated in soybean oil based on the peroxide value, anisidine value, Totox value, headspace volatiles and headspace oxygen. Antioxidant effectiveness was also evaluated in a cooked beef model system. DHM was more potent than BHA in preventing soybean oil oxidation. The crude extract was not as effective as BHA and DHM, possibly because it contained transition metals. In cooked beef, DHM and the crude extract showed lower activity than BHA, possibly due to their low solubility. Overall, Teng Cha extract and DHM are potential natural food antioxidants for future applications. / Master of Science in Life Sciences
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Caracterización fisicoquímica, tecnológica y funcional del residuo procedente de la obtención de la bebida vegetal de almendra. Estrategias de valorización.Duarte Serna, Stevens 09 October 2024 (has links)
Tesis por compendio / [ES] El mercado de bebidas vegetales está experimentando un crecimiento constante debido a la creciente demanda de productos de origen vegetal. Dentro de este mercado, la bebida de almendra, perteneciente al grupo de las oleaginosas, destaca por su alto contenido en nutrientes, compuestos fenólicos y sus propiedades antioxidantes. Por otra parte, la generación masiva de residuos y subproductos por parte de la industria alimentaria representa uno de los mayores desafíos a nivel global. De acuerdo con la Comisión Europea, aproximadamente se desperdicia un 13% de la producción alimentaria mundial, equivalente a 366 millones de toneladas dentro de la Unión Europea. La industria alimentaria ha estado trabajando en la implementación de los Objetivos de Desarrollo Sostenible (ODS) adoptados por las Naciones Unidas en 2015, con especial atención en el ODS 12, que promueve la producción responsable y sostenible. Este objetivo busca prevenir el desperdicio de alimentos, revalorizar residuos y promover la economía circular como parte de la Agenda 2030.
En este contexto, el objetivo general de la presente tesis fue estudiar las posibilidades de revalorización del subproducto resultante del proceso de obtención de la bebida vegetal de almendra. Determinar las propiedades fisicoquímicas, tecnológicas y funcionales de la materia prima. Evaluar el efecto de la deshidratación (secado con aire caliente y liofilización) sobre las propiedades fisicoquímicas, el contenido de componentes bioactivos, su bioaccesibilidad y su influencia sobre la microbiota. Finalmente, se consideró la posibilidad de obtener un producto deshidratado con probióticos.
La consecución de este objetivo se abordó desde tres enfoques que se presentan en tres capítulos en los que se ha estructurado el apartado de resultados. En el primer capítulo se evaluó el impacto del secado por aire caliente a 60 °C y 70 °C y de la liofilización, sobre las propiedades tecno-funcionales del bagazo de almendra. Se analizaron las curvas de secado y las isotermas de sorción. Luego, se evaluó el efecto del almacenamiento a temperatura ambiente y en condiciones aceleradas de los polvos obtenidos por ambos métodos de secado; durante 6 meses, se monitoreó el crecimiento microbiológico, la acidez, el índice de peróxidos, la capacidad antioxidante y el contenido de polifenoles. Finalmente, se evaluó la idoneidad del polvo de bagazo de almendra como sustituto en la elaboración de productos de panadería, concretamente galletas.
Tanto el secado por aire caliente como la liofilización resultaron ser operaciones adecuadas para estabilizar el bagazo de almendra. Ambos métodos de secado, combinados con un triturado adecuado, proporcionaron polvos con propiedades favorables para su uso en la industria alimentaria. En relación con la actividad antirradical, no se presentaron diferencias significativas entre las muestras deshidratadas, si bien el contenido en fenoles totales fue mayor en las muestras liofilizadas. En cuanto al almacenamiento durante 6 meses, al finalizar dicho periodo se observó un aumento en la capacidad antirradical, así como en el contenido de fenoles totales, especialmente notable en las muestras secadas por aire caliente y sometidas a almacenamiento acelerado. Los valores de acidez e índice de peróxido aumentaron considerablemente durante el almacenamiento acelerado, posiblemente debido a la descomposición de los ácidos grasos. Finalmente, se evaluó la idoneidad del polvo de bagazo de almendra como ingrediente sustitutivo en la elaboración de productos de panadería. Los resultados mostraron la idoneidad del subproducto para ser utilizado como sustituto de la harina de trigo en la elaboración de galletas ya que proporcionó un producto de textura adecuada con mayor contenido en fibra y componentes con capacidad antirradical. / [CA] El mercat de begudes vegetals està experimentant un creixement constant a causa de la demanda creixent de productes d'origen vegetal. Dins aquest mercat, la beguda d'ametlla, pertanyent al grup de les oleaginoses, destaca pel seu alt contingut en nutrients, compostos fenòlics i propietats antioxidants. D'altra banda, la generació massiva de residus i subproductes per part de la indústria alimentària representa un dels desafiaments més grans a nivell global. D'acord amb la Comissió Europea, aproximadament es desaprofita un 13% de la producció alimentària mundial, equivalent a 366 milions de tones dins de la Unió Europea. La indústria alimentària ha estat treballant en la implementació dels Objectius de Desenvolupament Sostenible (ODS) adoptats per les Nacions Unides el 2015, amb especial atenció a l'ODS 12, que promou la producció responsable i sostenible. Aquest objectiu cerca prevenir el malbaratament d'aliments, revalorar residus i promoure l'economia circular com a part de l'Agenda 2030.
En aquest context, l'objectiu general de la present tesi va ser estudiar les possibilitats de revaloració del subproducte resultant del procés d'obtenció de la beguda vegetal d'ametlla. Determinar les propietats fisicoquímiques, tecnològiques i funcionals de la matèria primera. Avaluar l'efecte de la deshidratació (assecat amb aire calent i liofilització) sobre les propietats fisicoquímiques, el contingut de components bioactius, la bioaccessibilitat i la influència sobre la microbiota. Finalment, es va considerar la possibilitat d'obtenir un producte deshidratat amb probiòtics.
La consecució d'aquest objectiu es va abordar des de tres enfocaments que es presenten en tres capítols en el que s'ha estructurat l'apartat de resultats. En el primer capítol es va avaluar l'impacte de l'assecat per aire calent a 60 °C i 70 °C, i de la liofilització, sobre les propietats tecno-funcionals del bagàs d'ametlla. Es van analitzar les corbes d'assecat i les isotermes de sorció. Després, es va avaluar l'efecte de l'emmagatzematge a temperatura ambient i en condicions accelerades de les pols obtingudes pels dos mètodes d'assecat; durant 6 mesos, es va monitoritzar el creixement microbiològic, l'acidesa, l'índex de peròxids, la capacitat antioxidant i el contingut de polifenols. Finalment, es va avaluar la idoneïtat de la pols de bagàs d'ametlla com a substitut en l'elaboració de productes enfornats, concretament galetes.
Tant l'assecat per aire calent com la liofilització van resultar ser operacions adequades per estabilitzar el bagàs d'ametlla. Ambdós mètodes d'assecat, combinats amb un triturat adequat, van proporcionar pols amb propietats favorables per al seu ús a la indústria alimentària. En relació amb l'activitat antirradical, no es van presentar diferències significatives entre les mostres deshidratades, si bé el contingut en fenols totals va ser més gran en les mostres liofilitzades. En relació amb l'emmagatzematge durant 6 mesos, en finalitzar aquest període es va observar un augment en la capacitat antirradical, així com en el contingut de fenols totals, especialment notable a les mostres assecades per aire calent i sotmeses a emmagatzematge accelerat. Els valors d'acidesa i índex de peròxid van augmentar considerablement durant l'emmagatzematge accelerat, possiblement degut a la descomposició dels àcids grassos. Finalment, es va avaluar la idoneïtat de la pols de bagàs d'ametlla com a ingredient substitutiu en l'elaboració de productes enfornats. Els resultats van mostrar la idoneïtat del subproducte per ser utilitzat com a substitut de la farina de blat en l'elaboració de galetes ja que va proporcionar un producte de textura adequada amb més contingut en fibra i components amb capacitat antirradical. / [EN] The vegetable beverage market is experiencing steady growth due to the increasing demand for products of vegetable origin. Within this market, the almond beverage, which belongs to the oilseed group, stands out for its high content of nutrients, phenolic compounds and antioxidant properties. On the other hand, the massive generation of waste and by-products by the food industry represents one of the major global challenges. According to the European Commission, approximately 13% of the world's food production is wasted, equivalent to 366 million tonnes within the European Union. The food industry has been working on the implementation of the Sustainable Development Goals (SDGs) adopted by the United Nations in 2015, with a particular focus on SDG 12, which promotes responsible and sustainable production. This goal aims to prevent food waste, revalue waste and promote the circular economy as part of the 2030 Agenda.
In this context, the general objective of this thesis was to study the possibilities of revaluing the by-product resulting from the process of obtaining almond plant-based beverage. To determine the physicochemical, technological and functional properties of the raw material. Evaluate the effect of dehydration (hot air drying and freeze-drying) on the physicochemical properties, the content of bioactive components, their bioaccessibility and their influence on the microbiota. Finally, the possibility of obtaining a dehydrated product with probiotics was considered.
The achievement of this objective was approached through three perspectives presented in three chapters, structuring the results section accordingly. In the first chapter, the impact of hot air drying at 60 °C and 70 °C and freeze-drying on the techno-functional properties of almond bagasse was evaluated. Drying curves and sorption isotherms were analysed. Then, the effect of storage at room temperature and under accelerated conditions of the obtained powders by both drying methods was evaluated; over a period of 6 months, microbiological growth, acidity, peroxide index, antioxidant capacity, and polyphenol content were monitored. Finally, the suitability of almond bagasse powder as a substitute in the production of bakery products, specifically biscuits, was assessed.
Both hot air drying and freeze drying proved to be suitable operations to stabilise almond bagasse. Both drying methods, combined with appropriate grinding, provided powders with favourable properties for use in the food industry. Regarding the antiradical activity, there were no significant differences between the dehydrated samples, although the total phenol content was higher in the freeze-dried samples. After a 6-month storage period, an increase in antiradical capacity and total phenolic content was observed, particularly noticeable in the samples dried by hot air and subjected to accelerated storage. Acidity and peroxide index values increased considerably during accelerated storage, possibly due to the decomposition of fatty acids. Finally, the suitability of almond bagasse powder as a substitute ingredient in the production of bakery products was evaluated. The results indicated its suitability as a substitute for wheat flour in the production of biscuits, providing a product with appropriate texture, increased fibre content, and components with antiradical capacity. / Duarte Serna, S. (2024). Caracterización fisicoquímica, tecnológica y funcional del residuo procedente de la obtención de la bebida vegetal de almendra. Estrategias de valorización [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/204146 / Compendio
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