Les aliments fonctionnels connaissent aujourd’hui un intérêt grandissant. Pour leur formulation, l'encapsulation de bioactifs représente une voie intéressante et les protéines de lactosérum (PS) présentent de bonnes potentialités en tant qu'agents d’encapsulation. Des travaux antérieurs ont démontré que deux PS, la beta-lactoglobuline (BLG) et la lactoferrine (LF), peuvent former spontanément des co-assemblages par coacervation complexe, une technologie d'encapsulation connue. Cette thèse étudie la coacervation BLG-LF pour l'encapsulation d'un bioactif modèle, la vitamine B9. En testant une gamme de pH et de ratios molaires, les conditions optimales de coacervation B9-PS sont obtenues dans l'eau, à pH 5,5, avec un ratio molaire LF:B9:BLG de 1:5:10, permettant d’atteindre des rendements de coacervation de 45 à 55%, et d’encapsulation de B9 de 98 %.L’échelle de production des coacervats est augmentée avec succès du µL au L, avec des solutions protéiques de qualité commerciale et un mélangeur statique. Les rendements de coacervation et d’encapsulation sont conservés, avec l’encapsulation d’environ 4 mg de B9/g coacervats. Par ailleurs, les coacervats montrent un effet protecteur de la forme native de B9 vis-à-vis des UV, de l’oxydation et pendant la lyophilisation. Une étude in vivo chez le rat démontre une augmentation de la biodisponibilité de B9 lorsque administrée sous forme de coacervats. Les coacervats apparaissent stables lorsqu’ils sont resuspendus en gouttelettes dans du lait. Ce travail permet d’approfondir les connaissances sur la coacervation hétéroprotéique et s / Encapsulation of bioactives is relevant for the development of functional foods. Food proteins as encapsulating agents could match the objective of industries to develop “clean label” products. Moreover, whey proteins (WP) exhibit good potentialities as encapsulating agents. Previous works have demonstrated that the WPs, beta-lactoglobulin (BLG) and lactoferrin (LF), are able to spontaneously co-assemble by complex coacervation. This study explores the ability of BLG-LF coacervates as a potential carrier for the encapsulation of a model bioactive, vitamin B9. Throughout screening experiments, we determined the domains where B9-WP coacervation occured according to a tested range of pH, proteins and vitamin concentrations and molar ratios. Optimal conditions for coacervation were found in water, at pH 5.5, with LF:B9:BLG molar ratio of 1:5:10, affording coacervation yields of 45 to 55% and B9 encapsulation up to 98%.Coacervation was scaled-up from laboratory to bench scale using commercial-grade protein sources and static mixing. Final efficiencies were obtained with coacervates containing 4 mg of B9/g coacervates. Under degradative conditions (UV light irradiation, oxidation, freeze-drying), WP coacervates provided good protective properties limiting chemical degradation of native B9. In vivo oral administration of B9-WP coacervates in rats enhanced the plasmatic concentrations of B9 compared to unencapsulated B9. In addition, good physical stability over time was found after incorporated and resuspension of formed coacervates in milk. The combined results of this thesis p

Orientador: Jaime Amaya-Farfan / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-14T12:35:54Z (GMT). No. of bitstreams: 1 Zaffani_VivianeCostaSilva_M.pdf: 1237742 bytes, checksum: 013e4cb87532470b0d0ebff8e7ade481 (MD5) Previous issue date: 2009 / Resumo: A ocorrência de desvios no metabolismo protéico durante o exercício depende tanto da intensidade, duração e freqüência do exercício, como também da ingestão alimentar, especialmente da qualidade da dieta consumida. Neste contexto, proteína do soro do leite (PSL) destaca-se pelo seu alto valor nutritivo, devido tanto à composição de aminoácidos, quanto à rápida digestão, além de outras funcionalidades relacionadas com a saúde. O objetivo deste estudo foi avaliar em ratos os efeitos da ingestão da proteína do soro do leite, na sua forma intacta e hidrolisada (~12,5% de hidrólise), em associação à atividade física de endurance, sobre os níveis séricos de aminoácidos, evolução ponderal, conteúdo protéico em gastrocnêmio e sóleo, conteúdo de DNA no gastrocnêmio, níveis séricos de IGF1, síntese e degradação protéica no grastrocnêmio e síntese no sóleo. Ratos Wistar foram distribuídos em 6 grupos, de acordo com a proteína consumida (12%): caseína (CAS), isolado protéico do soro do leite (IPSL) ou hidrolisado protéico do soro do leite (HPSL)) e submetidos a um protocolo de atividade física (sedentários (S) e treinados (T)). Os ratos treinados correram em esteira, durante 9 semanas, e foram sacrificados após 48 horas de repouso e 12 horas de jejum. As três dietas utilizadas apresentaram conteúdos semelhantes de aminoácidos totais, mas as dietas IPSL e HPSL destacaram-se apresentando maiores valores absolutos de leucina, isoleucina, lisina, treonina, cistina, alanina e ácido aspártico, em relação a CAS. No geral, os níveis séricos de aminoácidos indispensáveis foram semelhantes para os grupos IS e HS, em comparação com os ratos controle sedentários (CS), enquanto o grupo HT apresentou o maior nível destes aminoácidos, em relação ao CT. A evolução ponderal foi semelhante para todos os grupos de ratos até o final da oitava semana de treinamento. Na nona semana, os grupos treinados apresentaram peso significativamente menor que o CS. Não houve diferença estatística para o peso, conteúdo protéico dos músculos gastrocnêmio e sóleo, níveis séricos de IGF1 e taxas de degradação protéica muscular do gastrocnêmio, entre todos os grupos experimentais. O conteúdo e concentração de DNA no gastrocnêmio foi significativamente menor em ambos os grupos que consumiam a HPSL (HS e HT), independente da atividade física, comparado aos grupos que consumiam as proteínas intactas (CS, IS, CT e IT). As taxas de síntese protéica nos músculos gastrocnêmio e sóleo também foram menores para o grupo HT, comparado aos sedentários (CS, IS e HS), mas sem mostrar diferença com os grupos CT e IT. Os ratos do grupo HT destacaram-se por apresentar diminuição da demanda por nova síntese protéica, e da necessidade de utilização de aminoácidos do pool sérico diminuindo, consequentemente, a necessidade de aumentar a quantidade de DNA celular no músculo gastrocnêmio e ainda assim, manteve o peso, a concentração e o conteúdo protéico muscular sem diferença em relação aos demais grupos. Estes resultados, considerados em conjunto, sugerem que o consumo da proteína hidrolisada do soro do leite pode contribuir para a preservação da massa muscular no gastrocnêmio, quando associado à atividade física de endurance. / Abstract: Physical exercise promotes protein metabolic alterations depending not only on its intensity, duration and frequency, but also on food intake and especially on the quality of the diet. In this context, the milk whey proteins (PSL) stand out because of their high quality, meeting both amino-acid profile and digestibility requirements, besides other functional properties. The aim of this study was to assess the effects of milk whey protein intake in rats, in both the intact and hydrolyzed forms (~12,5% of hydrolysis), associated with physical activity of endurance, on serum amino acids levels, body weight, protein content in both the gastrocnemius and soleus muscles, total DNA content in the gastrocnemius, serum IGF1 levels, protein degradation rate in the gastrocnemius, and of protein synthesis in the soleus and gastrocnemius. Male Wistar rats were divided into six groups as follows: protein consumed (12%), casein - CAS, milk whey protein isolate - IPSL, or milk whey protein hydrolyzate -HPSL) and physical activity protocol (sedentary, S, and trained, T). The trained rats were exercised on the treadmill during nine weeks and sacrificed following 48 hours of rest; the last 12 hours being fasted. The three diets tested produced similar contents of total amino acids, although the IPSL and HPSL diets stood out because of the higher absolute values of leucine, isoleucine, lysine, threonine, cysteine, alanine and aspartate than those of CAS. As a whole, the serum indispensable amino acid levels were similar when comparing both IS and HS groups with the control group (CS). However, the HT group showed higher levels of these amino acids than the CT group. No difference in body weight evolution was apparent among the groups until the end of the eighth week of training. Nevertheless, on the ninth week the trained groups showed significantly lower weights than group CS. There were no significant differences, among all groups studied, in the weight, the content and concentration of both gastrocnemius and soleus muscles, and serum IGF1 levels, as well as the degradation rate of proteins in the gastrocnemius muscle. The content and concentration of DNA in the gastrocnemius were significantly lower in both groups fed HPSL (HS and HT), regardless of physical activity, than in the groups fed intact protein (CS, IS, CT and IT). The rate of protein synthesis in both gastrocnemius and soleus muscles were also lower in the HT group than those found in the CS, IS and HS groups. However, there was no difference when compared to those of the IT and CT groups. Summarizing, the HT group stood out because of its lower demand for new protein synthesis and amino acid utilization from the serum pool, consequently decreasing the need for higher amount of cellular DNA in the gastrocnemius muscle. Even so, this group kept the same muscle mass, protein content and concentration, as those of the other groups. These results suggest that the consumption of hydrolyzed milk whey protein may contribute to the preservation of the gastrocnemius muscle when associated with physical activity of endurance. / Mestrado / Nutrição Experimental e Aplicada à Tecnologia de Alimentos / Mestre em Alimentos e Nutrição

Mozzarella cheese was made from milk fortified with iron so that the cheese contained 25 and 50 ppm iron. Iron was added to the milk in three ways: (1) complexed to casein (ferric-casein), (2) complexed to whey protein (ferric-whey protein), and (3) ferric chloride (FeCl3·6H20) added directly to milk. Cheese quality was determined by chemical, physical, and sensory characteristics and compared with a control cheese. Chemical oxidation, during 28 days storage, was determined by absorbance of malondialdehyde at 535 nm using the thiobarbituric acid assay (TBA). Physical properties were assessed by the Arnott test for melt, helical viscometer for stretch, and b* value for cook color. Sensory properties were tested by panelists trained to detect metallic and oxidized off-flavors and by large, untrained consumer panels. There were no significant differences in iron-fortified cheeses based on the method of adding iron to milk. There were no significant differences in TBA-measured oxidation caused by adding iron, method of adding iron, or by storage ( α=.05). Stretch was increased by addition of iron. Melt and cook color were not affected by iron fortification. The trained sensory panel scored metallic and oxidized off-flavors slightly higher in the iron-fortified cheeses than in the controls, although at a level that was slightly perceptible. When cooked on a pizza, the iron-fortified cheese was rated comparable to the control cheese by consumer panels. Based on the popularity of pizza and on these observations, it was concluded that iron-fortified Mozzarella cheese can be used as an appropriate food vehicle to supplement the diets of populations that are at risk for iron deficiency anemia (e.g., children and pregnant women).

A primary emulsion with whey protein isolate (WPI) and hexanoic acid was prepared, and chitosan (Ch) (0.01%, 0.02%, and 0.03%) was added to evaluate its impact on particle size distribution of the emulsion. NaCl (0, 20, 40, and 80 mM) was added to increase ionic interactions to stabilize the multilayer emulsion. Lecithin (0.5%, 1%, 2%, 3 %, w/v) was mixed with the primary emulsion in order to form a multilayer, and casein hydrolysate (CH) was used to stabilize the tertiary emulsion system without the use of NaCl for 28 d at 4 °C. Stable O/W nanoemulsions were generated for use as nano-vesicular vehicles (NVV) to carry Curcumin (CU). Two important variables, (1) addition of casein hydrolysate (CH) (1:50, w/w WPI) and, (2) use of high pressure (140 and 210 MPa), were studied for their effect on the stabilization of monodispersed NVV and persistence of antioxidant activity of the CU as cargo in the NVV throughout storage. Addition of CH reduced nano-particle size and increased emulsion stability with UHPH pressure. The nanoparticle distribution was not changed by the addition of CU. Addition of casein hydrolysate reduced particle size as well as enhanced the positive functional properties of the NVV. Similar trends were observed in zeta-potential, surface energy, contact angle and antioxidant efficacy of the NVV, both with and without CU when UHPH was applied. The effect of Ultraviolet (UV) radiation (254 nm) on the stability of O/W nanoemulsion systems was investigated. A nano vesicular vehicle (NVV) was generated using ultra-high pressure homogenization (UHPH) that was stabilized using whey protein isolate (WPI) (1%, w/v), Tween 20 (20% w/w WPI) and casein hydrolysate (CH) (1:50 of WPI, w/w). Coarse emulsions were prepared by blending for three min. The coarse emulsion was exposed to UV radiation (0-60 min), followed by a single-pass of UHPH at 140 and 210 MPa. The UHPH treated NVV-CU had greater (P<0.05) short and long term antioxidant properties. After 28 d of storage, the CU-NVV treated at 210 MPa retained 7.0 and 1.4% greater AA and AP, respectively, when compared to the unpressurized CU-NVV.

Having access to clean water is not a certainty for every human being. Today, there are major problems with polluted water that not just affect us humans, but also the ecosystem around us. In recent years, research into making aerogels from protein nanofibrils (PNF) has increased. What is interesting about these gels is their properties of adsorbing contaminants in the water, such as organic molecules and metal ions. In this report, hydrogels and non-dry aerogels (called “non-dry” due to there being one additional heat-treatment step that can be performed to “dry” the aerogel to make it sturdier and more water-proof), have been produced by whey protein isolate (WPI), which is extracted from the dairy industry. This is a sustainable, cheap, and renewable raw material. The goals are thus: (1) to examine if there is a difference in adsorption capacity between hydrogels and non-dry aerogels in a static setup and (2) to understand and examine which product parameters give the gels the best adsorption efficiency. To achieve these goals, eight different gels were synthesized with eight different contents. The parameters have varied from the following; dialyzed or non-dialyzed WPI solution, straight or curly seeds and whether or not salt had been added to the gels. The samples’ adsorption efficiency was analyzed by micro equilibrium dialysis (MED) and UV-VIS spectroscopy. For hydrogels, the dialyzed solution with salt and curly seeds was the variant with the highest binding capacity for ThT at 34% of the initial ThT concentration. For non-dry aerogels the dialyzed solution with curly seeds and no added salt was the best variant for binding ThT, at 84% of initial ThT content bound. It was also seen that the gels that have non-dialyzed WPI solution or that the solutions contained salt increased the adsorption capacity. The conclusions drawn were that salt has a positive effect on the adsorption capacity of the gels that have formed a matrix, and a negative effect on the adsorption of loose fibrils as well as that the solutions may not need to be dialyzed. The type of seeds or fibrils effect on adsorption capacity was inconclusive. The adsorption capacity for non-dry aerogels was three times higher compared to hydrogels. / Att ha tillgång till rent vatten är inte en självklarhet för varje människa. Idag är det stora problem med förorenat vatten som inte bara påverkar oss människor utan också ekosystemet. På senare år har forskning inom att tillverka aerogeler av protein nanofibriller (PNF) ökat. Det som är intressant med dessa geler är deras egenskaper att adsorbera föroreningar i vattnet, som till exempel organiska molekyler och metalljoner. I detta arbete har icke-torra aerogels (kallas "icke-torra" på grund av att det finns ytterligare ett värmebehandlingssteg som kan utföras för att "torka" aerogelen för att göra dem robustare och mer vattentålig) och hydrogels producerats av vassleproteinisolat WPI, som utvinns från mjölkindustrin. Detta protein är ett hållbart, billigt och förnybart råmaterial. Målet med denna rapport är att (1) undersöka om det finns skillnader i adsorptionskapaciteterna mellan hydrogels och icke-torra aerogels i ett statiskt medium (2) förstå och undersöka vilka produktionsparametrar som ger den bästa adsorptionskapaciteten. För att uppnå dessa mål har åtta olika geler syntetiserats med åtta olika innehåll. De varierande parametrarna var följande; dialyserad eller icke dialyserad WPI-lösning, raka eller krulliga frön och om salt har tillsatts eller inte. Proverna analyserades med mikro-jämvikts-dialys och UV-VIS spektroskopi. För hydrogeler var den dialyserade lösningen med salt och krulliga seeds den variant som hade högst bindningskapacitet för ThT, vilket låg på 34 % av den orginellaThT-koncentrationen. För icke-tora aerogels var lösningen som var dialyserad med krulliga frön och inget tillsatt salt den variant som var bäst på att binda ThT, med en kapacitet på 84% av den orginella koncentrationen. Vi såg även att gelerna som hade odialyserad WPI-lösning alternativt att lösningarna som innehöll salt ökade adsorptionskapaciteten. Slutsatserna som dragits är att salt har en positiv påverkan på gelernas adsorptionsförmåga när de format en fibermatris och en negativ påverkan när de bara består av fria fibriller, samt att lösningarna kanske inte behöver dialyseras. Typ av frön eller fibrillers påverkan på adsorptionsförmåga kunde inte påvisas. Icke-torra aerogels hade en adsorptionsförmåga på ThT som är tre gånger högre jämfört med hydrogels.

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Crispness is one of the most desirable textural characteristics of breaded fried foods. Consumers often judge the quality of breaded fried foods based on the perceived crispness of the product. Furthermore, today's consumers are showing increasing concern over fat intake. As a result, there is great interest in being able to enhance the crispness and reduce the fat uptake in breaded fried foods without sacrificing other quality attributes. To achieve these goals, modifications to both frying equipment and product formulation have been explored in this study. In this study, two edible film coatings, methylcellulose (MC) and whey protein isolate (WPI) were incorporated into the batter and pre-dust to determine their effect on the crispness of breaded fried chicken nuggets held under a heat lamp for varying time intervals. Crispness was evaluated by both objective (ultrasonic non-destructive evaluation system) and subjective methods. An untrained sensory panel was used to obtain subjective measurements of product crispness. Panelists rated product attributes such as crispness, juiciness, oiliness and flavor on a simple intensity scale. Additionally, panelists rated the liking of the products on a nine-point hedonic scale (1=dislike extremely, 9=like extremely). Two pressure sources (nitrogen gas and steam naturally released from the food material) were used to determine their effects on product crispness, texture, pressed juice, moisture content, fat content and color. Products fried with nitrogen gas as the pressurizing medium produced samples that were comparable to or exceeding the quality of products generated by frying with steam, as it relates to product crispness, texture, pressed juice, moisture content, fat content and color. As related to objective crispness, chicken nuggets fried with nitrogen were significantly crispier (p<0.05) than those fried with steam. Coating type and application also had a significant effect on product crispness. Samples coated with MC in the pre-dust were crispier than samples coated with WPI. However, no significant differences were found in product crispness, juiciness, oiliness or flavor, and overall liking among samples tested by the sensory panel. The results of this study demonstrated that applying an edible film coating to the pre-dust and using nitrogen gas as the pressurizing medium can enhance and maintain the crispness of breaded fried foods. / Master of Science

Under flera månaders tid har ett kandidatexamensarbete utförts med syftet att optimera produktionen av protein-nanofibrer av vassleproteinisolat. Vassleproteinisolat består till stor del av proteinet β-laktoglobulin. Detta protein kan under upphettning bilda nanofibrer i sur miljö. Det var därför med avseende på parametrarna värme, koncentration och inkubationstid som processen optimerades eftersom det redan existerar ett pH-optimum vid pH-värdet 2. Lösningar av vassleproteinisolat med olika koncentrationer inkuberades under 24 timmar vid fyra olika temperaturer. Samtliga lösningar hade pH-värdet 2. För varje temperatur och inkubering togs proverna ut en åt gången för att sedan analyseras. De olika proverna analyserades sedan med Thioflavin T fluorescens för att se indikationer på fibrillering. De erhållna ThT spektrumen visade på fibrillbildning och resultaten för detta experiment visar på att utbytet av fibrilleringsreaktionen blir högre i takt med att hydrolysens hastighetskonstant blir lägre samt att lägre temperaturer kan gynna fibrillbildning . Ytterligare försök, tid och resurser bör läggas ner på detta område för att med säkerhet kunna optimera produktionen av nanofibrer av vassleproteinisolat. / This bachelor’s degree project’s aim was to optimize the production of protein nanofibrils originating from whey protein isolate. Whey protein isolate largely consists of the protein β-lactoglobulin, which can form nanofibrils while immersed in an acidic environment when heated. Therefore, the process was attempted to be optimized with regards to the yield of the final product of protein nanofibrils by varying parameters such as incubation time, initial concentration and temperature, with a constant pH-value of 2. Solutions of the whey protein isolate at different concentrations were incubated during a time interval of 24 hours and at different temperatures. For every temperature and time period of incubation, one sample at a time was taken out to be measured and analyzed, a total of four samples per initial concentration. The samples were analyzed with Thioflavin T fluorescence to see indications of the existence of fibrillation. The obtained ThT spectra showed intensity diagrams that can be related to the amount of formed nanofibrils, and this experiment shows that the yield of fibrils increases while the rate constant of the hydrolysis decreases, and that the fibrillation is favoured by lower temperatures. To optimize the production of nanofibrils of whey protein with certainty, further experiments, time and resources should be invested in this area.