Orientadores: José de Assis Fonseca Faria, Adriano Gomes da Cruz / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-20T10:29:44Z (GMT). No. of bitstreams: 1 Castro_WellingtondeFreitas_D.pdf: 1296410 bytes, checksum: 49d526e153c196243566d33d07ce840d (MD5) Previous issue date: 2012 / Resumo: A demanda por alimentos probióticos tem impulsionado o desenvolvimento de novos produtos formulados. Aproveitando tal cenário, as indústrias de alimentos vêm se dedicando basicamente aos lácteos, que se mostram ser ótimos carreadores de micro-organismos probióticos. O grande volume de soro proveniente das indústrias de queijos permite a elaboração de bebidas lácteas, visando o aproveitamento de subprodutos para a alimentação humana, devido ao seu elevado potencial nutricional. Este trabalho teve por objetivo avaliar o efeito dos níveis de soro de queijo nos parâmetros de qualidade e aceitação sensorial de bebidas lácteas probióticas, em comparação a produtos comerciais não probióticos. Modelos matemáticos como Análise de Sobrevida, Mínima Diferença Significativa e Aceitação Global Média foram utilizados para ajustar os níveis de soro de queijo mais aceitáveis em formulações de bebidas lácteas. Métodos sensoriais, como Mapa Projetivo, Análise Descritiva Quantitativa e Perfil Livre foram aplicados na avaliação das bebidas formuladas. A elaboração de bebidas lácteas probióticas provou ser uma boa alternativa para as indústrias de laticínios no aproveitamento do soro proveniente da fabricação de queijos, possibilitando assim redução dos custos de produção, além de propiciar novos produtos carreadores de micro-organismos benéficos à saúde / Abstract: The demand for probiotic foods has driven the development of new formulations. Taking advantage of such scenario, the food industry has been largely devoted to dairy, which proved to be excellent vehicles for probiotic microorganisms. The large volume of whey from the cheese industry has enabled the development of dairy drinks, considering the use of products for human food with high nutritional potential. This study evaluated the effect of whey levels in the quality parameters and sensory acceptability of probiotic milk drinks, as compared to commercial non probiotic products. Mathematical models as Survival Analysis, Minimal Significant Difference, and Mean Global Acceptance were used to adjust the whey levels in the most acceptable formulated dairy beverages. Sensory methods as Projective Mapping, Quantitative Descriptive Analysis, and Free Choice were applied in the evaluation of dairy beverages. The development of probiotic dairy drinks proved to be a good alternative for the dairy industry to take advantage of the whey from the cheese-making, by reducing production costs and providing probiotic foods with recognized human health benefits / Doutorado / Tecnologia de Alimentos / Doutor em Tecnologia de Alimentos

Doctor of Philosophy / Department of Animal Sciences and Industry / Jason C. Woodworth / A total of 6,465 nursery pigs were used in 8 experiments. Experiment 1 investigated the effects of Lactobacillus plantarum (LP) or fermented soybean meal (FSBM) on nursery pig growth performance. A LP × FSBM interaction was detected for G:F, where LP and FSBM individually improved G:F, but the effect was not additive. Experiment 2 evaluated the effects of increasing levels of LP on nursery pig performance. No evidence for differences in growth performance were observed among dietary treatments. Experiment 3 and 4 examined the effects of fish meal source and level on nursery pig growth performance. Overall, a source × level interaction for ADG, G:F and final BW was observed as increasing fish meal source 1 improved ADG and G:F; however, pigs fed fish meal source 2 had improved ADG and G:F at 3%, but decreased at 6%. Pigs fed fish meal source 3 had no further improvements in ADG and G:F beyond the 3% inclusion. No evidence for differences were detected between the dietary treatments for ADFI. Experiment 5 evaluated the effects of feeding fish solubles on nursery pig performance. Pigs fed diets with fish meal had increased ADG and ADFI compared to pigs fed the control diet. There was no evidence for differences in growth performance as fish solubles increased. Experiment 6 and 7 investigated the effects of enzymatically-treated soybean meal (ESBM) on nursery pig performance. Results indicated that nursery pigs fed diets with greater than 9% of ESBM resulted in decreased ADFI and final BW. Experiment 8 evaluated the effects of dietary electrolyte balance (dEB) on nursery pig performance. Increasing dEB in diets from weaning to 21-d after weaning resulted in an increase in ADG and BW, which was the result of a marginally significant improvement in ADFI and G:F. Finally, an experiment was conducted to determine the optimal strategy for collecting and submitting samples that adequately describe the nutrient levels in diets collected from a commercial swine facility. Sampling feeders with a probe resulted in less variability on an individual basis, but seemed to get washed out when individual samples were pooled to form a composite sample.

Magister Scientiae (Medical Bioscience) - MSc(MBS) / Stroke is the third leading cause of death in South Africa, killing about 240 people a day and leaving survivors with residual disabilities. There is no clinically approved neuroprotective agent for stroke at the moment but the consumption of plant polyphenols has been suggested to offer neuroprotection against stroke and other neurodegenerative diseases. In this study, we investigated the effects of long term consumption of fermented rooibos herbal tea (FRHT) on ischemia reperfusion brain injury (I-RBI) in rats. Male adult Wistar rats were fed FRHT ad libitum for 7 weeks prior to the induction of ischemic injury by the transient bilateral occlusion of the common carotid arteries (BCCAO) for 20 minutes followed by 24 hours, 4 and 7 days of reperfusion respectively. Rats were then evaluated for neurologic deficits before sacrifice and brains harvested for assessment of brain oedema, blood-brain-barrier (BBB) integrity through Evans blue extravasation (EBE), immunohistochemical studies of apoptosis and lipid peroxidation. Oxygen radical antioxidant capacity and ferric reducing antioxidant power assays were also conducted to assess total antioxidant capacity after ischemia-reperfusion injury. Notably, the long term consumption of fermented rooibos herbal tea prevented brain oedema by reducing cerebral swelling induced by I-RBI. We also observed that fermented rooibos herbal tea offered neuroprotection against damage to the BBB and delayed neuronal death associated with BCCAO as fewer apoptotic cells were identified 7 days post BCCAO reperfusion. Significantly reduced levels of lipid peroxidation and increased levels of total antioxidant capacity were also observed in brain specimens of rats treated with FRHT. Rats treated with FRHT also showed improved neurologic outcomes when compared with the untreated animals. Our results show that FRHT has potent antioxidant and anti-inflammatory properties which can provide neuroprotective effects against neuronal cell loss, cerebral swelling, BBB disruption, lipid peroxidation and neurologic deficits following I-RBI. The use of FRHT is therefore highly recommended for patients with conditions that predispose them to stroke.

Orientador: Jose Luiz Pereira / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-07T14:47:03Z (GMT). No. of bitstreams: 1 Pereira_KarenSignori_D.pdf: 795788 bytes, checksum: 3c56762962a9dfbb567a0cc78805f20c (MD5) Previous issue date: 2006 / Resumo: As bactérias pertencentes ao gênero Staphylococcus são bastante peculiares porque apesar de terem distribuição ubiqüitária e formarem a microbiota residente na pele e mucosa de humanos também podem ser causadoras de diversas enfermidades aos mesmos, tais como a intoxicação alimentar estafilocócica.Todavia, para a indústria de produtos cárneos a importância dos estafilococos está além do fato de serem microrganismos patogênicos. Algumas espécies do gênero são coadjuvantes de tecnologia para a fabricação de salames, estando presentes como componentes de culturas starter ou iniciadoras. Entre as características importantes das espécies utilizadas em culturas iniciadoras está a incapacidade enterotoxigênica, o que tem sido diretamente relacionado às espécies coagulase positiva. Diversos trabalhos, porém, têm demonstrado a capacidade de estafilococos coagulase negativa produzirem enterotoxina em meio de cultivo laboratorial e há, inclusive, registros de surtos de intoxicação estafilocócica associados a espécies não produtoras de coagulase. Assim, 90 amostras de salames industrializados, pertencentes a seis diferentes marcas, foram analisadas visando a enumeração, identificação e verificação do potencial enterotoxigênico das espécies de estafilococos coagulase negativa (ECN). Determinações de pH, Aw, análises de coliformes termotolerantes, Salmonella, Staphylococcus coagulase positiva e bactérias láticas também foram realizadas. Salmonella foi detectada em uma amostra. Entre os 266 isolados de ECN nenhum produziu enterotoxina, e dos 252 identificados cerca de 90% eram S. xylosus e S. carnosus / Abstract: Staphylococcus is ubiquitous distribution bacteria and present in skin of humans and other animals. However, staphylococci species can cause various diseases. Staphylococcal food poisoning is one of these diseases. But for meat industry staphylococci importance is not only because diseases. Some species are very important for the fermented sausage¿s manufacture like starter cultures. To be used, staphylococci have do not produce coagulase. However, many researches have demonstrated capacity of coagulase negative staphylococci (CNS) to produce enterotoxin and there are registers of staphylococcal food poisoning outbreaks linked to CNS. Ninety samples of industrialized salamis, for six different brands, had been studied. Enumeration, identification and potencial enterotoxigenic of CNS were analyzed. Additionally, termotolerants coliforms, staphylococci coagulase positive and lactic acid were counted; Salmonella isolated; pH and Aw measured. Salmonella was isolated of one sample. None of 266 CNS produced enterotoxins, 252 were identified and about 90% were S. xylosus and S. carnosus / Doutorado / Doutor em Ciência de Alimentos

This thesis deals with the isolation of probiotic DNA from meat products and its assesment by PCR methods. In this thesis is developed homogenization of samples of sausages with kopist, preparation of sausage cells lysates and isolation of DNA by using of magnetic microparticles. The DNA was isolated from sausage lysates by using magnetic microparticles. Isolated DNA was further amplified in genus and spesies-specific PCR methods. In tested products was proven presence of DNA of domain Bacteria, type Lactobacillus and Bifidobacterium. In one product was proven presence of species Lactobacillus acidophilus and Bifidobacterium animalis.

La sicurezza e la qualità degli alimenti sono tutt’ora un problema critico per i paesi in via di sviluppo. Le diete a basso contenuto di acido folico, per esempio, possono causare gravi problemi di salute, soprattutto nei bambini. Gravi disturbi legati al tubo neurale (DTN) nei neonati possono derivare infatti da madri che hanno insufficiente apporto di acido folico (400-600 g / giorno) durante il periodo di gravidanza. Inoltre, se non adeguatamente protetti o trattati, I prodotti alimentari possono essere vettori di funghi e batteri patogeni rappresentando una fonte potenziale di malattie per l’uomo e una perdita economica per le industrie agro-alimentari. Nella seguente tesi si è quindi quindi studiato il ruolo di batteri lattici selezionati (LAB) in grado di aumentare il valore nutrizionale del latte attraverso la produzione di acido folico durante il processo di fermentazione. Inoltre, ci si è concentrati sul loro uso come "bio-conservanti" contro funghi e batteri, attraverso la sintesi di composti antimicrobici (batteriocine) in grado di inibire la crescita di funghi filamentosi e/o batteri patogeni. / The safety and quality of food are still a critical issue in developing countries. Diets with a low content of folic acid, for example, may cause serious health problems, especially in children. Severe disorders related to neural tube (NTD) in infants may arise from mothers having inadequate intakes of folic acid (400-600 g/dia) during the mother pregnancy period. Moreover foods, when not properly protected or treated, can be vectors of pathogenic fungi and bacteria thereby representing a potential source of human diseases and an economical loss for the food industry. In the following thesis we have therefore investigated the role of selected lactic acid bacteria (LAB) in increasing the nutritional value of milk through the production of folic acid during the fermentation process. In addition, we focused on their use as “bio-preservatives” against fungal and bacterial spoilage, through the synthesis of antimicrobial compounds (bacteriocins) able to inhibit the growth of filamentous fungi and /or pathogenic bacteria.

<p>Proizvodnja fermentisanih mliječnih napitaka unapreijeđenih funkcionalnih karakteristika postala je jedan od glavnih fokusa u industriji prerade mlijeka. Cilj doktorske disertacije je ispitivanje biolo&scaron;ke aktivnosti fermentisanih mliječnih napitaka dobijenih primjenom nekonvencionalne starter kulture, kombuhe (kultivisane na crnom čaju zaslađenim saharozom u koncentraciji od 10%) i poređenje sa karakteristikma proizvoda dobijenih primenom konvencionalnih starter kultura, jogurtne odnosno probiotske, tokom skladi&scaron;tenja. Za fermentaciju je kori&scaron;ćeno mlijeko sa 2,8% mliječne masti na temperatura 42&deg;C.<br />Promjene tokom fermentacije mlijeka primjenom kombuhe i konvencionalnih starter kultura praćene su određivanjem stepena proteolize, sadržaja laktoze, D&ndash; galaktoze, D&ndash;glukoze i D&ndash;fruktoze i masnih kiselina pri sledećim pH vrijednostima: 6,4; 6,0; 5,5; 5,0 i 4,6. Promjene antihipertenzivne aktivnosti (AKE inhibitorna aktivnost), antioksidativne aktivnosti (ABTS i DPPH metod) kao i promjene stepena proteolize, reolo&scaron;kih i senzornih karakteristika sve tri vrste fermentisanih mliječnih napitaka praćene su tokom 21-og dana skladi&scaron;tenja. Osim toga praćene su i promjene sadržaja &scaron;ećera, masnih kiselina, minerala (kalcijuma, natrijuma i kalijuma), vitamina C i biogenih amina.<br />Tokom procesa fermentacije mlijeka primjenom različitih starter kultura može se zaključiti da postoji razlika u promjenama udijela pojedinačnih proteinskih frakcija analiziranih metodom kapilarne elektroforeze.<br />Različite starter kulture utiču na različitu AKE inhibitornu aktivnost tokom skladi&scaron;tenja, &scaron;to ukazuje na različitu proteolitičku aktivnost kori&scaron;ćenih starter kultura. Utvrđeno je da AKE inhibitorna aktivnost raste tokom skladi&scaron;tenja, pri čemu uzorci proizvedeni primjenom kombuhe imaju najveću AKE inhibitornu aktivnost na kraju 14 dana skladi&scaron;tenja i ona iznosi 79,4%, dok su u jogurtu i probiotskom jogurtu te vrijednsoti 63,4 i 64,6% redom. Takođe, tokom skladi&scaron;tenja stepen proteolize raste u svim uzorcima sa značajnim međusobnim varijacijama. Antiksidativna aktivnost svih uzoraka opada tokom skladi&scaron;tenja ali je u svim uzorcima zabilježena veća aktivnost na ABTS nego na DPPH slobodne radikale. Nakon 21-og dana skladi&scaron;tenja najveći antioksidativni potencijal određen metodom stabilizacije ABTS.+ katjona imali su uzorci sa jogurtnom starter kulturom (TEAC vrijednost 8,922 mmolmg-1). U pogledu sastava masnih kiselina, tokom 14 dana skladi&scaron;tenja u kombuha fermentisanim mliječnim napicima<br />kao i napicima dobijenim sa jogurtnom i probiotskom starter kulturom dolazi do porasta udjela zasićenih (SFA) i opadanje mononezasićenih (MUFA) i polinezasićenih masnih kiselina (PUFA). Nakon 21-og dana skladi&scaron;tenja sadržaj SFA; MUFA i PUFA u kombuha fermentisanom mliječnom napitku iznosio je 65,94; 30,73 i 3,33% redom, dok su te vrijednosti kod jogurta iznosile 66,02; 30,77 i 3,21% i probiotskog jogurta 66,04; 30,66 i 3,30 % redom. Najveći sadržaj vitamina C nakon proizvodnje i 14 dana skladi&scaron;tenja imali su uzorci sa kombuha starter kulturom (0,5457 &plusmn; 0,017 mg100g-1). Uzorci dobijeni upotrebom konvencionalnih startera pokazali su bolje reolo&scaron;ke osobine pri ispitivanim uslovima tokom 21 dana skladi&scaron;tenja. Kombuha fermentisani mlečni proizvod imao je karakterističan, blago kiseli, osvežavajući ukus i nagla&scaron;enu aromu.<br />Na osnovu dobijenih rezultata biolo&scaron;ke aktivnosti i promjena kvaliteta kombuha fermentisanog mliječnog napitka tokom skladi&scaron;tenja, u odnosu na karakteristike proizvoda dobijenih upotrebom konvencionalnih starter kultura može se objasniti opravdanost upotrebe kombuha starter kulture u fermentaciji mlijeka sa ciljem dobijanja novog funkcionalnog fermentisanog mliječnog proizvoda.</p> / <p><span style="font-size:11px;">Nowadays, production of fermented dairy products with elevated benefits on human health has become one of the major focuse in dairy industry. The aim of the PhD thesis is to examine the biological activity of fermented milk products obtained using non-conventional starter culture kombucha (cultivated on black tea with 10% of sucrose) and comparision with products obtained by conventional starter cultures, probiotic/yoghurt during storage. Milk with 2.8% of milk fat was used for the samples production at temperature of 42 &deg;C.<br />The changes of components content during the milk fermentation by kombucha and conventional starter cultures were monitored at the following pH values: 6.4; 6.0; 5.5; 5.0 and 4.6., by determining the degree of proteolysis, lactose, D-galactose, D-glucose and D-fructose, fatty acids. The antihypertensive activity (ACE inhibitory activity), antioxidant activity (ABTS and DPPH tests) and the degree of proteolysis, sensory and rheological characteristics of all three types of fermented milk products were observed during 21 days of storage. Moreover, the chemical qualities of samples were monitored analyzing the contents of sugars, fatty acids, minerals (calcium, sodium and potassium), vitamin C and biogenic amines.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; There were differences in protein fractions (analyzed by capillary electrophoresis) of products obtained by using different starter cultures during the milk fermentation. Different starter cultures affect different ACE inhibitory activity during the storage, which implies different proteolytic activity of used starter cultures. It has been found that the ACE inhibitory activity was increased during the storage; wherein the samples obtained using kombucha starter culture have the highest ACE inhibitory activity at the 14th day of storage, 79,4%, while in yogurt and probiotic yoghurt it was 63.4 and 64.6% respectively. Also, the degree of proteolysis during the storage was increased in all samples with significant mutual variations. In all products, higher ABTS than 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was determined, while both activities slightly decreased during the storage. The antioxidant activity of all samples decreases during storage. After 21 days of storage, the highest antioxidant potential, determined by the ABTS. + method had a yoghurt samples (TEAC value of 8.922 mmolmg-1). In terms of the fatty acids composition during 14 days of storage in all type of fermented dairy products relative content of SFA (saturated fatty acids - SFA) increased, while relative contents of MUFA (monounsaturated fatty acids) and PUFA (polyunsaturated fatty acids) decreased during that period of storage. After 21 days of storage the content of SFA; MUFA and PUFA in kombucha fermented milk product was 65.94; 30.73 and 3.33% respectively. In yogurt sample their content was 66.02, 30.77 and 3.21%, while in probiotic 66.04; 30.66 and 3.30% respectively. In all fermented milk products, long chain fatty acids were dominant with a total share of about 45% in all varieties of fermented dairy products. The highest content of vitamin C after production and 14 days of storage was in samples obtained by kombucha starter culture (0.5457 &plusmn; 0.017 mg100g-1). Samples obtained by conventional starter showed better overall rheological properties at the tested conditions for 21 days of storage. Kombucha fermented milk product had a characteristic, distinctive mild sour, refreshing taste and conspicuous aroma.<br />The obtained results of biological activity and the quality of kombucha fermented milk products during storage in comparison to the same characteristics of the products obtained using conventional starter culture, could explain that kombucha is convenient starter for milk fermentation with the aim of obtaining new functional fermented milk products with pronounced bioactive characteristics and distinctive sensory and rheology properties.</span></p>

<p>Glavni cilj doktorske disertacije bio je ispitivanje op&scaron;tih odlika industrijski proizvedenih, fermentisanih suvih kobasica u Srbiji i mogućnost dodatnog unapređenja njihove mikrobiolo&scaron;ke bezbednosti. Ispitivani su mikrobiolo&scaron;ki i fizičko-hemiijski pokazatelji u industrijskom proizvodnom lancu sremske kobasice i sudžuka, tipičnih fermentisanih suvih kobasica od svinjskog i goveđeg mesa. U sremskoj kobasici praćeno je prisustvo Salmonella а Escherichia coli O157 u sudžuku. Ispitane su i promene glavnih grupa mikrobiota, pH i aw vrednosti i hemijski sastav proizvoda. Mikrobiolo&scaron;ka kontaminacija u početnim koracima proizvodnje bila je uglavnom visoka. Salmonela je ustanovljena u fazi pripreme nadeva u dva od tri proizvodna pogona, dok je E. coli O157 potvrđena u jednom uzorku usitnjenog mesa i masnog tkiva jednog proizvodnog pogona. Rezultati ispitivanja proizvodnje kobasica slični su rezultatima istraživanja u drugim zemljama. Svi uzorci gotovih sremskih kobasica bili su zadovoljavajućeg nivoa mikrobiolo&scaron;kog kvaliteta, dok većina uzoraka sudžuka nije bila zadovoljavajuća. Početno prisustvo alimentarnih patogena može se smatrati bezbednosnim rizikom.<br />Preživljavanje Salmonella Тyphimurium, Escherichia coli O157 i Listeria monocytogenes tokom proizvodnje i skladi&scaron;tenja inokulisane, sremske kobasice i sudžuka, praćeno je u drugoj fazi istraživanja. Smanjenje brojnosti sva tri patogena u skladu je sa literaturnim podacima i može se zaključiti da postupci uobičajeno primenjeni u industrijskoj proizvodnji sremske kobasice i sudžuka ne osiguravaju uvek, u dovoljnoj meri, mikrobiolo&scaron;ku bezbednost proizvoda. Ispitiana je i mogućnost pasterizacije u cilju redukcije navedenih patogena u kobasicama od svinjskog, odnosno, goveđeg mesa, uz ocenu senzorskog kvaliteta proizvoda. Rezultati su pokazali da Salmonella Typhimurium i E. coli O157 mogu da budu uklonjene pasterizacijom gotovih fermentisanih suvih kobasica а dа senzorske odlike proizvoda i dalje оstanu prihvatljive. L. monoctogenes se pokazala kao patogen koji je značajno otporniji na zagrevanje, u oba tipa kobasica, zbog čega su potrebna dalja istraživanja radi redukcije dо prihvatljivog nivoa.</p> / <p>Glavni cilj doktorske disertacije bio je ispitivanje op&scaron;tih odlika industrijski proizvedenih, fermentisanih suvih kobasica u Srbiji i mogućnost dodatnog unapređenja njihove mikrobiolo&scaron;ke bezbednosti. Ispitivani su mikrobiolo&scaron;ki i fizičko-hemiijski pokazatelji u industrijskom proizvodnom lancu sremske kobasice i sudžuka, tipičnih fermentisanih suvih kobasica od svinjskog i goveđeg mesa. U sremskoj kobasici praćeno je prisustvo Salmonella a Escherichia coli O157 u sudžuku. Ispitane su i promene glavnih grupa mikrobiota, pH i aw vrednosti i hemijski sastav proizvoda. Mikrobiolo&scaron;ka kontaminacija u početnim koracima proizvodnje bila je uglavnom visoka. Salmonela je ustanovljena u fazi pripreme nadeva u dva od tri proizvodna pogona, dok je E. coli O157 potvrđena u jednom uzorku usitnjenog mesa i masnog tkiva jednog proizvodnog pogona. Rezultati ispitivanja proizvodnje kobasica slični su rezultatima istraživanja u drugim zemljama. Svi uzorci gotovih sremskih kobasica bili su zadovoljavajućeg nivoa mikrobiolo&scaron;kog kvaliteta, dok većina uzoraka sudžuka nije bila zadovoljavajuća. Početno prisustvo alimentarnih patogena može se smatrati bezbednosnim rizikom.<br />Preživljavanje Salmonella Typhimurium, Escherichia coli O157 i Listeria monocytogenes tokom proizvodnje i skladi&scaron;tenja inokulisane, sremske kobasice i sudžuka, praćeno je u drugoj fazi istraživanja. Smanjenje brojnosti sva tri patogena u skladu je sa literaturnim podacima i može se zaključiti da postupci uobičajeno primenjeni u industrijskoj proizvodnji sremske kobasice i sudžuka ne osiguravaju uvek, u dovoljnoj meri, mikrobiolo&scaron;ku bezbednost proizvoda. Ispitiana je i mogućnost pasterizacije u cilju redukcije navedenih patogena u kobasicama od svinjskog, odnosno, goveđeg mesa, uz ocenu senzorskog kvaliteta proizvoda. Rezultati su pokazali da Salmonella Typhimurium i E. coli O157 mogu da budu uklonjene pasterizacijom gotovih fermentisanih suvih kobasica a da senzorske odlike proizvoda i dalje ostanu prihvatljive. L. monoctogenes se pokazala kao patogen koji je značajno otporniji na zagrevanje, u oba tipa kobasica, zbog čega su potrebna dalja istraživanja radi redukcije do prihvatljivog nivoa.</p> / <p>The main aim of this doctoral thesis was to investigate the general characteristics of industrially-produced Serbian dry fermented sausages and the possibility of further improving their microbiological safety. Microbiological and physicochemical indicators were studied along the industrial production chains producing Sremska and Sudzuk sausage, typical of dry, fermented sausage prepared from pork or beef, respectively. The occurrences of Salmonella in pork sausages, and of Escherichia coli O157 in beef sausages were determined. Changes in the main groups of microbiota, pH, aw values and the chemical composition of the products were evaluated. Microbiological contamination in the initial stages of production was generally high. Salmonella was confirmed from the batter-preparation phase in two of three production lines, while E. coli O157 was confirmed in one sample of meat and fatty tissue from one production line. The results of this investigation of sausage production were similar to results obtained in other countries. All samples of finished pork sausage were of acceptable microbiological quality, while the majority of beef sausage samples were not microbiologically acceptable. The initial presence of foodborne pathogens can be considered a food safety risk.<br />The survival of Salmonella Тyphimurium, Escherichia coli O157 and Listeria monocytogenes during production and storage of inoculated pork and beef sausages was determined in the second phase of the investigation. All three pathogens declined in numbers in accordance with data from the literature, and it can be concluded that normal measures for pork and beef sausage preparation in industrial production do not always ensure, to a suitable level, the microbiological safety of the products. The possibility of pasteurising finished pork and beef sausages, with the aim of reducing Salmonella Typhimurium and E. coli O157, respectively, was investigated, and at the same time, sensory evaluation of product quality was performed. The results showed that pasteurisation eliminated Salmonella Typhimurium and E. coli O157 from finished dry fermented sausages, while sensory qualities of the products remained acceptable. L. monoctogenes proved to be a significantly more heat-resistant pathogen in both types of sausage, and therefore, further research is required to determine how to reduce numbers of this pathogen to acceptable levels.</p>

Tiger nuts (Cyperus esculentus L) are recognized as a high potential, alternative source of food nutrients. However, there is limited scientific literature on the technological possibilities for developing value-added foods, such as fermented products from tiger nut milk. Therefore, strategies for producing and improving the properties of fermented tiger nut milk were investigated for generating lactose-free, nutritious yogurt-like products with acceptable sensory properties and a prolonged shelf life quality. A wet-milling procedure was standardized for extracting tiger nut milk from tiger nuts, and the effects of the extraction process on nutrient distribution, colour properties and colloidal stability of the milk were analyzed. Next, tiger nut milk was enriched with proteins and/or hydrocolloids and the impact of the additives on the physical properties of the milk were determined. Enriched tiger nut milk was fermented by using classical yogurt cultures and the obtained products were analyzed for the microbiological, physico-chemical and sensory characteristics. Additionally, effects of enriching tiger nut milk with microbial transglutaminase cross-linked proteins on the microbiological and physico-chemical properties were evaluated. Higher wet-milling intensity improved the nutrient composition, colloidal stability and colour of the milk. Enrichment of tiger nut milk with milk proteins and xanthan gum enhanced the viscosity and stability, and after fermentation, led to homogenous gel-like products with superior microbiological, physico-chemical and different sensory properties compared to the fermented plain tiger nut milk. Microbial transglutaminase cross-linked proteins improved the physical characteristics of the fermented product, especially during storage. This product would be relevant in many developing countries with high prevalence of lactose intolerance, limited access to nutritious food but show a high distribution of tiger nut vegetation. / Erdmandeln (Cyperus esculentus L) haben ein hohes Potential als alternative Quelle Lebensmittelinhaltsstoffen. Allerdings gibt es nur in begrenztem Ausmaß Literatur über technologische Möglichkeiten zur Entwicklung von Mehrwert-Lebensmitteln wie fermentierter Erdmandelmilch. Daher wurden Strategien zur Herstellung und Verbesserung der Eigenschaften von fermentierter Erdmandelmilch zur Erzeugung laktosefreier joghurtähnlicher Produkte mit akzeptablen sensorischen Eigenschaften untersucht. Für die Extraktion der Erdmandelmilch wurde ein Nassmahlverfahren standardisiert und der Einfluss des Verfahrens auf die Nährstoffverteilung, die Farbeigenschaften und die kolloidale Stabilität der Milch analysiert. Als nächstes wurde Erdmandelmilch mit Proteinen und/oder Hydrokolloiden angereichert, und der Einfluss der Additive auf die physikalischen Eigenschaften des Extrakts bestimmt. Angereicherte Erdmandelmilch wurde mit klassischen Joghurtkulturen fermentiert, und die mikrobiologischen, physikalisch-chemischen und sensorischen Eigenschaften der Produkte wurden untersucht. Zusätzlich wurden Effekte der Anreicherung von Erdmandelmilch mit enzymatisch vernetzten Proteinen auf die mikrobiologischen und physikalisch-chemischen Eigenschaften bewertet. Eine höhere Nassmahlintensität verbesserte die Nährstoffzusammensetzung, die kolloidale Stabilität und die Farbe der Milch. Die Anreicherung erhöhte die Viskosität und Stabilität und führte nach der Fermentation zu homogenen gelartigen Produkten mit verbesserten mikrobiologischen, physikalisch-chemischen und sensorischen Eigenschaften im Vergleich zur fermentierten Erdmandelmilch. Mikrobielle Transglutaminase-vernetzte Proteine verbesserten die physikalischen Eigenschaften des fermentierten Produkts, insbesondere während der Lagerung. Dieses Produkt wäre in vielen Entwicklungsländern mit hoher Prävalenz von Laktoseintoleranz und begrenztem Zugang zu nahrhaften Lebensmitteln als Alternative von Interesse.

Resumo: Amidos e gomas são hidrocolóides usados freqüentemente em alimentos para conferir textura apropriada, controlar a umidade e a mobilidade da água. Estudos têm relatado que a interação de gomas e amidos em sistemas alimentícios pode alterar o inchamento dos grânulos, as propriedades de gelatinização e reológicas dos amidos. Em bebidas lácteas fermentadas, a maioria dos polissacarídeos de interesse comercial é incompatível com as proteínas do leite em solução, e desta forma, os hidrocolóides tipicamente utilizados são amido e carragena. Neste trabalho foi avaliado o efeito da adição das gomas xantana, carboximetilcelulose sódica e carragena (nas concentrações de 0,15, 0,25, 0,35 e 0,45% - p/v) nas propriedades de pasta, térmicas, de poder de inchamento (PI), reológicas e na microscopia do amido de mandioca, bem como o efeito de misturas de amido de mandioca e as referidas gomas nas propriedades reológicas de bebidas lácteas fermentadas. Os resultados obtidos sugerem que a goma carragena (CAR) praticamente não modifica as propriedades do amido em função da inexistência de interações entre a referida goma e o amido de mandioca; já a goma xantana (GX) envolve praticamente por completo os grânulos de amido, possivelmente através da formação de pontes de hidrogênio, promovendo desta forma aumentos nas viscosidades de pasta, poder de inchamento, nos módulos G' e G" e diminuição na tendência a retrogadação; a carboximetilcelusose sódica (CMC), por sua vez, aumenta drasticamente as viscosidades e o poder de inchamento do amido devido a sua grande capacidade de retenção de água e não a sua interação com o amido de mandioca. Nas bebidas lácteas fermentadas, as misturas quando empregadas praticamente não modificaram seu comportamento reológico, exceto para as bebidas elaboradas a partir das misturas amido - goma xantana, onde observou-se... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Starches and gums are hydrocolloids frequently used in food systems to provide proper texture, moisture and water mobility. Studies have reported that the gum and starch interaction in food systems can modify the granule swelling, the gelatinization and rheological properties of starches. In fermented dairy beverages, the majority of commercial interest polysaccharides is not compatible with milk proteins in solution, consequently, starch and carrageenan are the hydrocolloids typically used. In this work, the effect of gum addition such as xanthan, sodium carboxymethyl cellulose and carrageenan was evaluated (in the concentrations of 0,15, 0,25, 0,35 and 0.45% - w/v) in paste, thermal, swelling power (SP), rheological and microscopy properties of cassava starch, as well as the effect of mixtures of cassava starch and the referred gums in rheological properties of fermented dairy beverages. The results suggest that carrageenan gum (CAR) practically does not modify the starch properties since there is no interaction between this gum and cassava starch. Xanthan gum (GX) seems to involve the starch granules completely, possibly through the formation of hydrogen bonds, which increases paste viscosities, swelling power, increased the modulus G' and G" and decreased retrogradation behavior. Sodium carboxymethyl cellulose (CMC), in turn, drastically increases viscosities and the starch swelling power due to its great capacity of water retention and not to the interaction with the cassava starch. In fermented dairy beverages, the gum - starch mixtures practically didn't modify its rheological behavior, except for beverages with mixtures xanthan gum - starch, where an initial reduction in the shear stress as deformation rate was increased, followed by a gradual increase, suggesting a possible incompatibility between cassava starch, xanthan gum and milk proteins. Keywords: Cassava starch... (Complete abstract click electronic access below) / Orientador: Célia Maria Landi Franco / Coorientador: Ana Lúcia Barretto Penna / Banca: Ivo Mottin Demiate / Banca: Roger Darros Barbosa / Mestre