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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Qualidade de produtos lácteos fermentados produzidos no estado da Paraíba

Brasileiro, Jéssica Lisana Ouriques 13 February 2014 (has links)
Made available in DSpace on 2015-04-17T14:49:39Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 942615 bytes, checksum: 7f5e0611dc6b5d3af2061aab6c8cac86 (MD5) Previous issue date: 2014-02-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Yogurt and fermented milk beverages are fermented dairy products that have increased consumption worldwide, and the demand for functional foods spurred the expansion of these products. Thus, it was entended to evaluate the quality of fermented dairy foods produced in the state of Paraíba. Samples of yogurts and milk beverages of the four mesoregions of the state with federal or state registration were performed, the drinks were evaluated on their labeling, microbiological, physical, chemical and rheological properties. Observing the labels, it was found that 89% were in compliance with the legislation, the main irregularities detected were: unauthorized use of additives in the Technical Regulations and the illegibility of the dates of manufacture and validity, which puts at risk consumer health. Although there has been growth of molds and yeasts, 91% of the samples were within the microbiological parameters determined by current legislation. The centesimal composition varied depending on the mesoregion and inspection record. The rheological behavior varied between samples. Was observed relationship between physico-chemical parameters (total solids and protein) and the apparent viscosity. Overall, yogurts and fermented dairy beverages showed satisfactory quality, but should improve labeling requirements, standards of identity and sanitary quality in order to not endanger consumers health, satisfy the increasingly demanding market and to compete with major brands. / Iogurte e bebida láctea fermentada são produtos lácteos fermentados que tem consumo crescente em todo o mundo, e a demanda por alimentos funcionais impulsionou a expansão desses produtos. Assim, pretendeu-se avaliar a qualidade dos alimentos lácteos fermentados produzidos no Estado da Paraíba. Foram realizadas coletas de iogurtes e bebidas lácteas nas quatro mesorregiões do Estado, contendo registro federal ou estadual, as bebidas foram avaliadas quanto à sua rotulagem, características microbiológicas, físicas, químicas e reológicas. Observando os rótulos, verificou-se que 89% estavam em conformidade com a legislação, tendo como principais irregularidades detectadas: uso de aditivos não autorizados nos Regulamentos Técnicos e a ilegibilidade das datas de fabricação e validade, o que põe em risco à saúde dos consumidores. Embora tenha havido crescimento de bolores e leveduras, 91% das amostras mostrou-se dentro dos parâmetros microbiológicos determinados pela legislação vigente. A composição centesimal variou em função da mesorregião e do registro de inspeção. O comportamento reológico variou entre as amostras. Observou-se relação dos parâmetros físico-químicos (sólidos totais e proteína) com a viscosidade aparente. De modo geral, os iogurtes e bebidas lácteas fermentadas apresentaram qualidade satisfatória, porém devem melhorar requisitos de rotulagem, padrões de identidade e qualidade sanitária, a fim de não pôr em risco a saúde dos consumidores, atender o mercado cada vez mais exigente e competir com grandes marcas.
2

Caracterização bromatológica e perfil em ácidos graxos de bebidas lácteas não fermentadas / Bromatologic characterization and fat acids profile of milk beverages not fermented

Amaral, João Batista Silvestre do 11 October 2010 (has links)
The main objective of this work is to determine the fat acids profile of milk beverages not fermented available in the market of Maceió-AL city. Samples of milk beverage not fermented were acquired in Maceio s market and it were submitted for pH, lipids and protein analysis and fat acids profile by gas chromatographic GC-MS analysis of its methyl esters. The samples shows in the package s nutritional information null trans fat acid contents, and variations on the contents of proteins, total lipids and carbohydrates. The analytic results show that samples pH was between 6,6 and 7,0; the total carbohydrates content between 14,1 and 24,9 g/200mL; the total lipids content changes about 3,7 and 6,3 g/200mL; the proteins content on the range of 2,5 up to 4,9 g/200 mL. The chromatographic analysis shows that more abundant fat acids were C6:0, C8:0, C10:0, C11:0, C12:0, C14:0, C15:0, C16:1n7c, C16:0, C18:2n6c, C18:2n6t, C18:1n9c + C18:1n9t, C18:0. The analytical results disagree from package s nutritional information, the trans fat content is not null, and that food compound presents omega 6, but no omega 3 essentials fat acids. / O principal objetivo deste trabalho é determinar o perfil em ácidos graxos de bebidas lácteas não fermentadas disponíveis no comércio da cidade de Maceió-AL. Amostras de bebidas lácteas não fermentadas obtidas no comércio de Maceió foram submetidas a análises de pH, lipídios, carboidratos, proteínas, e o perfil em ácidos graxos por cromatografia gasosa de seus ésteres metílicos. As amostras apresentaram nas informações nutricionais da embalagem, teor de gorduras trans nulo e variação nos teores de proteínas, lipídios totais e carboidratos. Os resultados analíticos mostram que o pH das amostras esteve entre 6,6 e 7,0; o teor de carboidratos totais entre 14,1 e 24,9 g/200mL; o teor de lipídios totais variou de 3,7 a 6,3 g/200mL; o teor de proteínas de 2,5 a 4,9 g/200 mL. A análise cromatográfica mostrou que os ácidos graxos mais abundantes foram C6:0, C8:0, C10:0, C11:0, C12:0, C14:0, C15:0, C16:1n7c, C16:0, C18:2n6c, C18:2n6t, C18:1n9c + C18:1n9t, C18:0. Os resultados analíticos divergem das informações nas embalagens, o teor de gordura trans não é nulo, e o composto alimentar apresenta ácidos graxos essenciais ômega 6, mas nenhum ômega 3.
3

Biološka aktivnost fermentisanih mlečnih napitaka dobijenih primenom kombuhe i konvencionalnih starter kultura / Biological activity of fermented milk beverages obtained using kombucha and conventional starter culture

Hrnjez Dajana 26 September 2015 (has links)
<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>

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