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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.
21

Pectin in tomatoes as a protective colloid for casein

Paasche, Bette Marie 14 May 1963 (has links)
The purpose of this investigation was to study the role of pectin in protecting casein from coagulation by heat and acid during the preparation of tomato soup. Three varieties of tomatoes were used for the study, Ace, Improved Garden State and Campbell 146, and each variety was processed two ways, by heating the tomatoes rapidly to 100°C before juicing (hot break) and by holding the mascerated tomatoes for 30 minutes before heating (cold break). Juice of the Ace variety had the highest pH and Campbell 146 the lowest by both processing methods. In all cases, cold break juice had lower pH values than did the hot break juice. Proportion of serum to solids resulting from centrifugation of a sample of each juice was used as one index to the amount of degradation of the pectin. The amount of solids in the cold break juice was less than the amount of solids in the hot break juice. Serums from juices prepared by the hot break method were more viscous than those by the cold break method. Of the hot break juices, Improved Garden State was the most viscous and Campbell 146 the least. The concentration of pectin in the serums of juices prepared by the cold break method was from one-third to one-half that in serums of juices by the hot break method. Juices of the three varieties of tomatoes by both methods of processing were combined with reconstituted non-fat milk and heated as for tomato soup. Curdling was assessed by measuring the nitrogen in the filtrate by the micro-Kjeldahl method. Juices of Ace, the low acid variety, caused the least amount of curdling. Of the four juices from the two more acid varieties, Campbell 146 by the cold break method had the lowest concentration of pectin in the serum and the soup curdled most, while Improved Garden State by the hot break method was highest in pectin and resulted in the least curdling of the soup. Juice from Campbell 146 by the cold break method was the most acid of the four and that of Improved Garden State by the hot break method was the least acid. When an amount of high-methoxy pectin equal to the difference between the concentration of pectin in the cold break and that in the hot break juices of the Improved Garden State variety was added to a sample of the juice before making soup, curdling was less than when untreated juice was used, and the pH was slightly higher. Thus any protective effect that pectin might have had. on the casein was clouded by differences in the pH values of the juices. Pectin possibly has a role in protecting the casein, but the acidity certainly is the determining factor in the coagulation of casein in the preparation of tomato soup. / Graduation date: 1963
22

The viscosity of pectin extracts of loganberries and peaches as related to the quality of the frozen product

Aref, Moustafa 06 1900 (has links)
Graduation date: 1949
23

The bioavailability of folic acid in pectin - coated fortified rice in humans using stable isotope techniques

de Ambrosis, Alison, School of Food Science & Technology, UNSW January 2006 (has links)
Rice is an important dietary grain but may be difficult to fortify with water-soluble vitamins due to the losses incurred during processing and preparation. Edible coatings can offer reasonable protection against folate processing losses in fortified rice, in particular pectin (Shrestha, 2003). However, pectin, an indigestible fibre, may entrap or bind added folate, decreasing its absorption efficiency. Healthy volunteers (n=26, 18-39 yrs) received oral 400??g [13C5]PteGlu doses in three separate test meals in randomized cross-over trials as follows: 1) aqueous 2) 200g white rice and 3) 200g of pectin-coated rice premix. A plasma AUC0-8 was conducted (0, 1, 2, 5 and 8 hrs postprandial). Subjects followed a low folate basal diet (112??12 ??g/day) - verified using L.casei microbiological assay - during the AUC and for 24 hours prior. Optimisation of the pectin-coated rice premix gave folic acid coating and cooking losses of 33.5% and 15.5% respectively. The mean test dose error per 400??g folic acid was ?? 26 ??g. Single- or tri- enzyme extraction of fortified rice extracts did not significantly increase the mean assayable folate content compared to the mean folic acid content. The levels of plasma [13C5]5-methyl-THF, [13C5]PteGlu and 5-methyl-THF were quantified using a validated HPLC-tandem MS method. The calibration curves indicated good response linearity in the 0-100 ng/mL range (R2&gt0.9978). Inter- and intra-assay variation of 5-methyl-THF (100 ng/mL) was 6.9% (n=6) and 5.2% (n=4) respectively. The mean recovery of 5, 20 and 50 ng/mL 5-methyl-THF in spiked plasma extracts was 98.6 ?? 8.7%, 89.3 ?? 2.8% and 92.6 ?? 3.7% (n=3) respectively. Standard Reference Material-1846, infant formula (129??28 ??g/100g) was measured at 110 ?? 15 ??g folic acid/100g. The relative bioavailability of the folic acid in meals 2 and 3 was measured by comparing their [13C5]5-methyl-THF AUC???s relative to meal 1. The relative bioavailabilities (Mean % ?? CI) of meals 2 and 3 were 86.5 ?? 4.6 % and 68.7 ?? 5.4 % respectively. It appears the pectin coat moderately reduces short-term folic acid bioavailability. These studies define the basis for calculating the amount of folic acid to be added to rice so that an adequate amount can be absorbed after coating and cooking losses. Pectin coatings may be a useful means of increasing the folate status of populations that rely heavily on rice as a staple.
24

Salt and polyelectrolyte affect on food colloid function : polygalacturonic acid and egg albumen case studies /

Chen, Chi-Shen. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references. Also available on the World Wide Web.
25

Obtenção e caracterização de filmes de misturas de amido resistence e pectina como estratégia para liberação cólon específica de fármacos

Meneguin, Andréia Bagliotti [UNESP] 18 June 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:25:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-06-18Bitstream added on 2014-06-13T19:12:09Z : No. of bitstreams: 1 meneguin_ab_me_arafcf.pdf: 924510 bytes, checksum: c7719c1aa2118e915e7737ccc43d4dc2 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / O revestimento de formas farmacêuticas sólidas com polissacarídeos degradáveis pela microflora colônica representa uma importante e confiável estratégia para obtenção de sistemas de liberação cólon-específica de fármacos. No entanto, a maioria dos polímeros naturais, quando utilizados isoladamente e sem uma modificação prévia, apresenta a desvatangem de ser altamente solúvel em água, o que compromete a proteção oferecida pelo revestimento. Tal efeito pode ser evitado através do emprego do amido resistente, o qual possui estrutura cristalina tridimensional mais ordenada e resistência à degradação enzimática nas porções superiores do TGI. Sua posterior associação com a pectina mostra-se interessante, uma vez que ela permanece como agregados de macromoléculas em meio ácido. Além disso, a associação polimérica resulta em características físico-químicas inexistentes nos poliméros isolados. Devido às pesquisas com amido resistente na área farmacêutica ainda ser muito restrita, um estudo detalhado nesse campo faz-se necessário. Filmes de revestimento foram obtidos através do método de evaporação do solvente, a partir de dispersões de alta amilose retrogradada e pectina, às quais foram adicionados os plastificantes glicerina ou propilenoglicol. A caracterização dos filmes foi realizada por análises de reologia, morfologia, propriedades mecânicas, permeabilidade ao vapor d’água, intumescimento e difratometria de raios X. A avaliação do potencial como sistema de liberação cólon específica de fármacos foi realizada através da digestão enzimática in vitro dos filmes de revestimento em meios com diferentes valores de pH. O conjunto de resultados mostrou que a maioria das dispersões poliméricas apresenta comportamento de sistemas pouco organizados, com presença de comportamento... / Coating of solid dosage forms with polysaccharides that are degraded by colonic microflora represents an important and reliable strategy for obtaining colon specific delivery of drugs. However, most of natural polymers when used isolatedly or without a prior modification presents high water solubility, compromising the protection afforded by the coating. This effect can be avoided using resistant starch, which has more ordered three-dimensional crystalline structure and is resistant to enzymatic degradation in the upper portions of GI tract. The later association with pectin is interesting, since it remains as macromolecules aggregates in acidic medium. Furthermore, polymeric association results physical-chemical properties absent in the isolated polymers. Since resistant starch-related researches in the pharmaceutical field are still very limited, a detailed study in this field is required. Film coating was obtained by the method of solvent casting from retrograded high amylose and pectin dispersions, to which glycerol or propyleneglycol plasticizers were added. Films characterization was accomplished by rheology analysis, morphology, mechanical properties, water vapor permeability, swelling and X-ray diffraction. The potential as a colon specific drug delivery system was evaluated by performing in vitro enzymatic digestion of the coating films in media presenting different pH values. The result set showed that most of the polymeric dispersions has the behaviour of a poorly arranged system, with presence of a predominantly viscous behaviour, since the loss modules were superior to the storage modules. Dispersions containing the same proportion of polymers in the absence of plasticizers, originated more organized systems, whose samples showed less swelling index. Although the pectin have provided greater... (Complete abstract click electronic access below)
26

Obtenção e caracterização de filmes de misturas de amido resistence e pectina como estratégia para liberação cólon específica de fármacos /

Meneguin, Andreia Bagliotti. January 2012 (has links)
Orientador: Raul Cesar Evangelista / Coorientador: Beatriz Stringhetti Ferreira Cury / Banca: Ana Dóris de Castro / Banca: Newton Andréo Filho / Resumo: O revestimento de formas farmacêuticas sólidas com polissacarídeos degradáveis pela microflora colônica representa uma importante e confiável estratégia para obtenção de sistemas de liberação cólon-específica de fármacos. No entanto, a maioria dos polímeros naturais, quando utilizados isoladamente e sem uma modificação prévia, apresenta a desvatangem de ser altamente solúvel em água, o que compromete a proteção oferecida pelo revestimento. Tal efeito pode ser evitado através do emprego do amido resistente, o qual possui estrutura cristalina tridimensional mais ordenada e resistência à degradação enzimática nas porções superiores do TGI. Sua posterior associação com a pectina mostra-se interessante, uma vez que ela permanece como agregados de macromoléculas em meio ácido. Além disso, a associação polimérica resulta em características físico-químicas inexistentes nos poliméros isolados. Devido às pesquisas com amido resistente na área farmacêutica ainda ser muito restrita, um estudo detalhado nesse campo faz-se necessário. Filmes de revestimento foram obtidos através do método de evaporação do solvente, a partir de dispersões de alta amilose retrogradada e pectina, às quais foram adicionados os plastificantes glicerina ou propilenoglicol. A caracterização dos filmes foi realizada por análises de reologia, morfologia, propriedades mecânicas, permeabilidade ao vapor d'água, intumescimento e difratometria de raios X. A avaliação do potencial como sistema de liberação cólon específica de fármacos foi realizada através da digestão enzimática in vitro dos filmes de revestimento em meios com diferentes valores de pH. O conjunto de resultados mostrou que a maioria das dispersões poliméricas apresenta comportamento de sistemas pouco organizados, com presença de comportamento... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Coating of solid dosage forms with polysaccharides that are degraded by colonic microflora represents an important and reliable strategy for obtaining colon specific delivery of drugs. However, most of natural polymers when used isolatedly or without a prior modification presents high water solubility, compromising the protection afforded by the coating. This effect can be avoided using resistant starch, which has more ordered three-dimensional crystalline structure and is resistant to enzymatic degradation in the upper portions of GI tract. The later association with pectin is interesting, since it remains as macromolecules aggregates in acidic medium. Furthermore, polymeric association results physical-chemical properties absent in the isolated polymers. Since resistant starch-related researches in the pharmaceutical field are still very limited, a detailed study in this field is required. Film coating was obtained by the method of solvent casting from retrograded high amylose and pectin dispersions, to which glycerol or propyleneglycol plasticizers were added. Films characterization was accomplished by rheology analysis, morphology, mechanical properties, water vapor permeability, swelling and X-ray diffraction. The potential as a colon specific drug delivery system was evaluated by performing in vitro enzymatic digestion of the coating films in media presenting different pH values. The result set showed that most of the polymeric dispersions has the behaviour of a poorly arranged system, with presence of a predominantly viscous behaviour, since the loss modules were superior to the storage modules. Dispersions containing the same proportion of polymers in the absence of plasticizers, originated more organized systems, whose samples showed less swelling index. Although the pectin have provided greater... (Complete abstract click electronic access below) / Mestre
27

An investigation of the effects of sugar, acid and pectin on the quality of gels

Stratford, Reginald K. 01 January 1921 (has links) (PDF)
No description available.
28

The Hypolipidemic Effect of Pectin and Oats

Feilmann, Ann E. (Ann Elizabeth) 12 1900 (has links)
Pectin and oats as two sources of dietary fiber have been suggested as having a hypolipidemic effect. Ten subjects included either twenty grams of pectin or eighty grams of rolled oats daily in their self-selected diet. A baseline for each subject was calculated from blood samples taken prior to supplementation. Fasting blood samples were also taken ten, twenty-one, and thirty-one days after beginning supplementation. All blood samples were analyzed for these values; serum cholesterol, serum trigyceride, hematocrit, hemoglobin, serum albumin, and total serum protein. No significant changes were seen in the cholesterol, hematocrit, hemoglobin, and total protein values. A significant decrease was seen in nine triglyceride values. Albumin levels showed a significant increase in all subjects. No significant differences due to the two treatments were seen.
29

A critical study of certain phases of the structure and behavior of pulp fibers

Howells, T. Alfred (Thomas Alfred) 01 January 1937 (has links)
No description available.
30

Hemicelluloses and pectic material obtained from the wood of the catclaw, Acacia gregii, after chlorination

Cosulich, Donna Bernice, 1918- January 1940 (has links)
No description available.

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