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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

Physicochemical properties and phenolic composition of selected Saskatchewan fruits : buffaloberry, chokecherry and sea buckthorn

Green, Richard Christopher 31 July 2007
There is increasing interest in the commericalization of native fruits for utilization as foods and medicinal extracts. This study was undertaken to determine the physicochemical properties and phenolic composition of selected Saskatchewan native fruits, including buffaloberry (<i>Shepherdia argentea</i> Nutt.), chokecherry (<i>Prunus virginiana</i> L.) and sea buckthorn (<i>Hippophae rhamnoides</i> L.). The physicochemical analyses included carbohydrate content, CIELAB colour values, organic acid composition, phenolic content, % seed, soluble solids, pH, total solids, total titratable acidity and proximate composition. Fruit samples were collected and analyzed over four crop years. The proanthocyanidin content was also determined photometrically after acid depolymerization in acid-butanol. Buffaloberry contained a proanthocyanidin concentration of 505 ± 32 mg/100 g fresh fruit and this level was 10 fold higher than that of chokecherry and sea buckthorn. Chokecherry was found to contain an anthocyanin concentration of 255 ± 35 mg/100 g fresh fruit, as determined using the pH differential method. Two high performance liquid chromatography (HPLC) methods were developed for simultaneous determination of seven phenolic classes, including anthocyanins, hydroxybenzoic acids, hydroxycinnamic acids, flavanols, flavanones, flavones and flavonols in aqueous methanol extracts. Based on the semi-quantitative analysis of the total phenolic chromatographic index (TPCI), chokecherry contained the highest levels of phenolic compounds with a concentration of 3,327 ± 469 µg/g fresh fruit followed by buffaloberry (578 ± 73 µg/g fresh fruit) and sea buckthorn (477 ± µg/g fresh fruit). The antioxdant activity of the fruit extracts was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2´-azinobis-3-ethylbenzthiazoline-sulphonic acid (ABTS) radical scavenging assays. Buffaloberry and chokecherry produced the highest radical scavenging activity and were at least five fold greater than that of sea buckthorn. The major radical scavenging compounds in buffaloberry were ascorbic acid and proanthocyanidins. Radical scavenging activity of chokecherry fruit was largely attributable to its anthocyanins, flavonols and hydroxycinnamic acids. Prominent antioxidants in sea buckthorn included ascorbic acid, proanthocyanidins and flavonols. Certain individual compounds in the phenolic extracts were identified by HPLC-photodiode array and HPLC-mass spectrometry. Rutin was found in all of the extracts. Other phenolic compounds identified included catechin in sea buckthorn, and chlorogenic acid and quercetin in chokecherry. The chokecherry fruit pigments were comprised of two major anthocyanins and these were identified as cyanidin 3-glucoside and cyanidin 3-rutinoside. A preparative scale purification method for these anthocyanins using centrifugal partition chromatography (CPC) was determined. Under the CPC conditions employed, cyanidin 3-glucoside and cyanidin 3-rutinoside were purified to concentrations of 84 and 90%, respectively.
2

Physicochemical properties and phenolic composition of selected Saskatchewan fruits : buffaloberry, chokecherry and sea buckthorn

Green, Richard Christopher 31 July 2007 (has links)
There is increasing interest in the commericalization of native fruits for utilization as foods and medicinal extracts. This study was undertaken to determine the physicochemical properties and phenolic composition of selected Saskatchewan native fruits, including buffaloberry (<i>Shepherdia argentea</i> Nutt.), chokecherry (<i>Prunus virginiana</i> L.) and sea buckthorn (<i>Hippophae rhamnoides</i> L.). The physicochemical analyses included carbohydrate content, CIELAB colour values, organic acid composition, phenolic content, % seed, soluble solids, pH, total solids, total titratable acidity and proximate composition. Fruit samples were collected and analyzed over four crop years. The proanthocyanidin content was also determined photometrically after acid depolymerization in acid-butanol. Buffaloberry contained a proanthocyanidin concentration of 505 ± 32 mg/100 g fresh fruit and this level was 10 fold higher than that of chokecherry and sea buckthorn. Chokecherry was found to contain an anthocyanin concentration of 255 ± 35 mg/100 g fresh fruit, as determined using the pH differential method. Two high performance liquid chromatography (HPLC) methods were developed for simultaneous determination of seven phenolic classes, including anthocyanins, hydroxybenzoic acids, hydroxycinnamic acids, flavanols, flavanones, flavones and flavonols in aqueous methanol extracts. Based on the semi-quantitative analysis of the total phenolic chromatographic index (TPCI), chokecherry contained the highest levels of phenolic compounds with a concentration of 3,327 ± 469 µg/g fresh fruit followed by buffaloberry (578 ± 73 µg/g fresh fruit) and sea buckthorn (477 ± µg/g fresh fruit). The antioxdant activity of the fruit extracts was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2´-azinobis-3-ethylbenzthiazoline-sulphonic acid (ABTS) radical scavenging assays. Buffaloberry and chokecherry produced the highest radical scavenging activity and were at least five fold greater than that of sea buckthorn. The major radical scavenging compounds in buffaloberry were ascorbic acid and proanthocyanidins. Radical scavenging activity of chokecherry fruit was largely attributable to its anthocyanins, flavonols and hydroxycinnamic acids. Prominent antioxidants in sea buckthorn included ascorbic acid, proanthocyanidins and flavonols. Certain individual compounds in the phenolic extracts were identified by HPLC-photodiode array and HPLC-mass spectrometry. Rutin was found in all of the extracts. Other phenolic compounds identified included catechin in sea buckthorn, and chlorogenic acid and quercetin in chokecherry. The chokecherry fruit pigments were comprised of two major anthocyanins and these were identified as cyanidin 3-glucoside and cyanidin 3-rutinoside. A preparative scale purification method for these anthocyanins using centrifugal partition chromatography (CPC) was determined. Under the CPC conditions employed, cyanidin 3-glucoside and cyanidin 3-rutinoside were purified to concentrations of 84 and 90%, respectively.
3

The Beef Nutrient Database Improvement Project: Retail Cuts From the Chuck

West, Sarah 16 January 2010 (has links)
A total of 40 beef arm chucks were collected from three cities across the United States to study the proximate composition of their separable lean. Chucks were fabricated 5-7 d postmortem and later cooked and dissected, or dissected raw into four separable components, separable lean, external fat, separable seam (intermuscular) fat, and connective tissue (considered inedible). Proximate analysis was conducted on the separable lean component of each dissected retail cut. Dissection data showed that multiple muscled cuts had a numerically lower percent separable lean when compared to the retail cuts comprised of a single muscle. Proximate analysis showed that as the mean value for moisture decreased in the retail cut, the mean percentage of total fat increased. Least squares means of total fat percentage were reported on the retail cuts stratified by USDA quality grade (upper Choice, lower Choice, and Select). Some of the retail cuts had significantly different total fat percentage of the separable lean when considering the differences in USDA quality grade. Cooking yields for the three methods utilized were numerically different. The cuts that were roasted had the highest cooking yield (80.72 %), followed by cuts that were grilled (76.58%), and finally cuts that were braised (66.13%). Differences in final endpoint temperature for each cut may account for the differences between cooking methods. This study was designed to acquire data to update the National Nutrient Database for Standard Reference, as well as to provide nutritional information for cuts that are not presently in the database. This study evaluated thirteen cooked cuts and twelve raw cuts in an effort to increase the number of retail cuts available to search for nutrient information in the National Database.
4

The Beef Nutrient Database Improvement Project: Retail Cuts From the Rib and Plate

May, Laura 2010 December 1900 (has links)
The purpose of this study was to collect and analyze retail cuts from the beef rib and plate that had been identified as needing nutrient composition updates in the United States Department of Agriculture’s (USDA) National Nutrient Database for Standard Reference (SR). Twenty beef carcasses were selected from three different regions of the United States, and the rib and plate were collected for shipment via refrigerated truck to the Rosenthal Meat Science and Technology Center. Each rib and plate was fabricated 14 to 21 d postmortem into the appropriate retail cuts to be used for this study. The cuts were dissected, either raw or cooked (braised, grilled, roasted), into four separable components: separable lean, seam fat, external fat, and refuse. Bone and heavy connective tissue were considered refuse. Percent total chemical fat, moisture, protein, and ash analyses were conducted on the separable lean component obtained from dissection. Cooking yields were evaluated for each of the three cooking methods utilized in this study. Grilled cuts had the highest numerical yield followed by roasted and braised cuts. Dissection data showed single muscle cuts had a higher percentage of separable lean than retail cuts composed of multiple muscles. Boneless and lip-off retail cuts contained a higher percentage of separable lean when compared to their bone-in and lip-on counterparts. Finally, proximate analysis data showed that as retail cuts increased in the percentage of total chemical fat, the percentage of moisture decreased. When percentage of total chemical fat was stratified by USDA quality grade, most cuts showed differences between USDA Choice and Select quality grades. This study was a collaborative project; therefore, the results and discussion of this thesis are only based on findings from Texas A and M University's data. The final project results will be published in the USDA’s National Nutrient Database SR.
5

Pseudo proximate analysis: method using wireline logs to estimate components of coal bearing rock matrix without control data

McLean, Christopher Robert January 2015 (has links)
>Magister Scientiae - MSc / Lab conducted proximate analysis of coal bearing rock units calculates the weight percentage of ash, moisture, fixed carbon and volatile matter through a series of combustion steps. The data obtained is quintessential in establishing the coal rank and in the case of coal bed methane the gas-in-place estimates. In this study 105 proximate analysis samples, from 7 drilled wells, are taken from the south-eastern Kalahari Basin in Botswana. The pseudo proximate analysis, the method proposed in this thesis, calculates the lab proximate analysis results using the neutron, density and gamma ray wireline logs. The uniqueness of the method lies in the fact that no cut off values are needed for the wireline logs, nor are the results of the lab proximate analysis required for calibration. An in depth study of the relationship between the wireline logs and proximate analysis is conducted using a principle component analysis and the results tested using a combination of statistical techniques to determine the significance of the relationship. It is shown that the density and neutron logs model the proportion of ash and volatile matter in the rock matrix, respectively, with a high degree of accuracy. The multiple regression analysis shows that percentages fixed carbon and moisture components of the rock matrix correlate poorly to the proposed well logs, thus most error lies in the determination of these two components. It is statistically proven that the pseudo proximate analysis results are significantly different to the lab measured proximate analysis. This implies that the proposed pseudo proximate analysis method is unable to accurately determine the components of a coal bearing rock matrix using the density, neutron and gamma ray wireline logs. The application of the proposed method is a model to identity the coal bearing rock matrix and provide a predictive estimation of the coal quality, a priori lab measured data.
6

Modifying Lamb/Mutton Flavors in Processed Meat Products by Smoking, Curing, Spicing, Starter Cultures and Fat Modification. Investigating the Use of the Technicon InfraAlyzer 400R as a Rapid Method for Proximate Analysis

Osuala, Chima I. 01 May 1985 (has links)
Mutton meat was tested in different products in order to obtain prototype products in which mutton can effectively be used without the objectionable mutton off flavor. Mutton flavor reduction was achieved in the processed meat products by: (a) lowering mutton fat to a level of 10% or less, (b) using spices, smoking and/or curing, (c) substituting fat from beef or pork for mutton fat, and (d) the action of microbial starter cultures. Four taste panel sessions were set up to rate these products against an all beef or all pork control for consumer acceptability. Taste panel results indicate that flavor had the greatest effect on overall acceptability of these products, compared to texture and appearance. Proximate meat analysis for fat, protein, moisture and ash were performed using the Technicon InfraAlyzer 400R and the results were compared with values obtained by reference AOAC methods. Correlation coefficients of 0.992, 0.867, 0.992 and 0.511 were obtained for fat, protein, moisture and ash respectively. The two methods were not significantly different (p = .05). These results indicate that the InfraAlyzer may be used as a rapid method for proximate analysis of fat, protein and moisture.
7

Use of bioelectrical impedance analysis (BIA) to predict water and energy content of juvenile Rainbow Trout (Oncorhynchus mykiss)

Bourdages, Christopher 01 August 2011 (has links)
Accurate measurements of energy content and body composition are essential to effectively assess the well-being of fish. Bomb calorimetry and proximate analysis are currently the most dependable and accurate methods to estimate energy content and body composition. However, bioenergetic studies that employ the traditional methodology necessitate the killing of fish to determine physiological composition and energy content in a target tissue. The killing of the individual negates the ability for repeated measures on the same individual, and also suppresses compositional studies involving endangered or threatened species. Recent research has shown Bioelectrical Impedance Analysis (BIA), a quick, easy-to-use, non-invasive, and most importantly, non lethal technique to be an effective method for estimating the proximate composition and energy content of fish. The focus of this research is to evaluate the capability of BIA to accurately assess the bioenergetics of juvenile rainbow trout (Oncorhynchus mykiss), and to develop species-specific indices to predict energy content, total body water and dry mass. To do this, juvenile rainbow trout were subjected to one of three ration regimes: maintenance (0.4 % bw/day), optimum (1.9 % bw/day) and satiation (3.4 % bw/day) for 90 days. Subsamples from each treatment were taken every 30 days to be subjected to BIA testing. Tissue samples were collected from the subsampled trout for future caloric and compositional analysis via bomb calorimetry and proximate analysis. It was found that BIA demonstrated a strong predictive relationship with regard to energy content (r2 = 0.90), total body water (r2 = 0.89) and dry mass (r2 = 0.80). BIA was also able to successfully reflect a notable statistical difference between treatments with regard to total energy content, energy density, total body water, dry mass. These results, along with much of the existing literature, indicate that BIA may be an accurate and reliable tool to estimate the bioenergetics and proximate composition of fish. / UOIT
8

Avaliacão qualitativa de carnes de catetos (tayassu tajacu) e cutias (dasyprocta aguti) criados em cativeiro no semi-arido nordestino / Qualitative evaluation of peccary (tayassu tajacu) and agouti (dasyprocta aguti) meat bred in captivity in semi-arid northeast region

Barbosa, Polyanna Dantas Fernandes de Sousa Freitas 27 August 2010 (has links)
Made available in DSpace on 2016-08-15T20:30:57Z (GMT). No. of bitstreams: 1 PolyannaDFSFB_DISSERT.pdf: 473477 bytes, checksum: 697c9e37a3a564d799921bed252579ca (MD5) Previous issue date: 2010-08-27 / Eight samples of peccary meat (Tayassu tajacu) and thirteen samples of agouti meat (Dasyprocta agouti) were collected and analysed using physicochemical and microbiological parameter. In the analysis were used 08 peccaries and 13 agoutis, all intensive farming. The meats were tested for moisture, dry matter and minerals; in microbiological analysis searched for the presence of enterobacteria, Staphylococcus and mesophilic bacteria. In the determination of dry matter, the average performance was 26.87 ± 1.1% for agoutis and 29.17 ± 1.54% for peccaries. In the analysis of minerals, we obtained an average of 4.84 ± 0.87 for peccaries and 4.72 ± 0.37 for agoutis. For the determination of moisture, peccary samples showed 70.83% and agouti samples showed 73.13%. In the analysis of enterobacteria, peccary samples had an average of 1.57 log10 UFC/g, and agouti samples had an average of 1.5 log10 UFC/g. In the determination of Staphylococcus, the samples showed an average of 1.57 log10 UFC/g and 1.55 log10 UFC/g for peccaries and agoutis, respectively. For mesophilic bacteria, peccary samples showed an average of 1.72 log10 UFC/g and agouti samples showed an average of 1.77 log10 UFC/g. Therefore, the physicochemical results were satisfactory compared with other animals of the same order. The microbiological results showed low levels of contamination. / Foram coletadas e avaliadas físico-quimica e microbiologicamente oito amostras de carne de catetos (Tayassu tajacu) e treze de cutias (Dasyprocta aguti). Nas análises foram utilizados 08 carcaças de catetos e 13 de cutias todos criados em cativeiro de forma intensiva. As carnes foram testadas quanto à umidade, matéria seca e minerais; nas analises microbiológicas pesquisou-se a presença de enterobactérias, Staphylococcus e bactérias mesófilas. Na determinação de matéria seca a média dos resultados foi de 26,87±1,1% para cutias e 29,17±1,54% para catetos. Na análise de minerais obteve-se uma média de 4,84±0,87 para catetos e 4,72±0,37 para cutias. Para a determinação da umidade as amostras de cateto apresentaram 70,83% e de cutia 73,13%. Na análise de enterobactérias as amostras de cateto apresentaram média de 1,57 log 10 UFC/g e as de cutia 1,5 log10 UFC/g. Na determinação de Staphylococcus coagulase positivos as amostras apresentaram média de 1,57 log10 UFC/g e 1,55 log10 UFC/g para catetos e cutias respectivamente. Para as bactérias mesófilas as amostras de cateto apresentaram média de 1,72 log10 UFC/g, e as de cutia apresentaram uma média de 1,77 log10 UFC/g. Portanto os resultados físicos químicos foram satisfatórios quando comparados com animais da mesma ordem e no microbiológico houve baixa contaminação indicando que o produto apresenta boa qualidade.
9

Design and validation of a nutritional recipe for a snack made of green banana peel flour (Musa paradisiaca)

Acosta-Coello, Camila, Parodi-Redhead, Almendra, Medina-Pizzali, Maria Luisa 24 March 2021 (has links)
This study aims to design and validate a nutritional recipe for a snack made of Green Banana (Musa paradisiaca) Peel Flour (GBPF) and to assess the nutritional composition and microbiological quality of the flour. Banana peel, a food industry by-product, is a nutritious, low-cost material available for all year. Banana peel flower could be used as a functional ingredient due to its high fiber content and good functional properties. In general, university students have a deficient dietary fiber intake due to altered dietary patterns; thus, this study was focused on this population. The GBPFs were obtained from the peels of pre-climacteric bananas by fluidized bed (FDB) dryer, after which, microbiological, proximate, and dietary fiber analyses were applied. It was designed the nutritional recipe for the snack taking into account the energy and dietary fiber nutritional requirements of the target population. It could be validated and adjusted the recipe following the methodology of Centro Nacional de Alimentaci n y Nutrici n, concluding with the determination of dietary fiber in the end-product. The dietary fiber, total carbohydrate, protein, total fat and energy contents of the GBPF were as following: 38.7 g, 76.3 g, 5.9 g, 3.6 g, and 361.2 kcal, per 100 g of flour. The snack contained 7.74 g of dietary fiber per serving size, having a good acceptance among the university students' panelists based on an organoleptic test. In conclusion, the GBPF showed great potential as a source of dietary fiber, and it was an excellent source of carbohydrates and other nutrients to a lesser degree. When included as a functional ingredient in the nutritional formulation of a snack, it had an overall positive effect on the product's organoleptic characteristics. / Revisión por pares
10

Effects of Preblending and Water Addition on Physical and Sensory Characteristics of Seasoned Pork Patties

Field, Molly Sheppard 15 December 2012 (has links)
The objective of this study was to establish the consumer acceptability of preblended and nonpreblended post rigor seasoned pork patties with added water levels of 0, 3, 6, and 9 percent for each formula. Other parameters measured were proximate analysis, texture, cooking loss, and consumer acceptability. Nonpreblended treatments had a higher (P<0.05) percentage of protein and a lower (P<0.05) percentage of fat as compared to preblended treatments. Texture analysis revealed a lower (P<0.05) amount of total energy required to shear through a single patty in preblended treatments than nonpreblended treatments. No differences (P>0.05) were detected among treatments at varying water levels. Consumer acceptability showed no differences (P>0.05) among selected treatments. Consumer acceptability scores indicated that consumers would consume both preblended and nonpreblended seasoned pork patties at varying water levels.

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