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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

THE EFFECT OF SEED TEMPERING AND MICRONIZATION TEMPERATURE ON THE PHYSICOCHEMICAL PROPERTIES OF CHICKPEA FLOUR AND ITS PERFORMANCE AS A BINDER IN LOW-FAT PORK BOLOGNA

2014 April 1900 (has links)
The overall goal of this research was to investigate the effect of seed tempering moisture and micronization temperature on the physicochemical properties of chickpea flour and its subsequent performance as a binder in a model low-fat pork bologna product. This work was divided into three studies. In the first study, the effect of seed tempering moisture (untempered (7% moisture) or tempered to 15 or 22% moisture) and surface micronization temperature (115, 130, 150 or 165oC) and on the physical, chemical and functional properties of chickpea flour were investigated. Chickpea flour became darker as seed moisture or micronization temperature increased. Increasing the micronization temperature at 22% seed moisture increased starch gelatinization from 8.2 to 34.0%. The lipoxygenase activity of chickpea flour also was reduced by micronization of seed. Lipoxygenase activity in flour from non-micronized seed and flour from seed micronized at 115oC without tempering was determined to be 1.98×105 and 1.12×105 units/g of protein, respectively, with no activity found in any other treatments. There was an increase in the water holding (WHC) and oil absorption capacity (OAC) of flour when chickpea seed was tempered to 22% moisture before micronization. Flour from untempered seed and from seed tempered to 15% moisture exhibited small increases in WHC as micronization temperature increased. Micronization had no effect on the OAC of untempered flours, whereas OAC decreased in flour from seed tempered to 15% moisture at higher micronization temperatures. Rapid visco-analysis (RVA) revealed that peak viscosity and final viscosity of all flours from tempered seed decreased with increasing micronization temperature, whereas the trend for both peak viscosity and final viscosity was in the opposite direction with untempered seed. The effect of seed tempering moisture and micronization temperature on the performance of chickpea flour as a binder in a low-fat, comminuted meat product (i.e., low-fat bologna) was investigated in study 2. Both the textural and sensory properties (trained sensory panel, n=12) of the bologna (10% fat) were explored. In study 3, a consumer panel was performed with 101 untrained participants evaluating selected formulations in order to better understand consumer purchasing behaviour as it relates to comminuted meat products containing a pulse-based binder. Bologna containing flour from micronized chickpea was more yellow in colour (CIE system, trained panel and consumer panel evaluation) compared to those with added wheat flour or no binder. There was no effect of tempering or micronization conditions on cook loss or expressible moisture of bologna containing chickpea flour, whereas bologna produced with wheat flour had the greatest WHC among all bologna treatments. Texture profile analysis (TPA) showed that the addition of chickpea flour from seed tempered to 15% or 22% seed moisture and micronized to 115, 130 or 150oC or flour from untempered seed micronized to 130 or 150oC led to an increase in hardness to a level similar to that of bologna containing wheat flour; sensory evaluation by the trained panel did not produce a similar result. A difference in flavour intensity was not found among all bolognas containing chickpea flour during sensory evaluation. Bologna produced with chickpea flour from seed micronized to 150oC and from seed tempered to 22% moisture and micronized to 115oC was comparable to bologna containing wheat flour with respect to overall texture, overall juiciness and flavour acceptability. These results demonstrated that selection of appropriate seed tempering conditions and micronization temperatures is important with respect to the utilization of chickpea flour as a binder in low-fat bologna.
22

Gustatory effects of dietary fat

Song, Hae-Jin, Chemical Sciences & Engineering, Faculty of Engineering, UNSW January 2007 (has links)
This thesis investigates whether fats, akin to other taste stimuli, exhibit sensory properties such as mixture interactions. In order to determine gustatory, rather than tactile or olfactory effects, viscosity-controlled emulsions of deodorised oils were used as the base to which taste stimuli were incorporated and presented to a panel of trained assessors. In preliminary qualitative assessments, panellists described the 10% olive oil emulsion as saltier, stronger, fattier and having a more lingering aftertaste than the non-oil control, suggesting that oil modulates taste duration as well influencing taste intensity and/or perceived quality. Panellists were unable to rate the oil/fat taste per se with any degree of certainty hence further experiments examined the effect of oil on the perception of taste mixtures. In mixture interaction experiments, the addition of oil did not result in mixture suppression or enhancement for sweet, salty, sour or bitter while it significantly enhanced umami. To determine the locus of interaction, when MSG and oil were presented to each side of the tongue separately, the enhancement effect disappeared indicating a peripheral mechanism of interaction, similar to the attenuation of chilli burn by oil. In contrast, suprathreshold sucrose sweetness was enhanced by the contralateral presentation of oil, indicating sensory processing at a higher locus. Furthermore, the addition of oil significantly reduced bitterness in a caffeine-MSG mixture. Since earlier experiments did not indicate any interaction between oil and bitterness, the decrease in the perceived bitterness of this binary mixture is attributed to an increase in umami which is likely to have suppressed bitterness, the perceptually dominant component in this mixture. These findings suggest a gustatory role for fats in modulating the taste profile of mixtures, in particular, enhancing total taste intensity, prolonging taste duration, and enhancing umami. A taste receptor-based model of fat perception provides for an orosensory mechanism capable of signalling the arrival of the most energy-dense nutrient, essential fatty acids and fat-soluble vitamins. The chemosensory signal may also be the basis for hedonic responses with subsequent implications for intake.
23

Development of low-fat and fat-free strawberry ice creams using fat replacers /

Kruel, Toni Michelle, January 2004 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 136-143). Also available on the Internet.
24

Development of low-fat and fat-free strawberry ice creams using fat replacers

Kruel, Toni Michelle, January 2004 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 136-143). Also available on the Internet.
25

Physico-chemical and therapeutic properties of low-fat yogurt as influenced by fat replacers, exopolysaccharides and probiotics

Ramchandran, Lata. January 2009 (has links)
Thesis (Ph.D.)--Victoria University (Melbourne, Vic.), 2009.
26

Implementing a healthy eating strategy after heart and lung transplantation : a randomised controlled feasibility study

Entwistle, Timothy January 2017 (has links)
Background: Studies evaluating the possible health-promoting effects of sound nutrition in heart and lung transplant recipients are currently lacking. Despite advances in drug treatment and patient monitoring, lifestyle-associated complications such as obesity, diabetes and cardiovascular disease occur frequently. Following transplantation, a low-fat eating pattern is currently viewed as best standard care. However, a Mediterranean diet based on a varied range of fresh unprocessed foods and supplemented with extra virgin olive oil has demonstrated clinical benefit in various non-transplant populations. The aim of this study was to evaluate the feasibility and acceptability of a Mediterranean vs a low-fat diet intervention in heart and lung transplant recipients, and to assess clinical and biochemical outcomes. Methods: This was a randomised controlled feasibility trial to evaluate a Mediterranean diet supplemented with extra-virgin olive oil, vs a modified low-fat diet in heart and lung transplant recipients at a single centre. In total, 41 clinically stable male and female (median age 55 years) transplant recipients were randomly assigned (1:1) in two separate 12-month waves (n=24 and n=17) to one of these diet interventions. A range of validated food frequency and adherence questionnaires captured changes in participants' reported eating habits to 6 weeks post-study. Clinical and biochemical analysis was conducted at baseline, 25 and 52 weeks. Telephone and outpatient contact provided a support mechanism to reinforce dietary behavioural change. Caloric intake and physical exercise awareness were discussed, but not promoted. Results: Thirty nine participants completed the trial (95%). Adherence to both interventions improved significantly at week 25, and was maintained at 52 and 58 weeks. Compared with baseline, waist circumference decreased in both groups at week 25 (p=0.024). A decrease in blood pressure and heart rate occurred at 52 weeks in the low-fat group only. At 52 weeks, higher adherence resulted in significant improvements in fasting glucose in the Mediterranean (< 4.8%) and low-fat (< 5%) groups. This respective pattern was also observed with total cholesterol (≤ 9% and ≤ 7%), triglycerides (≤ 9% and ≤ 20%) and IGF-1 (≤ 9% and ≤ 15%). A significant decrease in the LDL/HDL ratio (≤ 12%) occurred in the Mediterranean group only. Moreover, clinically relevant lipid and glucose regulation changes were observed in each intervention. Conclusions: The implementation of a prospective 12-month Mediterranean or low-fat diet is feasible and acceptable in a heart and lung transplant outpatient setting. Both interventions were positively associated with improvements in lipid and blood glucose regulation and circulating IGF-1. As part of a multidisciplinary framework, these findings offer an additional therapeutic strategy to optimise outpatient care.
27

Investigating the Strategies to Improve the Quality of Low-Fat Mozzarella and Cheddar Cheeses

Wadhwani, Ranjeeta 01 May 2011 (has links)
Low-fat cheese faces great challenges associated with its texture being hard and rubbery, desirable flavors being missing, color being undesirably intense and translucent appearing, and melting being improper. In an effort of improving the quality of low-fat cheeses, several strategies have been tried to accomplish three major objectives, 1) improving the melting and baking properties of low-fat Mozzarella cheese, 2) improving the color of low-fat Cheddar cheese, and 3) investigating the feasibilities of enriching low-fat Cheddar cheese with dietary fibers. For objective 1, 4 batches of low-fat Mozzarella cheese with target fat of 6.0%, 4.5%, 3.0%, and 1.5% were made using a stirred curd method, comminuted in a bowl chopper and mixed with different levels of melted butter (0.0, 1.5, 3.0, and 4.5% (wt/wt), respectively) before pressing. This would made the cheese that had increased free oil, increased melting, and improved baking as the level of added butter increased. The added butterfat was present as free fat along the curd particle junctions as shown by laser scanning confocal microscopy while the fat droplets originating from the milk were distributed within the protein matrix of the cheese. In objective 2, consumer tests and flavor profile analysis were performed on 4 commercial brands of full-fat Cheddar cheese and 9 low-fat Cheddar cheeses manufactured at Utah State University with different colors. Low-fat cheeses were rated different (P < 0.05) for their liking by a consumer panel even though they were all made the same way except for addition of color. The only difference in flavor detected by a trained panel was for a slight variation in bitterness. Using a combination of annatto and titanium dioxide produced a cheese that was rated the highest. Annatto when added singly produced a low-fat cheese that was rated the lowest. Moreover, commercial cheeses were also ranked significantly different for liking and buying preference. For objective 3, several trials were conducted to enrich low-fat cheese with inulin, pectin, polydextrose, or resistant-starch either by incorporating them into cheesemilk, mixing with 15-d aged cheese followed by repressing, or by formulating a W/O/W emulsion with inulin and incorporating the emulsion into the milk prior to cheesemaking. Adding fibers directly to milk resulted in less or no retention of fibers in cheese, whereas fibers added to comminuted cheeses were too crumbly. Adding fiber as a W/O/W emulsion improved fiber retention in the cheese and produced an improved texture of low-fat cheese.
28

Effect of Adjunct Cultures, Sodium Gluconate, and Ripening Temperature on Low-Fat Cheddar Cheese Flavor

Lance, Rebekah M. 01 August 2011 (has links)
Low-fat Cheddar cheese flavor is different from full-fat Cheddar cheese and is not acceptable to many consumers. This 2-part experiment was designed to examine effects adjunct cultures have on low-fat Cheddar cheese flavor as determined through descriptive analysis and consumer feedback. In Part 1, low-fat (5%) Cheddar cheese was produced in duplicate, using 6 combinations of DVS850, LH32, CR540, CRL431, Emfour, and CR319 bacterial cultures. Due to a previously observed positive effect by sodium gluconate on low-fat cheese flavor, each replicate was split into treatments of 0.0% and 0.8% sodium gluconate. Each of these treatments was then split into ripening temperature treatments: 6°C for 21 ± 1 wk; or 6°C for 3 wk, 10°C for 8 wk, and 6°C for 10 wk. Cheese was tasted first by an informal panel. The 4 treatment combinations for the control cheese and the CR540 (a Lactococcus lactis ssp. and Lactobacillus ssp. blend) cheese, along with all culture combinations containing sodium gluconate and ripened only at 6°C, were selected for descriptive analysis. Some statistically significant differences in culture treatment were observed. Sodium gluconate addition had a positive influence on flavor while elevated ripening temperature resulted in undesirable flavor notes. Low-fat (5%) Cheddar cheese with the CR540 adjunct with and without sodium gluconate was evaluated in a consumer taste panel with commercial full-fat (33% fat) and commercial reduced-fat (25% fat) Cheddar cheese. The low-fat cheeses were not significantly different from the commercial reduced-fat, indicating comparable cheese. Part 2 involved making Cheddar-like cheese with non-Cheddar adjunct cultures, using the same process as Part 1. Sodium gluconate was again added but elevated ripening temperature was not included. Each treatment was also divided into a sodium treatment, full salt (2%) and reduced salt (1.5%). After 2 mo of storage at 6°C, cheese was tasted by an informal panel and found to be bitter because of the starter culture used. A culture was added to the second replicate of the experiment to reduce bitterness. This adjunct was found to be somewhat effective in reducing bitterness but not entirely. Descriptive analysis was performed on the high salt level treatments for both replicates. Some difference was observed among cultures and sodium gluconate treatments; however, no acceptable cheese was produced due to bitterness in both replicates. Sodium treatments were not analyzed.
29

Effects of physiological state, temperature, water, and extended mixing on low-fat, high-added water frankfurters

Sylvia, Stephen F. 04 September 2008 (has links)
Frankfurters with 15% fat and 25% USDA added water were formulated with either prerigor or postrigor lean meat and postrigor fat using typical manufacturing practices. These frankfurters were compared to others produced using a 30 min extended mixing process (EM) on the lean component at either 2° or 16°C and either 30 or 100% of the formulation water. Results indicated that prerigor lean offered no advantages in the cooking yield nor reduction in fluid accumulation in vacuum packaged product stored (5°C) for 30 days. In addition, prerigor treatments had lower (P<0.05) Instron hardness and distance to fracture values than postrigor treatments. EM with 30% of the formulation water resulted in lower distance to fracture (P<0.05), cohesiveness (P<0.05), springiness (P<0.05), and hardness (P<0.07) values compared to those with 100%. In general, the texture of EM frankfurters was not significantly different from traditionally processed products, though independent variables beyond physiological state could not be separately tested. Traditional mixing resulted in higher L*, a*, and b* values than EM treatments. Within EM treatments, mixing with only 30% of the water resulted in significantly lower CIE a* values, but increased L* and b* values. / Master of Science
30

The development and pilot testing of a Cholesterol Saturated Fat Index (CSI) scorecard for dietary self-monitoring

Mitchell, Dorothy T. 24 October 2009 (has links)
The National Cholesterol Education Program Adult Treatment Panel guidelines specify that dietary intervention is the cornerstone of treatment for hypercholesterolemia. Self-monitoring is a strategy used to achieve self-direction in adopting and maintaining a cholesterol-lowering dietary pattern. The Cholesterol Saturated Fat Index (CSI) illustrates the atherogenic potential of food. Given that saturated fat and dietary cholesterol are the two major dietary components known to raise serum cholesterol, a CSI Scorecard was developed and pilot tested as a dietary self-monitoring tool. Twelve nutritionists scored the same five food records with known CSI scores, the reference data. The food records represented CSI scores from the 10th, 25th, 50th, 75th, and 90th percentiles from a pool of 400 usual diet food records. Two-tailed, one-sample t-tests demonstrated that the CSI Scorecard scores were not statistically significant at only the 25th and 75th percentiles. Therefore, in three of five food record percentiles, nutritionists’ CSI scores differed from the corresponding reference CSI scores. Small sample size and years of experience may have been factors influencing the results. Comments from the nutritionists’ critique forms were incorporated into the revision of the CSI Scorecard. Twelve participants scored their four-day food records using the booklet. The Spearman’s rho correlation of the CSI Scorecard derived CSI scores to the reference CSI scores was r<sub>S</sub>=.8 (p<.05). These preliminary results and comments from the formative evaluation meetings suggested that the CSI Scorecard deserves further validity testing with a larger sample of subjects. The CSI Scorecard appeared to show promise as a dietary self-monitoring tool that would facilitate increased self-direction in the adoption of a cholesterol-lowering diet. / Master of Science

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