Browsing by Author "Barbeau, William E."

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    Abscisic acid ameliorates glucose tolerance and obesity-induced inflammation
    Guri, Amir Joseph (Virginia Tech, 2007-10-19)
    Obesity is a disease characterized by chronic inflammation and the progressive loss in systemic insulin sensitivity. One of the more effective medications in the treatment of insulin resistance have been the thiazolidinediones (TZDs), which act through the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma ). Due to the many side-effects of TZDs, our laboratory sought out a natural phytochemical, abscisic acid (ABA), with chemical similarities to TZDs. Our first study demonstrated that ABA activates PPARgamma in vitro and significantly ameliorates white adipose tissue (WAT) inflammation and glucose tolerance in db/db mice. We next further examined the effect of ABA on the phenotype of adipose tissue macrophages (ATMs). In doing so, we discovered two separate ATM populations which differed in their expression of the macrophage surface glycoprotein and maturation marker F4/80 (F4/80hi vs F4/80lo). Dietary ABA-supplementation significantly reduced F4/80hiCCR2+ ATMs and had no effect on the F4/80lo population. Utilizing a tissue-specific knockout generated through Cre-lox recombination, we were able to determine that this effect was dependent on PPARgamma in immune cells. To further characterize the differences between the ATM subsets that were affected by ABA, we performed a multi-organ assessment (i.e., WAT, skeletal muscle and liver) of the effect of diet-induced obesity on the phenotype of infiltrating macrophages and T cells into metabolic organs. Based on our new data, we formulated a model by which F4/80hiCCR2hi ATMs infiltrate WAT and ultimately induce a CD11c+ pro-inflammatory phenotype in the resident F4/80loCCR2lo subset. Ultimately, our findings provide evidence that ABA has potential as an alternative preventive intervention, expound the role of PPARgamma in immune cells and, in general, expand our knowledge concerning the immunopathogenesis of obesity-induced insulin resistance.
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    Addition of Soybean Lipoxygenase to All-Purpose Flour and its Effects on Dough Gluten Strength and Bread Quality
    Danielson, Erin Marie (Virginia Tech, 2007-06-01)
    The goal of this research is to determine the effects of added soybean lipoxygenase (LOX) on bread dough rheological properties and physical properties of bread loaves compared to controls, and to determine sensory attributes of bread loaves using quantitative descriptive analysis (QDA). Protein fractions were obtained through the use of isoelectric precipitation. The pH 4.8 precipitate was found to yield the greatest LOX activity when compared with other fractions (p<0.05). The addition of pH 4.8 precipitate improved rheological properties of bread dough, examined in a farinograph, when compared to the all-purpose control (p<0.05). Addition of soy flour also increased the gluten strength of all-purpose flour (p<0.05). The addition of pH 4.8 precipitate to all-purpose flour did not improve bread loaf volume or texture. Sensory panelists described pH 4.8 supplemented bread as having firmer crumb when compared with controls (p<0.05). There were slight color differences among the loaves. The crust and crumb of bread flour loaves was lighter in color than any other sample. It was concluded that the addition of pH 4.8 precipitate to all-purpose flour greatly improved the rheological properties when compared with all-purpose flour alone.
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    The anti-diabetic mechanisms by isoflavone genistein
    Fu, Zhuo (Virginia Tech, 2011-05-10)
    Diabetes is growing public health problem in the United States. Both in Type 1 and Type 2 diabetes, the deterioration of glycemic control over time is largely due to insulin secretory dysfunction and significant loss of functional β-cells. As such, the search for novel agents that promote β-cell survival and preserve functional β-cell mass are one of the essential strategies to prevent and treat the onset of diabetes. Genistein, a flavonoid in legumes and some herbal medicines, has various biological actions. It was recently shown that dietary intake of foods containing genistein improves diabetes in both experimental animals and humans. However, the potential anti-diabetic mechanisms of genistein are unclear. In the present study, we first investigated the effect of genistein on β-cell insulin secretion and proliferation and cellular signaling related to these effects in vitro and in vivo. We then determined its anti-diabetic potential in insulin-deficient and obese diabetic mouse models. The results in our study showed that exposure of clonal insulin secreting (INS1E) cells or isolated pancreatic islets to genistein at physiologically relevant concentrations (1-10 μM) enhanced glucose-stimulated insulin secretion (GSIS), whereas insulin content was not altered, suggesting that genistein-enhanced GSIS is not due to a modulation of insulin synthesis. This genistein's effect is protein tyrosine kinase- and KATP channel-independent. In addition, genistein had no effect on glucose transporter-2 expression or cellular ATP production, but similarly augmented pyruvate-stimulated insulin secretion in INS1E cells, indicating that genistein improvement of insulin secretion in β-cells is not related to an alternation in glucose uptake or the glycolytic pathway. Further, genistein (1-10 μM) induced both INS1 and human islet β-cell proliferation following 24 h of incubation, with 5 μM genistein inducing a maximal 27% increase. The effect of genistein on β-cell proliferation was neither dependent on estrogen receptors, nor shared by 17β-estradiol or a host of structurally related flavonoid compounds. Pharmacological or molecular intervention of PKA or ERK1/2 completely abolished genistein-stimulated β-cell proliferation, suggesting that both molecules are essential for genistein action. Consistent with its effect on cell proliferation, genistein induced cAMP/PKA signaling and subsequent phosphorylation of ERK1/2 in both INS1 cells and human islets. Furthermore, genistein induced protein expression of cyclin D1, a major cell-cycle regulator essential for β-cell growth. Dietary intake of genistein significantly improved hyperglycemia, glucose tolerance, and blood insulin levels in both insulin deficient type 1 and obese type 2 diabetic mice, concomitant with improved islet β-cell proliferation, survival, and mass. These changes were not due to alternations in animal body weight gain, food intake, fat deposit, plasma lipid profile, or peripheral insulin sensitivity. Collectively, these findings provide better understanding of the mechanism underlying the anti-diabetic effects of genistein. Loss of functional β-cell mass through apoptosis is central to the development of both T1D and T2D and islet β-cell preservation and regeneration are very important components of β-cell adaptation to increased apoptosis and insulin resistance and therefore holds promise as a treatment for this disease. In this context, these findings may potentially lead to the development of novel low-cost natural agents for prevention and treatment of diabetes.
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    Assessing the Perceptions of Black American Women Within Virginia's Faith Community Regarding Their Health and Nutrition Practices and Concerns
    Mondelus, Cyndy Victoria (Virginia Tech, 2003-07-21)
    Black Americans are one of the largest minority groups in the United States and were estimated to be 35 million (13%) by the 2000 U.S. Census. In that same year, the American Cancer Society reported that Black Americans are at higher risk of dying from the nations leading causes of death, such as cardiovascular diseases, cerebrovascular disease, cancer, accidents, and diabetes. Whereas the five leading causes of death among Black American women include cardiovascular diseases, cancer, diabetes, accidents, and kidney-related diseases as reported by the American Heart Association in 2002. Black American women, in general, are less likely to engage in health promoting activities, such as physical activity and proper dietary intake. Black American women consume diets that are high in fat and in 1998, only 15.2% of Black American women reported engaging in regular, moderate exercise. The lack of physical activity and poor nutrition has also been correlated with the occurrence of overweight and obesity among Black American women. The 1999-2000 National Health and Nutrition Examination Survey (NHANES) showed that 49.7% of Black American women are obese. The purpose of this study is to assess the perceptions of Black American women regarding their health and nutrition practices, concerns, and solutions. Qualitative (focus groups and key informant interviews) and quantitative (participatory activities) research data were collected from Black American women within the faith community of the Commonwealth of Virginia. Five focus group sessions were conducted with a total of 25 Black American church women. The participants answered focus group questions and engaged in visual participatory activities to rank top nutrition and health concerns and barriers. Key informant interviews were conducted with health professionals within the faith community. Overweight/obesity, diabetes, heart disease/stroke, high blood pressure were predominate health themes raised in the focus group sessions. Also, the women ranked overweight /obesity, diabetes, heart disease/stroke, and high blood pressure as their top health concerns. The key informant interview also confirmed that overweight/obesity, diabetes, and hypertension (high blood pressure) were the main health concerns among Black American women. The predominate nutrition themes were the reluctance in giving up traditional foods, not eating enough of the right foods, and the time of day when they ate. The top nutrition concerns ranked by the women were not drinking enough water, not eating enough fruit and vegetables, and eating too many sugars. Major barriers raised by the participants were not having enough time, conflicting schedules, and familial commitments prohibited proper nutrition and health activities. The key informants agreed that a major barrier for Black American women was not prioritizing their health and nutrition practices. The preferred learning method by the women was workshops or programs that were sponsored by the community using the church as a venue. Data obtained from this study will be used to develop useful nutrition education strategies to improve the dietary habits and overall status among women in this segment of the population.
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    Assessing the Potential Use of Teff as an Alternative Grain Crop in Virginia
    Coleman, Jennifer Marie (Virginia Tech, 2012-04-27)
    Teff (Eragrostis tef (Zucc.)) is an annual, warm-season cereal crop most notable for its gluten-free, nutrient-packed seed. Experiments were conducted in two regions of Virginia (Blacksburg and Steeles Tavern) in 2010 and 2011 to determine the grain production potential of two teff varieties (brown and white). Additionally, commercially purchased teff flour was evaluated for its suitability in producing a satisfactory baked product. Teff varieties were planted in early June and July at a seeding rate of 6 kg PLS ha??. Nitrogen fertilizer was applied at planting in the form of urea at a rate of 56 kg ha??. The experimental design was a randomized complete block with a two-way factorial treatment structure (variety and planting date) and four replications. Grain yield and nutritive value, straw yield and quality, and plant height were evaluated for each variety and planting date at Steeles Tavern in 2010. Due to failure in crop establishment and difficulties involved in threshing and processing the harvested crop, no data is available in 2010 or 2011 for Kentland or in 2011 for Steeles Tavern. In 2010 at Steeles Tavern, grain yield was significantly higher for the brown variety (367 kg ha??) compared to the white variety (97 kg ha??) for both planting dates. There was no significant difference in straw yield between varieties or planting dates with straw yield averaging 2645 and 2475 kg DM ha?? for brown and white varieties, respectively. Precipitation accumulation at Steeles Tavern was higher in 2010 (greater than 10 cm) during June and July compared to 2011 and the historic average. This may explain why the plots in 2010 were able to successfully establish and out compete weeds. In the lab, four types of baked products were tested to determine the suitability of teff for baked goods. Cakes, cookies, biscuits and bread were tested with varying treatments of teff: control (100% wheat flour) and 10, 20, 30, 40 and 100% teff flour. Each treatment was replicated three times for each product. Generally, bread and cake volumes decreased as the percent of teff increased. Teff flour was best suited for use in cookie and biscuit products compared to cakes and breads since cookies and biscuits require less leavening. Overall, both experiments (field and laboratory) demonstrated the potential of teff as an alternative grain crop in Virginia. However, additional research is needed to overcome problems associated with establishment, harvest, threshing and processing.
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    Baicalein, a novel anti-diabetic compound
    Fu, Yu (Virginia Tech, 2012-08-08)
    Both in type 1 (T1D) and type 2 diabetes (T2D), the deterioration of glycemic control over time is primarily caused by an inadequate mass and progressive dysfunction of ?-cells, leading to the impaired insulin secretion. Thus, the search for agents to protect b-cell and enhance its function is important for diabetes treatment. Studies have reported that baicalein, a flavone originally isolated from the roots of Chinese herb Scutellaria baicalensis, has various claimed beneficial effects on health, such as anti-oxidant, anti-viral, anti-thrombotic, and anti-inflammatory effects. However, it is unclear whether it exerts an anti-diabetic action. Here, we present evidence that baicalein may be a novel anti-diabetic agent. Specifically, dietary intake of baicalein significantly improved hyperglycemia, glucose tolerance, and blood insulin levels in high-fat diet (HFD)-fed middle-aged diabetic mice, which was associated with the improved isle t?-cell survival and mass. Baicalein treatment had no effect on food intake, body weight gain, circulating lipid profile, and insulin sensitivity in HFD-fed mice. In in-vitro studies, baicalein significantly augmented glucose-stimulated insulin secretion in insulin-secreting cells (INS1) and promotes viability of INS1 cells and human islets. These results demonstrate that baicalein may be a naturally occurring anti-diabetic agent by directly modulating pancreatic?-cell function.
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    Breastfeeding knowledge, attitudes, beliefs, and intentions regarding breastfeeding in the workplace among students and professionals in health-related fields
    Velpuri, Jayalakshmi (Virginia Tech, 2004-09-10)
    Effective educational efforts require knowledgeable health professionals to promote breastfeeding and instigate changes in individual behavior. This research was conducted to assess breastfeeding knowledge, and attitudes, beliefs, and intentions among students and professionals in health-related fields. A 5-year prospective study was conducted to investigate breastfeeding knowledge, and attitudes, beliefs, and intentions regarding breastfeeding in the workplace among nutrition students (n=69) while in school and later while in the workplace. A 47-item questionnaire was mailed to participants to survey knowledge, and attitudes, beliefs, and intentions related to breastfeeding in the workplace along with demographic information. From baseline to follow-up, nutrition students had a significant increase in breastfeeding knowledge (P<0.001), and change in attitudes (P<0.01) and change in intentions (P<0.02) regarding breastfeeding in the workplace. Sources of breastfeeding information were predictors of attitudes and intentions regarding breastfeeding in the workplace. In a separate study, a cross-sectional comparison of nutrition students (n=270) and non-nutrition students (n=271) at Virginia Tech demonstrated that nutrition students had significantly higher scores on breastfeeding knowledge, and attitudes, beliefs, and intentions regarding breastfeeding in the workplace scales (all P<0.001) compared to non-nutrition students. The 47-item questionnaire was also used in this investigation with junior, senior, and graduate students enrolled at Virginia Tech in spring of 20004. In both nutrition and non-nutrition students, attitudes and beliefs were significant predictors (both P<0.001) of intentions regarding breastfeeding in the workplace. In a final study, a cross-sectional evaluation of the Caribbean Association of Home Economics (CAHE) (n=71) revealed that respondents had mean (±SD) scores of 5.76 + 1.34 for breastfeeding knowledge, 3.67 + 0.50 for attitudes, and 4.23 + 0.68 for beliefs related to breastfeeding in the workplace. Based on the 35-item survey, attitudes regarding breastfeeding in the workplace were positive predictors of beliefs (P<0.001). Overall, nutrition students, nutrition graduates, and CAHE members are knowledgeable about breastfeeding and possess positive attitudes and intentions regarding breastfeeding in the workplace. Attitudes regarding breastfeeding in the workplace are critical to intended behaviors. Nutrition program graduates may be effective educators of and advocates for breastfeeding and for breaking barriers to breastfeeding in the workplace.
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    Changes in Pancreatic and Jejunal Histopatholgy and Serum IFN-γ, TNF-α Levels in Type 1 Diabetes: Role of Chloroform Methanol Soluble Gliadin Proteins
    Thakare, Kalpana (Virginia Tech, 2006-06-12)
    Chloroform methanol (CM) soluble extract of a cereal-based diet has been suggested to induce type 1 diabetes in an experimental animal model of type 1 diabetes. However, the individual constituent of this extract responsible for the disease induction and its disease pathogenesis mechanism remained unexplored. A previous study in our laboratory failed to show that the sphingolipid enriched fraction of CM soluble extract of wheat gluten triggers type 1 diabetes. Therefore, to study the involvement of CM soluble gliadin proteins in type 1 diabetes, we retrospectively analyzed proteins from sphingolipid enriched extract. SDS-PAGE analysis of CM soluble extract of wheat gluten and sphingolipid enriched fraction exhibited protein bands corresponding to the masses of the wheat gliadins, suggesting the presence of gliadin proteins in the CM soluble sphingolipid enriched extract. We studied the effect of five different dietary treatments on the histopathology of pancreatic tissue from BBdp rats includes insulitis scores i.e. lymphocytic infiltration in islet of Langerhans in order to test gliadin specific sphingolipid enriched extract (GSLEE) as possible a diabetogen. However, there were no significant differences in pancreatic insulitis scores and lymphoid tissue content due to addition of (GSLEE) to the hydrolyzed casein (HC) diet. We also investigated changes in jejunal histopathology and sera IFN-γ, TNF-α cytokine concentration in type 1 diabetes, induced by GSLEE. A decrease in jejunal CD4+ and γδ TCR + cell counts and inflammatory cell infiltrate were observed due to presence of CM soluble GSLEE in the HC diet, although this decrease was not statistically significant. A significant increase in sera IFN-γ cytokine concentration was found in BBdp rats fed the HC + GSLEE diet as compared to rats on HC diet. A numerical decrease in sera TNF-α concentration was also observed in BBdp rats fed the HC + GSLEE diet, when compared to BBdp rats on the HC diet. In contrast, a significant increase in serum IFN-γ concentrations in BBdp rats were observed after removing the CM soluble GSLEE from the wheat gluten based diet (WG) when compared to the WG diet alone. Removing GSLEE from WG diet resulted in insignificant increase in serum TNF-α concentration in BBdp rats when compared to WG dietary treatment group's BBdp rats. However, there were no significant differences in jejunal enteropathy parameters (i.e. lymphocytic infiltration, mucosal thickness, epithelial erosion, jejunal villi flattenings), jejunal CD4+ and jejunal γδ TCR+ cell counts; pancreatic insulitis scores, lymphoid tissue content after removing the CM soluble GSLEE from the WG diet when compared to the WG diet. Since overall findings regarding the CM soluble GSLEE's potential to induce type 1 diabetes by changing pancreatic and jejunal histopathology and elevating serum IFN-γ, TNF-α cytokine levels largely remained inconclusive, further investigations are warranted regarding immune suppression potential of the CM soluble sphingolipids in type 1 diabetes and the search of diabetogenic agents remaining in the residue after CM extraction.
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    Chemical, Physical and Sensory Characteristics of Lactose-reduced Baked Custards Made with a Low-fat, Low-cholesterol Egg Substitute
    Wu, Veronica Tong (Virginia Tech, 1996-09-24)
    Two experiments were conducted to examine the effects of type of milk (whole; nonfat; nonfat, 70% lactose-reduced) and type of egg (fresh, whole egg; egg substitute) on the quality of baked custards. The egg substitute was a combination of dried egg whit e solids, dried low-fat, low-cholesterol egg yolk solids, and xanthan gum. Custard formulations served as prototypes for use in studies conducted in the Department of Food Science and Technology, Virginia Tech. In those studies, the effects of processing parameters on the quality of the custards were examined. The goal of all the studies was to develop shelf-stable lactose-reduced custard mixes that have potential for use in the foodservice industry. In Experiment I, chemical, physical, and sensory characteristics of a dessert type baked custard, made with sucrose, were examined. In Experiment II, the same characteristics were examined for a cheese flavored, entree type custard made without sucrose. Results indicate that use of nonfat and nonfat, 70% lactose-reduced milk in place of whole milk decreased significantly total fat and cholesterol concentrations in both types of custard mixes. Lactose-reduced milk also decreased lactose and increased galactose concentrations. The egg substitute decreased total fat and cholesterol concentrations and increased protein concentration. In general, lactose reduction had little effect on the physical and sensory characteristics of both types of custards, but the egg substitute affected these characteristics. Custards made with the egg substitute had less intense yellow color and greater gel strength than those made with fresh, whole egg. These custards also were less bright and more uneven in color and had weaker egg flavor and aftertaste. Based on results of this study, development of a lactose-reduced custard is feasible. However, additional studies are needed to examine potential for use of the formulations in the foodservice industry. Because the mixes could be used as bases for other types of products, such as custard pies, filled pastries, and quiches, studies that focus on development of those products could help define the niche for the mixes in the foodservice industry. Because of the trend in today1s market for reduced-fat, reduced-cholesterol foods, additional studies could be done to examine the effects of various types of egg substitutes on the quality of the custards.
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    A comparative study of the thermal oxidative stability of high oleic acid sunflower and polyunsaturated soybean oil blends
    Wilkerson, Troy A. (Virginia Tech, 1996)
    The thermal oxidative stability was evaluated for 7 high oleic acid sunflower (HOSO) and polyunsaturated soybean oil (PUSB) blends ranging from 0.0% to 100.0% of each vegetable oil. Each blend was evaluated in quadruplicate over an eleven day period with 300 minutes of heating at 180°C per day. Thermal oxidative stability was determined by changes in peroxide values (PV), fatty acid and triglyceride composition, and percentage of major volatile products (%MVP). A 2 Way ANOVA, simultaneous confidence intervals, trend analysis, and Paired t-Test, each with a set p value of (0.01) were used for the statistical analysis. The triolein (OOO), trilinolein (LLL), and fatty acid contents were significantly different (p< 0.01) between each blend before and after heating, with the exception of stearic acid levels, which were not significantly different between each blend. Thermal stability increased for the triglycerides and fatty acids as the degree of saturation increased: (Saturated > Monoenic > Polyenic). The addition of HOSO to PUSB increased the thermal oxidative stability of all the blends when compared to the 100% PUSB. The PV and %MVP increased as the levels of OOO decreased and the levels of LLL increased in the blends. The blends with a (1:1) ratio of each vegetable oil experienced a unique breakdown pattern. The monoenic fatty acid levels decreased and the polyenic fatty acid levels increased for this blend only. Overall, blends with 10% to 75% HOSO addition performed equally as well in the thermal oxidative stability testing.
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    Determination of vitamin B-6, available lysine and pyridoxyllysine in a new instant baby food product
    Grün, Ingolf (Virginia Tech, 1989-06-02)
    The purpose of this study was to compare the nutrient content of a new instant baby food product to jar baby food of similar product formulation. Instant and jar "Vegetable and Beef" and "Bananas" products processed in 1985 and 1987 were analyzed for available lysine, vitamin B-6 and pyridoxyllysine content. The available lysine content of 100 grams of baby food was found to be higher in the instant products, but when adjusted for protein content, available lysine was higher in the jar products. This indicates that drum-drying used for the instant products is more detrimental in regard to lysine availability than retorting. The vitamin B-6 content of the instant products was found to be higher than that of the jar products. However, due to the addition of ingredients with little or no vitamin B-6 content to the jar products, no conclusion about processing effects on vitamin B-6 content can be made. Products processed in 1985 tended to be lower in nutrient content than the products processed in 1987. Pyridoxyllysine, a compound thought to affect vitamin B-6 bioavailability, could not be detected in any of the baby foods, either by amino acid or HPLC analysis. The instant products were found to be at least equal to the jar products with regard to available lysine and vitamin B-6 content. All products also appear to provide sufficient amounts of these nutrients to infants less than one year of age.
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    Development and Effectiveness of Three Hydrocolloid-Lipid Emulsion Coatings on Preservation of Quality Characteristics in Green Bell Peppers
    Ball, Jennifer Ann (Virginia Tech, 1999-04-09)
    Three hydrocolloid-lipid emulsion coatings were developed using Humkote brand partially hydrogenated cottonseed and vegetable oil, and one of three combined hydrocolloid bases: xanthan gum and propylene glycol alginate (xanthan coating), locust bean gum and xanthan gum (locust bean gum coating), and maltodextrin. Sensory testing using a ranking preference test indicated that these coatings had acceptable appearance and palatability. Quality characteristics of green bell peppers (Capsicum annum L. cv. King Arthur) measured during the 5-week storage period included: respiration rates, chlorophyll content, surface color, puncture force, pectin (uronic acid) content, ascorbic acid (AA) and dehydroascorbic acid (DHA) content, and cumulative weight loss. No significant differences between coated and uncoated peppers were noted in tests for respiration, puncture force, hue angle, chlorophyll content, and AA content. Uncoated peppers had significantly inferior moisture retention (p<0.05), which caused them to be unsaleable after 8 days, while coated groups were saleable for an additional 6 to 8 days. Uncoated fruits also had greater uronic acid breakdown (p<0.05) and higher DHA content (p<0.06) than coated peppers. Significant weekly changes (all treatment groups combined) included linear increases in respiration rates (p<0.01) and moisture loss (p<0.01), increasing linear and quadratic trends in uronic acid content (p<0.01 for both trends), increasing quadratic trends for both chlorophyll and AA content (p<0.05, p<0.01, respectively), and decreasing linear and quadratic (p<0.05 for both trends) in DHA content. The only significant difference between coated groups was in chroma value, with maltodextrin coated peppers appearing less vivid than locust bean coated peppers. Overall, all three coatings performed equally well during the storage study. However, coatings with higher lipid content, which included xanthan gum and locust bean gum groups, withstood humidity changes better than the maltodextrin coated peppers. Coating application provided the greatest benefits in terms of texture maintenance through water retention and prevention of pectin breakdown, despite the lack of differences observed in puncture force. Coatings may also have prevented AA oxidation as demonstrated by the higher DHA content in uncoated groups, however AA patterns do not confirm this concept. Future research should be directed toward further minimizing textural changes and maximizing coating durability.
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    Effect of 1B/1R Chromosomal Translocation on Dough Rheology of Soft Red Winter Wheat Flour
    Uriyo, Maria Jr. (Virginia Tech, 1997-01-29)
    Nine 1B/1R translocated soft red winter wheat (SRWW) varieties and six non-1B/1R varieties from two crop years (1995-1996 and 1996-1997), grown in two Virginia locations (Warsaw and Blacksburg), were studied to evaluate the effects of the 1R rye chromosome on soft wheat flour quality and baking performance. The presence of the 1B/1R chromosomal translocation in wheat has been reported to provide disease resistance, but produce sticky doughs. The 1995-1996 and 1996-1997 SRWW flours were subjected to farinograph analysis and dough stickiness testing. Dough stickiness was determined by the Schwarzlaff-Shepherd Dough Stripping Method. Wheat samples from 1995-1996 were also analyzed for protein, ash, and moisture content, alkaline water retention capacity (AWRC), cookie diameter, tensile stress and strain, and by ¹³C nuclear magnetic resonance (¹³C-NMR) spectroscopy techniques. Significant (p = 0.0001) negative correlations were found between AWRC and cookie diameter of SRWWs grown in Warsaw and Blacksburg. Location was found to exert a significant effect on AWRC, cookie diameter and stickiness (p < 0.05). Farinograph data revealed that mixing characteristics of SRWW were affected significantly by variety, crop year and location (p < 0.05). In some cases the 1B/1R varieties had lower breakdown rates, longer departure times (DT) and lower mixing tolerance index (MTI), than their non-1B/1R counterparts. There was a significant difference (p = 0.0133) in the stickiness of 1B/1R and non-1B/1R samples from Blacksburg. However no such difference was found in the corresponding Warsaw samples (p = 0.9826), indicating that location exerted a significant effect on stickiness. Two flour samples exhibiting stickiness (one with and one without 1B/1R) and two non-sticky samples (one with and one without the 1B/1R) were fractionated into gluten, starch and water-solubles (WS) in order to determine if the sticky dough factor resided in the 1B/1R and / or non-1B/1R WS. The peel time of the interchanged samples, as in the case of 'Massey' flour combined with the WS from VA52-22, increased to 79 seconds from the 30 seconds originally observed in the Massey flour. However when gluten and starch fractions from a non-sticky, non-1B/1R sample,VA54-21, were mixed with WS from VA54-211 (sticky, 1B/1R), the peel time went from 18 in the original flour to 8 seconds. Tensile measurements showed dough stress was not significantly affected by the presence or absence of 1B/1R (p = 0.7057). However, dough strain was lower in 1B/1R translocated SRWWs (p = 0.0048). A ¹³C-NMR spectra failed to show differences amongst selected 1B/1R and non-1B/1R dough samples. Proton relaxation time (T1-rho-[H]) - a ¹³C-NMR technique, indicated that water did not exert a significant influence on the molecular dynamics within the dough samples of Massey (non-1B/1R), VA54-211 (1B/1R) and VA52-22 (1B/1R). However, the non-sticky, non-1B/1R sample (VA54-21) had a higher proton relaxation time at 62 ppm which may indicate the size of starch-protein particles in VA54-21 doughs were larger and less flexible than in the other three doughs.
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    The Effect of Antioxidants on Flaxseed Stability in Yeast Bread
    Cachaper, Katherine Faith (Virginia Tech, 2005-03-17)
    The antioxidants BHA, BHT, and ascorbic acid were added to flaxmeal breads to prevent rancidity. Six types of yeast leavened breads were evaluated: control (100% bread flour), flaxmeal (15%) bread, and flaxmeal (15%) bread that contained 0.01% respectively of BHA, BHT, BHA and BHT, and ascorbic acid. Vital wheat gluten was added in all the flaxmeal breads. Chemical, objective and sensory tests were used to evaluate the breads. The crumb texture of all the experimental breads was significantly softer (p¡à 0.05) than the control breads, but the control breads were significantly moister (p¡à 0.05) than the flaxmeal breads that contained BHA and BHT, separately. No significant differences (p>0.05) were found in loaf volume of the control bread and the experimental breads. The crumb color of the experimental breads was significantly darker (p<0.0001) due to the incorporation of flaxmeal. The acid value of the flaxmeal breads was significantly higher (p¡à 0.05) than the control breads. No significant differences (p>0.05) were found in peroxide values between the control breads and experimental breads after eight weeks. The QDA sensory tests showed that breads containing BHA or in combination with BHT were moister, chewier and had the least noticeable stale taste when compared to the control breads. Ascorbic acid was not as effective as BHA or a combination of BHA and BHT in preventing lipid oxidation, but produced the softest bread. This study showed that flaxmeal breads made with BHA and BHT provided the best protection against lipid oxidation and produced a moist and chewy bread.
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    Effect of canopy manipulation and fermentation on grape aroma components
    Zoecklein, Bruce W. (Virginia Tech, 1995)
    Several experiments were conducted to determine optimum methods for extraction, isolation and analysis of selected aroma components and the influence of grapevine canopy manipulation and fermentation on those components. A polymeric styrene resin (XAD-2) was evaluated for its ability to absorb and desorb five monoterpene alcohols, three monoterpene hydrocarbons, four monterpene oxides, two aromatic alcohols and a glucopyranoside from White Riesling juice at two different pH values. The percent recovery and the coefficients of variation for each compound was compared with a continuous Freon 11 extraction system. The percent recovery averaged 90% or greater for both systems with the coefficient of variation being smaller with the resin extraction. In two separate studies canopy manipulation was evaluated for the effect on aroma components using the XAD-2 resin isolation procedure. The influence of shoot topping to 10 or 20 nodes or ethephon application on grape aroma components was measured for three seasons. Canopy modification by both topping levels and ethephon treatment increased sunlight penetration into the canopy fruiting zone. Free volatile terpenes (FVT) were increased by ethephon in two of three seasons while shoot topping increased FVT and potentially free volatile terpenes (PVT) in one of three seasons. In the second separate three-year study, two to four leaves were removed from the fruiting zone of grapes grown on two training systems. Selective leaf removal increased sunlight penetration into the grape canopy but generally did not influence FVT. However, PVT was frequently higher in the leaf-pulled fruit including four of six commercial harvest dates. The total quantity of the bound geraniol, nerol, linalool, and a terpineol was higher in fruit from the leaf-pulled vines at harvest. Four strains of Saccharomyces cerevisiae were evaluated for their influences on free and conjugated aroma components of White Riesling grapes, immediately following and 45 days post-fermentation with lees or Sur lie. Fermentation generally reduced free terpenes except for «- terpineol, hotrienol, citronellol, and linalool oxides. Fermentation also increased free benzyl and 2-phenylethanol. In newly fermented and aged wines the concentrations of free volatiles were always below the sensory threshold for each compound. The potentially volatile terpenes (PVT) were Similar among treatments following fermentation, the exception being the Fermiblanc (FB) yeast strain. Additional hydrolysis of bound compounds occurred in each wine following lees storage, the exception being the wine fermented with the Fermiblanc (FB) strain.
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    Effect of dough conditioners on the bread-making qualities of soft wheat flour
    Chlapowski, Yolantha Sophie (Virginia Tech, 1988-05-08)
    Low-protein (7.35%) and high-protein (11.59%) flours were tested for bread baking with and without the addition of two substances commonly used as dough conditioners: ascorbic acid and diacetyl tartaric esters of monoglycerides (DATEM). The breadmaking properties of the flours were evaluated by measuring the loaf characteristics by objective and sensory evaluation. In addition, the effect of the dough conditioners on the rate of staling of baked bread was examined. No significant differences were found among the treatments with respect to volume. moisture content, or crumb color. Loaves baked with the high-protein flour had significantly darker crust colors. High-protein loaves were significantly less tender. The sensory panel found no significant differences in crumb color t aroma, compressibility, mouth feel, moistness, flavor, or overall aftertaste. The panel did find that high-protein loaves were significantly darker in crust color, and loaves baked with high-protein flour and ascorbic acid had significantly larger cell sizes and less uniform cell structures. The addition of DATE-M to breads made with either flour resulted in significantly decreased rates of staling. Breads made with the high-protein flour staled slower than their law-protein counterparts with or without dough conditioners. In conclusion, the bread-making characteristics of both flours were good and resulted in bread of good quality, even without conditioners present. DATEM can be added to retard the rate of staling, but more is needed with lower protein flours.
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    The Effect of Lipid/Hydrocolloid Coatings on the Postharvest Storage Quality of 'Golden Delicious' Apples
    Totty, Jocelyn Anne (Virginia Tech, 2002-05-28)
    The performance of three different lipid/hydrocolloid coatings was tested on Golden Delicious apples. The coatings consisted of a mixture of lipid, wax, and various gum blends. The three treatments were compared to an uncoated group (control). Both objective and sensory tests were performed to determine the shelf-life stability of the apples. Objective results indicated that all three treatments significantly decreased (P<0.0083) the respiration rates of the apples when compared to the control. The treatment groups also significantly (P<0.0083) maintained the texture of the apples along with a lower (P<0.0083) starch degradation rate. The treatment groups also significantly (P<0.0083) maintained the malic acid level in the apple. There were no significant differences (P>0.0083) among the groups with regard to soluble solids and fresh weight loss. Externally, the treated apples had a significantly greener hue (Hunter color "a") than the control apples, however, there were no significant differences (P>0.0083) in yellow color (Hunter color "b") between the groups. Sensory results indicated that the treated apples were firmer, crisper and juicier (P<0.0083) than the control apples. However there were no significant differences (P>0.0083) in the sweetness, tartness, and appearance of all of the groups. Overall, the derived coatings could serve as a resource for extending and maintaining the shelf life of perishable fruit.
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    The Effect of Liquid or Dry Honey as a Partial Replacement for Sugar on the Baking and Keeping Qualities of Fat Reduced Muffins
    Strait, Matthew John (Virginia Tech, 1997-07-24)
    The food industry has responded to the American Heart Association's overwhelming concerns about the complications of obesity with an array of fat reduced products that maintain the functionality of fat in given systems. In baked products, it appears that no one single ingredient effectively mimics these functions. The present study investigated the effect of liquid or dry honey as a partial replacement for sugar on the baking and keeping qualities of fat reduced muffins. The fat reduced muffins also utilized a hydrocolloid fat replacer, bacterial and fungal amylases, and an emulsifier (DATEM). Results showed that both liquid and dry honey significantly (p<0.05) increased crust and crumb color at all replacement levels, however the use of 25% liquid honey was shown to favorably increase the crust color of fat reduced muffins. Volume was not significantly (p>0.05) affected but appeared to decrease with the addition of honey due to either premature starch gelatinization or a decrease in batter pH. The addition of honey increased moisture content, and decreased water activity, but did not decrease firmness or staling rates especially after prolonged frozen storage. Sensory panelists noted that the addition of liquid or dry honey increased the cohesive forces and decreased tenderness. The addition of moisture to the fat reduced system did not appear to improve the perceived moistness of the product.
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    The effect of nitrogen fertilization on protein content and bread baking properties of wheat flour
    Koenig, Karen (Virginia Polytechnic Institute and State University, 1988)
    The effects of variation in nitrogen application during two growing seasons to Coker 916, a soft red winter wheat, on wheat grain and flour protein content and bread baking properties were examined. Nitrogen fertilization regimens tested included the single spring application of 168 kg/ha in growth stages 25 or 30, the split spring application of 224 kg/ha in growth stages 25 and 30, and no nitrogen application either in growth stages 25 and 30. Variation in rate of nitrogen application had a more consistent effect on grain and flour protein than did variation in timing. Grain and flour protein content increased with increased nitrogen fertilization. The gliadin to glutenin protein ratio of the flour was reduced as the rate of grain nitrogen application increased. Significant differences were found in the flour gliadin percent protein with variation in spring nitrogen management. Fractionation and resolution of gliadin and glutenin components using SDS-PAGE revealed changes in the relative quantities present of two high molecular weight glutenin subunits (108,000 and 91,000 daltons), one low molecular weight glutenin subunit (40,500 daltons) and the ω-gliadin (44,000 daltons) fraction of experimental flours. Differences in dough rheological properties and baking characteristics of the flour were associated with variation in nitrogen management. Increased nitrogen fertilization resulted in a stronger, more extensible dough with improved mixing tolerance and dough handling characteristics. Increased flour protein was associated with larger bread loaf volume and darker crust color. Sensory panelists found significant differences in the bread crust color, texture and taste, bread aroma, crumb texture and chewiness. This experiment demonstrated that a change in nitrogen management of Coker 916 wheat resulted in a distinct change in protein composition and bread baking properties of experimentally milled flour.
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    The effectiveness of computer-aided feedback on nutrition-related practices of EFNEP homemakers
    Bowens, Juanita (Virginia Tech, 1993-04-12)
    A Food Behavior Checklist (FBC) was developed, validated, and pilot-tested with homemakers in Virginia's Expanded Food and Nutrition Education Program (EFNEP). The FBC was designed to measure nutrition-related practices that are taught in EFNEP, but cannot be measured by the 24-hour recall. During development, 20 EFNEP paraprofessionals in Virginia and 20 randomly selected state EFNEP coordinators helped to identify items that are most important in evaluating the overall effectiveness of EFNEP, and which could be used to establish content, face, and construct validity of a behavior assessment instrument. The Food Behavior Checklist contained 30 items, and responses were recorded on a Likert scale with four response levels: 0 = "never or seldom", 1 = "sometimes",2 = "usually", and 3 = "almost always". Cronbach-alpha revealed a reliability coefficient of 0.86. During the field test phase of this study, the FBC was used before and after EFNEP intervention to collect data on the nutrition-related practices of 147 low-income homemakers in three rural counties and one urban area in Virginia. In this phase, the experimental group, which consisted of 79 homemakers, received computer-aided feedback on their dietary practices, via a Diagnostic Report, which was used as a teaching tool. Paraprofessionals thoroughly explained the content of the diagnostic report to the homemaker at program entry and program exit. The control group, which consisted of 68 homemakers, did not receive computer-aided feedback on their dietary intakes, in that no mention was made of the computer print out to them. Results indicated that this instrument (FBC) may be useful in evaluating the overall effectiveness of EFNEP nationwide and may be useful in other nutrition programs. No significant differences were observed in the nutrient intake or Food Behavior Checklist practice change scores between the group who received computer-aided feedback and the group who did not received computer-aided feedback. The author concluded that the dietary analysis contained in the computer generated Diagnostic Report needs to be simplified if it is to become an effective tool with EFNEP homemakers. More research is needed on the use of computerized diet analysis as a teaching tool with low-income homemakers.