Yogurts were made from intermediate-high temperature (100, 110, 120, and 130°C for 4 or 16 s), ultra-high temperature (140°C for 4 or 16 s), and vat heat (82°C for 20 min) treatments of skim milk fortified to 5% protein by either ultrafiltration or the addition of nonfat dry milk (NOM). Whey protein denaturation in heated milks increased with temperature and holding time from indirect plate heating and was highest in vat-heated milks. Whey protein denaturation and yogurt water-holding capacity increased with protein levels in the fortified milks compared to skim milk. Penetrometer gel strength and stirred viscosity in 21 day-old yogurt made from heated ultrafiltered skim milk exceeded those of yogurts made from NOM-fortified skim milk, even though the NOM yogurts contained more solids (13.0 vs 11.4%). Maximum gel strength and viscosity, and least syneresis of yogurts from ultrafiltered and NOM fortified yogurts occurred following intermediate-high temperature treatments of 1 00°C for 16 s, 110°C for 4 or 16 s, and 120°C for 4 s. There was significantly lower whey protein denaturation at these intermediate-high temperatures compared to UHT or vat heating. Gel strength and viscosity were lower and syneresis greater in yogurts from ultrafiltered or NOM-fortified skim milk following UHT treatment compared to yogurts made with intermediate-high temperature treatments or vat heating. The water-holding capacity of yogurts from fortified milks treated at intermediate-high temperatures was comparable to that of yogurts from vatheated milks. Fortification by ultrafiltration, to lower total solids (and without use of stabilizers) resulted in yogurt with higher gel strength and viscosity, and reduced syneresis compared to yogurt from NOM fortification. Yogurt prepared by intermediate-high temperature treatment had comparable or better gel strength and viscosity, and reduced syneresis compared to yogurt prepared by traditional vat heating.

A suitable microtome sampling technique was used to sample cheese for analysis using FTIR spectroscopy. Well-separated fat- and protein-related bands were obtained in the spectra of Cheddar and Mozzarella cheese samples using this method. The absorbance intensity of the spectra was proportional to the thickness of the sample. The intensity of absorbance and fat- and protein-related bands increased with an increase in the fat and protein content in the sample. Strong and well-separated bands at 1744, 1450, 1240, 1170, and 1115 cm-1 arising mainly from fat content were observed using this method. Bands observed at 1650 and 1540 cm-1 were attributed to the protein present in the cheese. Bands at 1615-1639, 1640-1648, 1650-1658, and 1660-1688 cm-1 corresponding to β-sheet, random coil, helix, and the turns/sheet portion of the secondary structure were observed int he range of the amide I band. Characteristics of spectra for full-fat (FFCC) and reduced-fat Cheddar cheese (RFCC) during ripening were investigated. The absorbance of bands at 1116-1240 from C-C, C-O, C-N stretch, 1461 cm-1 from C-N bend (scissoring), 1744 cm-1 from ester carbonyl groups (fat A), 2850-2930 cm-1 from C-H stretch (fat B), 1650 and 1540 cm-1 from protein amide I and II varied druing cheese aging. Bands at 1116 and1240 cm-1 arising from C-O, C-N, and C-C stretch changed slightly during cheese aging. A correlation coefficient of 0.97 for bands between 1744 and 1167 cm-1 arising from fat, and that of 0.93 at 1650 and 1540 cm-1 arising from protein, respectively, showed that one of these fat or protein groups was highly related to the other. A correlation coefficient of greater than 0.80 among the bands of fat and protein groups indicated a strong interaction in those bands. Correlation of ripening time and absorbance at bands corresponding to each function group was analyzed. A ripening index model was obtained by correlating ripening time with predominant reactive group absorbance peaks. An R2 of 0.83 and 0.59 was obtained for full-fat and reduced fat Cheddar cheese, respectively. Texture development and its correlation with FTIR spectra data for FFCC and RFCC during aging were also studied. RFCC had a higher value of hardness, gumminess, and chewiness than its full-fat counterpart. The values decreased during the early stages of ripening and then increased with time. The change in hardness, adhesiveness, and springiness was expressed as a function of the change in absorbance of the FTIR spectra using multiple regression analysis. An R2 value of 0.67, 0.54, and 0.75 was obtained for full-fat Cheddar cheese, and a value of 0.51, 0.59, and 0.54 was obtained for reduced-fat Cheddar cheese for the respective texture parameters.

No description available.

Effects of two types of chelating agents on proteolysis and texture properties of low fat Cheddar cheese (LFC) were analyzed and compared to full fat Cheddar (FFC) control during ripening for 120 days at 8°C. We hypothesized that chelating agents would bind calcium ions from cheese matrix to give a softer curd due to a decrease of protein-protein interactions and simultaneously increasing moisture content. Cheese milk containing (0.59% fat) was divided into three lots (A, B & C). Sodium citrate (3Na) and disodium EDTA (EDTA) were added to A & B at the rate of (0.02% and 0.2% respectively. C served as control (LFC). Cheesemilk (88°F) was preacidified to pH 6.2 prior to setting using 34 ml chymosin/454 kg and starter culture addition. After cutting, curd was cooked to 96°F for 30 min and held for 10 min. After cooking, the curd was washed, salted, hooped and pressed. FFC was made on subsequence days from same batch of milk by the stirred curd method for Cheddar cheese, cheesemaking was replicated 5 times. Significant difference in moisture content (P˂0.05) was observed between FFC and LFC. Calcium content on the EDTA and 3Na was significantly reduced (P˂0.05) compared to FFC. No significant difference (P˃0.05) in hardness was observed between FFC and LFC at day 7 and 30. After day 30, significant differences (P

Processed meats have received negative publicity due to high fat contents that have been linked to adverse effects on human health. Fat is an essential ingredient in many processed meat products, so reducing this all while maintaining the desired characteristics of the product is a challenge. The purpose of this study was to generate low-fat meat products using a combination of hot-boning/crust-freeze-air-chilling (HB-CFAC) and cold-batter mincing (CBM) technologies. Pork hams were subjected to HB-CFAC or chill-boning/crust-freeze-air-chilling (CB-CFAC) prior to 3 min pre-mincing and 6 min mincing for control gels with back-fat addition or low-fat gels with water addition instead of the reduced back-fat. Raw meat quality, protein functionality and textural properties were analyzed through various analyses. The pH values of HB muscle and cooked gels were significantly higher than those of CB muscle and cooked gels. The fat and moisture contents of control gels was higher and lower, respectively, than those of low-fat gels, regardless of HB or CB. The protein functionality and gel forming ability of HB muscle were superior to those of the CB muscle, regardless of fat content. These results indicate that fat can be reduced with no loss of textural quality because cold-batter mincing of the HB-CFAC muscle resulted in higher gel forming ability than that of CB-CFAC muscle.

No description available.

This research project investigated a method to promote one low-fat, high-fiber choice in a national chain fast-food restaurant. It is an extension of efforts toward large-scale dietary change. A procedural extension of a prompting strategy was used in an attempt to influence customers to choose a salad. A simple visual and print message based on themes derived from formative and pilot research at the restaurant was presented during two intervention phases of a reversal design. The message, "Be Fit and Healthy; Eat a Low-fat SALAD as Your Meal or Add a Side Salad," was displayed in colorful posters and tent cards which were placed on all the tables. Data from a comparison base in a neighboring town were obtained. A one-month follow-up phase was included in the design. Prices and in-store advertisements were identical in both locations. The existing computerized cash register system was used to obtain accurate, objective data. Daily and weekly sales percentages of several entrees were obtained. Results of analysis using a correction procedure indicate that when graphically represented, salad sales across phases increased with the introduction of the prompts, and decreased with their removal. In addition, three entrees not represented by associated prompts remained stable across phases. For Salads-combined, results indicate that sales increased about 15% and 9%, respectively, for the first and second intervention phases. Daily temperature during this project was variable. Although a comparison site was used to control for the effects of weather, results indicate that salad prompting may have increased sales more during warmer temperature. Population demographics were recorded. Analyses of the customer population during this project indicate customers were about equal by gender, and consisted primarily of white, 18-39 years old individuals. The cost for each added salad bought during the intervention was about $.22, and the cost to raise the percent of salad sales, each percent, across the four weeks was about $16.00. Future research should attempt to foster longer term behavior change and integrate multifaceted promotions. / Master of Science

The purpose of this study was to determine attitudes toward low carbohydrate diets among consumers and the attributes that influence their purchase decision. A growing number of diet trends are spreading across the nation in an effort to improve health and lose weight such as the Atkins diet and the South Beach diet.

No description available.

College students engage in poor dietary behaviors which put them at risk of weight gain and subsequent future health problems. This necessitates implementation of nutrition interventions which target dietary behaviors in college students so that healthy dietary patterns can be adopted and maintained through adulthood. Dairy intake is one of the many dietary behaviors which has declined substantially in young adults (18-30 years of age) - a period which includes the college age population. According to 2005 dietary guidelines for Americans three or more than three servings of low-fat/fat-free dairy foods is recommended for young adults, which is associated with overall nutrient quality of the diet and several health benefits. Still dairy consumption in this age group is below two serving per day. As emerging adults, college students may be more receptive to health advice than young adults older than traditional college years whose health habits are more established; nutrition intervention to improve dairy intake may be well received. Psycho-socio variables from Social Cognitive Theory (self regulation, social support, self-efficacy and outcome expectations) have been associated with adoption of healthy eating habits in college students and are associated with dairy consumption in adolescents. A series of studies were conducted to assess and improve dairy intake in college students by changing the mediating psycho social variables from Social Cognitive Theory (SCT) of behavior change including social support, self efficacy, outcome expectations and self regulation. A pilot web based nutrition education intervention was conducted to improve dairy intake in college students using SCT. The aim of this study was to evaluate the effect of the intervention on self efficacy, outcome expectations, self regulation, behavior and dairy product intake. Two hundred and ninety four students participated in the study and data on dairy intake and SCT variables were collected using 7 day food records and questionnaires. A 5 week electronic mail intervention was conducted. The intervention improved some social cognitive factors such as self regulation and self efficacy regarding increased dairy intake in college students, though dairy intake did not change. Next, to understand factors associated with dairy intake in college students, qualitative data were collected using focus group discussions (n=3), elicitation interviews (n=13) and online asynchronous discussion forums (n=3) using identical questions. Fifty students participated in the study and the aim was to identify relevant barriers, motivators and facilitators to dairy and low-fat dairy consumption. The results indicated that there was widespread lack of clarity regarding amount of dairy/calcium required and whether students felt they were getting enough. Major barriers to consuming dairy foods included short shelf life, storage issues, taste and accessibility to dairy foods on campus. Major facilitators included constant reminders, knowing immediate benefits, more accessibility and breakfast consumption. The aim of the final study was to improve social support, self efficacy, outcome expectations, self regulation and behavior related to dairy intake in college students using Social Cognitive Theory (SCT). One hundred and ninety one students participated in the study which included 8 week electronic mail intervention. Data collected included 7 day food records and for dairy intake and questionnaires for SCT variables. The intervention resulted in significant improvement in total dairy intake and use of self regulation strategies by college students. Taken together, these results suggest that theory-based nutrition education interventions can improve nutrition behavior in college students, a population prone to poor dietary habits. Developing mastery experiences to improve self efficacy may enhance self regulatory skills like goal setting, planning and monitoring to improve dairy intake in college students. Health care providers should aim at dietary behavior modification via theory based intervention. / Ph. D.