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Effects of dietary conjugated linoleic acids (CLAs) and docosahexaenoic acid (DHA) on the fatty acid composition of different egg compartments after storage were studied. Four dietary treatments [supplemented with safflower oil (SAFF, control group), DHA, CLAs plus DHA (CAD), and CLAs alone] were administered to Single Comb White Leghorn (SCWL) laying hens. Eggs from the different treatment groups were collected and stored for 10 weeks at 4 degrees C before analysis. Fatty acids from the yolk (yolk granules and plasma), egg albumen, and vitelline membrane were analyzed by gas chromatography. The yolk of eggs from hens given CLAs had significantly higher amounts of saturated fatty acids, typically 16:0 and 18:0, but lower amounts of polyunsaturated fatty acids (PUFAs) compared to eggs from the control group (SAFF). CLA content was highest in the yolk and present in both neutral and polar lipids, with the greatest concentrations in neutral lipids. DHA was incorporated mainly into yolk polar lipids. Lipids in yolk plasma and granules contained similar amounts of CLAs. The fatty acid compositions of vitelline membrane and egg albumen mirrored that of the egg yolk. CLA supplementation resulted in hard and rubbery yolks when compared to hard-cooked eggs from the control group. This study showed that feeding CLAs to hens led to accumulation of the isomers in polar and neutral lipids of the egg yolk and that these isomers migrated into egg albumen. Because the sensory properties of hard-cooked eggs were negatively affected by the enrichment of a mixture of CLA isomers in this study, further research should be conducted to evaluate how the different isomers alter the properties of egg yolk and albumen so that the quality of designed eggs containing CLAs and DHA can be improved.

The purpose of this study was to evaluate the effects of conjugated linoleic acids (CLA) on neonatal fatty acid metabolism. In this study, layer hens (n = 40) were divided into four equal groups and subjected to the following treatments. Group A served as the control group, Group B received 1 g CLA every other day, Group C received 1 g CLA every 4th d, and Group D was sham-supplemented with 1 g safflower oil every other day. After 4 mo of feeding, Group B hens exhibited an increase in BW and egg size; however, there were no differences noted in feed consumption among the various treatment groups. At the same time, hens were inseminated with a constant dose of pooled rooster semen to evaluate changes in chick liver and yolk fatty acid metabolism during neonatal growth. At hatch and through 6 d of age, there were no significant differences in breakout data (fertility and numbers of early-, mid-, or late-dead chicks) or chick BW, respectively. However, Group B chicks exhibited an increase in liver 18:3n3 and 22:1n9 and a decrease in 20:3n6 and 22:5n3 fatty acids when compared with chicks from Groups A and D. Also noted for Group B chicks, yolk 18:0 fatty acid was higher than that for Group A and D chicks. These results suggest that CLA alters lipid metabolism in growing chicks.

Background: Postprandial plasma glucose concentration is an important diabetes management target. Glycemia-targeted specialized-nutrition (GTSN) beverages, containing various quantities and types of carbohydrates (CHO), have been formulated to blunt postprandial hyperglycemia. The objective of this research was to evaluate the effectiveness of these products on postprandial glycemic and hormonal responses based on comparisons of GTSN with differing carbohydrate quantities or types. Methods: In two randomized, double-blind, crossover studies, participants (mean age 61 years) with type 2 diabetes consumed GTSN in a meal tolerance test. In the CHO Quantity Study, a standard nutritional beverage (STD) was compared to a low carbohydrate nutritional beverage with tapioca dextrin (GTSN-TDX) and a balanced carbohydrate nutritional beverage containing a blend of the slowly-digesting carbohydrates maltodextrin and sucromalt (GTSN-SDC). In the CHO Type Study, the GTSN beverages had similar carbohydrate quantities but varied in carbohydrate composition with GTSN-SDC compared to a formula with tapioca starch and fructose (GTSN-TS&F), and one with isomaltulose and resistant starch (GTSN-I&RS). Postprandial (0-240 min) concentrations of blood glucose, insulin (CHO Quantity Study only) and glucagon-like-peptide (GLP)-1 (CHO Quantity Study only) were measured. Results: Despite having substantially different carbohydrate quantities, the GTSN blunted the glucose positive area under the curve (AUC 0-240 min) by 65% to 82% compared to the STD formulation (p < 0.001). GTSN also elicited ~50% lower insulin positive AUC 0-240 min (p < 0.05), while postprandial GLP-1 responses were increased (p = 0.018) vs. STD. In the CHO Type Study, glucose positive AUC 0-240 min tended to be lower for GTSN-SDC (1477 ± 460) than GTSN-TS&F (2203 ± 412; p = 0.062) and GTSN-I&RS (2190 ± 412; p = 0.076). No differences were observed between GTSN-TS&F and GTSN-I&RS. Conclusions: These results demonstrate the effectiveness of several GTSN products and suggest that both CHO quantity and type play important roles in postprandial glycemic response in men and women with type 2 diabetes. Furthermore, GTSN products containing slow-digesting carbohydrates can blunt postmeal glucose and insulin concentration despite delivering greater total grams of CHO, which provides a dietary benefit for people with diabetes.

Background. Energy-dense foods are inconsistently implicated in elevated energy intake (EI). This may stem from other food properties and/or differences in dietary incorporation, that is, as snacks or with meals. Objective. Assess intake pattern and food properties on acute appetitive ratings (AR) and EI. Design. 201 normal and overweight adults consuming a standard lunch. Test loads of 1255.2 kJ (300 kcal) were added to the lunch or provided as snack. Loads (peanuts, snack mix, and snack mix with peanuts) were energy, macronutrient, and volumetrically matched with a lunch portion as control. Participants completed meal and snack sessions of their randomly assigned load. Results. No differences were observed in daily EI or AR for meal versus snack or treatment versus control. Consumption of peanuts as a snack tended to strengthen dietary compensation compared to peanuts or other loads with a meal. Conclusions. Inclusion of an energy-dense food as a snack or meal component had comparable influence on AR and EI. Peanuts tended to elicit stronger dietary compensation when consumed as a snack versus with a meal. If substantiated, this latter observation suggests that properties other than those controlled here (energy, macronutrient content, and volume) modify AR and EI.

Critical thinking skills (CTS) are the core learning outcome measures for higher education. Generally, CTS are not extensively developed or practiced during primary and secondary education. As such, early cultivation of CTS is essential for mastery prior to collegiate matriculation. Weekly engagement in 50 min of classroom discussion with student feedback (CDSF) was utilized to develop the CTS of students in an introductory food science course at Purdue Univ. Students' critical thinking ability was assessed longitudinally over a 16-wk semester using the ACT-CAAP TM (Collegiate Assessment of Academic Proficiency) critical thinking test. The ACT-CAAP measures the students' ability to analyze, evaluate, and extend an argument described in a short passage. We hypothesized that the implementation of CDSF for 16 wk would expedite development of CTS for students enrolled in the course. The CDSF intervention significantly increased critical thinking ability for non-native English speaking students as compared to native English speaking students. Students who were classified as sophomore status or above when compared to freshmen and students enrolled as food science majors when compared to other majors also demonstrated increased critical thinking ability. Recitation size also significantly influenced critical thinking ability where students enrolled in a relatively small recitation section had elevated critical thinking when compared to the abilities of those students enrolled in a large recitation. These observations suggest that engaging students in classroom discussions with student-led feedback is a useful instructional technique for developing CTS. Further, the data suggest the development of critical thinking skill among food science majors can be augmented when classroom discussions with student-led feedback are conducted in smaller sized recitations.

The present study was designed to investigate the effects of conjugated linoleic acid (CLA) on yolk usage and circulating very low density lipoproteins (VLDL) during incubation (Day 15) and through 6 d post-hatch. Eggs enriched with CLA were obtained from hens subjected to the following treatments. Group A hens served as the control group, Group B hens received 1 g CLA every other day, Group C hens received 1 g CLA every 4th d, and Group D hens were sham-supplemented with 1 g safflower oil every other day. Enrichment with CLA did not effect fertility, hatch of fertile, BW, or yolk-free BW of embryos or chicks. However, there were significant changes in relative yolk sac weight (RYW) and composition of circulating VLDL particles. Across all dietary treatments (Groups B, C, and D), 15-d embryos had smaller RYW compared with Group A embryos; this difference remained through 2 d posthatch. During that period (15 d of incubation through 2 d posthatch), however, embryos and chicks from Group B hens exhibited a unique absorption pattern such that little to no yolk was utilized between hatch and 2 d posthatch, a period normally characterized by high yolk lipid utilization. Similar to the RYW effects, VLDL particles were also altered by hen-induced treatment. Specifically, at hatch, chicks from Group A hens had the highest percentage of triglycerides (TG) within their VLDL particles compared with chicks from hens under all other treatments. This trend in VLDL particles was continued at 4 d posthatch. The present study demonstrates that CLA enrichment of eggs alters relative yolk sac absorption and the composition of circulating VLDL particles.

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