Dose response to soluble fiber in barley in lowering blood lipids in hamster

Diets containing 0, 25, 50, or 75% finely ground barley (high in soluble fiber and soluble -glucans) were fed to groups of hamsters. After four weeks, serum total cholesterol (CH) levels in these animals were most elevated in the group fed the barley-free (0% barley) diet. Compared to animals eating this diet, the 25% barley diet lowered CH by 16.4%. However, the 50% barley diet lowered CH further by only 4.1% while the 75% barley diet caused virtually no further lowering of CH. Thus, the CH-lowering response to barley cannot be viewed as a dose dependent response. The lowering pattern for serum triglycerides, however, suggested a dose dependent response. Serum total-CH: high-density-lipoprotein (HDL)-CH or low-density-lipoprotein (LDL)-CH:HDL-CH ratios were not significantly affected by barley level in the diets.     

Effect of Shortenings Containing Stearic Acid on Blood Lipids and Fat Digestibilities in Hamsters

Tristearin (TS), a stearic acid-rich hard fat, and soybean oil (SO) were blended in different ratios to produce four functional shortenings (blends) for use in foods. Groups of hamsters were then fed diets containing TS, SO, and the four blends for four weeks. After four weeks, serum total cholesterol (CH) levels were measured: the group fed SO had 219 ± 19 mg/dL, and the groups fed four blends had a range of 214 ± 14 to 222 ± 15 mg/dL. Thus, TS in the blends exerted no hypercholesterolemic effect; it even lowered serum triglycerides (SO vs. blends). Liver CH levels were significantly lower only in the group fed the blend containing the highest level (60%) of TS. While SO was nearly completely digested (97.7%), digestibility of TS in the blends was low with a range of 10.2–26.3%, which was inversely related to the level of TS in the blend. Thus, functional shortenings produced by blending TS with edible oils may not only not raise blood CH levels, but they would be free of trans fatty acids and may be classified as reduced-calorie fats.     

Geologic approach to the long-term history of atmospheric circulation

Eolian dust preserved in deep-sea pelagic sediments can be used as a proxy indicator of paleoclimate. Analyses of the particle size, composition, and mass accumulation rate of dust grains provide independent evidence of the intensity of atmospheric circulation and the availability of material in the eolian source region. These data provide information on atmospheric circulation and on the climate of the source area at time scales ranging from 103 to 108 years and have the potential to test computer-generated global circulation models.     

Bioavailability of Calcium in Breads Fortified with Different Calcium Sources

This study used young rats as the test model to examine the relative bioavailability (RB) of calcium (Ca) in breads fortified with five different Ca sources. These sources included two inorganic (Ca carbonate and Ca sulfate) and two organic (Ca citrate and Ca lactate) Ca sources, and a brandname Ca supplement. RB was assessed based on rats' femur Ca content and Ca absorption data. No differences of any physiological significance were observed in RB of Ca among the five sources tested. Compared to Ca carbonate (bioavailability arbitrarily set at 100%), RB of Ca in Ca sulfate was 105%, in Ca citrate 103%, in Ca lactate 102%, and in the Ca supplement 102%. This suggests that foods fortified with Ca carbonate or Ca sulfate, which are commonly used for this purpose, may be as good a source of utilizable Ca as more expensive Ca sources such as prescribed or nonprescribed Ca supplements.     

Increase in Bone Calcification in Young Rats Fed Breads Highly Fortified with Calcium

Breads were prepared with flour fortified with calcium (Ca) at four levels: 211 (U.S. enrichment standard), 446, 924, and 1,412 mg/100 g of flour. Corresponding diets prepared with these breads and fed to growing rats for four weeks provided 25 (diet A), 50 (diet B), 100 (diet C), and 150% (diet D) of their Ca requirement. After four weeks, the Ca content of the femurs of these rats had increased significantly as Ca in the diet increased up to 100% of requirement but not beyond. The increase in femur strength was significant only between diet A and diet B. Apparent Ca absorption increased as Ca in the diet increased, but Ca absorbed from diet D was not retained any better than that absorbed from diet C. Overall, the data suggested that Ca in highly fortified breads was well absorbed and retained, and that the rats' Ca status early in life was greatly improved. Flour fortified with Ca up to the 924-mg level (4.4× the mandated enrichment level) had no adverse effect on bread quality. These breads can be labeled a “good source of ” or “high in” Ca.     

Utilization of Calcium in Breads Highly Fortified with Calcium as Calcium Carbonate or as Dairy Calcium

White pan breads were prepared with flour highly fortified with calcium (Ca), using Ca carbonate (Ca, 38.8%) or a high Ca whey powder (Ca, 5.6%) as the Ca source; bread was also prepared using Ca carbonate plus lactose. Ca was added to flour at 924 mg/100 g of flour, a level 4.4 times higher than specified under the U.S. enrichment standards. Breads were dried and finely ground to prepare test diets (Ca, 0.5%) which were then fed to growing rats for four weeks (growth phase) or eight weeks (approaching maturity). At either interval, femur ash content, femur Ca content, femur strength, or Ca absorption values did not differ significantly among groups fed breads fortified either with Ca carbonate, Ca carbonate + lactose, or whey. Thus, breads can be highly fortified with Ca carbonate to be labeled as “high” in Ca, and this Ca may be as well absorbed and utilized as dairy Ca.     

Effect of Tristearin and Other Functional Fats on Blood Lipids in Hamsters

Groups of hamsters were fed diets containing tristearin (TS), a baker's shortening (BS), soybean oil (SO), a blend (BL) of TS and SO, or a hard fat (HF). Only BS contained trans fatty acids. After four weeks, serum total cholesterol (T-CH) levels were most elevated in hamsters fed HF. In comparison, hamsters fed BS, BL, or SO showed 13.3, 15.4, or 23.7% reduction in serum T-CH, respectively. Reduction in serum T-CH was even more pronounced in hamsters fed TS. However, this group also showed poor weight gains, apparently because only 16.2% of ingested TS was absorbed. Reduction in T-CH occurred due to reduction of both high-density-lipoprotein (HDL)-CH and non-HDL-CH, but the pattern of reductions still favored lower T-CH-to-HDL-CH ratios. Like T-CH, serum TG levels were also most elevated in hamsters fed HF, with other groups showing significant reductions. Liver CH responses did not conform to responses observed for serum CH and TG levels. Tested in selected baked products prepared in-house, blended fat (BL) was found as functional as regular BS, and it contained no trans fatty acids.