Promotional effects of new types of additives on fat crystallization.

We examined the promotional effects of additives on fat crystallization, such as inorganic (talc, carbon nanotube (CNT), and graphite) and organic (theobromine, ellagic acid dihydrate (EAD), and terephthalic acid) materials. The triacylglycerols (TAGs) of trilauroylglycerol (LLL), trimyristoylglycerol (MMM), and tripalmitoylglycerol (PPP) were employed as the fats. The additives (1 wt%) were added to the molten TAGs, and then the mixtures were cooled at a rate of 1°C/min followed by heating at a rate of 5°C/min. The crystallization and melting properties were observed using differential scanning calorimetry, X-ray diffraction, and polarized optical microscope (POM). Consequently, we found that the above six additives remarkably increased the initial temperatures of crystallization (Ti) on cooling without changing the melting temperatures. For example, in the case of LLL, the increases in Ti were 2.6°C (talc), 3.9°C (CNT), 8.1°C (graphite), 1.1°C (theobromine), 2.0°C (EAD), and 6.8°C (terephthalic acid). Very similar effects were observed for the crystallization of MMM and PPP with the six additives. Furthermore, the polymorphs of the first occurring crystals were changed from metastable to more stable forms by many of these additives. The POM observation revealed that the crystallization was initiated at the surfaces of additive particles. This study has shown for the first time that the heterogeneous nucleation of fat crystals can be greatly promoted by new types of additives. Such additives have great potential to promote fat crystallization by not only hydrophobic but also hydrophilic molecular interactions between the fats and additives.

Consumption of a structured triacylglycerol containing behenic and oleic acids increases fecal fat excretion in humans.

We examined the fecal fat excretion of mildly hypertriacylglycerolemic subjects who ingested soft cookies containing 1(3)-behenoyl-2,3(1)-dioleoyl-rac-glycerol (BOO) for 7 days. The subjects included 14 healthy men (average age; 44.9 ± 1.7) whose fasting plasma triacylglycerol level ranged from 150 to 250 mg/dL. Every day for 7 days, the subjects ate 5 soft cookies containing margarine with the BOO-rich experimental oil (BOO intake, 2.46 g/day). The placebo group ate soft cookies containing margarine without BOO. This study was a randomized double-blind, placebo-controlled, crossover study. Feces were collected for 3 days prior to the end of the treatment period, and fecal fat and fatty acid composition were determined. The fecal wet weight was significantly increased in BOO group compared with that in the placebo group. Moreover, fecal fat and fatty acid level were significantly higher in the BOO group than in the placebo group. There were no significant differences in the fecal fatty acid composition of the BOO and placebo groups. These results suggest that dietary BOO increases fecal excretion of dietary fat in humans. However, BOO does not increase the excretion of specific fatty acids; it increases the excretion of all fatty acids of dietary origin, which may lead to lower and delay intestinal absorption of dietary fat.

The mechanism of weight-loss promoting effects of oil heated with vegetable protein.

We have previously reported that a soy oil-containing experimental diet (fat-free AIN93G containing oil thermally processed with soybean protein followed by filtration), inhibited body weight increases without any adverse effects when given ad libitum to male Wistar rats for 12 weeks. In the present paper, the mechanism of weight-loss promoting effects was investigated. Fasted 10-week-old rats were fed a slurry composed of AIN93G (fat-free), Cr(2)O(3) (marker), water, and 7 wt% soy oil or fresh oil (control) and sacrificed at 20, 60, 90, 120, 150, 210, 270 or 360 min. The stomach, small intestine, cecum, colon and feces were then collected to determine the distribution of the slurry in the digestive tract. The results indicated that the content was transferred faster from stomach to small intestine in the soy oil group than in the control group. Fecal excretion (derived from a commercial standard diet ingested before slurry administration) in the soy oil group was significantly higher than in the control group. Digestive enzyme activities, lipase, sucrose, and maltose, were not inhibited by soy oil. In addition, feces collected in the 12-week feeding experiment were more in the dry weight and contained higher levels of nitrogen and water in the soy oil group than in the control group, revealing that an increased amount of nutrition was continuously excreted in the former group. The above-described findings suggest that soy oil stimulated peristalsis of the gastrointestinal tract and that colon contents are actively excreted, resulting in safe and steady body weight decreases.

A novel body weight-loss promoting oil prepared with vegetable protein.

It has been reported that oil thermally processed with wheat gluten (gluten oil) exhibited safe weight-loss promoting effects in animal experiments. However, as the oil has a high color index, and its chemical properties and smell differ from those of fresh oil, it is uncertain if the oil will find market acceptance. In order to resolve the issue, frying oil was heated with soybean protein under reduced pressure (soybean protein oil), resulting in a product with an appearance, chemical properties and smell comparable to those of fresh oil. This improved oil was mixed (7 wt%) with powdered AIN93G no fat, defined standard diet and fed to 10-week-old Wistar rats ad libitum. The experimental rats grew normally, ingesting the same amount as that of the control rats; however, there was a negative correlation between body weight increases and fecal weight increases. After the 12-week feeding period, all the rats were sacrificed to obtain blood and organs. In the experimental group, liver weight, retroperitoneal fat tissue weight and serum triacylglycerol (TG) levels decreased significantly. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and histological analysis supported the safety of the improved oil. In conclusion, it was found that soybean protein oil inhibited body weight increases without any adverse effects in animal experiments. The oil holds promise as a novel dieting oil that steadily decreases body weight at an appropriate rate.

Role of vegetable protein in the preparation of weight loss-promoting oil.

We have reported that oil thermally processed with protein promoted safe and steady weight loss in animal experiments. In the present study, an oil for use in weight control was prepared by heating fresh oil with wheat gluten or soybean protein to determine the influence of protein differences on the weight loss-promotion effect. The 2 kinds of oil obtained, which differed neither from commercial fresh oil (starting oil) nor from one another in appearance, chemical properties, and aroma, were mixed (7%) with powdered AIN93G no-fat, defined standard diet and fed to 10-week-old Wistar rats ad libitum. After a 12-week feeding period, the rats were sacrificed to obtain blood and organs. There were no differences in amounts ingested, body weight increases, fecal excretion, organ weights, serum biochemical analyses, contents and fatty acid compositions of lipids of retroperitoneal fat tissue, or organ observations. Aspartate aminotransferase (AST), alanine aminotransferase (AST), and histological analysis supported the safety of the oil. In conclusion, the differences between wheat gluten and soybean protein in amino acid composition, both of the proteins and as free amino acids, were unrelated to the weight loss-promoting effect of the oil. Minor components in the vegetable proteins may have contributed to the effect on body weight.