A novel bio-based thermosetting elastomer was prepared by the lipase-catalyzed polymerization of methyl ricinoleate with subsequent vulcanization. Some mechanical properties of the cured carbon black-filled polyricinoleate compounds were evaluated as a thermosetting elastomer. It was found that the carbon black-filled polyricinoleate compounds were readily cured by sulfur curatives to produce a thermosetting elastomer that formed a rubber-like sheet with a smooth and non-sticky surface. The curing behaviors and mechanical properties were dependent on both the molecular weight of the polyricinoleate and the amount of the sulfur curatives. Cured compounds consisting of polyricinoleate with a molecular weight of 100,800 showed good mechanical properties, such as a hardness of 48 A based on the durometer A measurements, a tensile strength at break of 6.91 MPa and an elongation at break of 350%.
Fresh oil was heated for 20 h at 180°C with amino acids or gluten. A powdered diet (AIN93G; no fat) was mixed with 7 wt% of fresh oil (control), or supernatants of the heated oils described above, and fed to male Wistar rats for 12 weeks. No gross symptoms attributable to the heated oils were observed, but the gluten group showed a slow body weight increase; a significant difference was found in the weight after age 21 weeks in spite of diet consumption comparable to that of the control group. The serum of the heated oil groups showed a tendency toward lower values on various hematological measures, especially triacylglycerol and free fatty acid and toward higher values on aspartate aminotransferase (AST) and alanine aminotransferese (ALT), than those of the control group. All the rats except one in the gluten group had the same level of AST as those of the control rats, while the amino acid group included four rats with AST over 100 IU/L, the highest value in the control group. The number of dark red patches found on the surface of the liver and histological evaluation also showed frequent damage to the livers of the amino acid group. The difference in toxicity between the two heated oils seems to be related to the molecular sizes of amino acids and gluten. Gluten or melanoidin produced during heating probably decreased or counteracted the cytotoxicity of thermally oxidized oil. It is expected that oil heated with gluten can be used as a safe and effective oil for humans on weight-reduction diets.
We previously proposed that oil heated with gluten was suitable for use as a safe oil for weight-loss dieting. In the present paper, the properties of the oil were improved, and the weight-loss effect was compared with that of heated oil. Fresh oil was heated for 10 h at 180°C with or without gluten and filtered using filter paper. A powdered diet (AIN93G; no fat) was mixed with 7 wt% of fresh oil (control) or filtrates of the heated oils described above, and the mixture was fed to male Wistar rats for 12 weeks. The gluten and heated oil groups showed no gross symptoms attributable to the experimental oils but had a slowed body weight increase; a significant difference was found in weight on and after 21 weeks of age as compared to rats consuming the control diet, and fecal excretion was increased as compared to the control group. Serum levels of triacylglycerol, phospholipids, cholesterol, and glucose of the gluten and heated oil groups were significantly lower than those of the control group. High aspartate aminotransferase (AST) levels occurred more frequently in the heated oil group than the gluten group. The number of rats with dark red patches on the surface of the liver, which are indicative of liver damage, was higher in the heated oil group. In conclusion, the weight-reducing effect of the oil heated with gluten was confirmed and improved by removing traces of heated gluten from the oil.
Potato starch is known to have a higher concentration of phosphate than other starches. The presence of phosphate groups in amylopectin results in resistance to digestion by amylase. Therefore, there is a possibility that potato starch is slowly digested, inducing a physiological effect similar to that of resistant starch and indigestible oligosaccharides. The amount of phosphate group in starch differs with potato cultivar. In the present study, we investigated the effects of gelatinized potato starch containing a high level of phosphorus on lipid metabolism in rats. For this purpose, we determined lipid levels in the serum and liver in rats fed two kinds of gelatinized potato starches with different phosphorus contents. Four groups of male Sprague-Dawley rats were fed a 60% sucrose diet (control) or one of three diets containing cornstarch (CS), Benimaru (BM) potato starch or Hokkaikogane (HK) potato starch. Fat pad weight was slightly decreased in the HK diet group compared with that in the other groups. Free fatty acids in serum were significantly lowered by dietary HK starch compared with control, and serum triglyceride in rats fed the HK diet was also decreased. In the BM and HK diet groups, triglyceride levels in the liver were decreased compared with that in the control and CS groups. As for hepatic total cholesterol level, there were no significant differences among three starch diet groups. Fecal bile acid excretion was greater in the two potato starch groups than in the control group. On the other hand, there were no significant differences in cecal short-chain fatty acid content or pH. Thus, we conclude that dietary gelatinized potato starch reduces free fatty acid and triglyceride in serum and hepatic triglyceride, but does not affect cecal fermentation.
The objective of this study was to assess the suppressive effects of 13 naturally occurring carotenoids on the adipocyte differentiation of 3T3-L1. The relationship between carotenoid structure and suppressive effects was also examined. Treatment with neoxanthin significantly reduced lipid accumulation, as well as glycerol-3-phosphate dehydrogenase activity. This suppressive effect on adipose cell differentiation was not observed in the other 12 carotenoids used in this study. Neoxanthin treatment also decreased expression of CCAAT/enhancer binding protein α (C/EBPα) and peroxisome proliferator-activated receptor γ (PPARγ) mRNAs. An examination of structure and function suggested that carotenoids containing an allene bond and an additional hydroxyl substituent on the side group may show suppressive effects on adipocyte differentiation in 3T3-L1 cells.
We evaluated the allergen inactivating effect of colloidal silica by performing enzyme-liked immunosorbent assay (ELISA) whose wells were coated with 150 ng/mL of Japanese cedar pollen allergen (Cry j 1) or mite allergen (Der f 2). The allergens were almost 100% inactivated by 100 μg/mL of colloidal silica having a particle size 5 nm, and the inactivating effect was increased by aluminum binding to the surface of the colloidal silica. The results show that colloidal silica is a promising material for allergen inactivation. Since colloidal silica forms an insoluble nondispersive solid when dried, it is expected that airborne allergens can be reduced by binding them to colloidal silica.
Sophorolipids (SLs) are glycolipid biosurfactants abundantly produced from different feedstocks by yeasts, and have been widely developed for various applications. In this study, we searched for novel SLs, aiming to broaden the functions and application range. As a result of screening based on the phylogenetic information of a known SL producer, we found that Candida batistae CBS 8550 produces new types of SLs. Interestingly, the present product mainly constituted acid-form SLs (more than 60% of the total SLs), considerably different from conventional SLs that mainly constitute lactone-form ones. In the shake-flask culture with glucose and olive oil as the carbon sources, the yeast produced 6 g/L of SLs after 3 days cultivation. The critical micelle concentrations of the present SL product and isolated acid-form SL (GL-A) were 366 and 138 mg/L, respectively, while those of conventional SLs and isolated acid-form SL were 17 and 95 mg/L, respectively. From these results, the phylogenetic approach should lead to the discovery of new biosurfactant producers, and the yeast product possessing high hydrophilicity may facilitate a broad range of applications for SLs.