ascorbic-acid and propionaldehyde

During the microencapsulation process, the fish oil undergoes multiple changes in its physical properties such as bulkiness and dispersibility in aqueous phase and dry matrix. Autoxidation already occurred in the first stages of the microencapsulation process itself during emulsification and spray-drying. An efficient stabilization was achieved using a ternary combination of lipophilic antioxidants, synergistic compounds and a trace metal chelator, e.g. a combination of tocopherols, rich in the δ-derivative and low in the α-derivative, with ascorbyl palmitate and lecithin. Trace metal chelation by, e.g. Citrem or lecithin in combination with ascorbyl palmitate proved to be of particular importance in the emulsion, but not during the storage of the microencapsulated oil. In the microencapsulated oil, the addition of rosemary extract rich in carnosic acid to ternary blends of tocopherols, ascorbyl palmitate and lecithin or Citrem significantly retarded autoxidation.

Topics: Abietanes; Aldehydes; Antioxidants; Ascorbic Acid; Chelating Agents; Drug Compounding; Emulsions; Fatty Acids, Unsaturated; Fish Oils; Food Handling; Hydrogen Peroxide; Lecithins; Oils, Volatile; Oxidation-Reduction; Plant Extracts; Rosmarinus; Tocopherols

A new interface coupled to a mass spectrometer was developed for the direct analysis of volatile organic compounds from small volumes of aqueous samples, including blood or tissue homogenates (St-Germain et al. 1995, Anal. Chem. 67:4536-4541). The greatest advantages of our system are minimal sample treatment, an instantaneous response time coupled with detection limits in the range of < 1 ppb for most compounds. For the analysis of low-molecular weight aldehydes, such as formaldehyde, acetaldehyde, propanal, and hexanal, lower detection limits were obtained when samples were converted to methoxime derivatives prior to injection. The detection limit for hexanal in water or Krebs-Ringer solution was 0.01 microM (10 pmol injected). The reproducibility of replicate injections was 4.4%. The usefulness of our system was illustrated by measuring aldehyde accumulation in peroxidized solutions of polyunsaturated fatty acids and rat tissue homogenates. Data confirmed that peroxidation of omega-3 fatty acids produces propanal, whereas omega-6 fatty acids form hexanal. Peroxidation of heart and brain homogenates formed predominantly propanal. However, the recovery of hexanal after sample treatment with methoxylamine depended on the derivatization time and temperature, suggesting that this aldehyde may form Schiff base linkages. These results show that spray extraction coupled to mass spectrometry provides a quick (< 1 min), clean and reproducible way to detect aldehydes produced from lipid peroxidation in aqueous samples.

Topics: Aldehydes; Animals; Ascorbic Acid; Body Fluids; Butylated Hydroxytoluene; Deferoxamine; Fatty Acids, Unsaturated; Hydroxylamines; Iron; Lipid Peroxidation; Mass Spectrometry; Myocardium; Rats

Protein phosphatase activity associated with neurofilament (NF) rich (Triton X-100 insoluble) fraction was extracted and partially characterised by using known inhibitors of protein phosphatases such as vanadate and fluoride. Protein phosphatase activity was demonstrated with reference to the dephosphorylation of endogenous substrate, NF protein and exogenous protein substrates, casein and phosvitin. Phosphoamino acids and beta-glycerophosphate were found to be poor substrates. Further, new observations have been made regarding the in vitro inhibitory effect of aluminium and the differential effects of some of the neuropsychoactive drugs. The findings could possibly lead to studies explaining the biochemical basis of aluminium induced neurotoxicity as well as the side effects associated with the long term medication of neuropsychoactive drugs.

Topics: Acetaldehyde; Aldehydes; Aluminum; Aluminum Chloride; Aluminum Compounds; Animals; Ascorbic Acid; Cations; Cattle; Chlorides; Ditiocarb; Fluorides; Glutathione; Nerve Tissue Proteins; Neurofilament Proteins; Phosphoprotein Phosphatases; Phosphoproteins; Phosphorylation; Psychotropic Drugs; Spinal Cord; Substrate Specificity; Vanadates