Comparison of chemical and sensory methods of evaluating thermally oxidised groundnut oil

Seven chemical methods, namely peroxide value (PV), totox value (TV), anisidine value (AV), conjugable oxidation products (COP), oxodiene value (OV), induction period (IP), iodine value (IV) and a sensory analytical procedure (flavour score, FS) have been used in evaluating the oxidation state of groundnut oil heated at 100°C for varying lengths of time up to 20 h. As oxidation progressed, PV, TV, AV, COP and OV increased. IP and IV decreased with oxidation while FS showed a progressive deterioration on a seven-point scale from bland to very rancid. On the basis of sensitivity to oxidative changes, five of the methods (PV, TV, IP, IV and FS) were found to be satisfactory. However, the best correlation with flavour scores were obtained in the case of IP, IV and OV while AV and COP correlated poorly with FS. Three methods (PV, IP and IV) best satisfied the combined criteria of sensitivity to oxidative changes and correlation with flavour.     

Water-soluble polymers as retention aids in a model papermaking system. IV. Some block and graft copolymers

In an attempt to relate the retention behavior of water-soluble polymers in paper formation from cellulose fibers and titanium dioxide, several copolymer types were synthesized. These were acrylamide–acrylonitrile random copolymers; block copolymers of acrylamide, acrylonitrile, and 2-vinylpyridine with poly(ethylene oxide); and acrylamide graft copolymers of ethyl hydroxyethyl cellulose. Good retention and heteroflocculation behavior is shown only by the first of the above types of copolymers. Generally speaking, block copolymeric structures synthesized were of molecular size too small to act as good retention aids, although in a number of cases their performance was noticeably superior to that of the homopolymer analog. Adsorption isotherms are also reported and the overall results discussed in terms of a polymer bridging mechanism of heteroflocculation.     

Phosphatidyl ethanolamine as a synergist for primary antioxidants in edible oils

Dipalmitoyl phosphatidyl ethanolamine (DPE) is a potent synergist for a wide range of primary antioxidants in edible oils at elevated temperature, i.e., above 80 C. At lower temperatures it has very little synergistic action. At 120 C the synergistic effect increases progressively as the concentration of synergist increases from 0.025% to 0.25%. At a given level of synergist, its effect is proportionately greater at low rather than high levels of primary antioxidant.     

Effects of nimodipine on acute cerebral ischemia and reperfusion injury of rats

AIM: To study the effect of nimodipine (Nim) on ischemic cerebral damage. METHODS: The four-vessel occlusion method was performed on rats. Monoamines were measured by fluorospectrophotometry. RESULTS: Intraperitoneal injection of Nim 0.75 and 1.5 mg.kg-1 quickened the recovery of EEG changes to 19 +/- 3 and 17 +/- 4 min (P < 0.01), respectively. Nim reduced the decreases of monoamines (NE, DA, 5-HT, and 5-HIAA) contents after 30-min cerebral ischemia and 1-h reperfusion. CONCLUSION: Nim protects the brain from ischemic damage.     

Dipolar heat capacity of CMN

The magnetic contribution to the low-temperature specific heat of cerous magnesium nitrate (CMN) was determined by the Casimir-Du Pré ac susceptibility method in the region of 1 K. The value found for the coefficient of the major (T ^?2) term is in good agreement with that determined in this laboratory in magnetic cooling experiments. It is some 10% less than that calculated for the magnetic dipole interaction between the Ce ³⁺ ions.     

Observation of a partially-ordered void lattice in aluminium irradiated with 400 keV Al+ ions

Transmission electron microscopy observations of voids formed in aluminium during irradiation at 50°C and 75°C with 400 keV Al⁺ ions, have shown that partially-ordered void arrays are often present. These arrays occur in high-purity annealed aluminium, which has been implanted with 10^?4 atom/atom helium before ion irradiation. The void concentration is found to be $\text{～3 × 10}{}^{16}\text{/ cm}{}^3$, and the void lattice parameter ～ 700 Å. The ratio of void lattice parameter to void radius is ～ 12. Ordered void lattices have been observed frequently in irradiated body-centred cubic metals but the only previous observation for a face-centred cubic metal was in nickel. Theoretical predictions of void lattices in metals are discussed and related to the observations reported herein.     

Lipid stabilisation in leaf protein concentrates from ryegrass

The lipids of leaf protein concentrate show a high degree of resistance to autoxidation. Oxygen absorption studies show that very long induction periods operate for various lipid fractions. A close relationship exists between oxidative attack on α-linolenic acid and induction period, except when a more readily oxidised component, e.g. carotenoid, is also present, when the induction period corresponds to the degradation of such a component in preference to that of α-linolenic acid. The explanation for the unexpected stability of the lipids from leaf protein concentrate is believed to lie in the presence of very potent antioxidants whose nature remains to be elucidated.     

INSTITUTE OF BREWING HOPS ADVISORY COMMITTEE ANALYSIS OF HOPS OF THE 1972 CROP

Analytical values for 14 varieties of hops from the 1972 crop are presented in relation to the district of production. The tendency noted in 1971 for the variation within growths to diminish was continued in 1972. It was found that for Keyworth's Mid-season a sampling rate of 1 in 20 would be acceptable for commercial purposes.