The biobjective integer minimum cost flow problem—incorrectness of Sedeño-Noda and Gonzàlez-Martin's algorithm

In this paper, we show with a counterexample, that the method proposed by Sedeño-Noda and Gonzàlez-Martin for the biobjective integer minimum flow problem is not able to find all efficient integer points in objective space.     

Protecting oil during frying: A comparative study

The effect of carbon dioxide blanketing (CDB) and vacuum frying (VF) on the frying performance of regular canola oil was evaluated. For 7 h daily and for 7 days French fries were fried in regular canola oil at 185 ± 5 °C without and with CDB and in a vacuum fryer. The extent of changes in the oil was assessed by analysis of total polar compounds (TPC), anisidine value (AV), color component formation and changes in composition of fatty acids and tocopherols. Frying under CDB reduced the amount of TPC by 54%, while 76% reduction was observed during VF compared to standard frying conditions (SFC). Similarly, lower oxidative degradation was observed when measured by AV. At the end of the frying period, the reduction in unsaturated fatty acid content was 3.8, 1.9 and 12.7% when frying under CDB, vacuum and SFC, respectively. The rate of tocopherol degradation was three and twelve times slower in VF when compared to CDB and SFC, respectively.     

Antioxidant and radical-scavenging activities of buckwheat seed components

The search for endogenous components in food ingredients exhibiting antioxidant activity has been intensified in order to eliminate synthetic antioxidants. Tocopherols are widely used as natural antioxidants, although their protective ability is not always sufficient. Buckwheat seed components were evaluated for antioxidant and free radical-scavenging activities using solvents of different polarities to isolate components from hulls and groats. Components extracted from buckwheat hulls were pro-oxidant in canola oil. Antioxidant activity of extracts from buckwheat groats increased when more polar solvents were used for extraction. The highest activity was observed for the methanolic extract. Radical-scavenging activity of buckwheat extracts was analyzed with DPPH (2,2-diphenyl-2-picryl-hydrazyl). This activity increased when the more polar solvents were used for extraction, with the highest activity observed for the methanolic extract. It was also observed that the radical scavenging effectiveness of extracts was concentration dependent. Analysis revealed the presence of tocopherols in the hexane extract, while methanolic extracts were rich in phenolic acids and flavonoids.     

Novel caffeic acid amide antioxidants: Synthesis,radical scavenging activity and performance under storage and frying conditions

Twelve novel dihydro-caffeic acid amides were synthesised in good yields and fully characterised by ¹H NMR, ¹³C NMR, and MS. Their radical scavenging activities were assessed by DPPH assay. Additionally, their abilities to protect polyunsaturated oils under accelerated storage and frying conditions were evaluated. All the new compounds possessed significantly higher radical scavenging activities than α-tocopherol and butylated hydroxytoluene (BHT). The radical scavenging activity of N-decyl-N-(3,5-dimethoxy-4-hydroxybenzyl)-3-(3,4-dihydroxyphenyl) propanamide was 1.7 and 4 times higher than α-tocopherol and BHT, respectively. At the end of the storage period, the respective amounts of hydroperoxides in canola oil triacylglycerols (CTAG) fortified with α-tocopherol and BHT was 6.1 and 1.4 times higher, respectively, than CTAG containing the amide. The frying test showed that CTAG containing N-decyl-N-benzyl-3-(3,4-dihydroxybenzyl) propanamide was 1.3, 1.4, and 1.6 times more stable compared to oil fortified with dihydro-caffeic acid, α-tocopherol and BHT, respectively, as assessed by the amounts of the total polar compounds. Moreover, these compounds were remarkably thermally stable, making them suitable for frying applications.     

Phospholipid composition of canola oils during the early stages of processing as measured by TLC with flame lonization detector

Canola oils at initial stages of processing from different crushing plants were analyzed for phosphatides. The major phospholipid components identified and quantified in refined canola oils were phosphatidic acid and phos-phatidylinositol. Phosphatidic acid was the main phosphorus component identified in solvent extracted canola oil samples. The two-dimensional separation that was used combined classical thin-layer chromatography with quantitation on chromarods in an Iatroscan with a flame ionization detector. Phosphatides quantitated with this procedure ranged from 0.1 to 20 μg with a coefficient of variation of 4.4 to 7.2%. Using the modified procedure, recoveries of better than 90% were obtained for all phospholipids analyzed. Paper presented at the 50th Annual Meeting of the AOCS in Phoenix, Arizona, May 4-6, 1988.     

Influence of sulphidation on the metallic phase of an Fe94Si6 alloy

Using X-ray phase analysis and microanalysis, optical and scanning electron microscopy, and Mössbauer-effect spectroscopy, the influence of sulphidation on the metallic phase of an Fe₉₄Si₆ alloy is studied. It has been revealed that three distinct layers are formed: (a) the outermost one, called the outer scale, is composed of FeS; (b) the next one, called the inner scale, also contains iron sulphide; and (c) the one occurring on the metallic core is enriched in silicon and contains an admixture of DO₃ structure. A possible mechanism responsible for the enrichment and for the formation of the DO₃ structure is proposed.     

Thermal degradation of bridged polyaromatic sulphides investigated by direct pyrolysis in the mass spectrometer

The thermal degradation of three bridged polyaromatic sulphides (I–III) was investigated in the ion source of a mass spectrometer. The reactions were followed by detecting the thermal and electron impact induced fragments. The electron impact induced fragmentation reactions of the pyrolytic fragments are influenced by ortho-methyl substitution, and the mechanisms of these processes are discussed. The results indicate also that the disulphide bridge content in the methyl substituted polymers considerably lowers the thermal stability of these materials with respect to poly(phenylene sulphide).     

Manufacturing of resistant joints by rolling for light tubular structures

The idea of joining by rolling emerged as an alternative to existing joining and assembling methods for lightweight frame structures, offering flexibility in manufacturing, low costs and simplicity in handling. The present paper deals with research work on joining of nodes in tubular aluminium structures by external rolling accompanied by applying glue. Special attention was paid to the node resistance and material behaviour when rolling by means of a one-roller burnisher and a multi-roller burnishing head.     

Formation and partial characterization of canola oil sediment

The occasional development of a haze in canola oil represents a problem to the quality and acceptability of this oil. The present study examined the formation of sediment in bottled canola oil during storage at 2, 6 and 12°C over a 4-d period. Oils stored at 2°C showed the highest rate of sediment formation, followed by storage at 6°C. Removal of sediment from canola oil prior to storage by cold precipitation and filtration did not eliminate this phenomenon, which still developed rapidly at 2°C. Chemical composition and thermal properties of canola oil sediment were compared to sediment obtained from commercial winterization of this oil. The thermal properties of the purified winterization sediment (melting temperature, 74.9°C) closely resembled those of the sediment from bottled canola oil. Saponification of both sediments yielded large amounts of long-chain fatty acids and alcohols, which were identified by gas chromatography-mass spectrometry. Sediment from commercial winterization contained higher amounts of fatty acids and alcohols with more than 24 carbon atoms in the chain. Presented in part at the AOCS meeting in Toronto, Ontario, May 1992.