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Maximum Resistance (maximum + resistance)
Selected AbstractsNumerical local analysis of relevant internal variables for constitutive modelling of granular materialsINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 11 2010Yuhanis Yunus Abstract DEM simulations on spherical materials have been performed to study the behaviour of model granular materials not only under monotonous stress path such as triaxial compression or extension, but also under two-way cycling loading paths. Three reference states have been considered to characterize the behaviour of the granular material: the characteristic state, transitory state between volumetric contraction and dilation, the state of maximum resistance and the critical state. These states are regarded with respect to void ratio and anisotropy of fabric which are the two internal variables retained for the description of the internal state of the material. The characteristic state and the state at maximum resistance are clearly dependent on both levels of density and anisotropy at the beginning of a loading path. Bilinear models involving the two internal variables were designed for the characteristic state, the maximum dilatancy and the extent of the dilatancy domain for axisymetric loadings. They show that in each case the effect of density and anisotropy are different in compression and extension. The influence of anisotropy and density seems to be of the same order of magnitude. Copyright © 2009 John Wiley & Sons, Ltd. [source] Classification of protein content and technological properties of eighteen wheat varieties grown in IranINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 2006Mohammad Ali Sahari Summary The best method for wheat planning and its food industrial usage is evaluation of its technological properties. Classification of protein content and some technological properties of eighteen important Iranian wheat cultivars were investigated. Statistical analysis revealed, highest protein content (11%), protein quality (SDS = 35.6 mL), hardness degree (63%), in Rooshan of Karaj (I), Zagroos of Ahvaz (K) and Marvdasht of Karaj (O) varieties, respectively. On the basis of the quality, the Zagross of Ahvaz (K), Zarrine of Aurumieh (L), Rooshan of Karaj (I), and Chamran of Ahvaz (D) varieties were recognized for their farinograph and extensograph characteristics (water absorption = 61,65%, dough development time = 2.3,5.3 min, dough stability to break down = 15,19.3 min, mixing tolerance index = 22.3,32.3 BU, valorimetry index = 55,64.3 Unit, maximum resistance to extension = 134,450 BU, dough energy = 11.3,100.3 cm2 and extensibility = 156,179 mm). The dendrogram was classified into four groups and in general, the wheat cultivar K was the most separated from the other cultivars, followed by L and I. [source] Quality changes in frozen and thawed, cooked puréed vegetables containing hydrocolloids, gums and dairy powdersINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 8 2002Gerard Downey Summary Freezing and thawing have been shown to adversely affect the centrifugal drip loss and maximum resistance to penetration of cooked, puréed vegetables (potatoes, carrots and turnips). Amelioration of these effects has been investigated through the addition of cryoprotectants (xanthan gum, guar gum, pectin, carrageenan, sodium caseinate, whey protein concentrate). The effect of each cryoprotectant varied with vegetable type. In general, gums (xanthan and guar) proved most effective in reducing drip losses although carrageenan and pectin exhibited some ability in this regard. Dairy powders produced no effect on drip loss but did alter maximum resistance values after thawing. Depending on the vegetable, quality maintenance or improvement after thawing may be achieved through selection of an appropriate cryoprotectant. [source] Occurrence of sublethal injury after pulsed electric fields depending on the micro-organism, the treatment medium ph and the intensity of the treatment investigatedJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2005D. García Abstract Aims:, The objective was to investigate the occurrence of sublethal injury after pulsed electric field (PEF) depending on the treatment time, the electric field strength and the pH of the treatment media in two Gram-positive (Bacillus subtilis ssp. niger, Listeria monocytogenes) and six Gram-negative (Escherichia coli, Escherichia coli O157:H7, Pseudomonas aeruginosa, Salmonella serotype Senftenberg 775W, Salmonella serotype Typhimurium, Yersinia enterocolitica) bacterial strains. Methods and Results:, A characteristic behaviour was observed for the Gram-positive and Gram-negative bacteria studied. Whereas Gram-positive bacteria showed a higher PEF resistance at pH 7·0, the Gram-negative were more resistant at pH 4·0. In these conditions, in which bacteria showed their maximum resistance, a large proportion of sublethally injured cells were detected. In most cases, the longer the treatment time and the higher the electric field applied, the greater the proportion of sublethally injured cells that were detected. No sublethal injury was detected when Gram-positive bacteria were treated at pH 4·0 and Gram-negative at pH 7·0. Conclusions:, Sublethal injury was detected after PEF so, bacterial inactivation by PEF is not an ,all or nothing' event. Significance and Impact of the Study:, This work could be useful for improving food preservation by PEF. [source] Inhibitory effect of phenolics extracted from sorghum genotypes on Aspergillus parasiticus (NRRL 2999) growth and aflatoxin productionJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 6 2007CV Ratnavathi Abstract The inhibitory activity of bioactive polyphenols present in six sorghum genotypes,two red (AON 486 and IS 620), two yellow (LPJ and IS 17779) and two white (SPV 86 and SPV 462) varieties,on Aspergillus parasiticus (NRRL 2999) growth and aflatoxin production was evaluated. In the first experiment the production of aflatoxins in the six sorghum genotypes after removal of surface phenolics by acidic methanol treatment was studied and compared with that in untreated grains. Aflatoxin production was found to be fourfold higher in treated grains. The total phenols and bioactive polyphenols extracted by acidic methanol were quantified using the Folin,Denis method and the bovine serum albumin,benzidine conjugate procedure respectively. In the second experiment the effect of extracted sorghum phenolics under in vitro conditions on fungal growth and aflatoxin production was studied at two concentrations (0.01% and 0.1%) of phenolics. Extracted phenolics added to yeast extract sucrose (YES) medium at 0.1% concentration showed an inhibitory effect on aflatoxin production. At 0.01% phenolic concentration, aflatoxin production was minimal on day 3 after infection. At other time points the aflatoxin content was similar to that in the control. At 9 days after infection the fungal biomass in IS 620 was significantly lower than that in the control. At 0.1% phenolic concentration, aflatoxin production was minimal and the red genotype IS 620 showed maximum resistance. Fungal biomass was lowest at all growth stages in IS 620 as compared with the control. Polyphenol oxidase (PPO) activity was not detected in A. parasiticus grown on YES medium (control). PPO activity was not induced in A. parasiticus by the addition of phenolics to the liquid culture medium (no PPO activity was detected in the culture medium). The inhibitory activity of bioactive polyphenols could be attributed to the lack of PPO enzyme in this fungus. Copyright © 2007 Society of Chemical Industry [source] | ||||||||||