Lipase-catalyzed modification of rice bran oil to incorporate capric acid

Capric acid (C10:0) was incorporated into rice bran oil with an immobilized lipase from Rhizomucor miehei as the biocatalyst. Effects of incubation time, substrate mole ratio, enzyme load, and water addition on mole percent incorporation of C10:0 were studied. Transesterification was performed in an organic solvent, hexane, and under solvent-free condition. Pancreatic lipase-catalyzed sn-2 positional analysis and tocopherol analysis were performed before and after enzymatic modification. Products were analyzed by gas-liquid chromatography (GLC) for fatty acid composition. After 24 h of incubation in hexane, there was an average of 26.5 +/- 1.8 mol % incorporation of C10:0 into rice bran oil. The solvent-free reaction produced an average of 24.5 +/- 3.7 mol % capric acid. In general, as the enzyme load, substrate mole ratio, and incubation time increased, the mole percent of capric acid incorporation also increased. Time course reaction indicated C10:0 incorporation increased up to 27.0 mol % at 72 h, for the reaction in hexane, and up to 29.6 mol % at 12 h, for the solvent-free reaction. The highest C10:0 incorporations (53.1 and 43.2 mol %) for the mole ratio experiment occurred at a mole ratio of 1:8 for solvent and solvent-free reactions, respectively. The highest C10:0 incorporation (27.9 mol %) for the reaction in hexane occurred at 10% enzyme load, and the highest incorporation (34.4 mol %) for the solvent-free reaction occurred at 20% enzyme load. Incorporation of C10:0 into rice bran oil declined with the addition of increasing amounts of water after reaching 30.3 mol % at 2% water addition in hexane, and in the solvent-free reaction after reaching 35.9 mol %.     

Rust infections of some Allium species: An assessment of germplasm for utilizable rust resistance

Summary Isolates of three species of rust (Puccinia allii, P. mixta and Uromyces ambiguus) were each inoculated onto a range of potential host plants, selected to include the major European crop Allium species together with the commoner wild species in the section Allium. Measurements of incubation period, lesion type, latent period and pustule quantity were made in a single environment. Each isolate was able to sporulate on a range of Allium species. There was evidence of specialisation to particular sections of the genus; all the leek isolates performed well on the majority of hosts in section Allium, whilst the chive isolate grew poorly on most members of that section. Exceptions to this are exemplified by A. fistulosum being attacked by all three rust species and A. sativum being attacked by both leek and chive isolates. A continuum of reaction types was found which, for the leek isolates, ranged from the low levels of quantitative resistance in leek cultivars, through higher quantitative levels within the A. ampeloprasum complex, to qualitative resistance in several interactions in non-host sections of Allium, where the pathogen was able to infect and form colonies of some size without sporulating.     

Typology of non-industrial private forest owners in Tasmania

The heterogeneous nature of non-industrial private forest (NIPF) owners and the challenge this heterogeneity presents for effective policy and program design and delivery is widely recognised. Understanding the socio-economic and motivational differences between various types of landowners will better equip policymakers and forest extension professionals to design policies and programs that efficiently promote private sector timber production and forest conservation outcomes. The purpose of this study was to develop a survey-based empirical typology of Tasmanian NIPF owners based on their stated objectives of forest ownership and to relate owner type to a range of observable property and owner characteristics as well as to timber harvesting and forest management behaviour. Using principal component analysis (PCA) followed by means cluster analysis, four distinct groups are identified: income and investment owners, non-timber output owners, agriculturalists, and multi-objective owners. Members of these groups are found to differ significantly in terms of their personal and property characteristics, as well as their timber harvesting and management behaviour. For example, members of the non-timber output owners, who are motivated solely by objectives related to the production and protection of the non-timber outputs of forests, have similar proportions of timber on their property, but are less likely to have harvested timber from their property, than all other groups.     

Effects of an advance of darkness on the ovulatory cycle of the hen

Hens maintained on 16 h light: 8 h darkness were subjected to an abrupt advance of darkness by between 4 and 13 h. When darkness was advanced so that it occurred less than 6 to 8 h after ovulation, the next expected preovulatory release of luteinising hormone (LH) and ovulation was usually delayed or blocked. This was associated with a reduction in the ability of injected ovine LH to stimulate the secretion of progesterone. When the advance meant that darkness occurred at more than 6 to 8 h after ovulation subsequent ovulations were advanced by as much as 5 h within a 3 d period. The hastening effect of an advance of darkness on follicular maturation was associated with an increased secretion of LH in response to injected progesterone. An advance of darkness by 4 or 7 h was associated with an earlier onset of the circadian increase in the secretion of corticosterone and changes in the tonic secretion of LH, notably a tendency for plasma concentrations of LH to increase during the first 4 to 5 h of advanced darkness, followed by a steep decline.