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Maitland, Australia

Tan S.H.,Eh Graham Center For Agricultural Innovation | Tan S.H.,Charles Sturt University | Tan S.H.,Industrial Transformation Training Center for Functional Grains | Mailer R.J.,NSW DPI | And 6 more authors.
Food Research International | Year: 2014

Gelling properties of canola albumin and globulin fractions, and canola protein isolate (CPI) were examined in this study. The effects of pH and salt concentration on canola protein gelling properties were studied primarily by means of dynamic oscillatory rheology and gel texture analysis. The findings were supported by confocal laser scanning microscopy (CLSM) images of the gels, isoelectric point, and solubility measurement data. All canola proteins showed typical heat-set gel protein profiles. Gels formed at higher pH had better gelling properties including higher overall resistance to deformation (G*), higher gel elasticity (low tan δ ), higher fracture stress and firmness, and denser gel microstructure. Isoelectric points of canola proteins used in this study were in the range of pH. 3.0-4.7 where low protein solubility was observed. The albumin fraction was able to form a very weak gel at pH. 4, whereas the globulin fraction and CPI precipitated due to loss of protein surface charge. The effects of NaCl on gelling were protein sample dependent. The presence of NaCl negatively affected gelling properties of albumin and globulin fractions, with decreases in overall resistance to deformation (G*), and fracture stress and firmness, but positively affected CPI gels in the same aspects. The elasticity (tan δ) of all canola protein gels remained constant in the presence of NaCl. Frequency sweep analysis revealed that the albumin fraction and CPI formed weak gels, whereas the globulin fraction formed a strong gel. Strain sweep analysis further confirmed that the globulin fraction formed a stronger gel with a critical strain of at least 10%. This study demonstrates the high potential of canola proteins, particularly the globulin fraction, as a prospective gelling agent. © 2014 Elsevier Ltd. Source

Tan S.H.,Eh Graham Center For Agricultural Innovation | Tan S.H.,Charles Sturt University | Mailer R.J.,NSW DPI | Blanchard C.L.,Eh Graham Center For Agricultural Innovation | And 3 more authors.
LWT - Food Science and Technology | Year: 2014

Canola protein albumin fraction, globulin fraction, and canola protein isolate (CPI) were compared to commercial soy protein isolate (SPI) in terms of their emulsifying properties at various pH values. The globulin fraction had higher emulsifying capacity (EC), higher emulsifying activity index (EAI), and the droplet size of emulsions it stabilized was consistently smaller irrespective of pH compared to albumin fraction or CPI. In comparison to SPI, globulin fractions also had higher EC at all pH values tested, higher EAI at acidic pH, and smaller or comparable average emulsion droplet size at both pH 4 and 7. The stability of canola protein based emulsions were comparable to those of SPI based emulsions at most pH values (except the emulsion stabilized by the CPI at pH 4), with no significant (p<0.05) changes in droplet size during storage for up to 7 days at room temperature. These emulsions, however, experienced separation into the emulsion and serum phases after 24h storage at room temperature with the exception of CPI- and SPI-stabilized emulsions at pH 9. This study demonstrates the comparable emulsifying properties (forming or stabilizing) of some canola proteins to commercially available SPI, suggesting the potential use of canola proteins in food applications. © 2014 Elsevier Ltd. Source

Hinch G.N.,University of New England of Australia | Hoad J.,University of New England of Australia | Lollback M.,Formerly NSW DPI | Hatcher S.,NSW DPI | And 4 more authors.
Animal Production Science | Year: 2013

This paper reports changes in livestock weights recorded in a whole-farmlet experiment, which aimed to examine the profitability and sustainability of three different pasture and grazing management strategies. The assessment of liveweights was considered a key component of measuring the integrated effects of the farmlet-scale treatments. The three farmlets comprised a typical management regime, which employed flexible rotational grazing over eight paddocks with moderate soil fertility (farmlet B), a system based on the same grazing management and paddock number but with higher levels of sown pasture and soil fertility (farmlet A) and a farmlet with moderate soil fertility and intensive rotational grazing over 37 paddocks (farmlet C). Early in the experimental period, there were no significant differences between farmlets in the liveweight of any class of livestock. However, from the second year onwards, as the pasture renovation, soil fertility and grazing management treatments took effect, differences in liveweight between farmlets became more apparent and significant. The stocking rate, which was treated as an emergent property of each farmlet, reached a maximum annual average value after 5 years of 12.6, 8.5 and 7.7 dry sheep equivalents (dse)/ha on farmlets A, B and C representing 84, 113 and 51% of their respective target stocking rates which were 15, 7.5 and 15 dse/ha. The liveweights of ewes, both before joining and during pregnancy, varied with year and farmlet with those on farmlets A and B tending to be significantly heavier than those on farmlet C. From 2003 to 2006, liveweights were significantly (P < 0.001) affected by a wide array of factors and their interactions including: date, ewe age, green digestible herbage, legume herbage mass, proportion of farmlet grazed, stocking rate and level of supplementary feeding. The weights of lambs/weaners/hoggets, both pre- and post-weaning, were at times also higher on farmlets A and B compared with those on farmlet C and were affected by a similar range of factors to those which affected ewe weights. Similar relative differences also applied to the liveweights of the other livestock run on the farmlets, namely wethers and non-reproductive cattle. The results suggest that stocking rate was able to be increased towards the higher target of farmlet A due to the higher level of pasture renovation and soil fertility on that farmlet, which led to high liveweights per head as well as the higher stocking rate. However, as the stocking rate increased on farmlet A, the differences between farmlets in liveweight per head diminished and the need for supplementary feeding increased. In contrast, the intensive rotational grazing practised on farmlet C did not allow the farmlet to increase its stocking rate towards its higher target. It appears that the higher proportion of each of farmlets A and B grazed at any one time allowed all classes of livestock to reach higher liveweights per head than on farmlet C, due presumably to the greater proportion of those two farmlets grazed at any one time. Source

Hinch G.N.,University of New England of Australia | Lollback M.,Formerly NSW DPI | Hatcher S.,NSW DPI | Hoad J.,University of New England of Australia | And 3 more authors.
Animal Production Science | Year: 2013

As part of the Cicerone Project's whole-farmlet experiment on the Northern Tablelands of New South Wales, Australia, the fat scores and reproductive performance of ewes were measured to assess the effect of different management systems on these important production parameters over time. The three farmlets (each of 53 ha) included one (farmlet B) subjected to 'typical' district management consisting of moderate levels of inputs and a target stocking rate of 7.5 dse/ha, with flexible grazing management across eight paddocks. A second farmlet (A) was managed in a similar fashion to farmlet B with respect to number of paddocks and grazing management, but modified by high rates of pasture renovation and higher levels of soil fertility, with a target stocking rate of 15 dse/ha. The third farmlet (C) was managed at the same level of moderate inputs as farmlet B but employed intensive rotational grazing over 37 paddocks and also had a high target stocking rate of 15 dse/ha. The experiment was conducted over 6.5 years from July 2000 to December 2006. In spite of the fact that target levels of stocking rate were chosen at the beginning of the experiment, stocking rate, together with fat scores and reproduction were treated as emergent properties of each farmlet system. Joining took place in April-May and lambing occurred in September-October of each year. Over the first 2 years of the experiment, there were few differences among farmlets in ewe fat scores or reproductive performance. From 2003 onwards, while the percentage of ewes pregnant was similar between farmlets, the average proportion of multiple births (ewes scanned in late July, with twins) was 30%, 16% and 12%, respectively, on farmlets A-C. However, lamb losses were greater on farmlet A, with average lamb mortalities recorded on farmlets A-C of 29%, 10% and 19%, respectively. Over the duration of the experiment, ewes on farmlets A and B were more often above a fat score level of 3, and less often below 2.5, than were ewes from farmlet C. Differences among farmlet ewes in fat score were found to be significant in 7 of the total of 13 assessments over the duration of the experiment. A generalised additive model applied to whole-farmlet data showed that green digestible herbage, legume herbage, stocking rate, the amount of supplement fed and especially the proportion of each farmlet grazed at any one time all influenced fat scores of ewes. While fat scores and conception rates tended to be highest on farmlet A, farmlet B had slightly better reproductive outcomes due to less lambing losses, whereas ewes on farmlet C tended to have somewhat lower fat scores and levels of reproduction. These farmlet-scale findings highlighted the importance for livestock managers to focus not only on grazing management, stocking rate and stock density during lambing, but also on the availability of sufficient green, and especially legume herbage, and the difficulty of overcoming a deficit in quality herbage with supplementation. Source

Scott J.M.,University of New England of Australia | Gaden C.A.,Beaumont | Edwards C.,NSW DPI | Paull D.R.,CSIRO | And 5 more authors.
Animal Production Science | Year: 2013

The Cicerone Project was a collaborative effort by livestock producers, researchers and extension specialists, which aimed to explore the profitability and sustainability of grazing enterprises on the Northern Tablelands of New South Wales, Australia. A major part of the Project was the creation of a moderate scale, unreplicated farmlet experiment. The process of selecting the farmlet treatments and the design of the experiment involved considerable negotiation over an extended period in order to achieve 'ownership' by all those involved. The farmlets were designed to compare a typical farmlet (B) as the control with a second farmlet (A), which received higher levels of pasture renovation and soil fertility, and a third (C), which employed intensive rotational grazing management with short graze and long rest periods. Management guidelines were developed for all soil, pasture, livestock and grazing management decisions on the three farmlets. Whole-farmlet data are presented for the pastures sown, fertiliser applied, supplement fed, the stocking rates attained and the pattern of graze and rest periods over the experimental period from July 2000 to December 2006. Over the first 4 years of the trial, pastures were renovated on 71% of farmlet A while 8% of each of farmlets B and C were renovated. The rates of fertiliser applied to the three farmlets varied according to soil test values and the different target values for soil phosphorus and sulfur. In the first year of the trial (2000-01), the annual average stocking rates on farmlets A, B and C were 9.5, 7.9 and 9.1 dry sheep eqivalents/ha, respectively, whereas by the fifth year (2005), the stocking rates were 11.2, 7.8 and 7.4 dry sheep equivalents/ha, respectively. This paper provides details of the general methods used in the farmlet trial, of relevance to a series of related papers which explore all aspects of the farmlet experiment and its findings. It also reports on the selection and definition of the farmlet treatments and describes how the guidelines evolved over the duration of the trial in response to the practical realities of conducting this complex, agroecosystem experiment. Source

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