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News Article
Site: http://phys.org/biology-news/

PhD student in UQ's School of Agriculture and Food Science (SAFS) Alyce Swinbourne is tickling the rumps of sleepy female southern hairy-nosed wombats as a prelude to collecting their wombat wee into a tiny frypan. "People need to go when they wake up, and so do wombats," Alyce said. "This study uses knowledge of wombats' natural behaviour to collect urine samples in a non-invasive way with little stress to them. I simply pull out the frypan by the handle when they're finished." Alyce's classical conditioning methods have enabled her to collect close to 2500 urine samples —an approach believed to have never before attempted in a marsupial. The research has a serious purpose. Wombats have proved a notoriously difficult species for which to develop assisted breeding techniques (artificial insemination) in captive management. While she is working with the southern species, found widely in southern Australia, she hopes the work ultimately will assist in developing breeding programs to conserve their northern cousins—among the rarest land animals in the world. There are only 200 known northern hairy-nosed wombats in the wild, most at Epping Forest National Park near Clermont, Central Queensland. Floods in 2001 led to the translocation of a smaller "insurance" population in case of further natural disasters at the first site. "If we want to ensure their future, we need to develop assisted reproductive technologies to help in their recovery in reserve areas in the wild and this is where the scientific development of breeding programs comes in, based on better understanding of the animals' biology," she said. Alyce has worked with wombats over two breeding seasons at Safe Haven - AACE (Australian Animals Care and Education) sanctuary for Australian wildlife in Mt Larcom, Central Queensland. Associate Professor Steve Johnston and Dr Tamara Keeley of UQ's SAFS are supervising her research, and samples are being analysed at the Wildlife Endocrinology Laboratory at UQ's Gatton campus. Alyce is working with Dr Keeley and Associate Professor Johnston to develop new diagnostic techniques to analyse reproductive hormones. She is also observing wombat behaviour using infrared cameras, for six hours a day, for up to nine months, to gain a better understanding of the breeding behaviour. Professor Clive Phillips, Director of UQ's Centre for Welfare and Ethics is also providing expert advice. "I hope that the skills developed in this project will be transferable to other Australian marsupial species, such as koalas and gliders," Alyce said. Now living in Adelaide where her husband, Mike, is also undertaking a PhD, Alyce said she had had "a ball" during her studies, although it was financially quite challenging. During her studies she has been a finalist in UQ's Three Minute Thesis competition, attended a Reproduction conference in South Australia, a wildlife conference in Hobart and was awarded a SAFS Travel Scholarship to present her findings in Germany in August, 2016.


Recent research from Aarhus University demonstrates that a relation exists between changes in wild rocket quality and the build-up of the so-called volatile organic compounds (VOCs). VOCs develop according to the raw material quality at the time of packing, the O2 permeability of the packaging material, storage temperature and storage time. The results are achieved by means of a new analytical method developed by Research Assistant Alexandru Luca from the Department of Food Science at Aarhus University in his recently finished PhD project. "To evaluate the quality of packaged wild rocket it is not sufficient just to evaluate colour - you also have to evaluate odour and whether leaves are rotten, which is almost impossible without opening the packaging material," says Alexandru Luca, who further explains that there was a need to develop a method to identify if packaged wild rocket was rotten. Thus, the superior project aim was to develop a method to examine quality changes in packaged leafy green vegetables after harvest - based on the release of VOCs. The actual analytical method which is based on solid-phase microextraction and gas chromatography coupled with mass spectrometry is complex and time-consuming. The method was applied to examine the changes in the VOCs of various wild rocket qualities stored at different temperatures and O2 and CO2 concentrations. Further, Alexandru Luca examined the causes for the emission of the different volatile compounds: "The project demonstrates that the release of VOCs from wild rocket may be related to the quality of the raw material at the time of packing, the O2 permeability of the packaging material and the storage temperature and time after harvest. This knowledge may be used by the industry and scientists to develop new management and packing systems for leafy green vegetables," says Alexandru Luca and he further explains that there is a need to further develop the method before it is ready for commercial use. In the long term perspective we hope that the method will be used by companies that produce and manage packaged fresh fruit and vegetables in the supply chain, e.g. seed companies, producers, packaging companies, transporters and retailers, thus providing consumers higher quality packaged fresh produce.


News Article
Site: http://phys.org/biology-news/

Don't worry: it's all on the up-and-up. Dr. MacIntosh, from the Department of Process Engineering and Applied Science, has been answering media calls from around the world after helping test a long-lost bottle of Alexander Keith's beer discovered at the bottom of Halifax's Northwest Arm this fall. The unopened bottle dates back to the 1800s. "It was far more attention than I expected" says Dr. MacIntosh. "For some reason this is a story that has really taken off. We've been in contact with Canadian Press, this morning we chatted with Global News on their breakfast show and [the Discovery Channel TV show] Daily Planet will be airing their segment [in an upcoming episode]." The Daily Planet visit, which happened while the tests were taking place, was particularly exciting for Dr. MacIntosh, as he grew up watching the show when it used to be called Discovery CA. "It was quite a pleasure to move from them inspiring me as a kid to working with them now." Amateur scuba diver John Crouse found the bottle in late November last year, near the Northwest Arm's Dingle, buried in the mud under several meters of water. The bottle's markings suggest it dates sometime between 1872 and 1890, with ink preserved on the cork indicating it as a product of "A. Keith's Brewers." The discovery was covered in local news outlets, which is where Dr. MacIntosh heard about it. "I thought to myself that it would be a fun opportunity to test that," he recalls. Another person who noticed the news coverage was Christopher Reynolds of Halifax's Stillwell Beer Bar. He approached Crouse and, together, decided to get the bottle's contents tested. "They contacted Propeller [Brewery]," says Dr. MacIntosh, "and their QA manager Jessica Forbes is a former student of ours: she went through our Food Science program, and she completed research in the brewing field under Dr. Alex Spears. So she was familiar with the lab and what we are capable of doing so she pointed Chris in our direction." A professor of chemical engineering and food science, Dr. MacIntosh says the two fields are very closely related. "I specifically study fermentation which takes many forms," he explains. "[There's] pharmaceutical fermentation, when you are trying to create an antibiotic. We do bio algae fermentation to try to make biofuels and, of course, production of food products such as beers, ciders and eventually spirits." Dr. MacIntosh says the department does "a lot of work with the local brewing market to try and advance their technology" and that their connections to the Canadian Institute of Fermentation Technology (CIFT) help make that happen. Dr. MacIntosh teaches a class called Advanced Brewing Science, which is mostly taken as an elective for Chemical Engineering students. It's a class that's well-aligned with the rising popularity of craft brewing. "The students coming into that course are now more educated than they have been previously about the many different styles, the many different techniques that are used in brewing and that has helped to offer a much more involved course," says Dr. MacIntosh. "It's really a fun course to teach." Many of the students are able to take what they've learned into careers in brewing. Dr. MacIntosh says he knows of students working at Olands, Propeller, a brewery in England and one student at a brewing research station in the United States. "It's quite exciting to maintain connections with students who proceed into this field and see how it's being done elsewhere in the world. One of our professors, Alex Spears, is on leave from Dalhousie but he's now acting as the chair of the Institute of Brewing and Distilling in Scotland. So we're really able to collaborate with people all around the world." Dr. MacIntosh is looking forward to the science that will come from testing the contents of the discovered bottle. "All of the chemicals that make up the beer, whether it's skunky or buttery, all of those have a peculiar chemical that contributes to that flavor. We can identify those, quantify those and it will give us some clues about the raw materials that were used in the production of that beer. They are set up to do that in Scotland with Dr. Spears, so we've taken a sample that we'll be sending to him that's leaving tomorrow [Friday] and between our two analyses we'll be able to paint a complete picture of that beer which we plan to publish." Which begs the question: did Dr. MacIntosh get the chance to taste the 130-year-old brew? "At the end [of the testing] we had a couple of millilitres left that couldn't go back into the bottle. It tasted terrible. Beer does not age like wine. Don't go drinking random bottles you find in the harbour." Explore further: Scientists to study one of world's oldest beers


News Article
Site: http://phys.org/chemistry-news/

"There is still a lot we don't know about the structure of food, but this is a good step on the way to understanding and finding solutions to a number of problems dealing with food consistency, and which cost the food industry a lot of money," says Associate Professor Jens Risbo, Department of Food Science at the University of Copenhagen, Denmark. He is one of the authors of a recently-published scientific paper in Food Structure, which deals with the new groundbreaking insight into the 3D structure of food. The researchers used a cream based on vegetable fat for the research. The cream system is a good test material, since it can represent the structures of a large group of food systems, for example cheese, yogurt, ice cream, spreads, but also the more solid chocolate. All the aforementioned products contain liquid water or fat as well as small particles of solid materials, which stick together and form three-dimensional structures - i.e. a network that provides the consistency that we like about cheese, yogurt or chocolate. In cheese and yoghurt the casein particles form the network. In chocolate it is the fat crystals and in ice cream and whipped cream it is the fat globules. "If you understand the structure, you can change it and obtain exactly the texture you want," says Jens Risbo. Electrons with close to speed of light generate intense X-rays To create a three-dimensional model of the food and convert it into images and video, the scientists have been in Switzerland, where they have used the Swiss Light Source (SLS) synchrotron at the Paul Scherrer Institute. In the synchrotron electrons are accelerated to near speed of light. The synchrotron is used for research in materials science in areas such as biology and chemistry. The method the researchers used is called "Ptychographic X-ray computed tomography." This is a new method for creating images on the nanometer scale, which also provides a high contrast in biological systems. The synchrotron in Switzerland is one of the leading places in the world in this area, and it was the first time ever that it was used within food science. "We have been using the tomography principle, also known from an X-ray CT (computed tomography) scanner. The sample of the food system is rotated and moved sideways back and forth with nanometer precision, while we send a very strong and focused X-ray beam through it. The X-rays are deflected by colliding with electrons in the food, and we shoot a lot of pictures of the patterns that the defleted X-rays form. The patterns are combined in a powerful computer, which reconstructs a 3D image of the sample. The Swiss scientists of the team have created a device that can move and rotate the sample with ultra-high precision, allowing us to see the small details," says Research Assistant Mikkel Schou Nielsen, who has recently completed his Ph.D. in tomographic methods applied to food at the Niels Bohr Institute in Copenhagen. The number of electrons reveals the various food components The reconstructed 3D image can be described as a three-dimensional table of numbers describing the electron density (the number of electrons per volume) through the entire sample. The various food components, such as water and fat, have different densities and hence different electron density. Water is heavier than fat, which is known from oil that settles on top of water when you try to mix them, and it is this contrast in electron density which causes X-rays to deflect to different degrees and eventually to form 3D-images of the sample. Figure 1 shows a 2D slice of the three dimensional structure. Areas with higher electron density appear lighter on the figure. Water thus appears light grey, while fat appears dark grey, and the glass around the sample with a high density is seen as a white ring. One may now use the electron density (greyscale) to identify the various food components and study their location and structure. The vegetable-based cream which the method is used on consists of several ingredients. In addition to water and vegetable fat, it contains milk protein, stabilizers and emulsifiers. By adjusting the addition of emulsifiers, it is possible to achieve a state in which the cream continues to be fluid until you whip it to foam, whereby all the fat globules are reorganized and sticking together on the outside of the air bubbles in a three-dimensional system (see Figure 2). "It is a difficult balance, because you only want the fat globules to stick together when the cream is whipped - not if it is simply being exposed to vibration or high temperatures. When the fat globules nevertheless begin to stick together prematurely - for example due to too many shocks during transport - the cream will get a consistency reminiscent of cream cheese. It becomes a relatively hard lump that can be cut," says Postdoctoral Researcher Merete Boegelund Munk, Department of Food Science, University of Copenhagen. Merete Boegelund Munk's Ph.D. project, "The physical stability of whippable oil-in-water emulsions. Effects of monoglyceride-based emulsifiers and other ingredients", was fundamental for the research. The Ph.D. project was made as a collaboration between the Department of Food Science at the University of Copenhagen and the food ingredient company Palsgaard A / S. This undesirable cream cheese-like state of the vegetable cream system is nevertheless extremely interesting for researchers. "The organization of the fat globules and the network structure after the cream has been converted into a 'cream cheese-like' product is exciting because the mass is now sliceable, even though the system consists of 65% water and only 25% fat and some other ingredients and sugars. That means we have a network structure that captures a lot of water. There are many foods with similar network systems of something solid in something liquid, where the liquid is typically, but not always, water. This applies to all semi-solid and solid products such as chocolate, butter, cheese and spreads. The network of the cream cheese-like system is thus a model for something general in our food," says Associate Professor Jens Risbo, Department of Food Science, University of Copenhagen. It is the structure of the networks which forms a texture that makes you want to bite into a piece of chocolate and cut yourself a piece of cheese. But the structure and the networks are something of a mystery, because until now you could only see the surface and slightly underneath the surface of the food material on the microns scale and the images you could see have only been two-dimensional. "If we eventually come to understand the structure of chocolate, we can change it and obtain exactly the consistency that we want. A lot of money is wasted because the consistency of chocolate is really hard to control, so the end product is not good enough and must be discarded. A possible future understanding of the crystal network in chocolate might mean that we will be able to develop components that prevent the chocolate from becoming grey and crumbly, and thus unsaleable. It is certainly a possibility that tomographic methods could be developed so we would be able to understand the mysteries of chocolate," says Associate Professor, Jens Risbo, Department of Food Science, University of Copenhagen. "Ptychographic X-ray computed tomography can be compared with a CT scanner in a hospital. Instead of getting an image of a patient's organs, we are looking into food. But, unlike a CT scanner, we can go down to the nanometer scale," says Jens Risbo. The sample with the cream cheese-like system that the scientists X-rayed was about 20 microns thick. "It would take too much time and too many calculations to develop a nanometer resolution of the cream system for a whole package of cream cheese from the fridge. The amount of information and calculations would simply be too great. Although X-rays can almost go through everything, you lose the intensity of the beams, the more they have to shoot through," says Jens Risbo. Basically, you can make X-rays in two different ways. If you go to the dentist and have an X-ray done, this is done using an X-ray tube, which can be compared with a cathode ray tube showing the pictures in an old type of television, where electrons are not accelerated to very high speeds. In the X-ray tube the electrons collide with a metal, such as copper, which now emits X-rays. The X-ray tube is not so powerful, but you can make medical photos and also do some research work with this type of X-rays. But if you want to examine very small samples, things that are changing rapidly, or make tomography at the nanometer scale, you will use facilities like Swiss Light Source or the Swedish synchrotron MAX IV which opens in Lund, Sweden, this year. "Technically, it is electrons that are accelerated to nearly the speed of light and circulates in a ring controlled by electromagnets. The electron beams are then deflected and will then emit intense and energetic X-rays," says Associate Professor Jens Risbo, Department of Food Science, University of Copenhagen. The Swiss Light Source, SLS, is funded by the Swiss government and scientists from around the world can apply to use syncroton X-rays and related scientific equipment under the guidance of local scientists. Explore further: Ice cream goes Southern, okra extracts may increase shelf-life More information: Mikkel Schou Nielsen et al. Ptychographic X-ray computed tomography of extended colloidal networks in food emulsions, Food Structure (2016). DOI: 10.1016/j.foostr.2016.01.001


News Article | December 17, 2015
Site: http://phys.org/chemistry-news/

The passion fruit is used around the world in juices, salads, syrups and even ice cream.  A team of researchers from the University of Sao Paulo, Brazil have discovered that the passion fruit seed oils, which are typically discarded in production, are a good source of nutrients and might be able to be used as edible oils in functional foods. Their findings are detailed in a recent study in the Journal of Food Science study, published by the Institute of Food Technologists (IFT).

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