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Scientists Find Chemical-Free Way To Extend Milk's Shelf Life For Up To 3 Weeks (digitaltrends.com)
An anonymous reader writes from a report via Digital Trends: Researchers at Purdue University and the University of Tennessee have found a non-chemical way to extend regular milk's shelf life to around 2-3 weeks, and without affecting the nutrients or flavor. The technology they've developed involves increasing the temperature of milk by just 10 degrees for less than a second, which is well below the 70-degree Celsius threshold needed for pasteurization. That quick heat blast is still able to eliminate more than 99 percent of the bacteria left from pasteurization. "The developed technology uses low temperature, short time (LTST) in a process that disperses milk in the form of droplets with low heat/pressure variation over a short treatment time in conjunction with pasteurization," Bruce Applegate, Purdue's associate professor in the Department of Food Science, explained to Digital Trends. "The resultant product was subjected to a taste panel and participants had equal or greater preference for the LTST pasteurized milk compared to normally pasteurized milk. The shelf was determined to be a minimum of two weeks longer than the standard shelf life from pasteurization alone." As for whether or not this method will make its way to store shelves, it won't in the near future. "Currently an Ohio-based milk processor is using this technology and distributing the milk," Applegate says. "The unit is approved for processing milk in Ohio and distribution nationwide. The product is currently being distributed, however it has not been labeled as extended shelf life milk. Once the commercial application is validated the milk will be labelled with the extended shelf life." Scientists from Duke University believe there may be a large source of hydrogen gas under the ocean, caused by rocks forming from fast-spreading tectonic plates.
What does hydrogen found under tectonic plates have to do with milk pasteurization? Is this some kind of reading proficiency test?
They applied the process to pasteurized milk inoculated with Lactobacillus and Pseudomonas bacteria, and those bacteria were eliminated without affecting taste. Tests with unpasturized milk have not been done yet. So at this point this is about pasteurized milk with an extended shelf life, although the process needs to be validated before they start labeling the mik as having and extended shelf life.
Irradiation degrades the flavor of milk more than heat pasteurization does. Milk, as it turns out, is very sensitive to radiation and develops an off flavor very quickly with exposure.
In the US, at least, the FDA has also not approved irradiation as a treatment for milk. Because of the issues with flavor, it's also very doubtful that manufacturers will go to the expense of lobbying for approval.
Wow... so much incorrect information in such a small space.
First, CJD is caused by prions which can come from several sources including your own body if you're unlucky enough to have the wrong genetic mutation.
Second, the prion that causes Bovine spongiform encephalopathy cannot be destroyed by any level of pasteurization that would leave cattle feed in an edible state. It remains viable at temperatures below 600 degrees C. Trying to pasteurize cattle feed at that temperature would incinerate it and leave you with prion-laden ashes. Changes to regulations on the pasteurization of cattle feed would have no effect whatsoever on this.
Third, the outbreaks of BSE were caused by cattle feed containing the remains of sick cattle and sheep. At the time, it was seen as a way to minimize lost profits while disposing of sick animals, so it rapidly became a wide-spread practice which resulted in the huge outbreaks of the dease.
BeauHD has proven to be a complete jackass. This is embarrasing and ridiculous.
As the son-in-law of a dairy farmer I can tell you that stressed/unhappy cows are bad for business. They create poor quality milk, which reduces the quality of the entire tank.
That is to say, cow happiness is very much in the financial interest of the farmer.
That isn't to say that all farming is great, but in dairy, there is much more pressure to make the animal happy than in say, chicken farming or, pretty much anything else.
38.6C, the temp it comes out of the cow.
Is it really that god damn difficult for you high UID monkeys to use a bit of simple logic? Do you really need literally everything spoon-fed to you?
Are you seriously going to chastise someone when you didn't even bother to try to figure out what the hell is going on yourself? It's pretty obvious from TFS (which is admittedly poorly written, based on a poorly written TFA, based almost directly on a completely ignorant university press release linked in TFS) that the milk is still pasteurized and this is an ADDITIONAL step. So the "temperature" we're raising by "10 degrees" is completely confusing in all of these sources.
SLASHDOT EDITORS: STOP PUTTING UP CRAP ARTICLES WITHOUT A LINK TO THE ORIGINAL SCIENTIFIC SOURCE!!!
This is the kind of stupid ignorant discussions we get without the actual scientific source, which can be found here.
Now everyone go read actually what this study did. Most stuff in TFS is confused if not downright wrong. Let me explain the basics of this process, based on the actual scientific study:
(1) Pasteurization is good, but it only results in limited shelf life. Other techniques used for increasing shelf life (ultra-high temp or UHT pasteurization, low-temperature long time or LTLT pasteurization) produce undesirable effects on flavor and/or nutrients, etc.
(2) This process is what the authors describe as "low temperature, short time (LTST) amendment for pasteurization" which could be added after normal pasteurization to increase shelf life dramatically without some of the negative effects described above.
(3) The statement from TFS "The technology they've developed involves increasing the temperature of milk by just 10 degrees for less than a second, which is well below the 70-degree Celsius threshold needed for pasteurization" is complete BS. I don't know what it's supposed to mean. If you go to the actual scientific study, you'll find the temperatures in the chamber for the 5 trials varied between 64.8 C and 83.8 C. In general, chamber temperatures in the trials below 70 C seemed to be much less effective at increasing shelf life and weren't recommended. So TFS -- and the university press it's based on -- are completely wrong.
(4) What is the process really? Well, just after pasteurization (which occurs at or above 72.7C), the milk is reheated in a special chamber and dispersed in droplets. The reheating step only raises the temperature of the milk by 1 to 10C over what it was before (in the words of the authors "at or below pasteurization temperatures" of less than or equal to 72.7C) for 0.02 seconds. As I noted above, the actual temperature achieved in the chamber seems important (definitely above 70 C seems desirable), with higher temperatures being more effective at increasing shelf life.
(5) The process is potentially an improvement over other proposals to increase shelf-life for a number of reasons:
-- No significant loss in nutrients compared with standard pasteurization.
-- No significant taste difference or perceived quality difference among tasters with this additional step.
-- The minimal heat energy required for this step could be incorporated into a standard pasteurization process setting to siphon off heat energy already present from the pasteurization tube, so this wouldn't necessarily require additional energy (and is thus very efficient).
OK? That's what's actually going on here. Now that we know what the original science is actually about, please continue your random Slashdot insults and debates.... perhaps slightly more informed.
Or, how about we just sell milk in bag-in-boxes like they do in other countries. They can sit on the shelf for up to 6 months as long as they're not opened. Grocery stores could still refrigerate them so they're cold and ready to go when people get home.
Care killed the cat, but satisfaction brought it back.
Do you not know how bioavailability works?
While I'm no expert I have a crude idea. Do you? You seem to be conflating bio-availability some other concepts. It's a lot more complex than raw food = good bacteria = healthy person.
Many of those bacteria help us digest stuff we lost the ability to digest after infancy.
You are grossly oversimplifying the process. Bacteria help us digest stuff throughout our life. Remove them and we can barely survive at any age. We aren't born with all the bacteria we need to digest stuff and our gut flora change as we age. Some comes from mom, some comes from the geography and environment around us, some comes from our diet. Antibiotics have a strong effect on our gut flora.
The debate about the health benefits of raw vs pasteurized milk has not yet yielded much in the way of firm conclusions. A few things seem clear. Pasteurizing does unquestionably kill harmful (and helpful) microbes and on balance it seems clear that it has a net benefit in reducing illness and mortality from pathogens. Most studies conducted so far that have found benefits to raw milk have not controlled for the fact that the individuals studied lived on a farm (hard to get raw milk elsewhere) and there are many variables relating to that so it is hard to draw any strong conclusions. There may be benefits but we haven't clearly teased them out yet. The available evidence and studies so far seems to show that any negative impact on nutrition from pasteurization is small to negligible though future studies may revise that conclusion as more data is gathered.