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posted by n1 on Saturday August 06 2016, @04:29PM   Printer-friendly
from the isn't-this-just-uht-milk? dept.

Rapidly heating milk for less than a second can eliminate most of the bacteria left behind after the pasteurization process and extend the shelf life of cold milk by several weeks:

Bruce Applegate, Purdue associate professor in the Department of Food Science, and collaborators from Purdue and the University of Tennessee published their findings in the journal SpringerPlus, where they show that increasing the temperature of milk by 10 degrees for less than a second eliminates more than 99 percent of the bacteria left behind after pasteurization. "It's an add-on to pasteurization, but it can add shelf life of up to five, six or seven weeks to cold milk," Applegate said.

[...] The low-temperature, short-time (LTST) method in the Purdue study sprayed tiny droplets of pasteurized milk, which was inoculated with Lactobacillus and Pseudomonas bacteria, through a heated, pressurized chamber, rapidly raising and lowering their temperatures about 10 degrees Celsius but still below the 70-degree Celsius threshold needed for pasteurization. The treatment lowered bacterial levels below detection limits, and extended shelf life to up to 63 days. "With the treatment, you're taking out almost everything," Applegate said. "Whatever does survive is at such a low level that it takes much longer for it to multiply to a point at which it damages the quality of the milk."

The LTST chamber technology was developed by Millisecond Technologies, a New-York-based company. Sensory tests compared pasteurized milk with milk that had been pasteurized and run through MST's process. Panelists did not detect differences in color, aroma, taste or aftertaste between the products.

The effect of a novel low temperature-short time (LTST) process to extend the shelf-life of fluid milk (open, DOI: 10.1186/s40064-016-2250-1)


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  • (Score: 1, Funny) by Anonymous Coward on Saturday August 06 2016, @04:32PM

    by Anonymous Coward on Saturday August 06 2016, @04:32PM (#384780)

    > Panelists did not detect differences in color, aroma, taste or aftertaste between the products.

    http://i.imgur.com/EftNKxa.jpg [imgur.com]

  • (Score: 3, Interesting) by frojack on Saturday August 06 2016, @04:57PM

    by frojack (1554) on Saturday August 06 2016, @04:57PM (#384787) Journal

    This sounds interesting. Its probably also possible to scale it up just as easy as industrial scale pasteurization .

    But I's like to see more tests with a whole lot more infectious agents that a couple tame lab bacteria strains. There is a lot more stuff floating around in milk, some bad, some highly desirable, that might be altered. CDC acknowledges that pasteurization inactivates certain enzymes and reduces certain vitamins like Vitamin C, and it certainly does change the taste.

    What (if any) damage does this process induce?

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    • (Score: 0) by Anonymous Coward on Saturday August 06 2016, @07:03PM

      by Anonymous Coward on Saturday August 06 2016, @07:03PM (#384812)

      What (if any) damage does this process induce?

      That depends on if they do it before or after the milk is removed from the cow.

  • (Score: 2) by mtrycz on Saturday August 06 2016, @05:50PM

    by mtrycz (60) on Saturday August 06 2016, @05:50PM (#384798)

    So it's like UHT, but without the taste alteration? I'm kinda sold.

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    • (Score: 2) by frojack on Saturday August 06 2016, @06:12PM

      by frojack (1554) on Saturday August 06 2016, @06:12PM (#384804) Journal

      I thought it was odd that the only taste comparison was to normally pasteurized milk.
      Nobody in this day and age knows what milk really tastes like.

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      • (Score: 2) by blackhawk on Saturday August 06 2016, @07:24PM

        by blackhawk (5275) on Saturday August 06 2016, @07:24PM (#384813)

        Apparently you can buy milk that hasn't been pasteurised at some shops, but it's sold as a beauty product or similar, since it's not legal here in Oz to sell it as food. Still, if you want to taste real milk, it's not that hard to do so.

        I'd be happy just to have the old fatty milk of my childhood back again which came in silver foil capped pint bottles and had cream clotted at the top of the bottle. Silver tops was regular and gold tops was extra creamy...mmm, so good.

        Milk today tastes so horribly watered down it's hardly worth using.

      • (Score: 2) by KritonK on Sunday August 07 2016, @04:56AM

        by KritonK (465) on Sunday August 07 2016, @04:56AM (#384888)

        Nobody in this day and age knows what milk really tastes like.

        Nobody knows what milk really tastes like, not because of pasteurization, but because of homogenization. It's funny how dairy products have been modified to prevent the formation of the best part: cream at the top of milk bottles and skin at the top of yogurt.

        Before pasteurization, people knew that they had to boil milk before drinking it, if they didn't want to get sick, so few people ever knew (and lived to tell) how raw milk tastes like. I have had boiled raw milk, and the only thing I remember about it is that it was too hot to drink; waiting for it to cool to room temperature would have taken too long to wait, and may even have defeated the purpose.

        • (Score: 1) by AthanasiusKircher on Sunday August 07 2016, @09:53PM

          by AthanasiusKircher (5291) on Sunday August 07 2016, @09:53PM (#385057) Journal

          Nobody knows what milk really tastes like, not because of pasteurization, but because of homogenization. It's funny how dairy products have been modified to prevent the formation of the best part: cream at the top of milk bottles and skin at the top of yogurt.

          It's true that most people seem to think of lack of homogenization when they remember milk "in the good old days." Although, it's certainly a trade-off: the cream on top of the milk tastes good, but the milk below it tastes more like 1%. If you like a richer milk in general, homogenization is good. (And I really don't miss "skin" on yogurt, nor is that actually always a normal part of the process of making yogurt. If you ferment in a semi-closed vessel, you won't get skin. Perhaps you're thinking of custard?)

          Before pasteurization, people knew that they had to boil milk before drinking it, if they didn't want to get sick, so few people ever knew (and lived to tell) how raw milk tastes like.

          Sorry, that's just wrong. If it were true, the entire cow species would be extinct as all the calves die drinking raw milk. In reality, in the days before pasteurization, it was also the days before true refrigeration -- which means people tended to use up milk quickly. They knew very well that natural bacteria would cause the milk to sour and clabber in a day or two (which, in 95% of cases, tended to prevent too many bad bacteria from growing). If you look at old cookbooks (even sometimes those from the early 20th century after pasteurization became widespread), you'll find recipes asking for "sour milk," which was what you tended to do with older raw milk... there were other uses.

          Pasteurization (which is effectively "boiling" the milk in more controlled manner) ultimately was seen as more necessary for three reasons: (1) concentration of people into cities in the late 19th and early 20th centuries meant poorer sanitation for cows, milk transport, etc., and thus more disease, (2) urban environments began to prohibit cows, meaning milk had to be transported over larger distances rather than consumed when fresh, giving time and opportunity for more bacteria to grow and thrive, and (3) the same concentration led to milk from larger herds combined and then distributed to larger numbers of people, which could turn one infected cow into a public menace for hundreds of people.

          In reality, while there are dangers from raw milk, the rate of death (which is what you imply by "and lived to tell...") from raw milk is exceedingly low, and probably was much lower before cities created the opportunity for concentrated health hazards. All that said, I personally have only drunk it a few times, and I wouldn't encourage other people to drink it. The danger is low but there's little reason to take the risk, even from a "reputable" small farm source.

          • (Score: 2) by KritonK on Monday August 08 2016, @09:01AM

            by KritonK (465) on Monday August 08 2016, @09:01AM (#385228)

            All I can say is that when I was offered raw milk at a Greek village, they insisted on boiling it first. This could have either been knowledge passed down through the ages or a more modern practice. I also know that my father, a doctor, told me that he would never drink unpasteurized milk that was not boiled, unless it was fermented into yogurt, where the process of fermentation would ensure that the yogurt-making bacteria consumed all other bacteria in the milk.

            As for yogurt, traditional yogurt does have skin, presumably because it is fermented in uncovered, small containers and not in industrial-sized vats. You can still find such yogurt in Greece, and I assure you that the skin is the best part.

    • (Score: 2) by Runaway1956 on Saturday August 06 2016, @09:48PM

      by Runaway1956 (2926) Subscriber Badge on Saturday August 06 2016, @09:48PM (#384840) Journal

      UHT never has been very common in the US. All those years ago when I was in the Navy, we commonly bought UHT when in Europe. We never bought it in the US. I don't believe I've ever seen it in any US grocery. Google shopping says that Staples and Quills has it, $43 bucks for 12 quarts. Staples? Office products? WTF?

      Other listings want me to jump through hoops with my ad blockers and script blockers, it's unclear whether those are UHT or not.

      Jet is listed among the results, $3.80 per gallon, but it's unavailable in my area. Looks like regular pasteurized homogenized vitamin D milk to me.

      As I recall, I didn't especially like the flavor of Parmalat and similar products, but the taste wasn't really objectionable. It was much better than powdered milk, of course. The longer the ship had been without dairy products, the better Parmalat tasted. Of course, the same was true of cheeses, ice cream, yogurt, etc.

      • (Score: 2) by urza9814 on Tuesday August 09 2016, @10:02PM

        by urza9814 (3954) on Tuesday August 09 2016, @10:02PM (#385989) Journal

        UHT never has been very common in the US.

        It's used almost exclusively for organic milk in the US -- from what I've heard it's because they need the longer shelf life as organic milk tends to get shipped greater distances. I've only ever seen one organic brand that wasn't UHT (the store brand at Wegman's). Never seen a non-organic UHT bottle though...

        Never used to buy it, but I'm starting to lately. Still not a fan of the taste of it, but I don't drink milk so much these days so I care more about the shelf life. Used to down a gallon in under a week, now a quart of UHT might spoil before I finish it!

        This tech sounds like the best of both, so that's...not a big deal really, but kinda nice I guess. It'll be kinda interesting if the way this combines with the shipping issues means we end up with conventional milk that lasts longer than organic. Of course you could do that today with UHT, but nobody does...

  • (Score: 3, Interesting) by opinionated_science on Saturday August 06 2016, @06:11PM

    by opinionated_science (4031) on Saturday August 06 2016, @06:11PM (#384803)

    this is probably a lysing effect - the bacteria in question is not equipped to adapt. Try ecoli, it has evolved to survive being dropped in acid and then dilution into the gut!!

  • (Score: 0) by Anonymous Coward on Saturday August 06 2016, @07:52PM

    by Anonymous Coward on Saturday August 06 2016, @07:52PM (#384818)

    A couple of months ago I was in walmart and saw some really expensive milk ($6.50/gallon) that had expiration dates 2 months out. The label had a bunch of stuff about being organic. I bought a couple because I was about to go in for surgery and wouldn't be able to get back to the grocery for over a month. Well the milk did just fine, so I guess the labels were right.

    • (Score: 0) by Anonymous Coward on Saturday August 06 2016, @09:45PM

      by Anonymous Coward on Saturday August 06 2016, @09:45PM (#384839)

      A lot of grocery stores sell UHT organic milk. Taste is probably off, and the milk likely took a trip across the country too.

  • (Score: 2) by Bot on Saturday August 06 2016, @10:48PM

    by Bot (3902) on Saturday August 06 2016, @10:48PM (#384845) Journal

    so good that bacteria want nothing to do with it, and they have been around much longer than you meatbags.

    Food for thought, huh?

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    • (Score: 2) by Hartree on Sunday August 07 2016, @12:10AM

      by Hartree (195) on Sunday August 07 2016, @12:10AM (#384855)

      Organisms are perfectly happy with it. There just aren't many of them there when it's sealed up in an organism proof container.

      A lot like that newfangled 1800s technology called canning, you just don't have to heat it as thoroughly.

      And yes, I'm sure it's safe for zombies too if you're really worried about that.

      • (Score: 2) by dak664 on Sunday August 07 2016, @04:45PM

        by dak664 (2433) on Sunday August 07 2016, @04:45PM (#384995)

        But bacteria enter as soon as it is opened. My take is, if the bugs won't touch it, I won't eat it.

        • (Score: 2) by Hartree on Sunday August 07 2016, @09:21PM

          by Hartree (195) on Sunday August 07 2016, @09:21PM (#385046)

          Yes, bacteria enter it immediately. That's why shelf life doesn't mean lifetime after opening. Once you open it, all bets are off.

          They're talking about the time while it's shipped/on the shelf in the store unopened. After it's opened, the bacteria chow down on it just like any other milk. This only deals with the bacteria leftover by pasteurization.

    • (Score: 2) by butthurt on Sunday August 07 2016, @12:17AM

      by butthurt (6141) on Sunday August 07 2016, @12:17AM (#384857) Journal
  • (Score: 1) by pTamok on Sunday August 07 2016, @08:54AM

    by pTamok (3042) on Sunday August 07 2016, @08:54AM (#384924)

    Anything that allows supermarkets (or middleman suppliers) to stockpile 'fresh' milk will make it difficult for the smallest farmers to compete. If the choice for the supermarket is to buy fresh milk from the small farmer at x+delta, or treated milk at x from the stockpile, then it makes it difficult for the small farmer to charge over the base cost of the largest farmers. You might not care, as agriculture is a business, but lack of smaller farms depopulates rural areas, and you might have an opinion on that.

    Certain places are reverting to scrubland as no-one can farm them economically any more. This may or may not be a good thing.

    • (Score: 0) by Anonymous Coward on Sunday August 07 2016, @11:12AM

      by Anonymous Coward on Sunday August 07 2016, @11:12AM (#384941)

      The whole agricultural sector is ill... pretty bad... not only from a biological point of view, but also from an economical point of view. Here in Europe the milk quotum was released two years ago and since a year the price has dropped half. Now the sector needs financial injections (subsidies) to survive. Not only the dairy farming is ill. Agriculture here in the Netherlands had a major blow with a hail storm a few weeks ago, destroying more or less all produce for the year. In the store I noticed last week there were no Dutch apples... all, except one from France, were from Chile or New Zealand.

      Banks have proposed changes for the agricultural sector, but IMHO, they are the wrong changes. You need a whole restructuring of the sector (change the fundamental way of how things are done) to overcome these problems.

  • (Score: 0) by Anonymous Coward on Sunday August 07 2016, @08:43PM

    by Anonymous Coward on Sunday August 07 2016, @08:43PM (#385040)

    Since almost all milk is homogenized, just do the heating in the homogenization nozzle?