I am trying to understand this sentence, but just using a dictionary is not helpful:

Prepared by treating starch with acetic acid anhydride and adipinic acid anhydride. This results in a starch that is resistant against stirring and high temperatures.

I am interested in the word "stirring". What does this sentence actually say the starch is resistant against?

closed as general reference by user2683, user13141, Matt E. Эллен, Mitch, kiamlaluno Jan 11 '12 at 19:18

This question is too basic; it can be definitively and permanently answered by a single link to a standard internet reference source designed specifically to find that type of information. If this question can be reworded to fit the rules in the help center, please edit the question.

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    @WillHunting Incidentally, this is a question on English itself rather than chemistry. The context is a bit of a diversion! – Kris Jan 11 '12 at 10:16
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    +1 : when I first read the sentance I thought that the starch would "resist stirring" by being so stiff. I had to had to read Kris's answer to realise what the sentence meant. – cindi Jan 11 '12 at 10:54
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    Why would stirring mean anything other than stirring? As it reads, I could only interpret stirring to mean stirring. – Matt E. Эллен Jan 11 '12 at 12:11
  • @cindi: Ditto. Apparently Kris is something of a chemist. This isn't "general reference" at all - we're dealing with a highly domain-specific sense of resistant against stirring. If it should have been closed at all, the only justifiable reason must surely be "too localised". – FumbleFingers Jan 12 '12 at 16:33
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    Vote Reopen : Agree with @FumbleFingers The comments indicate that the people closing didn't try to understand the question. What are the odds? The dictionary meaning of 'stirring' is irrelevant in this case. – – cindi Jan 12 '12 at 17:29

Stirring here means exactly as it is understood in general English.

The starch is not liable to break down or otherwise become ineffective when the product is (vigorously) stirred, as also when exposed to higher temperatures.

For general clarification: 'Stirring' is one of the standard unit operations in chemical processing. Also, it mimics the activity of stirring as part of cooking in food preparation. Starches are important both in Food Technology as well as the broader chemical process industry where it is properly known as 'agitation' (=stirring, not shaking as may be commonly interpreted), 'mixing' (more than one constituent), etc.

  • "Cross linking improves process tolerance, which means the starch can withstand heating, acid ingredients, stirring, pumping and packing. This starch does not break down during cooking."¹ – MetaEd Jan 11 '12 at 15:43

At first I thought OP's sentence was badly-formed.

resistant against high temperatures means able to withstand high temperatures [without degrading].

...and without specialised knowledge of the "materials science" context,

resistant against stirring would ordinarily mean difficult to stir (by virtue of being viscous/thick).

Those two meanings involve very different roles for the term resistant against (like saying "I made haste and jam" to mean you made the jam quickly), which would be poor use of language.

BUT, per @Kris's answer and various comments, starch formulations may be degraded by stirring. Thus, in this particular context, resistant against stirring doesn't mean difficult to stir - it means not adversely affected by stirring.

Note that in more familiar "ability to withstand xxxx" contexts, we often encounter expressions like heat-resistant, frost-resistant, etc. However, given that Google Books records not a single instance of stirring-resistant, I don't think OP should feel too crestfallen at not having understood the usage.

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    Stirring is a recognized method by which the physical properties of a material can be modified. Unstable starches possibly breakdown and lose their binding property when stirred (as part of food preparation, in the process of cooking; in an agitator as part of a chemical process ...). – Kris Jan 12 '12 at 4:50
  • @Kris: oic. well in that case I think the question should have been closed as "too localised" rather than "general reference". – FumbleFingers Jan 12 '12 at 16:27
  • Funny! If I use a common English word in my specialized field, it becomes a localized word? Even though it still means exactly the same thing? That is overselling the point! – Kris Jan 13 '12 at 4:12
  • @Kris: Well obviously it's not the actual meaning of the word "stirring" that's at issue here. It's the meaning of the phrase resistant against stirring, which in most normal contexts would obviously be likely to mean mechanical resistance (viscosity, or whatever that funny thing is called when a starch/water mixture stiffens against sudden shocks, but flows easily with slower forces). – FumbleFingers Jan 13 '12 at 17:26
  • True, generally speaking, your argument holds well enough. However, in the technical context, resistant simply means 'withstands', or more specifically, 'does not change its properties/ behavior', as in heat-resistant. A heat-resistant material does not prevent you from heating it, rather, it ignores the heating and continues to behave the same way as if nothing happened! – Kris Jan 14 '12 at 5:34

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