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Page 16. Point (b) is missing.
Page 16 – Purity and source of alpha-amylase and AMG.
Detailed specifications on the source of alpha-amylase are given. However, it must be remembered
that these enzymes are made for industrial use. There may be variation from batch to batch in
contaminants important in an analytical procedure but of no consequence in the intended industrial
application.
Industrial AMG cannot be used in analytical procedures because it contains glucose, but more
importantly, because they contain contaminating activities that interfere with starch determination in
plant samples. As far as I am aware, the Megazyme purified AMG (E-AMGDF) is the only AMG pure
enough to use in such assays other than pure AMG, which is too costly to use in such assays.
Page 17, line 336. Change “amylase” to “amyloglucosidase”
Page 17 (e). A statement should be made about the required purity of glucose oxidase and peroxidase.
Page 17, line 378. Phenol is generally not used in glucose determination reagents because it is
carcinogenic and also is not very stable. The chemical most commonly used in its place is
p
-
hydroxybenzoic acid.
ER 9
For me the term "dietary starch" is new, especailly in connection with animal feed and pet food.
Fromenergetic viewpoint, I can agree to include maltodextrins, glycogen fromanimal and microbial
origin in the new term dietary starch. However I have problems what to do with the4 different types of
resistant starhes, the RS1, RS2, RS3 and RS4. Starch incubation with alpha-amylase at 100 C will
hydrolyse the RS1, RS2 and RS4 resistant starch but certainly not the RS3 resistant starch, the so-called
retrograded starch.
Different animals have different intestinal tracks, for example, pets, pigs, cows some can digest
resistant starches, others not. So the content of dietary starch in a feed sample depends also on which
kind of animal consumes the feed.The for digestion available "dietary starch" in one sample containing
resistant starch categories RS1+RS2+RS3+RS4 is most likely different for pets (originally carnivores and
less capable to digest native starches), pigs, cows.
Method Clarity
ER 1 Positive feedback from collaborators
ER 2
Good with the exception how the limitation of the method in application to matrices containing
hydrophilic antioxidant contents/activity exceeding 10-20 micromol as ascorbic acid) per 0.1 g of test
dry matter.
ER 3
Easy to read. No issues.
ER 4
Well written and understandable
Candidates for 2016 Method of the Year
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