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It's the proverbial curate's egg - good in parts (not so good in others). But for someone who pioneered resistant starch research, way back in the mid-80s, and saw it referred to once as "the trendiest form of dietary fiber" (in the US that is, not my own UK) there are one or two aspects of the article that I find depressing. That's unless, unless I grasp at one tiny straw, or should that be tiny crumb of starchy comfort offered . Maybe resistant starch DOES need a new sexier name, as the writer - a working scientist no less - proposes.
Apologies if you are an early bird to have stumbled on this new posting, because I'm going to be (seemingly) self-indulgent by completing this posting in bite-sized instalments over the next few days or so. Sorry, but it's the way I work. I find it better than trying to assemble in one go.
So off I go to retrieve the writer's crucial words (and tell you something about him - he being a welcome change from your usual MSM nutrition writers. This one has a bent for research - real research - and has come up with what (for me) was a welcome confirmation of something I reported back in 1986, namely that levels of resistant starch increase on re-heating of cold, cooked pasta and other sources of wheat starch..
So what's this with the name? Here's an excerpt from the article (my highlighting):
"The subject of our experiment? Resistant starch.It's hard to think of a less inspiring name for a food, so you can imagine my disappointment when the producers of the series Trust Me, I'm A Doctor said this was what I was going to investigate.My co-presenters were flying to tropical locations, reporting on brain transplants and trying the latest aphrodisiacs, but I was off to Guildford to do an experiment about something that sounded only slightly more appealing than my other task for the programme: waxing my legs*…We need more research into resistant starch done by scientists such as Denise Robertson, but she's going to need to get in touch with some PR people for a name change if it's going to take off."
*Me again: don't be deceived. It's a bloke, one Dr Christoffer van Tulleken who is described as an infectious disease specialist at
University College London (one of my three alma maters, MSc (Biochemistry) 1970). The footnote goes on to say that his research is funded by the Medical Research
Council. "Trust Me, I'm A Doctor" can be seen on BBC 2 tomorrow at 8pm. I'll say more about him (and his twin brother) later.
OK, so what's my stake in all this stuff about the 'boringly named' resistant starch. First, I did not discover it. The credit for that goes (primarily) to Professor John Cummings and Dr. Hans Englyst, then at the Dunn Clinical Nutrition Centre, Cambridge, UK. I had been researching the claimed long-term protective effects of cereal dietary fibre, using the rat as an experimental model, and discovered with colleagues (notably Dr.Nat Fisher and Mr.John Gregory) that cereal DF did indeed give a modest protection against colonic diverticulosis (outpouchings or herniations of the wall of the colon). The question was what to do next, while MAFF, our funding body was still ready to inject more funding. Interest turned to starch, based on the realization that only a small proportion of that major food constituent would need to escape digestion in the small intestine for it to enter the lower bowel and act in a DF-like fashion, providing nutrition to our resident gut flora (anaerobic bacteria for the most part). Some wheat starch escapes gelatinization on cooking and baking, but I could find little evidence that raw wheat starch was indigestible, comparable say to raw potato starch. The breakthrough came on the day I got wind of Englyst and Cumming's latest research findings, ahead of publication, showing that "enzyme resistant starch" was a reality in COOKED COOLED starchy foods, and that amylomaize (high amylose corn) starch whether raw OR COOKED was abundantly endowed with resistant starch (RS).
So, there was a flurry of research, in which all the stops were pulled out, and a year or so later I published in the then newish Journal of Cereal Science what I believe is/was the first paper to be devoted entirely to this new topic.
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After an infusion of caffeine, I have two answers to those questions. YES, it should be renamed, switching the emphasis from what does not happen to RS in the small intestine to what it does in large intestine, i.e. to turn a negative attribute into a positive one.
Name? Here's one for starters. Call it PREBIOTIC STARCH. Important -that's PREbiotic. not PRObiotic.
The difference? There are any number of googleable sites that explain the difference between prebiotic and probiotic components of the diet. Here's a link to one, not necessarily the best, though it seems reasonable.
Probiotics are living bacteria that one might consume in the hope they survive passage through the acid stomach and then small intestine, with no guarantee that they do (see the large literature on yogurt). Prebiotics are the substances that lower bowel bacteria feed on, usually taken to mean "good" aka "friendly" strains, allowing them to grow and proliferate. Resistant starch is known to favour the growth of an important class of bowel bacteria that generate the 4-carbon butyrate, which has been an important consideration even since Roediger discovered that butyrate is a specific metabolic fuel for the mucosal cells that line the colon. In other words, one has what appears to be a symbiotic relationship between human cells and microorganisms, or rather CERTAIN strains of microorganism (not all). Not all gut bacteria are friendly e.g. Campylobacter, so it's a rational strategy to try and swamp them with good bacteria.
Late addition: see the informative wiki entry on prebiotics in nutrition, which lists resistant starch as an obvious candidate for inclusion in that category.
Afterthought: I guess one could qualify and/or expand the description to incorporate some physics and chemistry, e.g. by renaming RS as 'prebiotic starch crystallites' (PSCs).
noun: crystallite
- an individual perfect crystal or region of regular crystalline structure in the substance of a material, typically of a metal or a partly crystalline polymer.
- a very small crystal.
Here's a video clip I've unearthed showing Chris van T and his twin brother Alex on their bikes, apparently comparing high fat v sugar diets to see who performs best (I've still to figure that out from the rather too short clip).
Congrats to Chris and his BBC2 team for setting up that commendable controlled testing of the RS diets, especially the finding that a second heating improved the ability of the pasta offering to blunt the rises in blood sugar and insulin. It was especially gratifying to this retired science bod, having reported precisely the same effect back in '86, with (see above abstract) successive cycles of cooling and re-heating in two different systems (a concentrated gel of wheat starch, subject to autoclaving, and a dilute suspension of the same, subject to cycles of boiling and cooling). Each new cycle appears to "melt" additional starch that then retrogrades on cooling, i.e. re-orders or 're-crystallizes'. One of the noteworthy findings of my paper was that RS formation depends on the minor amylose component of starch, which unlike the major amylopectin component is unbranched, i.e. linear. Up till that point there had been a widespread assumption that RS formation involved the same phenomena that give rise to bread staling, largely attributable to amylopectin retrogradation. I was able to disprove that by showing that amylopectin produced scarcely any RS on heating or cooling, but RS yields became spectacular if/when the amylopectin was first digested with an enzyme (pullulanase) that acts specifically at the branch points, converting it to a collection of small linear UNBRANCHED fragments. There have been a number of patent applications in recent years based on that discovery with pullulanase. Some acknowledge my paper, some do not. C'est la vie.
Blog site: Chris and 'Xand' van Tulleken
Update: October 15.
Have just added "prebiotic starch" to the title of this posting (and search words, natch). But am I the first to deploy the new name? Nope, as a quick Google search reveals. Loadsa folk have deployed "prebiotic starch" in the past.
Update: October 16
Am pleased to see that the University of Surrey is assisting with the BBC series and (especially) overseeing the new research.
"That is what I was tasked with doing for the BBC, under the expert guidance of Dr Denise Robertson, a senior nutrition scientist from the University of Surrey. The subject of our experiment? Resistant starch."
I have a soft spot for those Guildford-based nutritionists and biochemists. Why? Because I had two of their (then) PhD students spend some time in my laboratory at the Flour Milling and Baking Research Association at Chorleywood. (I was a kind of temporary supervisor/mentor for them, having plugged them into my ongoing dietary fibre research programme - prior to the specific focus on RS). That was when Prof. Dennis V.Parke was the (formidable) head of department, though he sadly is no longer with us.
One of the two researchers was Dr.Michele Sadler, who is now a high-powered nutritionist, as seen by this screen grab from the internet.
Hello there Michele (if you ever get to see this posting). Sorry to have overworked you (yes, methinks you were looking a tad pale by the time you left ;-).
The other was Dr. David Moore. The last I heard, he had gone off to the States and was making an impact there. But it's not an uncommon name, even when prefaced with Dr. so I'll need to keep researching for a while longer.
Progress! I've been able to track down a reference to his 1983 PhD thesis which, handily, gives his middle initial.
David J.Moore. Now we're motoring!
Back to the BBC:
The BBC has this morning put up a short feature on the re-heated resistant starch trial - not surprising really.
It's good to see the focus on cooling and re-heating, since this is a simple practical step one can take that not only increases that allegedly protective 'prebiotic starch' input to the lower bowel, but can help reduce food wastage as well (most folk probably prefer to cook too much than too little pasta than needed for single servings).
Here's a photo that accompanied the article, with both of the prime movers and human guinea pigs in the frame.
The Independent now carries the reheated-pasta story.
It's now Friday October17, and I've been busy condemning the latest excrescence of pseudoscience in the wacky world of Shroudology. The price for doing so was to have an extraordinary attack made on my own scientific competence, notably the 'kitchen experiments' reported here on this blog and elsewhere. I'll return to that later in the day, and mount what I hope will look like a credible defence of my (relatively intact) professionalism despite having now been retired for well over a decade. (Do decades away from the bench make one, er. decadent?)
Before I do that, I must share with the blogosphere an article in this morning's Daily Mail which if nothing else will prove this science bod is at least 5 years ahead of the game where calorie-counting is concerned (arguably 28 years if one can include the gap between my discovery re re-heating cooked, cooled starches and the main subject of this posting).
Here's the article and its splendid advice.
But now spare a moment to look at this blog's sidebar, and look not for a bottle of coke (which I regards as one of the New World's worst contributions to mankind - essentially dietary barbarism).
Look instead for the bottle of wine, (nope, I've spared you the trouble) and the caption that accompanies it (inserted at or close to this blog's inception in 2009, not 2005 as I mistakenly stated yesterday). Yes, this science bod prides himself on being boringly and tediously ahead of the game. (That's the trouble - I'm usually too far ahead, and by the time folk catch up, I'm usually too absorbed in my new and latest idea/project to be bothered one way or the other).
One of the less satisfactory aspects of WordPress and the blogs it hosts is the absence of a Comment archives for given individuals. One has instead to rely on search engines to track down what someone said days or weeks ago that may still rankle, and which one finally decides cannot be allowed to go unchallenged.
Fortunately, Google has on this occasion obliged:
Following that link, back to a posting on shroudstory.com 5 days ago (even 1 day can seem a long time in blogging), I see the comment in question was in response to this one from me, spotlighting the perennial bugbear of this site - pseudoscience.
October 13, 2014 at 3:45 pm
“Isn’t that what science is all about?”
That depends. What model is being proposed that can:
(a) generate a superficial negative image?
(b) make it seem 1400 years younger than it really is in radiocarbon dating?
(c) is experimentally testable in principle?
One suspects that (c) is the brick wall. How does one get a cadaver in a laboratory or elsewhere (rock tomb etc) to suddenly start spontaneously emitting neutrons?
If one cannot, if that step is deemed to have been a ‘one off’ miracle, then it’s emphatically not a scientific model. It’s an attempt to foist a preconceived narrative that while wrapped up in the language of science is untestable and therefore NOT science. In short, it’s our old friend, the bane of 90% of sindonology – it’s pseudoscience.
Back came Mike M, who as I recall is a Canada-based pharmacist with this hand grenade of a second paragraph:
That depends. What model is being proposed that can:
(a) generate a superficial negative image?
(b) make it seem 1400 years younger than it really is in radiocarbon dating?
(c) is experimentally testable in principle?
One suspects that (c) is the brick wall. How does one get a cadaver in a laboratory or elsewhere (rock tomb etc) to suddenly start spontaneously emitting neutrons?
If one cannot, if that step is deemed to have been a ‘one off’ miracle, then it’s emphatically not a scientific model. It’s an attempt to foist a preconceived narrative that while wrapped up in the language of science is untestable and therefore NOT science. In short, it’s our old friend, the bane of 90% of sindonology – it’s pseudoscience.
Back came Mike M, who as I recall is a Canada-based pharmacist with this hand grenade of a second paragraph:
October 13, 2014 at 6:05 pm
I disagree, testing if the shroud was exposed to neutrons should
not bundled up with fries and coke (image formation mechanism, trying
to replicate the resurrection). It’s a simple test on its own that
should demonstrate that the shroud was irradiated, period. If it proves
positive then we can look into the possible reasons why?
If the test was done according to a good protocol and performed according to the scientific method, proper controls, proper documentation, peer review, then why not. You can’t just flag anything you don’t like as pseudoscience and then perform your own kitchen experiments away from any protocol/proper documentation/controls/peer review and claim it’s proper science since you are doing it.
If the test was done according to a good protocol and performed according to the scientific method, proper controls, proper documentation, peer review, then why not. You can’t just flag anything you don’t like as pseudoscience and then perform your own kitchen experiments away from any protocol/proper documentation/controls/peer review and claim it’s proper science since you are doing it.
Oh dear.Where does one start? Does one start with the crazy logic on display there, which seems to think that pseudoscience and (allegedly) sloppy experimentation are one and the same thing, such that no one deemed less than perfect in their experimentation is allowed to condemn pseudoscience when they see it.
Let's remind ourselves first what is meant by pseudoscience, which needless to say is an attempt to deploy the language of science in a manner deliberately planned to foster a personal agenda, giving it an undeserved air of objectivity and authority.
More to follow (much more, as one of this blogger's other perennial bugbears is internet trolling, and sites that not only tolerate it, but seemingly encourage it by 'benign neglect' of what some commentators say, while jumping on perceived and usually minor indiscretions others who find themselves the targets of the Trolling Tendency. Read: operating a double standard.
So what provoked that attack on my science, kitchen-based though it might be (but then I'm in good company there, thinking of Newton's seminal home-based experiments on the splitting of white light into the colours of the visible spectrum AND their recombination into white light, all achieved with glass prisms bought from the local marke)?
Might it have been this September posting see full title below, that he had in mind (there being only one for that entire month) with what I consider was ultra-cautious cin flagging up the exploratory nature of my new project, hardly needing the circulation of a "protocol", given I work independently, not as part of a research team.
Title: "More on that enigmatic negative and superficial Turin Shroud image. Let's not strangle at birth a possible working model based on invisible-ink technology."
Note the care taken to flag up the preliminary, tentative nature of what I was doing or trying to do, i.e.enter into new and unfamiliar territory. It's what scientists do - real ones that is, as distinct from pseudoscientists who use conference platforms to launch untested hypotheses (including wacky wild-eyed speculation) on an audience which they know is desperate for "fresh new evidence" to back up their convictions but who can be fobbed off instead with science fiction.
Poor documentation? Every claim in that September posting was accompanied and supported by a photograph - some 10 in all, not counting photos from my literature searches that revealed I was not the first to ponder on the reasons why lemon juice etc give an "invisible ink" effect.
Let's look at a single typical photograph from that posting, and ask whether the experiment was lacking controls or poorly planned or executed in other respects.
There you see a strip of linen that had been impregnated with lemon juice butted up against one that had been treated with a mixture of citric acid and glucose, and a hot template then pressed down serially as it cooled across the junction of the two strips. There's clearly a difference in the way the two linens responded, best seen at lower temperatures (right side) where the template has cooled with each successive imprinting of its image and progressively lost heat.
In what way was did that experiment lack controls or proper documentation?
In fact it confirmed what others had previously discovered and reported, though one has to look hard to find it, namely that the invisible ink effect with lemon juice is NOT due to its citric acid or sugar content. It's due to an entirely different component namely ascorbic acid (Vitamin C), which I was able to verify in the same posting, comparing Vit C impregnation with suitable CONTROLS (plain water, citric acid etc).
What's more, the design of my experiments featuring the serial imprinting off a single heated template provide a systematic exploration of the effect of temperature, even if I'm unable to put numbers on those strips (though I have a rough idea from earlier experiments with an oven thermometer).
When did you last see the scorch-dismissal tendency bother to investigate temperature variation and/or attempt to vary it systematically. Certainly not in the put-down that Paoli Di Lazzaro was invited/inveigled into posting on shroudstory.com back in February 2012, where he was content to use a single excessively-high temperature/contact time, apparently with no reverse-side protection (damp backing cloth etc) that inevitably overscorched.
Colin Berry’s idea is untenable, and heat cannot produce a superficial coloration
February 21, 2012
After Colin Berry posted his statement about image formation, referenced here,
I personally requested comments from members of the Shroud Science
Group. This is Paolo Di Lazzaro’s answer to me and other SSG members who
might not be expert enough in physics to understand why Colin Berry’s
model (without experiments) is untenable. Now with Paolo’s kind
permission those notes to SSG members are being published here:Dear Dan and All:
I checked the idea of Colin Berry in the website you quoted. In short, from a physics point of view, his model is untenable, especially concerning the depth of coloration. Let me explain why.
This was from the same individual who had earlier claimed to have spent "years" trying to reproduce the Shroud image with conventional physics before being forced to use his employer's uv excimer lasers after hours to produce much-trumpeted faint yellow discoloration on the supereficial fibres of linen.
How many on that site took PDL to task for his sloppy one-off scorch experiment with no attempt to explore a range of temperature systematically as I have done and ALWAYS DO in all my scores of experiments.
Just one, in fact - the very first comment from a rare visitor, one "ArtScience". Here's his perceptive observation and my appreciative response:
ArtScience
February 21, 2012 at 5:14 pm
Nice experiment, and easy to do, Dr. Lazzaro. Thanks.
I suppose the next obvious experiment would be: how about heating the coin up away from the cloth and then place it down on the cloth for 1, 2, 3, 4, 5 seconds, then 10s, then 15s etc. Getting a series of scorching
It seems as though it should be possible to catch a partial scorch, no?
I suppose the next obvious experiment would be: how about heating the coin up away from the cloth and then place it down on the cloth for 1, 2, 3, 4, 5 seconds, then 10s, then 15s etc. Getting a series of scorching
It seems as though it should be possible to catch a partial scorch, no?
February 21, 2012 at 5:32 pm
Nice comment Art. I’ve just said much the same on my own site
(like he should have tested lower temperatures). Is Dr.Lazzaro
seriously suggesting that a scorch is all-or-nothing, with no means of
fine-tuning the colour intensity?
Where were all the regulars on that site who are instantly dismissive of my kitchen experimentation when PDL, with all the facilities at his disposal, chose to report that woefully inadequate and self-servingly designed one-off experiment that "proved" contact scorching was too fierce and uncontrollable.
Note too the site-owner's choice of graphic, all part of the attempt to ridicule anyone daring to challenge their view that some kind of exotic physics suggestive of divine intervention was needed to account for the superficiality and other 'subtle' characteristics of the TS image. I say that faint contact scorches at the limit of visibility are also subtle, and should have been meticulously excluded by thorough EXPERIMENTATION before foisting their wacky physics on suggestible folk via their daily newspapers. It is they who lacked the protocols, the controls, the proper documentation, not I, while acknowledging that my resources are limited.
More to follow (including some observations on what has been dubbed "disconfirmation bias").
Yes, probably most have heard of 'confirmation bias ', with Shroudology being a textbook example of the genre. From wiki:
"Confirmation bias, also called confirmatory bias or myside bias, is the tendency to search for, interpret, or prioritize information in a way that confirms one's beliefs or hypotheses. It is a type of cognitive bias and a systematic error of inductive reasoning."
Probably fewer have heard of 'disconfirmation bias':
What is that? Again, from the body of that same wiki entry:(my italics):
"The results illustrated that people set higher standards of evidence for hypotheses that go against their current expectations. This effect, known as "disconfirmation bias", has been supported by other experiments.[27]"
Yes, that's the long and the short of it. This retired science bod, labouring away in his kitchen laboratory, is being held to a higher standard of evidence than any number of shroud researchers and commentators, and though I say it myself, is actually delivering that higher standard of performance. And what happens? Second hand reports of my experiments., light on detail, appear on that Other Site, and it's quite clear that my critics over there cannot be bothered to log in here to read the full report, and who then proceed to make hostile, ill-informed judgements that attempt to trash my credentials as a purveyor of sound science.
Have none of them ever asked themselves this: where are the step-by-step photographs that go with all the mantras that arose when STURP team members continued to experiment post the appearance of the Summary (including I might add Raymond Rogers subsequent to his retirement in his HOME SWEET HOME, though whether his microscope was in a kitchen or study I could not say)?
How many photographs have you seen, dear reader, to back up Rogers' claim for an image-receptive impurity coating on linen, described as starch or partially-degraded starch? How many images are there to back up the claim of Adler and Heller's from that protease experiment that blood is under image, not vice versa? How many images or even numerical data are there to back up the claim of the same pair of STURP heavies (though neither went to Turin to collect their own blood samples) that the blood contains "extraordinary" levels of bilirubin? (I strongly suspect there was no bilirubin, none whatsoever. It was simply a pigment of someone's imagination. Sorry. Couldn't resist that).
How many shroudologists have commented (adversely or otherwise) on the extraordinary absence of documentation, whether illustrated or not, to back these major claims, now mantras, at least in general circulation as one would expect them to be, and not secreted away in personal memoirs etc that are still copyrighted and still earning income for someone, despite these STURP personalities having sadly shuffled off their mortal coil?
Finally, there was this comment yesterday from the fluent David Goulet:
October 16, 2014 at 11:49 am
Perhaps Yannick and Colin can organize the anti-St. Louis
conference. I can appreciate your criticisms of the conference, but talk
is cheap gents. To quote the kids today, “be the change you wish to
see”. Reading from the Book of Lamentations gets us nowhere.
Yes, but don't you realize David that is PRECISELY what I have been doing for nigh on three years, NOT engaging in non-stop carping criticism, but instigating (or trying to instigate) the change I wish to see.
Come to think of it, was it worth posting that research proposal in response to the invite extended on that same site? It elicited zero response, despite an ongoing so-called conference that did at least have an allocated time-slot to discuss directions for future research.
October 11, 2014 at 10:55 am
Where future research on the TS image is concerned, it’s time to
discriminate between, on the one hand, the STURP view that saw the
image as pyrolysed carbohydrates and, on the other, the idea of it being
some kind of Maillard reaction product. (That’s whether or not one buys
into Rogers’ putrefaction vapour model (it not being the only means of
ending up with a Maillard product).
The problem one is up against, from a chemical standpoint, is the superficiality of the image and its chemistry, relative to the bulk carbohydrates of flax fibres. It’s a tall order, analytically-speaking, to distinguish image signal (or should that be signature?) from substrate background noise.
There is a possible way it might be done, though it’s admittedly a bit of a long shot.
Ray Rogers employed the technique of pyrolysis mass spectrometry, which basically fragments a specimen and then collects and measures those fragments according to their m/e (mass to charge) ratios. It was that technique that allowed him to pick up a signal for hydroxyproline in the “blood”, an important finding, even if his conclusions were open to differing interpretations.
So how might that technique be refined to discriminate between pyrolysis and Maillard products? The crucial difference is the small amount of additional Maillard-reacted nitrogen in the image compared to the non-image areas.
If one simply took image and non-image areas and performed pyrolysis-mass-spec, looking for differences in fragmentation pattern that could be related to known chemistry, there would almost certainly be a signal/noise problem, as already stated. But there’s a possible way of filtering out some of that noise, or at any rate pinpointing the crucial fragments.
Adler and Heller discovered that the TS image is bleachable with diimide (N2H2), which is a powerful reducing agent. The latter can be reasonably assumed to decolorise chromophores by adding hydrogen atoms across double bonds. So the trick is to do difference spectrums, before and after diimide treatment, and look for all those fragments that differ by m/e =2, corresponding to addition of two hydrogen atoms per molecule or fragment thereof. Having located those key fragments, one then looks up their m/e values, giving preference (where any ambiguities might exist) to those which contain the element nitrogen, bearing in mind there can be no Maillard reaction without a source of that element in the form of amino (-NH2) groups.
If one finds nitrogen in the key diimide-reducible fragment, then one should think Maillard reaction. If one does not, then think simple pyrolysis.
The problem one is up against, from a chemical standpoint, is the superficiality of the image and its chemistry, relative to the bulk carbohydrates of flax fibres. It’s a tall order, analytically-speaking, to distinguish image signal (or should that be signature?) from substrate background noise.
There is a possible way it might be done, though it’s admittedly a bit of a long shot.
Ray Rogers employed the technique of pyrolysis mass spectrometry, which basically fragments a specimen and then collects and measures those fragments according to their m/e (mass to charge) ratios. It was that technique that allowed him to pick up a signal for hydroxyproline in the “blood”, an important finding, even if his conclusions were open to differing interpretations.
So how might that technique be refined to discriminate between pyrolysis and Maillard products? The crucial difference is the small amount of additional Maillard-reacted nitrogen in the image compared to the non-image areas.
If one simply took image and non-image areas and performed pyrolysis-mass-spec, looking for differences in fragmentation pattern that could be related to known chemistry, there would almost certainly be a signal/noise problem, as already stated. But there’s a possible way of filtering out some of that noise, or at any rate pinpointing the crucial fragments.
Adler and Heller discovered that the TS image is bleachable with diimide (N2H2), which is a powerful reducing agent. The latter can be reasonably assumed to decolorise chromophores by adding hydrogen atoms across double bonds. So the trick is to do difference spectrums, before and after diimide treatment, and look for all those fragments that differ by m/e =2, corresponding to addition of two hydrogen atoms per molecule or fragment thereof. Having located those key fragments, one then looks up their m/e values, giving preference (where any ambiguities might exist) to those which contain the element nitrogen, bearing in mind there can be no Maillard reaction without a source of that element in the form of amino (-NH2) groups.
If one finds nitrogen in the key diimide-reducible fragment, then one should think Maillard reaction. If one does not, then think simple pyrolysis.
October 11, 2014 at 11:24 am
PS: I see from googling that one can purchase deuterated and
tritiated diimide (N2D2 and N2T2 respectively). Those reagents would
greatly simplify the task of spotting the reduced fragments on mass
spectrographs, given they contain heavier isotopes with m/e ratios 2 and
3 times greater than hydrogen.
------------------------------------------
Oh, but I'm being forgetful. There's a requirement to be "one of us", not "one of them" in order to have one's scientific views and credentials taken seriously. That posting from PDL above shows what one is up against when dealing with members of the self-appointed Shroud Science Club, sorry, Group, a ploy if ever there was to keep shroudology 'in the family' , to block out outsiders. Don't believe me. Read what Giulio Fanti wrote on shroudstory a while ago (July 2012)------------------------------------------
Personally, I have nothing against the Shroud Science Group as such (while preferring myself to remain free of 'clubs'). But I do take exception to someone who says he "does not want to waste time in discussions outside the Shroud Science Group". That's not how science operates. All that matters in science are the ideas, wherever they come from. Personally, I'll listen to anyone who can deliver new thinking on the Shroud. There are no 'card-carrying shroudologists' where this blogger is concerned.
Draft title for next posting: "It's high time Shroudology dumped the exponents of authenticity-promoting science fiction, and returned to first principles."
Saturday 18 October
Fancy. No sooner have I flagged up a more proactive stance against the purveyors of pseudoscience, or at any rate, those who have blind spots for conventional physics, and what do I find? Six visits today, no less, to a posting I did on my WordPress site, way back in September 2012, which I'd forgotten about, but which on re-reading said pretty well everything I would have said in my next posting.Yes, 6 visits to a particular posting. Yup, that is most unusual, nay, exceptional, indeed totally unique in my experience. Summat's afoot!
Here's a link.
And here's a screen grab with the title:
So who's picked up on that posting and why? Is it a single individual, or a group, dare one say club, that is preparing some kind of attack, or more fancifully on my part, a defence or even prospective damage-limitation exercise? I'm on tenterhooks now, wondering how this might pan out.
Still Sat 18 October (19:20)
There's a difference between (a) slaving away at the bench for years, as claimed, attempting to reproduce the TS image with one or other experimental approach, each failing to tick all those boxes, as distinct from (b) doing nothing experimentally year after year, on the grounds that increasing knowledge of the fine details of the TS image reveals it to be far too subtle to be capable of replication in the laboratory with conventional science, far less medieval technology.
If (b), one cannot claim that "heating linen cannot give a superficial discoloration" if one has not in fact bothered to test that proposition experimentally, notably by contact scorching, claiming instead that the experiment could never give a positive result (and then, late in the day, finally getting round to doing the experiment, albeit in cack-handed fashion, but under conditions that are virtually guaranteed to deliver the "predictable" negative result.
I do believe that to be an accurate account of why we come to be where we are. That's almost 3 years after the claim that the TS image has never been replicated with conventional science, DESPITE TRYING, or so we are told. Frankly, I fail to see any evidence that genuine attempts were made to do that initially as claimed. However, I'm prepared to concede that's an uncharitable view, and that I've missed things in my reading.
Well, I have some lengthy papers, pdfs etc to read, or in most cases re-read, to seek evidence for the claimed years of work ever having been done, as distinct from theorizing as to what is/was not worth doing. It may take some time away from this blog to complete that reading, but if my hunch is correct, namely that what is claimed as activity was in fact sheer inertia - a disinclination to embark on activity, then I shan't mince my words. If that were the case, as I strongly suspect, then we've all been led up the garden path by exponents of a certain brand of pseudoscience, and the sooner we get back to Square 1 and re-examine the entire issue of the TS image provenance from first principles, ie. CONVENTIONAL physics and chemistry, the better.
I may be gone some time (but will continue to keep an eye open for new developments in the world of science and ideas generally).
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