Which type of flour is better for modelling the Man on the Turin Shroud? Aristocratic fine white wheat or monkish rye wholemeal?

This posting is simply a record of yesterday’s experiments, caught on my digital camera. In other words it’s just the facts, although my title hints of a broader context – to do as much if not more with medieval French history than borrowed bread-baking technology.

To keep things simple (I like simplicity), I’ll postpone discussion of the facts in relation to the Shroud’s likely provenance – authentic 1st century (highly improbable) versus medieval fabrication (consistent with the radiocarbon dating) to my own COMMENTS section.  See inconspicuous tab at end of posting. Feel free to participate, with just two ground rules: stay civil, and no attempting please to flummox  readers with pseudoscience. This blogger loathes pseudoscience. It damages (and indeed HAS damaged) real science enough already, so-called sindonology  (Shroud studies) being a prime example.

Wholemeal rye flour, approx 10% protein, 17% dietary fibre. Compare with typical white wheaten flour (sieved to remove bran flakes) which is also about 10% but only 3% or so dietary fibre.

1. Wholemeal rye flour, approx 10% protein, 17% dietary fibre. Compare with typical white wheaten flour (sieved to remove bran flakes) which is also about 10% protein  – good for Maillard browning reactions –  when reducing sugars are present – but much less  dietary fibre (typically 3%).

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My hand coated with either wheat flour (left) of rye flour (right). Note the hand is vertical in both cases, signifying that one attempts to dislodge as much surplus flour as possible. The imprinting technique works best with a LIGHT DUSTING of flour onto the skin that has been lightly smeared with vegetable oil, the latter acting as weak adhesive.

2. My hand coated with either wheat flour (left) of rye flour (right). Note the hand is sloping downwards in both cases, signifying that one  has endeavoured  to dislodge as much surplus flour as possible. The imprinting/modelling  technique works best with a LIGHT DUSTING of flour onto the skin that has first been lightly smeared with vegetable oil, the latter acting as a weak adhesive. Too much flour creates problems at the final washing step.

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We've now jumped some steps (like imprinting the flours onto wet linen, drying in warm air, then transferring to a fan oven at max temperature setting - see previous postings for details. Here are the flour imprints immediately after 10 mins or so of roasting, their colour being due mainly (one considers) to Maillard reactions between reducing sugars and protein, as in bread baking, toasting etc. That's wheat flour on the left, rye flour on the right. Which has worked better?

3. We’ve now telescoped the photographic record  (like omitting the imprinting  pix of the flours onto wet linen, drying in warm air, then transferring to a fan oven at max temperature setting – see previous postings for details). Here are the flour imprints immediately after 10 mins or so of roasting, their colour being due mainly (one considers) to Maillard reactions between reducing sugars and protein, as in bread baking, toasting etc.
That’s wheat flour on the left, rye flour on the right. Which of the  two has worked better?

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4. Here are before and after comparisons of the final washing step (step) for each of the two flours. The washing step is needed to convert the intense red-brown imprint one sees straight from the oven into the much fainter, ghostly, arguably more Shroud-like body image.

4. Here are before/after comparisons of the final washing step for each of the two flours. The washing step was needed to convert the intense red-brown imprint one sees straight from the oven into the much fainter, more ghostly, arguably more Shroud-like  image. Is that final image still a Maillard product, or merely scorched linen that was in close proximity with a Maillard reaction? Answer: PASS. 

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Here's a screen grab from a page of a book written by two of this blogger's colleagues at the Flour Milling and Baking Research Association, Chorleywood, Herts, UK, now part of the CCFRA  (Chipping Campden).  It's included to disabuse folk of the common misconception that white flour is a 19th century innovation that arrived with roller milling. Not so. White flour, obtained by sieving wholemeal flour to remove bran flakes, has been an article of commerce for centuries, probably millennia, albeit for the better off, like the aristocracy of medieval France, but not for humble monks in monasteries. Why the need to make this distinction? See the Comments under this posting, to be added in the next day or two.

5. Here’s a screen grab from a page of a book written by two of this blogger’s colleagues at the Flour Milling and Baking Research Association, Chorleywood, Herts, UK, now part of the CCFRA (Chipping Campden).
It’s included to disabuse folk of the common misconception that white flour is a 19th century innovation that arrived with roller milling. Not so. White flour, obtained by sieving wholemeal flour to remove bran flakes, has been an article of commerce for centuries, probably millennia, albeit for the better off, like the aristocracy of medieval France, but not for humble monks in monasteries. Why the need to make this distinction? See the Comments under this posting, to be added in the next day or two.

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To see the initial response to this blogger’s ‘flour imprinting’ model, one could do worse (but sadly better too, at least in an ideal world) to see the reception it received on Dan Porter’s now retired-from-the-fray shroudstory site back in September last year.

PS: something’s that’s just occurred to me is that the ‘flour imprinting’ effect could have been discovered purely by accident. Where?  In a bread or other bakery. How? A baker with floury hands (or dough-coated ones) wipes his hands on a cloth. The cloth is left close to or even inside an oven by mistake. Hey presto, our baker comes back later to find an image of his hands and/or fingers. Imagine the effect on someone who lived centuries before the discovery of photography to see the kind of detail (possibly) that one sees on my flour imprints, the white wheaten flour one especially, where even the crumpled skin folds at the finger joints are imprinted.

Did our baker immediately rush out yelling “Eurkea”, disclaiming that he had obtained negative images that were possibly 3D-enhancible, given the right technology, still to be discovered?

Nope. Bit I’m willing to bet he slipped it into conversation with his friends and relatives, and somebody’s ears pricked up. Hmmm. Might there be a small or even huge fortune to be made if/when a practical application could be found for the ‘floury fingers’ proto-fax machine?

Now imagine a remote location like medieval Lirey, with a tiny population where everyone, the lord of the manor included, probably bakes his own bread.  It only takes one baker, private or commercial, on friendly terms with his neighbours or customers,  making small talk. to provide the germ of an idea for fabricating an imaginary sheet of linen, bearing not just a hand, but an entire two-fold body imprint of a crucified man…  Wounds? Substitute bloodstains  for actual wounds? Hmmm.  Thinks…

New addition: 5th Jan 2015

Here’s a test with corn starch, known in the UK (misleadingly) as cornflour, in the new(ish) flour imprinting using my own hand as template . It’s the same starch I tested back in October 2014 under a range of experimental conditions, obtaining ambiguous or unsatisfactory results, but that was before the present methodology had been fine-tuned).

Why the importance of testing corn starch?

DSC02022

It has only 0.3% protein so is unlikely to give a strong Maillard browning reaction, assuming reducing sugar is present. Can that prediction be confirmed?

DSC02046

Prediction confirmed: there’s a far more intense image of my hand after oven-roasting with the white wheat flour, 10.2% protein, right, than with the corn starch, 0.3% protein, left.

.compare corn starch with white wheat flour labelled

Here’s the appearance after the final soap/water washing stage. No surprises here.

See Comments for discussion of these and earlier results.

As indicated earlier, this blogger had begun to experiment with flour as an imprinting agent well over a year ago though using metal horse brasses etc as template instead of my hand.

Link to sciencebuzz posting, October 24, 2014

Here’s a screen grab from that posting:

 

cropped first flour imprinting october 2014 sciencebuzz.

Why the disenchantment, due to the image being so fragile, such that one could brush it off the linen? Answer: although the technology was similar to that used here on my hand, i.e. first smear the brass with vegetable oil, dust with flour, imprint onto linen, roast in fan oven, there was one crucial difference. The linen was DRY instead of being pre-soaked in water. Use of dry powdered flour as imprinting agent is what gives the TS-like fuzzy image, even before washing, but the imprint has to be made onto WET linen to get proper bonding of flour particles to the surface of the fabric.

 

 

 

 

 

 

 

 

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About Colin Berry

Retired science bod, previous research interests: phototherapy of neonatal jaundice, membrane influences on microsomal UDP-glucuronyltransferase, defective bilirubin and xenobiotic conjugation and hepatic excretion, dietary fibre and resistant starch.
This entry was posted in contact imprint, Shroud of Turin, Turin Shroud and tagged , , , , . Bookmark the permalink.

4 Responses to Which type of flour is better for modelling the Man on the Turin Shroud? Aristocratic fine white wheat or monkish rye wholemeal?

  1. Colin Berry says:

    Have been looking back through my published posts, not only here but my neglected sciencebuzz site, and find that I had been imprinting with flours as far back as October 2014.

    http://colinb-sciencebuzz.blogspot.co.uk/2014/10/modelling-shroud-of-turin-image-with.html

    That was before I was imprinting off my own flesh-and-blood hand, and was imprinting off brass bas relief or 3D templates as an alternative to hot scorching. The technique was very similar to the current one, i.e. to smear the metal template with vegetable oil, then dust with flour, then imprint onto linen (dry, not wet as currently) then oven-bake.

    There were some very promising results ( bas relief templates) and some ghastly ones (3D brass crucifix) and it was disconcerting to find that even the good images off the shallow-relief horse brasses could be brushed off (in retrospect, a result of imprinting onto DRY linen).

    But there’s an important detail, namely that an image of sorts was obtained using “cornflour”, better described as corn starch, despite the latter having scarcely any protein, and thus unlikely to generate a Maillard browning reaction – though a simple caramelization reaction of sugars was possible to explain the final image. Caramelization of sugars does not need protein or other amine functional groups. It’s a sugar-only reaction (maybe atmospheric oxygen too).

    Why mention it now? Maybe it’s premature to be talking about Maillard reactions. Maybe caramelization is a better description. Tomorrow I shall try imprinting off my hand using that low-protein corn starch, not because it’s relevant to medieval France (it’s not, being a New World product), but to see whether the imprinting mechanism proposed with solid “flour” as dry powder and heat, albeit onto wet linen, can work with carbohydrates alone – indicative of caramelization – independent of proteins.if it’s caramelization alone, then the final attenuated image after washing may still be described fairly as a “scorch”, that much maligned description where sindonology is concerned.

    Reminder: this site is not a bound collection of fait accompli pdfs. It’s a running day-by-day, week-by-week log of a (hopefully progressive) learning curve.

  2. Colin Berry says:

    Have done that crucial experiment today with the corn starch aka cornflour in the UK, and added three photographs to the end of this posting. Here’s one of them that shows the predicted result was obtained.

    https://shroudofturinwithoutallthehype.files.wordpress.com/2016/01/dsc02046.jpg?w=640&h=480

    It doesn’t prove conclusively that the bold imprints I am seeing are exclusively due to Maillard browning (protein/reducing sugar interaction) but can be seen as supportive evidence.

    It still leaves unanswered the question as to the nature of the resistant ‘ghost’ image that remains after soap/water washing. Is that much fainter image also a Maillard reaction product formed by reaction between the added carbohydrates and protein of flour, or does it have an entirely explanation, maybe involvingone or more of the components of linen?

    Naturally, our putative medieval artisans, working away in Lirey or elsewhere, would not have been bothered about such things. All they needed was a faint sepia-tone image on linen that could be displayed to visiting pilgrims, claiming it to be a seriously age-degraded 1350 year old sweat imprint, with added bloodstains in all the correct biblical locations to complete the illusion… Look, no brush marks, no sign of artists’ pigments, and indeed a self-evident IMPRINT, like a muddy footprint on a marble floor, entirely different in character from a mundane painting.

  3. Colin Berry says:

    Here’s a screen grab from my sciencebuzz site from back in October 2014 that show the white flour imprinting technique was being tentatively explored even when using horse brasses and crucifixes as inanimate metal templates instead of my own hand.

    The images were very satisfactory, as can be seen above. But there was a snag. They brushed off the linen too easily.Why? Because i was imprinting onto DRY, not wet linen. One lives and one learns about the right and wrong way to do things. See the latest addition to this posting for further details from that long and winding memory lane that brought us to the present.

  4. Colin Berry says:

    Tomorrow’s experiments?

    The immediate aim is to get some more detailed data on the final faint ghostly image after washing.

    Two variants of existing methodology will be tested. The first will be to pre-bake linen at different temperatures up to a max of 220 degrees to produce some yellowing, then imprint white flour onto that baked linen, and repeat the oven-roasting. One expects to see the initial bold Maillard product, but will there still be a ghost image after washing? What if the pre-roasting has oxidized or otherwise chemically altered linen components (lignin? hemicelluloses?) that are needed to get the ghost image?

    I will also substitute cotton for linen. Cotton, being seed hairs, not phloem bast fibres, is said to be purer than linen, having less of the non-cellulosic polysaccharides (hemicelluloses, pectins etc). Will there still be a final ghost image with cotton.?

    I may also pre-treat linen and cotton with domestic bleach (sodium hypochlorite) to see if there’s still a ghost image finally.

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