Gluten Index for Wheat Products Main Variables in Affecting the Value and Nonlinear Regression Model
Gluten HMM subunits importance (update 20-01-2020)
Extract from the study: The structure and properties of gluten
“…..omissis. One group of gluten proteins, the HMM subunits of glutenin, is particularly important in conferring high levels of elasticity (i.e. dough strength). These proteins are present in HMM polymers that are stabilized by disulphide bonds and are considered to form the ‘elastic backbone’ of gluten. However, the glutamine-rich repetitive sequences that comprise the central parts of the HMM subunits also form extensive arrays of interchain hydrogen bonds that may contribute to the elastic properties via a ‘loop and train*’ mechanism. Genetic engineering can be used to manipulate the amount and composition of the HMM subunits, leading to either increased dough strength or to more drastic changes in gluten structure and properties.
….omissis. These properties are usually described as viscoelasticity, with the balance between the extensibility and elasticity determining the end use quality. For example, highly elastic (‘strong’) doughs are required for breadmaking but more extensible doughs are required for making cakes and biscuits. Omisdsis….The grain proteins determine the viscoelastic properties of dough, in particular, the storage proteins that form a network in the dough called gluten (Schofield 1994). Consequently, the gluten proteins have been widely stud ied over a period in excess of 250 year, in order to determine their structures and properties and to provide a basis for manipulating and improving end use quality.
*
…omissis. As a result of the formation of a protein matrix, individual cells of wheat flour contain networks of gluten proteins, which are brought together during dough mix ing. The precise changes that occur in the dough during mixing are still not completely understood, but an increase in dough stiffness occurs that is generally considered to result from ‘optimization’ of protein–protein interactions within the gluten network. In molecular terms, this ‘optimization’ may include some exchange of disulphide bonds as mixing in air, oxygen and nitrogen result in different effects on the sulphydryl and disulphide contents of dough (Tsen & Bushuk 1963; Mecham & Knapp 1966).
Mixture of grains (evolutive grain): no thanks!
“Ma di che si tratta esattamente? Una popolazione evolutiva non è altro che una mescolanza di tantissime varietà diverse della stessa specie. Un concetto tanto semplice, quanto concretamente utile: Questi miscugli servono a far fronte al cambiamento climatico grazie alla loro capacità di evolversi nel tempo. Proprio per questa loro capacità Ceccarelli preferisce chiamarle popolazioni evolutive, e non miscugli come si fa spesso. Vi faccio un esempio concreto: nel 2008 mentre lavoravo ad Aleppo ho mescolato un migliaio di tipi di semi di orzo e li ho portati ad alcuni agricoltori in cinque paesi diversi: Siria, Algeria, Eritrea, Giordania e Iran. Il risultato è stato subito un raccolto abbondante, che poi è stato distribuito ad altri agricoltori, e le sementi così selezionate sono state diffuse. L’anno successivo ho fatto lo stesso con frumento duro (mescolando 700 tipi diversi) e con il frumento tenero (mescolando 2000 tipi diversi). Con gli anni queste tre popolazioni si sono moltiplicate, hanno viaggiato per tutto il Medio Oriente e nel 2010 sono arrivate e hanno cominciato a diffondersi in Italia. Una diffusione avvenuta spontaneamente tra gli agricoltori con il semplice passaparola. I vantaggi. Si tratta di miglioramento genetico partecipativo-evolutivo, facilmente spiegabile attraverso la teoria dell’evoluzione, secondo cui coltivando una popolazione evolutiva, ci si mette al riparo da malattie ed erbe infestanti nuove o cambiamenti climatici perché tra gli individui di una popolazione ce ne sarà sempre una parte che riuscirà a cavarsela. Non solo, con le popolazioni evolutive si evita di sottostare al monopolio dei semi e all’impoverimento dei raccolti e della dieta quotidiana. “ Fonte: https://www.gamberorosso.it/notizie/articoli-food/grano-evolutivo-storia-e-vantaggi-del-miscuglio/ intervista al Dott. Salvatore Ceccarelli.
The consumer demand is increasingly oriented to knowing what they put on the plate, or rather to have the possibility to know the whole product chain and its characteristics. The wine and oil supply chain, to cite just two important examples, testify to the importance of complete and possibly exhaustive information, which is also the key, together with the quality, of the success of the most famous products. With wheat do we want to walk this path backwards? Do we eat what the field produces as mother nature decides?
Monococcum wheat (einkorn) and the market offer
Scientific research has long highlighted the peculiar characteristics of the monococcum wheat reported in (https://glutenlight.eu/2019/03/11/il-grano-monococco/) and can be summarized as follows:
- High digestibility of gluten
- High tolerability in relation to gastro-intestinal disorders (celiac disease excluded)
- High mineral and vitamin content
- High availability of bioactive components
- A different ratio between the components of starch sugar with a prevalence of slow absorption.
Monococcum wheat has, for some time, been the focus of producers-transformers and consumers. The offer, especially of flour, as well as of products is constantly increasing. The products offered, however, do not have, except in rare cases, complete traceability starting from the field to the table. On the flour packages it is rare to find indications regarding the variety of wheat from which it derives; on the final products we find the mandatory ingredients by law but, rarely, the preparation method. The speech, however, applies to all grains both ancient and modern. The greater attention to the monococcum wheat (einkorn) is due to the evocative force of its ancestral origin and to its characteristics of high digestibility, tolerability and healthy contents.
The variety of wheat used and the indicators that inform us about the quantity and “strength” of gluten would be particularly valuable to be able to include more digestible products in our diet when needed. Gluten, as it is formed during water and flour are kneaded, cannot be digested by our intestines, it must first be “broken” by digestive enzymes into very small “fragments”. In this way other digestive enzymes in the intestine will complete the work in order to make the gluten components “amino acids” assimilable. The lower amount of gluten and less strength will sometimes make our task much easier. Products made with monococcoum wheat flour (einkorn) and generally those made with “ancient grains” are advertised as “very digestible” or “highly digestible”. Both terms are very generic since they can present strong differences in terms of gluten quantity and “gluten strength”. Recently I bought two different monococcum wheat flours of which I pointed out the amount of gluten: one has a percentage of dry gluten of 9.6% the other of 17.1%! Same thing with the strength of gluten whose index in one case was 33 in another 71!These indicators are a first valid help that we could have to better balance, with the support of the doctor, our diet. It should also be remembered that the final digestibility of the product made with flours, whatever they may be, is also greatly influenced by the way in which the products are prepared: just think of the considerable contribution to digestibility that we can obtain by using sourdough, but this information is also generally absent or present in an ambiguous way or without specification of which flour was used: “… made with sour dough”. https://glutenlight.eu/2019/05/08/la-fermentazione-della-pasta-acida-ii-parte/.