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Einkorn, emmer and durum wheat

by luciano

Einkorn, emmer and durum wheat: they do not have the “33mer” fraction considered the most active in activating the adverse response of the immune system in celiac subjects. Also for this reason they are the most suitable genotypes for the researches whose aim is to “detoxify” the flours or to intervene with particular enzymes to hydrolyse the “toxic peptides”, however present; they are also more suitable for non-celiac gluten sensitive subjects.

“Quantitation of the immunodominant 33-mer peptide from α-gliadin in wheat flours by liquid chromatography tandem mass spectrometry.

Kathrin Schalk , Christina Lang , Herbert Wieser , Peter Koehler  & Katharina Anne Scherf. Scientific Reports volume 7, Article number: 45092 (2017)

Abstract

Coeliac disease (CD) is triggered by the ingestion of gluten proteins from wheat, rye, and barley. The 33-mer peptide from α2-gliadin has frequently been described as the most important CD-immunogenic sequence within gluten. However, from more than 890 published amino acid sequences of α-gliadins, only 19 sequences contain the 33-mer. In order to make a precise assessment of the importance of the 33-mer, it is necessary to elucidate which wheat species and cultivars contain the peptide and at which concentrations. This paper presents the development of a stable isotope dilution assay followed by liquid chromatography tandem mass spectrometry to quantitate the 33-mer in flours of 23 hexaploid modern and 15 old common (bread) wheat as well as two spelt cultivars. All flours contained the 33-mer peptide at levels ranging from 91–603 μg/g flour. In contrast, the 33-mer was absent (<limit of detection) from tetra- and diploid species (durum wheat, emmer, einkorn), most likely because of the absence of the D-genome, which encodes α2-gliadins. Due to the presence of the 33-mer in all common wheat and spelt flours analysed here, the special focus in the literature on this most immunodominant peptide seems to be justified……Omissis…..

Analysis of durum wheat, emmer and einkorn

The 33-mer peptide was also analysed in two durum wheat and two emmer cultivars (genome AABB) as well as two diploid einkorn cultivars (genome AA) (Table 1). In each of these wheat species, the 33-mer was not detected (<LOD). In comparison to hexaploid common wheat, durum wheat, emmer, and einkorn do not contain the D-genome, which originated from hybridisation of T. turgidum dicoccum (genome AABB) with Aegilops tauschii (genome DD)36. The absence of the 33-mer peptide can be explained by the fact that this peptide is encoded by genes located in the Gli-2 locus on chromosome 6D, which is missing in durum wheat, emmer, and einkorn. Studies by Molberg et al. showed clear variations in intestinal T-cell responses between common wheat and tetra- or diploid species due to different degrees of T-cell immunoreactivity between the gluten proteins encoded on the A-, B-, and D-genome. Einkorn cultivars were only recognized by DQ2.5-glia-α1a-specific T-cell clones, but not by DQ2.5-glia-α1b- and DQ2.5-glia-α2-specific T-cell clones. Emmer and durum wheat cultivars were all recognized by DQ2.5-glia-α1a-specific T-cell clones, but only two out of four emmer cultivars and three out of ten durum wheat cultivars activated DQ2.5-glia-α1b- and DQ2.5-glia-α2-specific T-cell clones37. Consistent with our results, Prandi et al.38 found that the 33-mer was not present in durum wheat. As a consequence, this peptide was used as a marker peptide to identify the presence of common wheat in durum wheat flours. One durum wheat cultivar was also analysed by van den Broeck et al.33 and the 33-mer peptide was not detected either”. https://creativecommons.org/licenses/by/4.0/deed.it

 

Monococcum wheat (einkorn) and the market offer

by luciano

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:

  1. High digestibility of gluten
  2. High tolerability in relation to gastro-intestinal disorders (celiac disease excluded)
  3. High mineral and vitamin content
  4. High availability of bioactive components
  5. 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/.

Grain varieties with low toxic fraction content: an opportunity for products dedicated to children

by luciano

LC/MS ANALYSIS OF GLUTEN PEPTIDES DERIVED FROM SIMULATED GASTROINTESTINAL DIGESTION OF DIFFERENT WHEAT VARIETIES: QUALITY AND SAFETY IMPLICATIONS. Sforza, Stefano & Prandi, Barbara & Bencivenni, Mariangela & Tedeschi, Tullia & Dossena, Arnaldo & Marchelli, Rosangela & Galaverna, Gianni. (2011):

Abstract:

“Gluten content of wheat is highly variable, depending on the plant genetics and the growing conditions. Beside short peptides, gastrointestinal digestion of gluten also produces longer ones, since the high proline content of gliadins (16-26%) and glutenins (11-13%) makes them very resistant to the degradation by digestive proteases. In the present work, a method for the extraction of the prolamine fraction was applied to different wheat varieties, followed by a simulated gastrointestinal digestion of the gliadin extracted. The peptide mixtures generated were characterized by LC/MS, and most abundant peptides were identified by low- and high-resolution multiple stage MS techniques and through synthesis of authentic standards. These peptides were also semiquantified in the different samples against a suitable internal standard. The peptide mixtures were found to be highly variable, according to the different content and type of gliadins present in wheat varieties, with strong differences among the varieties tested, both qualitatively (the sequences of the peptides generated) and quantitatively (their amount). The greatest difference was found between common and durum wheat varieties. Peptides present only in the former varieties were identified, and used as molecular markers for identifying and quantifying the presence of common wheat when added to durum wheat samples. Most of the peptides identified were also already known to be pathogenic for people affected by celiac disease, an autoimmune enteropathy triggered by gluten proteins, which develops in some genetically susceptible subjects after gluten consumption. Some samples belonging to defined varieties showed a lower amount of celiac-related pathogenic peptides upon digestion, due to a lower gliadin content. Albeit not safe for celiac patients, the use of these varieties in the formulations of baby food could be of great help for lowering the spread of the disease, since the prevalence of celiac disease seems to be promoted by an early exposure to a large amount of gluten peptides”.

Ancient and modern grains, gluten intolerance and pesticides: Enzo Spisni answers readers’ questions

by luciano

Grani antichi e moderni, intolleranza al glutine e pesticidi: Enzo Spisni risponde alle domande dei lettori
(DA: Redazione Il Fatto Alimentare 11 Agosto 2017)

La questione dei grani antichi e della sensibilità al glutine fa molto discutere. Non sorprende quindi, che l’articolo “Pasta con grano antico o moderno: il problema dell’intolleranza al glutine è lo stesso? Spisni risponde a Bressanini” abbia scatenato un acceso dibattito. Ecco le risposte di Enzo Spisni, docente di Fisiologia della Nutrizione all’Università di Bologna, ai tanti commenti dei lettori del Fatto Alimentare.
Prima l’incipit. Ho sottolineato che tutti possono fare divulgazione scientifica, ma solo tre figure hanno le competenze e possono (per la legge italiana) modificare il modo di alimentarsi e la dieta delle persone. In un paese in cui troppi parlano di diete senza avere competenze e in cui famosi farmacisti vanno in televisione a suggerire diete e dichiarano di avere migliaia di “pazienti”, mi sembra quantomeno un appunto doveroso.
Veniamo alle definizioni. Si definiscono antichi o tradizionali le cultivar presenti prima della cosiddetta “Rivoluzione Verde”. Le differenze sostanziali tra i grani pre-rivoluzione e quelli post-rivoluzione possiamo riassumerle in quattro punti:
1. La forza del glutine. Si parte da grani che hanno un valore W di forza del glutine di 10-50 e si arriva ai moderni che hanno una forza intorno ai 300-400. È evidente che la struttura del glutine cambia per venire incontro alle necessità dell’industrializzazione degli alimenti.
2. La taglia. I grani pre-rivoluzione sono a taglia alta (diciamo oltre il metro e trenta), mentre i post sono a taglia bassa (molto al di sotto del metro).
3. La produttività per ettaro, che aumenta molto nei moderni a fronte però dell’aumento dell’input di azoto attraverso la concimazione. Lascio il discorso su quanto azoto per ettaro agli agronomi, ma chi in campo è passato dal coltivare moderni in convenzionale a grani antichi in biologico si è reso ben conto del risparmio in denaro generato dalla minore concimazione e dal minore uso di chimica.
4. La minore variabilità genetica, nel senso che le cultivar antiche erano un insieme di genotipi con una biodiversità complessivamente elevata, mentre post-rivoluzione si è andati verso la selezione di grani “in purezza”, fatta di piante tutte geneticamente identiche, con una perdità netta di biodiversità non trascurabile. In altre parole è cambiato il concetto di adttamento: mentre una variabilità genetica ampia è in grado di adattarsi ai mutamenti ambientali, una variabilità genetica ridotta richiede un maggior intervento dell’uomo nel tentativo di meglio adattare il campo al tipo di grano coltivato. E l’intervento dell’uomo molto spesso si traduce in utilizzo di prodotti chimici.

Surdough fermentation (II part)

by luciano

Surdough and phytates
“Increasing fiber content in flour may result in a lower assimilation of minerals complexed by phytates. An optimisation of the fermentation step with surdough allowed to improve both the bioavailability of minerals as well as the sensory attributes of the resulted bread. (16mo. IFOAM Organic World Congress, Modena, Italy, June 16-20, 2008 Archived at ttp://orgprints.org/view/projects/conference.html)”.

Note: Phytic acid is traditionally considered an anti-nutritional factor, ie a substance that can limit the absorption or use of nutrients. In the specific case, by binding to them to form insoluble salts (phytates and phytin), phytic acid hinders the absorption of some minerals (calcium, iron, magnesium and zinc).

Sourdough fermentation and basic baking properties
“Unfortunately, there is often a trade- off between degradation of reactive gluten and retention of gluten for basic baking properties. Large amounts of time and heat may be needed for microbial enzymes to break down problematic pep- tides. To fully degrade the 33-mer α-gliadin peptide in wheat required 24 h at 30 °C (Gallo and others 2005), while durum required 72 h of fermentation at 37 °C to meet gluten-free la- beling standards (De Angelis and others, 2010). HMW glutenins, which are important for baking and pasta integrity, are degraded prior to and more extensively than reactive prolamins during sour- dough fermentation (Ga ̈nzle and others 2008; Wieser and others 2008). Extensively fermented dough has a high ratio of gliadins to glutenins, which is very undesirable for bakers. The disulfide bonds holding together the gluten macropolymer (GMP), an in- tegral component of baking quality, begin to degrade long before glutens. Only 5 h of fermentation with Lactobacilli or acidic chem- icals degraded GMP by up to 46% (Wieser and others 2008). Pentosans, an important component for baking rye bread, were also hydrolyzed in germinated sourdough (Loponen and others 2009). Consequently, the long and hot sourdough fermentation to hydrolyze prolamins compromises functional baking properties of the dough. (A Grounded Guide to Gluten: How Modern Genotypes and Processing Impact Wheat Sensitivity – Chapter Fermentation and microbial enzymes – Lisa Kissing Kucek, Lynn D. Veenstra, Plaimein Amnuaycheewa, and Mark E. Sorrells. Comprehensive Reviews in Food Science and Food Safety Vol. 14, 2015.)”.

Microbiology of sourdough
“It is well known that the type of bacterial flora developed in each fermented food depends on water activity, pH (acidity), minerals concentration, gas concentration, incubation temperature and composition of food matrix (Font de Valdez et. al. 2010). The microflora of raw cereals is composed of bacteria, yeast and fungi (104 – 107 CFU/g), while flour usually contains 2 x 104 – 6 x 106 CFU/g (Stolz, 1999). In sourdough fermentation major role play heterofermentative species of LAB (Salovaara, 1998; Corsetti & Settani, 2007), especially when sourdoughs are prepared in a traditional manner (Corsetti et. al., 2003). Lactobacillus sanfranciscensis, Lactobacillus brevis and Lactobacillus plantarum are the most frequently lactobacilli isolated from sourdough (Gobbetti, 1998; Corsetti et. al. 2001; Valmorri et. al., 2006; Corsetti & Settanni, 2007). The following yeasts have been detected in cereals (9 x 104 CFU/g) and flour (2 x 103 CFU/g): Candida, Cryptococcus, Pichia, Rodothorula, Torulaspora, Trychoporon, Saccharomyces and Sporobolomyces. Saccharomyces cerevisiae is not found in the raw materials. Its occurance in sourdough has been explained by the application of baker’s yeast in most daily bakery practice (Corsetti et. al., 2001). The importance of antagonistic and synergistic interactions between lactobacilli and yeasts are based on the metabolism of carbon hydrates and amino acids and the production of carbon dioxide (Gobetti & Corsetti 1997). Lactic and acetic acid are predominant products of sourdough fermentation). Influence of Acidification on Dough Rheological Properties Daliborka Koceva Komlenić, Vedran Slačanac and Marko Jukić Faculty of Food Technology, Josip Juraj Strossmayer University of Osijek, Croatia 2012- www.intchopen)”.