Glutenlightgrani con glutine leggero e tollerabile
Header Image - Gluten Light
Gluten LightMagazine & Library

luciano

Spelt and emmer flours

by luciano

Premise: the research highlighted the importance of sourdough made with selected LABs and with autochthonous ones of emmer and spelt flour to fully exploit the potential of these “ancient grains”. The optimum will be, therefore, starting from a sourdough with a selection of lactobacilli (LAB) and refreshing it with the flours in question, thus making the contribution of the Lab present in the same flours.

“Lactobacillus brevis 20S, Weissella confusa 24S and Lact. plantarum 31S were used as pool 1 to start spelt flour. Lactobacillus plantarum 6E, Lact. plantarum 10E and W. confusa 12E were used as pool 2 to start emmer flour. ‘Ancient grains’ could serve as an abundant source of protein and soluble fibre, oleic acid and macro- and micro-elements (Bonafaccia et al. 2000; Ruibal-Mendieta et al. 2005). In spite of this increasing interest, few results are available on the microbiota of spelt and emmer and on their suitability for bread making. Selection of starters within endogenous strains was considered the most important pre-requisite. Some recent studies (Di Cagno et al. 2008a,b,c) on fermented vegetable foods, which also included strains of Lact. plantarum, have clearly shown that endogenous strains are preferred to those of the same species isolated from different matrices to promote a rapid and intense process of acidification with a positive influence on nutritional and technological properties. To use, mixed starters was considered functional to completely exploit the potential of spelt and emmer flours. Mixture of strains with dif- ferent carbohydrate metabolism is frequently used because it may guarantee optimal acidification and sensory properties (Gobbetti 1998). Mixed obligate and facultative heterofermentative lactic acid bacteria starters, as selected in pool 1 and 2, ensured rapid growth and acidification, the capacity to liberate FAA and exploited the rheology, sensory and nutritional properties of the raw flours. This was according to a two-step fermentation process. The use of sourdough comprising selected and autochthonous strains of lactic acid bacteria was considered the most suitable biotechnology to exploit the potential of spelt and emmer flour in bread making. Fermentation of spelt, emmer or wheat flours by pool 1 and 2 was allowed according to a two-step fermentation process (Fig. 1). As the general rule, it was possible to keep it lower than 4Æ0 in spelt and emmer sourdoughs, which implied a considerable synthesis of acetic acid (Gobbetti et al. 2005). Acidity of spelt and emmer breads was perceived through sensory analysis and positively influenced the volume and crumb grain of breads. Flavour of bread is known to be influenced by the combination of raw materials, fermentation and baking process (Gobbetti et al. 2005). Spelt and emmer sourdough breads received the highest score for acid taste, and a clear preference for the global taste was assigned to spelt sourdough bread. First, this study showed the suitability of spelt and emmer flours to be used for bread making according to a two-step fermentation process. Sourdough biotechnology based on selected starters was indispensable to completely exploit the potential of these ‘ancient grains’. Spelt and emmer flours were purchased from a local market. The characteristics of emmer flour were water content, 15,0%; protein (N · 5,70), 15,1% of dry matter (d.m.); fat, 2,5% of d.m.; ash, 1,9% of d.m.; and total soluble carbohydrates, 2,6% of d.m. The characteristics of spelt flour were water content, 15,0%; protein (N · 5,70), 19,1% of d.m.; fat, 2,2% of d.m.; ash, 2,0% of d.m.; and total soluble carbohydrates, 2,7% of d.m. Spelt and emmer flours: characterization of the lactic acid bacteria microbiota and selection of mixed starters for bread making. (
R. Coda, L. Nionelli, C.G. Rizzello, M. De Angelis, P. Tossut and M. Gobbetti. 1 Department of Plant Protection and Applied Microbiology, University of Bari, Bari, Italy 2 Puratos N. V., Industrialaan, 25 B-1702z, Groot-Bijgaarden, Belgium. 2009).”

Genetic Diversity of wheat

by luciano

A-B-D Genomes

Wheat occurs in a range of diploid, tetraploid and hexaploid forms (summarised in Table 1). The earliest cultivated forms were the A genome diploid einkorn (T. monococcum var monococcum) and tetraploid emmer (T. turgidum var. dicoccum) with the A and B genomes. These are closely related to wild forms: diploid T. monococcum var. monococcum and T. ururtu and tetraploid T. turgidum var. dicoccoides, respectively. Modern tetraploid durum (pasta) wheat (T. turgidum var. durum) probably arose from mutations in cultivated emmer.
Hexaploid wheat (Triticum aestivum) (genomes ABD)
Hexaploid wheat (Triticum aestivum) (genomes ABD) has never existed as a wild species and no wild hexaploid wheats are known. It probably arose by hybridization of cultivated emmer with the related wild grass T. tauschii (goat grass, also called Aegilops tauschii and Ae. squarossa). This hybridization probably occurred in south-eastern Turkey about 9000 years ago (Feldman, 1995, Dubcovsky and Dvorak, 2007) and contributed the D genome. All cultivated hexaploid wheats, including spelt, are forms of T. aestivum.
A major difference between “ancient” cultivated wheats (einkorn, emmer, spelt) and their wild relatives and modern durum and bread wheats is whether the grain are hulled or free threshing. In hulled wheats the glumes and palea adhere to the grain and the threshed material consists of intact spikelets.
α-gliadins
As the most coeliac-active T-cell epitopes are present on the α-gliadins, emphasis has been placed on exploring differences in the amounts and sequences of proteins of this class. Kasarda
et al. (1976)
33mer fragment of α-gliadin
The studies of van Herpen et al. (2006) showed that T-cell stimulatory epitopes were more abundant in α-gliadins encoded by the D genome, and Molberg et al. (2005) who demonstrated that the immunodominant 33mer fragment of α-gliadin was encoded by chromosome 6D (and hence absent from diploid einkorn and tetraploid wheats).
The absence of the D genome from durum wheat
The absence of the D genome from durum wheat could result in lower coeliac activity due to the absence of the T-cell stimulatory epitopes at the Gli-D2 locus. van den Broeck et al. (2010a) therefore screened 103 accessions of tetraploid wheat by immunoblotting of gluten protein extracts with monoclonal antibodies against the Glia-α9 and Glia-α20 epitopes. This identified three accessions with significantly reduced levels of both epitopes. Further analysis of 61 durum wheat accessions by high throughput transcript sequencing similarly identified some accessions with lower abundances of transcripts containing coeliac disease epitopes (Salentjin et al., 2013).
Other gluten proteins
Although impressive progress has been made with identifying variation in the abundances of coeliac disease epitopes in α-gliadins, it must be borne in mind that other groups of gluten protein also contain coeliac active sequences. This was demonstrated in the survey of gluten protein sequences in the Uniprot protein sequence database by Spaenij-Dekking et al. (2005) which is referred to above. They showed that T-cell stimulatory epitopes were present in all γ-gliadin sequences (17/17), in 95.5% (21/22) of HMW subunit sequences and in 5% of LMW subunit sequences (3/57), in addition to 66% (19/29) of α-gliadin sequences. (Improving wheat to remove coeliac epitopes but retain functionality. Peter R. Shewry and Arthur S. Tatham 2016).
 

The role of additives in flour

by luciano

Autore: Simona Lauri (www.quitidiemagazine.it)

“Premessa
Qualche mese fa, una nota azienda alimentare commercializzò una farina riportante sulla confezione la dicitura “senza additivi”. Questo fatto suscitò immediatamente molte polemiche (false o presunte, non entro nel merito) ed indignazione da parte degli Operatori del Settore.

E’ chiaro che il più indignato in assoluto è stato l’inerme consumatore, che si è visto crollare addosso l’ultimo baluardo di sana alimentazione: la farina può non essere solo tale e contenere additivi volontari.
L’incipit “senza additivi” ha svelato finalmente a tutti che le farine non sono tutte uguali (non mi riferisco naturalmente alla sola classificazione botanica, merceologica e reologica), ma soprattutto non è purtroppo vero che tutte le farine in commercio siano prive di additivi volontari.
Quando parlo di “farine”, faccio riferimento agli sfarinati la cui denominazione di vendita è riportata nel Decreto del Presidente della Repubblica n°187/2001 e non all’immenso mondo dei mix, semilavorati, preparati, miglioratori, miscele già pronte all’uso per pane bianco, ai cinque cereali, nero, pizza soffice, croccante, dolci, ecc. che molte aziende commercializzano e che nulla hanno a che vedere con la parola “farina”.

Additivi ammessi nelle farine
Parlando di “farina”, vi è il DPR n°187/2001 che disciplina sia i TIPI, sia la denominazione di vendita, sia la modalità (art. 4); purtroppo è anche vero che nelle farine è consentito aggiungere glutine secco (all’uopo vedasi il DM n°351/1994) oltre alla L-cisteina (E920), l’acido ascorbico (E300) nella quantità quantum satis, senza cioè uno specifico limite secondo Reg. (UE) n°1129/2011, oltre all’acido fosforico, di-, tri- e poli-fosfati (E338 – E452) e l’additivo biossido di silicio e silicati (E551-E559) consentito in tutte le categorie di alimenti, farine comprese, in dose massima di 10.000 mg/kg o mg/l a seconda degli alimenti.
Oltre a ciò, si aggiunga che sono ammessi anche gli enzimi Reg. (CE) n°1332/2008 e Reg. (CE) n°1829/2003. In virtù di una trasparenza d’informazione, in teoria e anche in pratica, tutti gli additivi volontari dovrebbero essere dichiarati in etichetta, ma purtroppo questo, da parte di molte aziende non succede pur restando nella legalità.