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Prodotti da forno e gluten-free

by luciano

Il problema principale dei prodotti gluten-free è quello di creare una struttura “simile alla maglia glutinica” senza le proteine della farina in modo che il prodotto finale soddisfi le aspettative dei consumatori in relazione alla “leggerezza della struttura” e all’apparenza del pane fresco.
Per raggiungere questo scopo vengono utilizzati principalmente:
1. Idrocolloidi per la costruzione di una rete interna in grado di contenere la struttura dei prodotti fermentati;
2. Enzimi capaci di legare le proteine come glucosio ossidasi (1), transglutaminasi e laccasi per creare una rete proteica senza le proteine della farina

A – Estratto dallo studio: “Gluten-Free Products for Celiac Susceptible People:

TECHNOLOGICAL APPROACHES FOR MIMING GLUTEN IN GLUTEN-FREE BAKERY PRODUCTS
The formulation of gluten-free bakery products is still a challenge to both for cereal-cum-baking technologists. Replacing gluten functionality has been a challenge for food technologists. The absence of gluten leads to weak cohesion and elastic doughs which results in a crumbling texture, poor color, and low specific volume in bread. Hence, during the last few years, numerous studies have been attempted for improving the physical properties of gluten-free foods, especially baked and fermented foods, by utilizing the interaction of the many ingredients and additives which could mimic the property of gluten (28). Approaches proposed for obtaining gluten-free baked foods include the utilization of different naturally gluten-free flours (rice, maize, sorghum, soy, buckwheat) and starches (maize, potato, cassava, rice), dairy ingredients (caseinate, skim milk powder, dry milk, whey), gums and hydrocolloids (guar and xanthan gums, alginate, carrageenan, hydroxypropyl methylcellulose, carboxymethyl cellulose), emulsifiers (DATEM, SSL, lecithins), non-gluten proteins from milk, eggs, legumes and pulses, enzymes (cyclodextrin glycosyl tranferases, transglutaminase, proteases, glucose oxidase, laccase), and non-starch polysaccharides (inulin, galactooligosaccharides) (Table 1). Strengthening additives or processing aids has been fundamental for miming gluten’s iscoelastic properties (93), where mainly hydrocolloids have been used for building an internal network able to hold the structure of fermented products. Simultaneously with the same intention, different crosslinking enzymes such as glucose oxidase, transglutaminase, and laccase have been used to create a protein network within the flour proteins (94). However, the success of gluten-free products relied on the type of effect of the enzymes as gluten-free processing aids, type of flour, enzyme source, and level. Generally, the combinations of ingredients and the optimization of the breadmaking process have resolved the technological problems, yielding gluten-free products that met the consumer’s expectations concerning texture and appearance of the fresh bread (95).

Pasta madre e prodotti per persone geneticamente predisposte per la celiachia

by luciano

I batteri lattici presenti nella madre hanno dimostrato di avere notevoli capacità di idrolizzate le proteine del glutine; alcune selezioni di batteri lattici utilizzati con specifiche temperature, tempi e concentrazioni possono anche idrolizzare i peptidi più resistenti alla digestione gastro-intestinale. I prodotti da forno realizzati con pasta acida possono, pertanto, essere considerati una ottima opportunità e una valida scelta per le persone geneticamente predisposte per la celiachia.

Estratto dallo studio “Gluten-Free Products for Celiac Susceptible People”:

A – “ omissis…… The 33-mer peptide from α2-gliadin (amino acid sequence positions 56–88, LQLQPFPQPQLPYPQPQLPYPQPQLPYPQPQPF) contains three overlapping T-cell epitopes (3 × PQPQLPYPQ, 2 × PYPQPQLPY and PFPQPQLPY) for CD sensitive individuals. The human gastrointestinal enzymes pepsin, trypsin, and chymotrypsin were unable to hydrolyze the 33-mer peptide due to their inability to cleave before or after proline or glutamine, leaving the epitopes intact. Comparatively, large CD immunogenic peptides (≥9 amino acid residues) reach the small intestine (11) after crossing through the epithelial barrier and initiate immunogenic cascade in the laminapropria.

B – “omissis …Wheat flours modified to eliminate or reduce the immune toxicity of gluten have been used to prepare pasta and baked products. The large peptides of gluten need to be modified/converted into peptides of <9 amino acid residues to minimize the CD-induced immunoreactivity. This has been achieved through numerous approaches, including exogenous enzyme treatment, use of sourdough/lactic acid bacteria, use of genetically modified wheat, etc.”

C – “ omissis…The sourdough was prepared by fermenting flour with naturally occurring lactic acid bacteria (LAB) and yeasts. In the mature sourdoughs, the lactic acid bacteria were higher in number (> 10cfu/g) than the number of yeasts. Type I sourdough has a final pH of 4.0 at room temperature (20–30C) and is manufactured by continuous daily refreshments with the aim to maintain the microorganisms in an active state. It takes 2–5 (>30C) days of fermentation for developing type II sourdough as an acidifier with a pH that is <3.5 after 24 h of fermentation (131). The microorganisms were used in the late stationary phase of growth and exhibited restricted metabolic activity. The type III sourdough, as an acidifier supplement and aroma carrier in bread making, is a dried powder used for fermentation by certain starter cultures. A few reports are available about the use of sourdough for the preparation of gluten-free bread (84, 85). In one study it was reported that food processing by selected sourdough lactobacilli and fungal proteases may be considered an efficient approach for eliminating gluten toxicity, reducing the gluten level below 12 ppm (119). Further, sourdough fermentation, usually with a mixture of lactic acid bacteria (LAB) and yeasts, is traditionally used to produce leavened bread, especially from rye flour. Lactobacillus sp. are predominant among lactic acid bacteria (LAB) and they produce numerous mixed proteolytic enzymes, including metalloendopeptidases, such as PepO and PepF; aminopeptidases, such as PepN and PepC; dipeptidases, such as PepD; and dipeptidyl and tripeptidylpeptidases, such as the proline-specific Xaa-Pro dipeptidyl-peptidase (PepX) (132). The combination of wheat germination and sourdough fermentation with Lactobacillus brevis L62 extensively hydrolyzed wheat prolamin down to <5% of the initial content (133). A cell-free extract of two LABs, L. plantarum and Pediococcus pentosaceus, had a higher gliadin-degrading capacity (83%) in doughs than the corresponding cell suspension (70%), and complete gliadin degradation without using live LAB may be optimized (134). High molecular weight polymers, namely exopolysaccharides, are produced by lactic acid bacteria in presence of sucrose that mimics physiochemical properties of commercial hydrocolloids or gums, such as the ability to form a network and bind water. It counteracts the negative effects of excessive sourdough acidification and enhances loaf volume, shelf-life, the staling rate, and textural properties of products (129).”

Approfondimento
Gluten-Free Products for Celiac Susceptible People. Sweta Rai, Amarjeet Kaur and C. S. Chopra. Front. Nutriens 17 december 2018.

ATI (inibitori dell’amilasi/tripsina) Parte I

by luciano

Riassunto
Gli inibitori dell’amilasi/tripsina (ATI) sono tra i fattori scatenanti della sensibilità al glutine non celiaca (NCGS). Le Ati (le ati ritenute predominanti 0,19 + 0,53, 0,28, CM2, CM3 e CM16) di otto cultivar ciascuna di grano tenero, grano duro, farro spelta, farro dicocco e monococco, coltivati ​​nelle stesse condizioni ambientali, sono state quantificate mediante spettrometria di massa liquida-tandem mirata liquida (LC) -MS / MS) e saggi di diluizione isotopica stabile (SIDA) utilizzando peptidi marker specifici come standard interni. I risultati sono stati confrontati con un’analisi LC-MS / MS non mirata senza etichetta, in cui le concentrazioni di proteine ​​sono state determinate mediante quantificazione assoluta basata sull’intensità (iBAQ). Entrambi gli approcci hanno prodotto risultati simili. Il farro spelta e il farro dicocco avevano un contenuto di ATI più elevato rispetto al grano tenero, con grano duro in mezzo. Solo tre delle otto cultivar Einkorn contenevano ATI in concentrazioni molto basse. La distribuzione dei tipi di ATI era caratteristica per le specie di grano esaploide, tetraploide e diploide ed utilizzabile come impronta digitale specifica per specie. I risultati indicano che il grano monococco, avendo un contenuto di ATI totale molto basso, presenta una migliore tollerabilità per i pazienti con NCGS. (Targeted LC-MS/MS Reveals Similar Contents of α-Amylase/Trypsin-Inhibitors as Putative Triggers of Nonceliac Gluten Sensitivity in All Wheat Species except Einkorn). Article in Journal of Agricultural and Food Chemistry 66(46) · October 2018. Sabrina Geisslitz, Christina Ludwing, Katharina Scherf (Technische Universität München Munich, Bayern, Germany).

Reintroduzione del glutine, dopo un certo periodo, in una dieta priva di glutine per soggetti sensibili al glutine non celiaci.

by luciano

“Una volta ragionevolmente raggiunta la diagnosi di NCGS, la gestione e il follow-up dei pazienti sono completamente oscuri. Un approccio logico consiste nell’intraprendere un regime dietetico senza glutine per un periodo limitato (ad esempio, sei mesi), seguito dalla graduale reintroduzione del glutine. Durante la dieta priva di glutine, dovrebbe essere evitata l’ingestione del peptide prolaminico (gliadina), derivato da grano, segale, orzo, avena, bulgur e ibridi di questi cereali. Riso, mais e patate sono stati i tipici sostituti, ma oggigiorno si possono usare altri cereali e pseudocereali diversi come amaranto, grano saraceno, manioca, fonio, teff, miglio, quinoa e sorgo. Dopo un po ‘di tempo con una dieta priva di glutine, la reintroduzione del glutine può iniziare con cereali a basso contenuto di glutine (ad es. Avena). Inoltre, è possibile utilizzare il farro einkorn (Triticum monococcum), che non presenta tossicità diretta in vitro o ex vivo e basso contenuto di glutine (7%)[41]”. (Non-celiac gluten sensitivity: Time for sifting the grain. Luca Elli, Leda Roncoroni, and Maria Teresa Bardella. Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved).