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Bakary products and gluten-free

by luciano

The main problem of gluten-free products is to create a protein network within the flour proteins so that final products met the consumer’s expectations concerning texture and appearance of the fresh bread.
To achieve this purpose they are used:

1. hydrocolloids for building an internal network able to hold the structure of fermented products;
2. different crosslinking enzymes such as glucose oxidase (1), transglutaminase and laccase to create a protein network within the flour proteins.

A – Extract from: “Gluten-Free Products for Celiac Susceptible People. Sweta Rai, Amarjeet Kaur and C. S. Chopra. “

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).

Sourdough lactic acid bacteria and products for Celiac Susceptible People

by luciano

The lactic acid bacteria present in the sourdough have been shown to have significant abilities to hydrolyze gluten proteins; some strains of lactic bacteria used with specific temperatures, times and concentrations can also hydrolyse the peptides most resistant to gastro-intestinal digestion. Baked products made with sourdough can therefore be considered an excellent opportunity and a valid choice for people genetically predisposed to celiac disease.

Extract from the study “ 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 lamina propria.

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).”

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

ATI (Amylase/trypsin-inhibitors) First part

by luciano

Abstract
Amylase/trypsin-inhibitors (ATIs) are putative triggers of non-celiac gluten sensitivity (NCGS), but contents of ATIs in different wheat species were not available. Therefore, the predominant ATIs 0.19+0.53, 0.28, CM2, CM3 and CM16 in eight cultivars each of common wheat, durum wheat, spelt, emmer and einkorn grown under the same environmental conditions were quantitated by targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) and stable isotope dilution assays (SIDA) using specific marker peptides as internal standards. The results were compared to a label-free untargeted LC-MS/MS analysis, in which protein concentrations were determined by intensity based absolute quantitation (iBAQ). Both approaches yielded similar results. Spelt and emmer had higher ATI contents than common wheat, with durum wheat in between. Only three of eight einkorn cultivars contained ATIs in very low concentrations. The distribution of ATI types was characteristic for hexaploid, tetraploid and diploid wheat species and suitable as species-specific fingerprint. The results point to a better tolerability of einkorn for NCGS patients, because of very low total ATI contents. 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).

Reintrodution gluten after after some period on a gluten-free diet for NCGS (non celiac gluten sensivity)

by luciano

“Once the diagnosis of NCGS is reasonably reached, the management and follow-up of patients is completely obscure. A logical approach is to undertake a gluten-free dietary regimen for a limited period (e.g., six months), followed by the gradual reintroduction of gluten. During the gluten-free diet, the ingestion of prolamine peptide (gliadin)-derived from wheat, rye, barley, oats, bulgur, and hybrids of these cereal grains-should be avoided. Rice, corn, and potatoes have been the typical substitutes, but nowadays other different cereals and pseudocereals, such as amaranth, buckwheat, manioc, fonio, teff, millet, quinoa, and sorghum, can be used. After some period on a gluten-free diet, the reintroduction of gluten can start with cereals of low gluten content (e.g., oats). In addition, einkorn farro (Triticum monococcum) can be used, having no direct in vitro or ex vivo toxicity and low (7%) gluten content[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).