title: Combination of transglutaminase and sourdough on gluten-free flours to improve dough structure.
abstract: The aim of this work was to evaluate the effects of microbial transglutaminase (mTG) and sourdough on gluten-free (GF) flours. Besides deamidation and incorporation of amines, mTG catalyses protein cross-links, modifying dough structure. Sourdough from lactic acid bacteria (LAB) and yeast modifies dough protein composition, determining proteolysis, which induce the formation of aroma precursor metabolites. The chemical-physical interactions of volatile molecules with various constituents of the matrix affect the retention of aroma compounds. Here, the effect on volatile molecule profiles and on protein networks formation after mTG treatment in sourdoughs obtained with four GF flours belonging to cereals, pseudo-cereals and legumes (rice, corn, amaranth and lentil) was investigated. Sourdough was prepared with a two-step fermentation using Lactobacillus sanfrancisciensis (LSCE1) and Candida milleri (PFL44), then mTG was added after 21 h of fermentation at increasing levels. The results showed that mTG had the capacity to modify GF flour proteins and improve protein networks formation, involving mainly the prolamin protein fraction. This is particularly relevant for the production of GF backed goods generally lacking of technological, structural and sensorial features compared with products obtained with wheat flour sourdough fermentation. Interestingly, mTG treatment of sourdough affected also the volatile composition and indeed possibly the final organoleptic properties of the products.
authors.affiliation: Department of Biological, Geological and Environmental Sciences, University of Bologna, Via Irnerio 42, Bologna, Italy.
authors.forename: Lucilla
authors.initials: L
authors.lastname: Scarnato
authors.affiliation: Interdepartmental Center for Industrial Agro-food Research, University of Bologna, Cesena, Italy.
authors.forename: Diana Isabella
authors.initials: DI
authors.lastname: Serrazanetti
authors.affiliation: Department of Biological, Geological and Environmental Sciences, University of Bologna, Via Irnerio 42, Bologna, Italy.
authors.forename: Iris
authors.initials: I
authors.lastname: Aloisi
authors.affiliation: Interdepartmental Center for Industrial Agro-food Research, University of Bologna, Cesena, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Montanari
authors.affiliation: Department of Biological, Geological and Environmental Sciences, University of Bologna, Via Irnerio 42, Bologna, Italy. stefano.delduca@unibo.it.
authors.forename: Stefano
authors.initials: S
authors.lastname: Del Duca
authors.affiliation: Interdepartmental Center for Industrial Agro-food Research, University of Bologna, Cesena, Italy.|Department of Agricultural and Food Science, University of Bologna, Campus of Food Science, Cesena, Italy.
authors.forename: Rosalba
authors.initials: R
authors.lastname: Lanciotti
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D002175:Candida / Q000201:enzymology*; D055050:Diet, Gluten-Free; D005433:Flour; D005524:Food Technology / Q000379:methods*; D005656:Fungal Proteins / Q000737:chemistry*; D007778:Lactobacillus / Q000201:enzymology*; D011503:Transglutaminases / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D005656:Fungal Proteins; D011503:Transglutaminases
keywords: Gluten-free; Lactobacillus; Protein network; Sourdough; Transglutaminase; Volatile compounds