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Carlo Giuseppe Rizzello
Ruolo
Professore Associato
Organizzazione
Università degli Studi di Bari Aldo Moro
Dipartimento
DIPARTIMENTO DI SCIENZE DEL SUOLO,DELLA PIANTA E DEGLI ALIMENTI
Area Scientifica
AREA 07 - Scienze agrarie e veterinarie
Settore Scientifico Disciplinare
AGR/16 - Microbiologia Agraria
Settore ERC 1° livello
Non Disponibile
Settore ERC 2° livello
Non Disponibile
Settore ERC 3° livello
Non Disponibile
This study aimed at investigating the antifungalactivity of sourdoughfermented (Lactobacillus plantarum LB1 and Lactobacillus rossiae LB5) wheatgerm (SFWG). Preliminarily, methanol and water/salt-soluble extracts from SFWG were assayed by agar diffusion towards Penicillium roqueforti DPPMAF1. As shown by hyphal radial growth rate, the water/salt-soluble extract showed the inhibition of various fungi isolated from bakeries. The antifungalactivity was attributed to a mixture of organic acids and peptides which were synthesized during fermentation. Formic (24.7 mM) acid showed the highest antifungalactivity. Four peptides, having similarities with well known antifungal sequences, were identified and chemically synthesized. The minimal inhibitory concentration was 2.5–15.2 mg/ml. Slices of bread made by addition of 4% (wt/wt) of freeze dried SFWG were packed in polyethylene bags and stored at room temperature. Slices did not show contamination by fungi until at least 28 days of storage and behaved as the calcium propionate (0.3%, wt/wt).
Preliminarily, 146 strains of yeasts were screened for the antifungal activity toward the indicator Penicillium roqueforti DPPMAF1. The strain Meyerozyma guilliermondii LCF1353 was selected and used for dough fermentation. The water/salt soluble extract of the dough was analyzed by HPLC and GC/MSSPME. The synthesis of the extracellular cell wall-degrading enzyme b-1,3-glucanase and ethyl-acetate was shown. The effect on conidia germination mainly suggested a fungistatic activity. M. guilliermondii LCF1353 was used as starter for dough fermentation in combination with Wickeramomyces anomalus 1695 and Lactobacillus plantarum 1A7, which were previously selected for antifungal activity. The growth of the strains was monitored by plate count and molecular techniques, and competitive or antagonistic interactions among them were excluded. Bread started with the combination of M. guilliermondii LCF1353,W. anomalus LCF1695 and L. plantarum 1A7 showed a more prolonged shelf life compared to the other breads. Fungal growth was delayed at least until 14 days of storage, under conditions of high artificial inoculum. The bread manufactured with the above combination showed good chemical and textural characteristics and, as shown by sensory analysis, it was appreciated for elasticity, color and taste.
This study aimed at investigating the antifungal activity of Wickerhamomyces anomalus and sourdough lactic acid bacteria to extend the shelf life of wheat flour bread. The antifungal activity was assayed by agar diffusion, growth rate inhibition, and conidial germination assays, using Penicillium roqueforti DPPMAF1 as the indicator fungus. Sourdough fermented by Lactobacillus plantarum 1A7 (S1A7) and dough fermented by W. anomalus LCF1695 (D1695) were selected and characterized. The water/salt-soluble extract of S1A7 was partially purified, and several novel antifungal peptides, encrypted into sequences of Oryza sativa proteins, were identified. The water/salt-soluble extract of D1695 contained ethanol and, especially, ethyl acetate as inhibitory compounds. As shown by growth inhibition assays, both water/salt-soluble extracts had a large inhibitory spectrum, with some differences, toward the most common fungi isolated from bakeries. Bread making at a pilot plant was carried out with S1A7, D1695, or a sourdough started with a combination of both strains (S1A7-1695). Slices of the bread manufactured with S1A7-1695 did not show contamination by fungi until 28 days of storage in polyethylene bags at room temperature, a level of protection comparable to that afforded by 0.3% (wt/wt) calcium propionate. The effect of sourdough fermentation with W. anomalus LCF1695 was also assessed based on rheology and sensory properties.
Weissella cibaria, Lactobacillus plantarum, Lactobacillus sp. and Lactobacillus pentosus were variously identified from blackberries, prunes, kiwifruits, papaya and fennels by partial 16S rRNA gene sequence. Representative isolates from each plant species were screened based on the kinetics of growth on fruit juices. A protocol for processing and storage of red and greensmoothies (RS and GS) was set up, which included fermentation by selected lacticacid bacteria starters and exo-polysaccharide producing strains. Starters grew and remained viable at ca. 9.0 log cfu g−1 during 30 days of storage at 4 °C. No contaminating Enterobacteriaceae and yeast were found throughout storage. Values of soluble solids, total titratable acidity and viscosity distinguished started RS and GS compared to spontaneously (unstarted) fermented smoothies. Color difference dE∗ab and browning index were positively affected by lacticacidfermentation. Consumption of carbohydrates by lacticacid bacteria was limited as well as it was the lacticfermentation. Consumption of malic acid was evident throughout storage. Polyphenolic compounds and, especially, ascorbic acid were better preserved in started RS and GS compared to unstarted samples. This reflected on the free radical scavenging activity. A statistical correlation was only found between the level of ascorbic acid and free radical scavenging activity. As shown by a first-order equation, the rate of degradation of ascorbic acid through storage were found to be higher in the unstarted compared to started RS and GS. Fermentation by lacticacid bacteria clearly improved the sensory attributes of RS and GS.
Lactic acid bacteria strains were identified from wheatgerm by 16S rRNA partial sequencing, subjected to RAPD-PCR typing and screened. Lactobacillus plantarum LB1 and Lactobacillus rossiae LB5 were used as starters to produce sourdough fermented wheatgerm (SFWG). The chemical and nutritionalcharacteristics of SFWG were compared to those of the raw wheatgerm (RWG). Lipase activity in SFWG was ca. 2.6-fold lower than that found in RWG. As shown by SPME/GC/MS analysis, most of the volatile compounds derived from lipid oxidation during storage (40 days) were at markedly lower levels in SFWG compared to RWG. Fermentation of wheatgerm increased of ca. 50% the concentration of free amino acids. Glu markedly decreased in SFWG, due to its conversion in GABA. The concentration of the anti-nutritional factor raffinose also decreased in SFWG. The in vitro protein digestibility, the concentration of total phenols, phytase and antioxidant activities were increased by fermentation.
Strains of Lactobacillus plantarum, Pediococcus acidilactici, Pediococcus pentosaceus and Leuconostoc mesenteroides subsp. mesenteroides were identified from 8 cultivars of sweetcherry by partial 16S rRNA gene sequence and subjected to typing by Random Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) analysis. Representative isolates from each species and each cultivar were screened based on the kinetics of growth on cherrypureeadded of (10%, v/v) steminfusion (CP-SI). A protocol for processing and storage of CP-SI, which included fermentation by selectedautochthonousP. pentosaceus SWE5 and L. plantarum FP3 (started CP-SI) or spontaneous fermentation (unstarted CP-SI), was set up. Starters grew and remained viable at elevated cell numbers (ca. 9.0 log cfu g−1) during 60 days of storage at 4 °C. The number of presumptive lacticacidbacteria of the unstarted CP-SI did not exceed the value of ca. 3.0 log cfu g−1. Consumption of carbohydrates (e.g., glucose and fructose) by starter lacticacidbacteria was limited as well as it was the lacticacidfermentation. Consumption of organic acids (e.g., malic acid) and free amino acids was evident, especially, throughout storage. Compared to CP-SI before processing, the concentrations of total phenolic compounds and anthocyanins did not vary in the started CP-SI. The concentration of anthocyanins slightly decreased in the unstarted CP-SI. The antioxidant activity, expressed as the scavenging activity toward DPPH radical, was found at highest level in the started CP-SI which approached that found in CP-SI before processing. During storage, viscosity and, especially, color indexes of started CP-SI were higher than those found in the unstarted CP-SI. Fermentation by autochthonouslacticacidbacteria seemed to also positively interfere with the sensory attributes of CP-SI.
Functionalmilkbeverages (FMB100 and FMB200) fortified with phenoliccompounds (100 and 200 mg/l) extracted from olive vegetable water, and fermented with γ-amino butyric acid (GABA)-producing (Lactobacillus plantarum C48) and autochthonous human gastro-intestinal (Lactobacillus paracasei 15N) lacticacidbacteria were manufactured. A milkbeverage (MB), without addition of phenoliccompounds, was used as the control. Except for a longer latency phase of FMB200, the three beverages showed an almost similar kinetic of acidification, consumption of lactose and synthesis of lacticacid. Apart from the beverage, Lb. plantarum C48 showed a decrease of ca. Log 2.52–2.24 cfu/ml during storage. The cell density of functionalLb. paracasei 15N remained always above the value of Log 8.0 cfu/ml. During fermentation, the total concentration of free amino acids markedly increased without significant (P > 0.05) differences between beverages. The concentration of GABA increased during fermentation and further storage (63.0 ± 0.6–67.0 ± 2.1 mg/l) without significant (P > 0.05) differences between beverages. After fermentation, FMB100 and FMB200 showed the same phenolic composition of the phenol extract from olive vegetable water but a different ratio between 3,4-DHPEA and 3,4-DHPEA-EDA. During storage, the concentrations of 3,4-DHPEA-EDA, p-HPEA and verbascoside of both FMB100 and FMB200 decreased. Only the concentration of 3,4-DHPEA increased. As shown by SPME-GC-MS analysis, diactetyl, acetoin and, especially, acetaldehyde were the main volatile compounds found. The concentration of phenoliccompounds does not interfere with the volatile composition. Sensory analyses based on triangle and paired comparison tests showed that phenoliccompounds at the concentrations of 100 or 200 mg/l were suitable for addition to functionalmilkbeverages.
Objectives: This study was aimed at showing the safety, for young patients with celiac disease (CD), of sweet baked goods made of wheat flour, which was rendered gluten-free during sourdough fermentation. Methods and Results: As shown by R5 antibody-based sandwich and competitive enzyme-linked immunosorbent assay (ELISA), selected lactobacilli and fungal proteases, routinely used in bakeries, degraded gluten to <10 ppm during sourdough fermentation. The resulting flour was mainly a mixture of water-/salt-soluble low-size peptides and free amino acids. Gliadin and glutenin fractions extracted from the pepsin-trypsin (PT) digest of the fermented wheat flour induced the expression of interferon (IFN)-γ at the level comparable with the negative control. After fermentation, the wheat flour was spray dried and used for making sweet baked goods. Eight patients with CD in remission were enrolled for the clinical challenge, and they daily consumed 200 g of sweet baked goods equivalent to 10 g of native gluten. Hematology, serology (total serum IgA, IgG and IgA antigluten, endomysial and tissue transglutaminase IgA antibodies), and intestinal permeability analyses were carried out over time. One patient interrupted the trial after 15 days and another after 30 days only due to difficulties in the compliance of the daily consumption. All of the other patients showed normal values of hematology, serology, and intestinal permeability during 60 days of challenge. Conclusions: This study showed that a wheat flour–fermented product, having gluten completely degraded, is not toxic for patients with CD. Nevertheless, these foods should not be recommended for patients with celiac disease until a formal trial has been done.
Sourdough fermentation is one of the oldest food biotechnologies, which has been studied and recently rediscovered for its effect on the sensory, structural, nutritional and shelf life properties of leavened baked goods. Acidification, proteolysis and activation of a number of enzymes as well as the synthesis of microbial metabolites cause several changes during sourdough fermentation, which affect the dough and baked good matrix, and influence the nutritional/functional quality. Currently, the literature is particularly rich of results, which show how the sourdough fermentation may affect the functional features of leavened baked goods. In the form of pre-treating raw materials, fermentation through sourdough may stabilize or to increase the functional value of bran fractions and wheat germ. Sourdough fermentation may decrease the glycaemic response of baked goods, improve the properties and bioavailability of dietary fibre complex and phytochemicals, and may increase the uptake of minerals. Microbial metabolism during sourdough fermentation may also produce new nutritionally active compounds, such as peptides and amino acid derivatives (e.g., g-amino butyric acid) with various functionalities, and potentially prebiotic exo-polysaccharides. The wheat flour digested via fungal proteases and selected sourdough lactobacilli has been demonstrated to be probably safe for celiac patients.
Autochthonous lacticacidbacteria from emmer flour were screened based on the kinetic of acidification and used to ferment beverages containing emmer flour, emmer gelatinized flour, and emmer malt at percentages ranging 5–30% (wt/wt). Preliminarily, the concentration of raw flour and malt was selected based on sensory analysis. Different protocols were set up for the manufacture of four different beverages which used Lactobacillus plantarum 6E as the starter. Emmerbeverages were mainly differentiated based on the concentration of organic acids, carbohydrates, amino acids, dietary fibers, vitamins, antioxidant and phytase activities, and volatiles and sensory profiles. Wheat flour bread was used as the control to determine the hydrolysis index (HI = 100), as an indirect estimation of the glycemic index. The beverage made with 30% (wt/wt) of gelatinized flour showed an HI of 56%, its viscosity was improved by using an EPS-producing strain and it allowed the survival of the potential probiotic Lactobacillus rhamnosus SP1 at cell density of ca. 5 × 108 cfu/ml throughout storage at 4 °C. Among the exploited biotechnological options, this latter beverage could be considered as a promising novel functional food.
Fractions from debranning of durumwheat (Triticum durum sp.) were subjected to micronization and air fractionation, obtaining coarse (Cf) and fine (Ff) fractions. These fractions mainly differed for particle size, total dietary fiber, protein and fat. Wheat flour (Triticum aestivum sp.) doughs, containing 5% of Cf or Ff, were subjected to fermentation by baker's yeast alone or fermented by Lactobacillus sanfranciscensis DE9 and Lactobacillus plantarum 3DM. White flour doughs, without addition of bran fractions, were also manufactured. The kinetics of growth and acidification of lactic acid bacteria did not differ between sourdoughs with or without Cf or Ff. Breads were manufactured at pilot plant scale. Compared to wheat flour, the addition of micronized bran fractions increased the concentration of free amino acids, total phenols and dietary fiber as well as the phytase and antioxidant activities of doughs. Sourdoughfermentation further improved these nutritionalfeatures, and enhanced the textural and sensory properties of breads containing bran fractions. In particular, the combination of sourdoughfermentation and Cf increased the concentration of functional compounds and decreased the value of hydrolysis index (HI).
This study was aimed at determining the probiotic potential of a large number of autochthonous lactic acid bacteria isolated from fruit and vegetables. Survival under simulated gastric and intestinal conditions showed that 35% of the strains, mainly belonging to the species Lactobacillus plantarum maintained high cell densities. Selected strains did not affect the immune-mediation by Caco-2 cells. All strains stimulated all 27 immune-mediators by peripheral blood mononuclear cells (PBMC). A significant (P < 0.05; P < 0.01) increase of the major part of cytokines and growth factors was found. A few chemokines were stimulated. Immune-mediators with pro-inflammatory activity (IL-17, EOTAXIN and IFNγ) were significantly (P < 0.01) stimulated by all strains, followed by IL-1b > IP-10 > IL-6 > MIP1α. Stimulation of IL-12, IL-2 and IL-7 was strain dependent. Only a few strains increased the synthesis of cytokines with anti-inflammatory activity. Six L. plantarum strains were further selected. Four were defined as the strongly adhesive strains (more than 40 bacteria adhering to one Caco-2 cell), and 2 as the adhesive strains (5–40 bacteria adhering to one Caco-2 cell). Five strains grew and acidified chemically defined medium with fructo-oligosaccharides (FOS) as the only carbon source. End-products of FOS fermentation were found. All strains inhibited enterohemorragic Escherichia coli K12 and Bacillus megaterium F6 isolated from human sources. The results of this study showed that some autochthonous lactic acid bacteria from rawfruit and vegetables have functional features to be considered as novelprobioticcandidates.
This study aimed at investigating the robustness of selected sourdough strains of Lactobacillusplantarum. Seven strains were singly used as sourdoughtype I starters under daily back-slopping propagation (ten days) using wheatflour. Cell numbers of presumptive lactic acid bacteria varied slightly (median values of 9.13–9.46 log cfu g−1) between and within started sourdoughs, as well as the acidifying activity (median values of 1.24–1.33). After three days also the control sourdough (unstarted) had the same values. As shown by RAPD-PCR analysis, five (DB200, 3DM, G10C3, 12H1 and LP20) out of seven strains maintained elevated cell numbers (ca. 9 log cfu g−1) throughout ten days. The other two strains progressively decreased to less than 5 log cfu g−1. As identified by partial sequencing of 16S rRNA and recA genes, L. plantarum (11 isolates), pediococci (7), Lactobacillus casei (3) and Lactobacillus rossiae (2) dominated the flour microbiota. Monitoring of lactic acid bacteria during sourdoughpropagation was carried out by culture dependent approach and using PCR-DGGE (Denaturing Gradient Gel Electrophoresis). Except for the sourdough started with L. plantarum LP20, in all other sourdoughs at least one autochthonous strain of L. plantarum emerged. All emerging strains of L. plantarum showed different RAPD-PCR profiles. L. rossiae and Pediococcus pentosaceus were only found in the control and sourdough started with strain 12H1. The characterization of the catabolic profiles of sourdoughs (Biolog System) showed that sourdoughs containing persistent starters behaved similarly and their profiles were clearly differentiated from the others. One persistent strain (DB200) of L. plantarum and Lactobacillus sanfranciscensis LS44, previously shown to be persistent (Siragusa et al., 2009), were used as the mixed starter to produce a wheatfloursourdough. Both strains cohabited and dominated during ten days of propagation.
A pool of selected lactic acid bacteria was used for the sourdough fermentation of various cereal flours with the aim of synthesizing antioxidant peptides. The radical-scavenging activity of water/salt-soluble extracts (WSE) from sourdoughs was significantly (P<0.05) higher than that of chemically acidified doughs. The highest activity was found for whole wheat, spelt, rye, and kamut sourdoughs. Almost the same results were found for the inhibition of linoleic acid autoxidation. WSE were subjected to reversephase fast protein liquid chromatography. Thirty-seven fractions were collected and assayed in vitro. The most active fractions were resistant to further hydrolysis by digestive enzymes. Twenty-five peptides of 8 to 57 amino acid residues were identified by nano-liquid chromatography-electrospray ionization-tandem mass spectrometry. Almost all of the sequences shared compositional features which are typical of antioxidant peptides. All of the purified fractions showed ex vivo antioxidant activity on mouse fibroblasts artificially subjected to oxidative stress. This study demonstrates the capacity of sourdough lactic acid bacteria to release peptides with antioxidant activity through the proteolysis of native cereal proteins.
Sourdough fermentation, a traditional biotechnology for making leavened baked goods, was almost completely replaced by the use of baker’s yeast and chemical leavening agents in the last century. Recently, it has been rediscovered by the scientific community, consumers, and producers, thanks to several effects on organoleptic, technological, nutritional, and functional features of cereal-based products. Acidification, proteolysis, and activation of endogenous enzymes cause several changes during sourdough fermentation, carried out by lactic acid bacteria and yeasts, which positively affect the overall quality of the baked goods. In particular, the hydrolysis of native proteins of the cereal flours may improve the functional features of baked goods. The wheat flour processed with fungal proteases and selected lactic acid bacteria was demonstrated to be safe for coeliac patients. This review article focuses on the biotechnologies that use selected sourdough lactic acid bacteria to potentially counteract the adverse reactions to gluten, and the risk of gluten contamination.
Aims: This study aimed at characterizing the lactic acid bacteria microbiota and selecting mixed endogenous starters to be used for sourdough fermentation of spelt or emmer flours. Methods and Results: Identification of lactic acid bacteria was carried out by partial sequencing of the 16S rRNA, recA, 16S/23S rRNA spacer region and pheS genes. Spelt flour showed the largest biodiversity, while Lactobacillus plantarum dominated in emmer flour. Isolates were subjected to RAPD-PCR analysis and screened based on the kinetics of growth and acidification, quotient of fermentation and liberation of free amino acids (FAA) during sourdough fermentation. After selection, mixed starters were used according to a two-step fermentation process. Wheat flour was fermented by the same starters. Spelt and emmer sourdoughs had slightly higher pH than wheat sourdoughs but titratable acidity, concentration of FAA and phytase activity were higher. Specific volume and crumb grain of emmer and, especially, spelt breads approached those of wheat breads. Sensory analysis confirmed the suitability of spelt and emmer for bread making. Conclusions: The sourdough biotechnology was indispensable to completely exploit the potential of spelt and emmer flours. Significance and Impact of the Study: Results filled up the lack of knowledge on the lactic acid bacteria microbiota and technological performances of spelt and emmer flours.
Agriculture surplus were used as substrates to synthesize !-aminobutyric acid (GABA) by Lactobacillus plantarum DSM19463 for the manufacture of a functional beverage or as a novel application for dermatological purposes. Dilution of the grape must to 1 or 4% (w/v) of total carbohydrates favored higher cell yield and synthesis of GABA with respect to whey milk. Optimal conditions for synthesizing GABA in grape must were: initial pH 6.0, initial cell density of Log 7.0 cfu/mL, and addition of 18.4 mM L-glutamate. L. plantarum DSM19463 synthesized 4.83 mM of GABA during fermentation at 30°C for 72 h. The fermented grape must also contain various levels of niacin, free minerals, and polyphenols, and Log 10.0 cfu/g of viable cells of L. plantarum DSM19463. Freeze dried preparation of grape must was applied to the SkinEthic® Reconstructed Human Epidermis or multi-layer human skin model (FT-skin tissue). The effect on transcriptional regulation of human beta-defensin-2 (HBD-2), hyaluronan synthase (HAS1), filaggrin (FGR), and involucrin genes was assayed through RT-PCR. Compared to GABA used as pure chemical compound, the up-regulation HBD-2 was similar while the effect on the expression of HAS1 and FGR genes was higher.
One hundred and three strains of lactic acid bacteria, isolated from various food ecosystems, were assayed for β-glucosidase activity toward p-nitrophenyl-β-d-glucopyranoside substrate. Lactobacillus plantarum DPPMA24W and DPPMASL33, Lactobacillus fermentum DPPMA114, and Lactobacillus rhamnosus DPPMAAZ1 showed the highest activities and were selected as the mixed starter to ferment various soy milk preparations, which mainly differed for chemical composition, protein dispersibility index, and size dimension. The soy milk made with organically farmed soybeans (OFS) was selected as the best preparation. All selected strains grew well in OFS soy milk, reaching almost the same values of cell density (ca. 8.5 log cfu/mL). After 96 h of fermentation with the selected mixed starter, OFS soy milk contained 57.0 μM daidzein, 140.3 μM genistein, 20.4 μM glycitein, and 37.3 μM equol. Fermented and nonfermented OFS soy milks were used for the in vitro assays on intestinal human Caco-2/TC7 cells. Fermented OFS soy milk markedly inhibited the inflammatory status of Caco-2/TC7 cells as induced by treatment with interferon-γ (IFN-γ) (1000 U/mL) and lipopolysaccharide (LPS) (100 ng/mL), maintained the integrity of the tight junctions, even if subjected to negative stimulation by IFN-γ, and markedly inhibited the synthesis of IL-8, after treatment with interleukin-1β (2 ng/mL). As shown by using chemical standards, these effects were due to the concomitant activities of isoflavone aglycones and, especially, equol, which were synthesized in the fermented OFS soy milk preparation.
Pichia guilliermondii was the only identified yeast in pineapple fruits. Lactobacillus plantarum and Lactobacillus rossiae were the main identified species of lacticacidbacteria. Typing of lacticacidbacteria differentiated isolates depending on the layers. L. plantarum 1OR12 and L. rossiae 2MR10 were selected within the lacticacidbacteria isolates based on the kinetics of growth and acidification. Five technological options, including minimal processing, were considered for pineapple: heating at 72 °C for 15 s (HP); spontaneous fermentation without (FP) or followed by heating (FHP), and fermentation by selected autochthonousL. plantarum 1OR12 and L. rossiae 2MR10 without (SP) or preceded by heating (HSP). After 30 days of storage at 4 °C, HSP and SP had a number of lacticacidbacteria 1000 to 1,000,000 times higher than the other processed pineapples. The number of yeasts was the lowest in HSP and SP. The Community Level Catabolic Profiles of processed pineapples indirectly confirmed the capacity of autochthonousstarters to dominate during fermentation. HSP and SP also showed the highest antioxidant activity and firmness, the better preservation of the natural colours and were preferred for odour and overall acceptability.
Food allergy is recognized as one of the major health concerns. It is estimated that ca. 4% of the population is affected by food allergenic disorders. Food allergies are defined as IgE-mediated hypersensitivity reactions. Foods such as peanuts, tree nuts, wheat, soy, cow's milk, egg, fish and shellfish are regarded as responsible for the majority of reactions. The ubiquitous presence of allergens in the human foods coupled with an increased awareness of food allergies warrants to undertake appropriate preventive measures for protecting sensitive consumers from unwanted exposure to offending food allergens. 2-DE followed by immunoblotting and identification of IgE-reactive proteins, as a proteomic approach to identify new allergens in foods, are reviewed. Specific examples of identification of allergens in foods and beverages by using 2-DE and IgE are described. Protein profiling using 2-DE and allergens detection by IgE has become a powerful method for analyzing changes of allergens content in complex matrix during food processing.
This study aimed at investigating the addition of legume (chickpea, lentil and bean) flours to wheat flour bread. Type I sourdough containing legumes or wheat–legume flours were prepared and propagated (back slopped) in laboratory, according to traditional protocols that are routinely used for making typical Italian breads. Based on kinetic of acidification and culture-dependent data, the wheat–legume sourdough was further characterized and selected for bread making. As determined by RAPD-PCR and partial sequencing of 16S rDNA gene analyses, lactic acid bacteria in wheat–legume sourdough included Lactobacillus plantarum, Lactobacillus sanfranciscensis, Leuconostoc mesenteroides, Lactobacillus fermentum, Weissella cibaria, Lactobacillus pentosus, Lactobacillus coryneformis, Lactobacillus rossiae, Lactobacillus brevis, Lactobacillus parabuchneri and Lactobacillus paraplantarum. Two breads containing 15% (w/w) of legume (chickpea, lentil and bean) flours were produced using selected wheat–legume sourdough (WLSB) and traditional wheat sourdough (WSB). Compared to wheat yeasted bread (WYB), the level of total free amino acids (FAA) was higher in WSB and WLSB. Phytase and antioxidant activities were the highest in WLSB. Compared to bread WYB, the addition of legume flours decreased the in vitro protein digestibility (IVPD) (WYB versus WSB). However, the dough fermentation with WSLB favored an increase of IVPD. According to the levels of carbohydrates, dietary fibers and resistant starch, WSB and WLSB showed lower values of hydrolysis index (HI) compared to WYB. As showed by texture and image analyses and sensory evaluation of breads, a good acceptability was found for WSB and, especially, WLSB breads.
Lactobacillus plantarum LB1 and Lactobacillus rossiae LB5, isolated from wheat germ and selected based on the kinetics of acidification, were used as starters for the manufacture of sourdough fermented wheat germ. A bread containing sourdough fermented wheat germ as an ingredient (SFWGB) was compared to breads made with (raw wheat germ bread, RWGB) or without (wheat flour bread, WFB) raw wheat germ. The higher concentration of free amino acids mainly differentiated SFWGB from WFB and RWGB. The in vitro protein digestibility of WFB was the highest, even if sourdough fermentation of wheat germ attenuated the difference. Phytase and antioxidant activities of SFWGB were highest. The specific volume and cell-total areas were also the highest for SFWGB. As determined by texture profile analysis, the values of hardness, resilience and fracturability of breads containing wheat germ were lower than those found in WFB. The crust lightness showed a decrease from WFB to SFWGB. As determined by sensory analysis, SFWGB had mainly acid taste and flavour and resulted more salty. Sourdough fermented wheat germ is an ingredient able to enhance nutritional, texture and sensory properties of bread.
Lactobacillus plantarum C48 and Lactococcus lactis subsp. lactis PU1, previously selected for the biosynthesis of γ-aminobutyricacid (GABA), were used for sourdoughfermentation of cereal, pseudo-cereal and leguminousflours. Chickpea, amaranth, quinoa and buckwheat were the flours most suitable to be enriched of GABA. The parameters of sourdoughfermentation were optimized. Addition of 0.1 mM pyridoxal phosphate, dough yield of 160, inoculum of 5 × 107 CFU/g of starter bacteria and fermentation for 24 h at 30 °C were found to be the optimal conditions. A blend of buckwheat, amaranth, chickpea and quinoa flours (ratio 1:1:5.3:1) was selected and fermented with baker's yeast (non-conventional flourbread, NCB) or with Lb. plantarum C48 sourdough (non-conventional floursourdoughbread, NCSB) and compared to baker's yeast started wheat flourbread (WFB). NCSB had the highest concentration of free amino acids and GABA (ca. 4467 and 504 mg/kg, respectively). The concentration of phenolic compounds and antioxidant activity of NCSB bread was the highest, as well as the rate of in vitro starch hydrolysis was the lowest. Texture analysis showed that sourdoughfermentation enhances several characteristics of NCSB with respect to NCB, thus approaching the features of WFB. Sensory analysis showed that sourdoughfermentation allowed to get good palatability and overall taste appreciation.
Acha and Iburu flours were singly subjected to sourdough fermentation with previously selected autochthonous starters. Sourdoughs were used (30%, wt/wt) as aroma carriers and acidifiers during short time fermentation with the addition of baker's yeast. Acha and Iburu sourdough breads were compared to wheat sourdough bread started with the same strains and to breads made with the same formula but using baker's yeast alone. During Acha and Iburu sourdough fermentations, starter lactic acid bacteria reached almost the same cell density found in wheat sourdoughs. Acidification was more intense. Iburu sourdough bread had the highest total titratable acidity, the lowest pH, and contained the highest levels of free amino acids and phytase activity. The values of in vitro protein digestibility did not differ between Acha sourdough and wheat sourdough breads, while Iburu sourdough bread showed a slightly lower value. Acha and Iburu sourdough breads showed lower specific volume and higher density with respect to wheat sourdough breads. Nevertheless, Acha and Iburu sourdough breads were preferred for hardness and resilience. As shown by sensory analysis, Acha and especially Iburu sourdough breads were appreciated for color, acid taste and flavor, and overall acceptability.
This invention relates to a process for the production of gamma- aminobutyric acid (GABA) from Lactococcus lactis ssp. DSM 19464 and from Lactobacillus plantarum DSM 19463 or from their associations on must. In particular, this invention contemplates the selection and use of Lactococcus lactis ssp. DSM 19464 and of Lactobacillus plantarum DSM 19463 or their associations on must whose composition has been suitably optimized as to its composition, for the production of a preparation based on GABA, containing also vitamins, minerals, polyphenols and alive vital lactic bacteria for its potential use in the dermatological field.
PROCESS OF MICROBIC BIOTECHNOLOGY FOR COMPLETELY DEGRADING GLUTEN IN FLOURS The present invention concerns the use of lactic acid bacteria selected and fungal enzymes for the gluten complete degradation from both bread and durum wheat, barley, rye and oat flour. In particular, the invention concerns the use of lactic acid bacteria selected and fungal enzymes for the gluten complete degradation (residual gluten concentration lower than 20 ppm) of cereal flours, which after detoxification can be used according to a standardized biotechnological protocol for the production of various gluten- free foods.
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