Fundamental study on changes in the FODMAP profile of cereals, pseudo-cereals, and pulses during the malting process.

Whole grains and pulses are rich in nutrients but often avoided by individuals with gastrointestinal disorders, due to high levels of fermentable oligo-, di-, monosaccharides and polyols (FODMAPs). This study investigated the impact of malting as delivery-system for endogenous enzymes. Malts from barley and wheat (naturally high in fructans), lentils and chickpeas (high in galactooligosaccharides), oat and buckwheat (low in FODMAPs) were produced. While barley and wheat malts had slightly elevated fructan-levels, in oat malt 0.8 g/100 g DM fructans were de novo synthesized. In lentils and chickpeas galactooligosaccharides diminished by 80-90%. Buckwheat did not contain any FODMAPs commonly investigated, but fagopyritols which may have a similar physiological effect. Also fagopyritols were degraded. While malted pulses and buckwheat are directly suitable for low FODMAP applications, using the combined approach of malting and fermentation, malted cereals could contribute to high nutritional values of such products.

Mashes to Mashes, Crust to Crust. Presenting a novel microstructural marker for malting in the archaeological record.

The detection of direct archaeological remains of alcoholic beverages and their production is still a challenge to archaeological science, as most of the markers known up to now are either not durable or diagnostic enough to be used as secure proof. The current study addresses this question by experimental work reproducing the malting processes and subsequent charring of the resulting products under laboratory conditions in order to simulate their preservation (by charring) in archaeological contexts and to explore the preservation of microstructural alterations of the cereal grains. The experimentally germinated and charred grains showed clearly degraded (thinned) aleurone cell walls. The histological alterations of the cereal grains were observed and quantified using reflected light and scanning electron microscopy and supported using morphometric and statistical analyses. In order to verify the experimental observations of histological alterations, amorphous charred objects (ACO) containing cereal remains originating from five archaeological sites dating to the 4th millennium BCE were considered: two sites were archaeologically recognisable brewing installations from Predynastic Egypt, while the three broadly contemporary central European lakeshore settlements lack specific contexts for their cereal-based food remains. The aleurone cell wall thinning known from food technological research and observed in our own experimental material was indeed also recorded in the archaeological finds. The Egyptian materials derive from beer production with certainty, supported by ample contextual and artefactual data. The Neolithic lakeshore settlement finds currently represent the oldest traces of malting in central Europe, while a bowl-shaped bread-like object from Hornstaad-Hörnle possibly even points towards early beer production in central Europe. One major further implication of our study is that the cell wall breakdown in the grain's aleurone layer can be used as a general marker for malting processes with relevance to a wide range of charred archaeological finds of cereal products.

Overview on the mechanisms of coffee germination and fermentation and their significance for coffee and coffee beverage quality.

Quality of coffee is a complex trait and is influenced by physical and sensory parameters. A complex succession of transformations during the processing of seeds to roasted coffee will inevitably influence the in-cup attributes of coffee. Germination and fermentation of the beans are two bioprocesses that take place during post-harvest treatment, and may lead to significant modifications of coffee attributes. The aim of this review is to address the current knowledge of dynamics of these two processes and their significance for bean modifications and coffee quality. The first part of this review gives an overview of coffee germination and its influence on coffee chemistry and quality. The germination process initiates while these non-orthodox seeds are still inside the cherry. This process is asynchronous and the evolution of germination depends on how the beans are processed. A range of metabolic reactions takes place during germination and can influence the carbohydrate, protein, and lipid composition of the beans. The second part of this review focuses on the microbiota associated with the beans during post-harvesting, exploring its effects on coffee quality and safety. The microbiota associated with the coffee cherries and beans comprise several bacterial, yeast, and fungal species and affects the processing from cherries to coffee beans. Indigenous bacteria and yeasts play a role in the degradation of pulp/mucilage, and their metabolism can affect the sensory attributes of coffee. On the other hand, the fungal population occurring during post-harvest and storage negatively affects coffee quality, especially regarding spoilage, off-tastes, and mycotoxin production.

Mold spoilage of bread and its biopreservation: A review of current strategies for bread shelf life extension.

Microbial spoilage of bread and the consequent waste problem causes large economic losses for both the bakery industry and the consumer. Furthermore the presence of mycotoxins due to fungal contamination in cereals and cereal products remains a significant issue. The use of conventional chemical preservatives has several drawbacks, necessitating the development of clean-label alternatives. In this review, we describe current research aiming to extend the shelf life of bread through the use of more consumer friendly and ecologically sustainable preservation techniques as alternatives to chemical additives. Studies on the in situ-production/-expression of antifungal compounds are presented, with special attention given to recent developments over the past decade. Sourdough fermented with antifungal strains of lactic acid bacteria (LAB) is an area of increasing focus and serves as a high-potential biological ingredient to produce gluten-containing and gluten-free breads with improved nutritional value, quality and safety due to shelf-life extension, and is in-line with consumer's demands for more products containing less additives. Other alternative biopreservation techniques include the utilization of antifungal peptides, ethanol and plant extracts. These can be added to bread formulations or incorporated in antimicrobial films for active packaging (AP) of bread. This review outlines recent progress that has been made in the area of bread biopreservation and future perspectives in this important area.

Nutritional therapy - Facing the gap between coeliac disease and gluten-free food.

The market of gluten-free bakery products is considerably growing since better diagnostic methods allow identifying an increasing number of people suffering coeliac disease and other gluten-related disorders such as dermatitis herpetiformis, gluten ataxia, wheat allergy and non-coeliac gluten sensitivity. The only and safe treatment available nowadays for these types of disorders is to follow a strict and permanent lifelong gluten-free diet. Beside the people needing to follow a gluten-free diet for health reasons, a new segment of consumers has arisen who consume gluten-free products as a lifestyle choice. Among the bakery products, bread is a major staple food consumed daily all over the world. The dough and bread quality characteristics (such as gas retaining ability, mixing tolerance, resistance to stretch and extensibility and crumb structure) are mostly attributed to the presence of gluten. Despite the improved quality of gluten-free breads in the last number of years, most products on the market are still described as low quality product. In addition to the low overall quality of gluten-free products, the nutritional value of a large number of them is quite poor. In this context, this review gives an overview on the consumers, which need to follow a gluten-free diet for health reasons. The trends in this gluten-free bakery segment will also be reviewed based on the current analysis of marketing studies. An overview of the major ingredients used in gluten-free bread products will be given. The choice of the ingredients discussed in this paper is based on a comprehensive study of the leading gluten-free breads available on the market, as well as a detailed study of the scientific literature. The impact of the various ingredients on bread-making process and bread quality is also part of this review. Major emphasis will be placed on the application of sourdough as a means to improve gluten-free bread quality.

Influence of dextran-producing Weissella cibaria on baking properties and sensory profile of gluten-free and wheat breads.

Breads based on gluten-free buckwheat, quinoa, sorghum and teff flours were produced with addition of 20% sourdough fermented with exopolysaccharide (EPS) producing Weissella cibaria MG1. Wheat bread was baked as a reference. Dough rheology, bread quality parameters and sensory properties of the sourdough-containing breads were compared to sourdough non-containing control breads of the respective flour. The specific volume remained unaffected by sourdough application. In buckwheat, sorghum, teff and wheat sourdough breads acidification increased crumb porosity compared to control breads. Crumb hardness was significantly reduced in buckwheat (-122%), teff (-29%), quinoa (-21%) and wheat sourdough breads (-122%). The staling rate was significantly reduced in buckwheat, teff and wheat sourdough breads. Water activity of the sourdough containing bread crumb was not influenced by the presence of EPS. Due to the presence of exopolysaccharides (EPS) and influence of acidification, the dough strength, AF, as measured by oscillation tests decreased significantly in sourdough-containing buckwheat, sorghum and wheat dough, but increased in sourdough-containing quinoa and teff dough. Microbial shelf-life was significantly prolonged neither for gluten-free sourdough nor for wheat sourdough breads. Scanning electron microscopy of control and sourdough bread crumbs did not show differences concerning structural starch features. In addition, the aroma of most bread was not improved by sourdough addition.

The effects of liquid versus spray-dried Laminaria digitata extract on selected bacterial groups in the piglet gastrointestinal tract (GIT) microbiota.

In this study, the effects of supplementing animal feed with a liquid and spray-dried fucoidan and laminarin extract, derived from the seaweed Laminaria digitata on the porcine gastrointestinal microbiota, specifically the communities of Lactobacillus, Bifidobacterium and enterobacteria were evaluated. Twenty four piglets were fed one of three diets over a 21-day period to determine the effect that each had on the bacterial communities. The dietary treatments were as follows; (1) control diet, (2) control diet plus spray-dried formulation of laminarin fucoidan (L/F-SD) extract, (3) control diet plus a liquid formulation of (L/F-WS) extract. Control diet consisted of wheat, soya bean meal, soya oil and a vitamin and mineral mixture. The L/F-SD and L/F-WS supplemented diets had equal proportion of 500 ppm laminarin and fucoidan. At the end of the 21 day feeding period all animals were sacrificed and samples were collected from the ileum, caecum and colon. Counts were determined for Lactobacillus, Bifidobacterium and enterobacteria. Plate count analysis revealed that the L/F-SD diet caused a statistically significant 1.5 log and 2 log increases in the Lactobacillus and Bifidobacterium counts of ileum samples respectively. A greater difference was observed with the L/F-WS diet in that Lactobacillus and Bifidobacterium increased by 2 log and 3 log respectively. Alterations in the Lactobacillus species composition of the gastrointestinal tract (GIT) were analysed using specific PCR - denaturing gradient gel electrophoresis (PCR-DGGE). The DGGE profiles indicated that Lactobacillus species richness decreased along the gastrointestinal tract i.e. the number of dominant species detected in the colon was less than those detected in the ileum and caecum irrespective of the diet consumed. Consumption of both the L/F-SD and L/F-WS diets resulted in a richer Lactobacillus species composition in the ileum, with the L/F-SD diet being associated the emergence of Lactobacillus agilis in the colon. The study indicated that the L/F-WS extract was superior to the L/F-SD extract in increasing the titre of beneficial bacteria in the gastrointestinal tract (GIT).

Wheat bread biofortification with rootlets, a malting by-product.

BACKGROUND: Barley rootlets, a malting by-product, are currently discarded or used as fodder. In this study, milled rootlets and Lactobacillus plantarum FST 1.7-fermented rootlets were incorporated into wheat bread. The objective was to formulate a high-nutrition alternative to wholemeal breads with improved technological attributes. RESULTS: Chemical analyses showed that rootlets contribute nutrients and bioactive compounds, including proteins, amino acids, fatty acids, carbohydrates, dietary fibre, polyphenols and minerals. Rootlets are particularly rich in essential amino acids, especially lysine, the typically limiting essential amino acid of cereals. Additionally, rootlets offer potential dietary fibre health benefits such as protection against cardiovascular disease, cancers and digestive disorders. CONCLUSION: Breads prepared with a (fermented) rootlet inclusion level of up to 10% compared favourably with wholemeal breads from nutritive, technological and textural perspectives. Furthermore, they were well accepted by sensory panellists. Using rootlets as a food ingredient would have the added benefit of increasing this malting by-product's market value.

Germination of oat and quinoa and evaluation of the malts as gluten free baking ingredients.

Germination can be used to improve the sensory and nutritional properties of cereal and pseudocereal grains. Oat and quinoa are rich in minerals, vitamins and fibre while quinoa also contains high amounts of protein of a high nutritional value. In this study, oat and quinoa malts were produced and incorporated in a rice and potato based gluten free formulation. Germination of oat led to a drastic increase of α-amylase activity from 0.3 to 48 U/g, and minor increases in proteolytic and lipolytic activities. Little change was observed in quinoa except a decrease in proteolytic activity from 9.6 to 6.9 U/g. Oat malt addition decreased batter viscosities at both proofing temperature and during heating. These changes led to a decrease in bread density from 0.59 to 0.5 g/ml and the formation of a more open crumb, but overdosing of oat malt deteriorated the product as a result of excessive amylolysis during baking. Quinoa malt had no significant effect on the baking properties due to low α-amylase activity. Despite showing a very different impact on the bread quality, both malts influenced the electrophoretic patterns of rice flour protein similarly. This suggests that malt induced proteolysis does not influence the technological properties of a complex gluten free formulation.

Effects of cereal ß-glucans and enzyme inclusion on the porcine gastrointestinal tract microbiota.

This study was designed to evaluate the effect barley-based diets vs. oats based diets on levels of Lactobacillus, Bifidobacterium and Enterobacterium in the porcine gastrointestinal tract (GIT). In addition the effect of enzyme supplementation in both diets was explored. Twenty-eight boars were used in a 2 × 2 factorial arrangement and were assigned to 1 of 4 dietary treatments: barley-based (B) diet; barley-based diet plus an enzyme supplement (B + ES); oat-based (O) diet or oat-based diet plus an enzyme supplement (O + ES). The enzyme supplement contained endo-1,3-ß-glucanase and endo-1,4-ß-xylanase. Faecal samples were collected from the pigs prior to initiations of the experiment and at slaughter. At slaughter digesta samples were collected from the stomach, ileum, caecum, proximal and distal colon. Alterations in Lactobacillus species composition in the gastrointestinal tract (GIT) were analysed by genus-specific PCR - denaturing gradient gel electrophoresis (DGGE). DGGE profiles indicated that cereal source provoked shifts in Lactobacillus population. The most diverse populations of lactobacilli emerged after feeding the O diets. Enzymes inclusion altered the composition of Lactobacillus species prevalent throughout the GIT in animals fed the B diet, causing a shift in the dominant lactobacilli present in the caecum and proximal colon. No such effect was evident in animals fed the enzyme supplemented O + ES diet. Microbial plate counts revealed that the O diets gave rise to higher counts of Lactobacillus in the caecum and colon and Bifidobacterium counts in the ileum, caecum and colon than the B diets. The O diet caused a 2 log increase in Enterobacterium counts in the proximal colon, no such effects were observed in animals fed the B, the B + ES or the O + ES diets. Overall both O diets had a more positive influence on the counts of the beneficial microorganisms and richness of the Lactobacillus population in the porcine GIT.

Ecofriendly control of potato late blight causative agent and the potential role of lactic acid bacteria: a review.

In times of increasing societal pressure to reduce the application of pesticides on crops, demands for environmentally friendly replacements have intensified. In the case of late blight, a devastating potato plant disease, the historically most widely known plant destroyer has been the oomycete Phytophthora infestans. To date, the most important strategy for control of this pathogen has been the frequent application of fungicides. Due to the aforementioned necessity to move away from traditional chemical treatments, many studies have focused on finding alternative ecofriendly biocontrol systems. In general, due to the different modes of actions (i.e. antagonistic effects or induction of plant defence mechanisms), the use of microorganisms as biological control agents has a definite potential. Amongst them, several species of lactic acid bacteria have been recognised as producers of bioactive metabolites which are functional against a broad spectrum of undesirable microorganisms, such as fungi, oomycetes and other bacteria. Thus, they may represent an interesting tool for the development of novel concepts in pest management. This review describes the present situation of late blight disease and summarises current literature regarding the biocontrol of the phytopathogen P. infestans using antagonistic microorganisms.

Medical nutrition therapy: use of sourdough lactic acid bacteria as a cell factory for delivering functional biomolecules and food ingredients in gluten free bread.

Celiac disease (CD) is an immune-mediated disease, triggered in genetically susceptible individuals by ingesting gluten from wheat, rye, barley, and other closely related cereal grains. Currently, the estimated prevalence of CD is around 1 % of the population in the western world and medical nutritional therapy (MNT) is the only accepted treatment for celiac disease. To date, the replacement of gluten in bread presents a significant technological challenge for the cereal scientist due to the low baking performance of gluten free products (GF). The increasing demand by the consumer for high quality gluten-free (GF) bread, clean labels and natural products is rising. Sourdough has been used since ancient times for the production of rye and wheat bread, its universal usage can be attributed to the improved quality, nutritional properties and shelf life of sourdough based breads. Consequently, the exploitation of sourdough for the production of GF breads appears tempting. This review will highlight how sourdough LAB can be an efficient cell factory for delivering functional biomolecules and food ingredients to enhance the quality of gluten free bread.

Biodiversity of lactic acid bacteria and yeasts in spontaneously-fermented buckwheat and teff sourdoughs.

In this study, four different laboratory scale gluten-free (GF) sourdoughs were developed from buckwheat or teff flours. The fermentations were initiated by the spontaneous biota of the flours and developed under two technological conditions (A and B). Sourdoughs were propagated by continuous back-slopping until the stability was reached. The composition of the stable biota occurring in each sourdough was assessed using both culture-dependent and -independent techniques. Overall, a broad spectrum of lactic acid bacteria (LAB) and yeasts species, belonging mainly to the genera Lactobacillus, Pediococcus, Leuconostoc, Kazachstania and Candida, were identified in the stable sourdoughs. Buckwheat and teff sourdoughs were dominated mainly by obligate or facultative heterofermentative LAB, which are commonly associated with traditional wheat or rye sourdoughs. However, the spontaneous fermentation of the GF flours resulted also in the selection of species which are not consider endemic to traditional sourdoughs, i.e. Pediococcus pentosaceus, Leuconostoc holzapfelii, Lactobacillus gallinarum, Lactobacillus vaginalis, Lactobacillus sakei, Lactobacillus graminis and Weissella cibaria. In general, the composition of the stable biota was strongly affected by the fermentation conditions, whilst Lactobacillus plantarum dominated in all buckwheat sourdoughs. Lactobacillus pontis is described for the first time as dominant species in teff sourdough. Among yeasts, Saccharomyces cerevisiae and Candida glabrata dominated teff sourdoughs, whereas the solely Kazachstania barnetti was isolated in buckwheat sourdough developed under condition A. This study allowed the identification and isolation of LAB and yeasts species which are highly competitive during fermentation of buckwheat or teff flours. Representatives of these species can be selected as starters for the production of sourdough destined to GF bread production.

Development of buckwheat and teff sourdoughs with the use of commercial starters.

In this study we investigated the suitability of commercial starters for the production of gluten free sourdoughs. For this purpose, four different laboratory scale sourdoughs were developed from the flours buckwheat or teff. Two different starters (SA, SB) were used to start the fermentations, which were carried out under two technological conditions. Sourdoughs were propagated by back-slopping until the stability was reached. The composition of the stable sourdoughs was investigated by culture dependent techniques and the development of the dominant biota was monitored by PCR-DGGE. Unique and complex LAB and yeasts communities were detected in each sourdough, comprising strains which originated from the flours. The competitiveness of the starter LAB varied according to the substrate and the fermentation conditions applied. Among the LAB present in both SA and SB, L. helveticus and L. paracasei strains did not persist in buckwheat or teff sourdoughs. Lc. argentinum was competitive only in buckwheat sourdoughs, whereas L. reuteri persisted only in teff sourdough. L. fermentum and L. helveticus present in both starters dominated only the sourdoughs fermented at the higher temperature. Remarkably, the starter yeasts were outcompeted by spontaneous yeast strains, i.e. Kazachstania barnetti and Saccharomyces cerevisiae in teff sourdoughs, whereas no yeasts were isolated from buckwheat sourdoughs. The isolation of autochthonous LAB and yeasts from the stable teff and buckwheat sourdoughs indicates that both flours represent an important reservoir for the isolation of novel and competitive starters for the production of gluten free sourdough bread.