RESUMO
A large portion of global food waste is caused by microbial spoilage. The modern approach to preserve food is to apply different hurdles for microbial pathogens to overcome. These vary from thermal processes and chemical additives, to the application of irradiation and modified atmosphere packaging. Even though such preservative techniques exist, loss of food to spoilage still prevails. Plant compounds and peptides represent an untapped source of potential novel natural food preservatives. Of these, antimicrobial peptides (AMPs) are very promising for exploitation. AMPs are a significant component of a plant's innate defense system. Numerous studies have demonstrated the potential application of these AMPs; however, more studies, particularly in the area of food preservation are warranted. This review examines the literature on the application of AMPs and other plant compounds for the purpose of reducing food losses and waste (including crop protection). A focus is placed on the plant defensins, their natural extraction and synthetic production, and their safety and application in food preservation. In addition, current challenges and impediments to their full exploitation are discussed.
Assuntos
Peptídeos Antimicrobianos , Eliminação de Resíduos , Alimentos , Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , PlantasRESUMO
PURPOSE: Brewers' spent grain (BSG) represents the largest by-product of the brewing industry. Its utilisation as an animal feed has become less practical today; however, its high fibre and protein content make it a promising untapped resource for human nutrition. BSG contains mainly insoluble fibre. This fibre, along with protein, is trapped with the complex lignocellulosic cell structure and must be solubilised to release components which may be beneficial to health through modulation of the gut microbiota. METHODS: In this study, the application of a simultaneous saccharification and fermentation process for the extraction and solubilisation of arabinoxylan from BSG is demonstrated. RESULTS: Processing of the BSG was varied to modulate the physicochemical and molecular characteristic of the released arabinoxylan. The maximum level of arabinoxylan solubilisation achieved was approximately 21%, compared to the unprocessed BSG which contained no soluble arabinoxylan (AX). Concentration of the solubilised material produced a sample containing 99% soluble AX. Samples were investigated for their microbiome modulating capacity in in-vitro faecal fermentation trials. Many samples promoted increased Lactobacillus levels (approx. twofold). One sample that contained the highest level of soluble AX was shown to be bifidogenic, increasing the levels of this genus approx. 3.5-fold as well as acetate (p = 0.018) and propionate (p < 0.001) production. CONCLUSION: The findings indicate that AX extracted from BSG has prebiotic potential. The demonstration that BSG is a source of functional fibre is a promising step towards the application of this brewing side-stream as a functional food ingredient for human nutrition.
Assuntos
Grão Comestível , Microbiota , Animais , Fermentação , Humanos , XilanosRESUMO
Achieving a high monosaccharide composition in malt wort is instrumental to achieve successful lactic acid bacteria fermentation of malt based beverages. The conversion of monosaccharides to alternative metabolites such as the sweet polyol, mannitol with heterofermentative strains presents a novel approach for sugar reduction and to compensate for the loss of sweetness. This work outlines the application of an adopted mashing regimen with the addition of exogenous enzymes to produce wort with high fructose content which can be applied to different malted grain types with consistently efficacious monosaccharide production for bacterial fermentation. The so produced worts are then fermented with Leuconostoc citreum TR116 a mannitol hyper-producer. Malted barley, oat and wheat were mashed to stimulate protein degradation and release of free amino acids along with the enzymatic conversion of starch to fermentable sugars. Amyloglucosidase and glucose isomerase treatment converted di- and oligo-saccharides to glucose and provided a moderate fructose concentration in malt worts which was consistent across the three cereals. Fructose was completely depleted during fermentation with Lc. Citreum TR116 and converted to mannitol with high efficiency (>90%) while overall sugar reduction was >25% in all malt worts. Differences in amino acid composition of malt worts did not significantly affect growth of Lc. Citreum TR116 but did affect the formation of the aroma compounds diacetyl and isoamyl alcohol. Organic acid production and acidification of wort was similar across cereal substrates and acetic acid formation was linked to yield of mannitol. The results suggest that differences in amino acid and fructose content of malt worts considerably change metabolite formation during fermentation with Lc. Citreum TR116, a mannitol hyper-producer. This work gives new insight into the development of consumer acceptable malt based beverages which will provide further options for the health conscious and diabetic consumer, an important step in the age of sugar overconsumption.
Assuntos
Grão Comestível/microbiologia , Fermentação , Alimentos Fermentados/microbiologia , Leuconostoc/metabolismo , Manitol/metabolismo , Açúcares/metabolismo , Avena/química , Avena/microbiologia , Reatores Biológicos , Frutose/metabolismo , Hordeum/química , Hordeum/microbiologia , Lactobacillales/metabolismo , Leuconostoc/crescimento & desenvolvimento , Triticum/química , Triticum/microbiologiaRESUMO
Economic losses due to post-harvest fungal spoilage and mycotoxin contamination of cereal crops is a frequently encountered issue. Typically, chemical preservatives are used to reduce the initial microbial load and the environmental conditions during storage are controlled to prevent microbial growth. However, in recent years the consumers' desire for more naturally produced foods containing less chemical preservatives has grown increasingly stronger. This article reviews the latest advances in terms of novel approaches for chemical decontamination, namely application cold atmospheric pressure plasma and electrolyzed water, and their suitability for preservation of stored cereal crops. In addition, the alternative use of bio-preservatives, such as starter cultures or purified antimicrobial compounds, to prevent the growth of spoilage organisms or remove in-field accumulated mycotoxins is evaluated. All treatments assessed here show potential for inhibition of microbial spoilage. However, each method encounters draw-backs, making industrial application difficult. Even under optimized processing conditions, it is unlikely that one single treatment can reduce the natural microbial load sufficiently. It is evident that future research needs to examine the combined application of several treatments to exploit their synergistic properties. This would enable sufficient reduction in the microbial load and ensure microbiological safety of cereal crops during long-term storage.
Assuntos
Grão Comestível , Conservação de Alimentos , Micotoxinas , Contaminação de Alimentos , Conservantes de Alimentos , FungosRESUMO
A large range of ingredients for food and food products are subject to fungal contamination, which is a major cause of destruction of crops, exposure of animals and humans to invasive mycotoxins, and food spoilage. The resistance of fungal species to common preservation methods highlights the necessity of new ways to increase the shelf life of raw material for food and food products. Antimicrobial peptides and proteins (AMPs) are essential members of the immune system of most living organisms. Due to their broad range of activity and their stability to commonly used food processes, they represent promising alternatives to traditional preservatives. However, despite the growing number of reports of potential food applications of these AMPs, the number of approved peptides is low. Poor solubility, toxicity, and a time-consuming extraction are hurdles that limit their application in food products. Thanks to a deep understanding of the key determinants of their activity, the development of optimized synthetic peptides has reduced these drawbacks. This review presents natural and synthetic antifungal peptides/proteins (AFPs), effective against food-related fungi, with particular emphasis on AFPs from plant sources. The design of novel antifungal peptides via key elements of antifungal activity is also reviewed. The potential applications of natural and synthetic AFPs as novel antifungal food preservatives are finally discussed.
RESUMO
Acetic acid bacteria (AAB) have, for centuries, been important microorganisms in the production of fermented foods and beverages such as vinegar, kombucha, (water) kefir, and lambic beer. Their unique form of metabolism, known as "oxidative" fermentation, mediates the transformation of a variety of substrates into products, which are of importance in the food and beverage industry and beyond; the most well-known of which is the oxidation of ethanol into acetic acid. Here, a comprehensive review of the physiology of AAB is presented, with particular emphasis on their importance in the production of vinegar and fermented beverages. In addition, particular reference is addressed toward Gluconobacter oxydans due to its biotechnological applications, such as its role in vitamin C production. The production of vinegar and fermented beverages in which AAB play an important role is discussed, followed by an examination of the literature relating to the health benefits associated with consumption of these products. AAB hold great promise for future exploitation, both due to increased consumer demand for traditional fermented beverages such as kombucha, and for the development of new types of products. Further studies on the health benefits related to the consumption of these fermented products and guidelines on assessing the safety of AAB for use as microbial food cultures (starter cultures) are, however, necessary in order to take full advantage of this important group of microorganisms.
RESUMO
Weissella is a genus of lactic acid bacteria (LAB) consisting of species formerly included in the Leuconostoc paramesenteroides group. Similar to other LAB, they are commonly found in fermented foods but have also been isolated from environmental and human samples. Currently there are 20 recognized species. Herein, three Weissella cibaria genomes were sequenced using Illumia Mi-Seq and Roche 454 technologies. Annotation was performed using the Prokka and JGI IMG pipelines. A thorough analysis of the genomics of the W. cibaria strains was performed, in addition to brief comparative analyses of the genus Weissella as a whole. Genomic sequence data from the newly sequenced W. cibaria strains and data available in GenBank for other Weissella strains was used (nâ=â10; four Weissella cibaria, one Weissella ceti, one Weissella confusa, one Weissella halotolerans, two Weissella koreensis and one Weissella paramesenteroides). The genomes had sizes varying from 1.3 to 2.4 Mb. DNA G+C contents ranged from 35 to 45 mol%. The core- and pan-proteome at genus and species levels were determined. The genus pan-proteome was found to comprise 4712 proteins. Analysis of the four W. cibaria genomes indicated that the core-proteome, consisting of 729 proteins, constitutes 69â% of the species pan-proteome. This large core-set may explain the divergent niches in which this species has been found. In W. cibaria, in addition to a number of phosphotransferase systems conferring the ability to assimilate plant-associated polysaccharides, an extensive proteolytic system was identified.
Assuntos
Genômica , Característica Quantitativa Herdável , Weissella/genética , Weissella/metabolismo , Adaptação Biológica , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bacteriófagos , Metabolismo Energético , Genômica/métodos , Sequências Repetitivas Dispersas , Dados de Sequência Molecular , Consumo de Oxigênio , Filogenia , Proteoma , Proteômica , RNA Ribossômico 16S/genética , Alinhamento de Sequência , Weissella/virologiaRESUMO
Water kefir is a sparkling, slightly acidic fermented beverage produced by fermenting a solution of sucrose, to which dried fruits have been added, with water kefir grains. These gelatinous grains are a symbiotic culture of bacteria and yeast embedded in a polysaccharide matrix. Lactic acid bacteria, yeast and acetic acid bacteria are the primary microbial members of the sugary kefir grain. Amongst other contributions, species of lactic acid bacteria produce the exopolysaccharide matrix from which the kefir grain is formed, while yeast assists the bacteria by a nitrogen source that can be assimilated. Exactly which species predominate within the grain microbiota, however, appears to be dependent on the geographical origin of the grains and the fermentation substrate and conditions. These factors ultimately affect the characteristics of the beverage produced in terms of aroma, flavour, and acidity, for example, but can also be controlled and exploited in the production of a beverage of desired characteristics. The production of water kefir has traditionally occurred on a small scale and the use of defined starter cultures is not commonly practiced. However, as water kefir increases in popularity as a beverage - in part because of consumer lifestyle trends and in part due to water kefir being viewed as a health drink with its purported health benefits - the need for a thorough understanding of the biology and dynamics of water kefir, and for defined and controlled production processes, will ultimately increase. The aim of this review is to provide an update into the current knowledge of water kefir.
Assuntos
Bebidas/microbiologia , Alimentos Fermentados/microbiologia , Kefir/microbiologia , Lactobacillales/isolamento & purificação , Saccharomyces cerevisiae/isolamento & purificação , Ácido Acético/metabolismo , Grão Comestível/microbiologia , Fermentação , Ácido Láctico/metabolismo , Lactobacillales/metabolismo , Microbiota , Saccharomyces cerevisiae/metabolismo , Água , Microbiologia da ÁguaRESUMO
The demand for sugar reduction in products across the food and beverage industries has evoked the development of novel processes including the application of fermentation with lactic acid bacteria. Heterofermentative lactic acid bacteria (LAB) are diverse in their ability to utilise fermentable sugars and can also convert fructose into the sweet tasting polyol, mannitol. The sourdough microbiota has long been recognised as an ecological niche for a range of homofermentative and heterofermentative lactic acid bacteria. A leading determinant in the biodiversity of sourdough microbial populations is the type of flour used. Ten non-wheat flours were used and back-slopped for 7 days resulting in the isolation of 52 mannitol producing isolates which spanned six heterofermentative species of the genera Lactobacillus, Leuconostoc and Weissella. Assessment of mannitol productivity in fructose concentrations up to 100 g/L found Leuconostoc citreum TR116, to have the best mannitol producing characteristics, consuming 95% of available fructose and yielding 0.68 g of mannitol per gram of fructose consumed which equates to the maximal theoretical yield. Investigation of the effects of initial pH on mannitol production and other fermentation parameters in the isolates found pH 7 to be best for isolates Lactobacillus brevis TR052, Leuconostoc fallax TR111, Leuconostoc citreum TR116, Leuconostoc mesenteroides TR154 and Weissella paramesenteroides TR212, while pH 6 was optimal for Leuconostoc pseudomesenteroides TR080. The fermentation of apple juice with each isolate resulted in sugar reduction ranging from 30.3-74.0 g/L (34-72%). When apple juice fermentation with Leuconostoc citreum TR116 was scaled up to 1 L bioreactor a reduction in sugar of 98.6 g/L (83%) was achieved along with the production of 61.6 g/L mannitol. This demonstrates a fermentative process for sugar reduction in fruit juice with concomitant production of the sweet metabolite mannitol to create a fermentate that is suitable for further development as a low sugar fruit juice alternative.
Assuntos
Lactobacillales/isolamento & purificação , Lactobacillales/metabolismo , Manitol/metabolismo , Açúcares/metabolismo , Biodiversidade , Reatores Biológicos/microbiologia , Pão/microbiologia , Fermentação , Microbiologia de Alimentos , Frutose/metabolismo , Concentração de Íons de Hidrogênio , Lactobacillales/classificaçãoRESUMO
The spoilage of foods caused by the growth of undesirable yeast species is a problem in the food industry. Yeast species such as Zygosaccharomyces bailii, Zygosaccharomyces rouxii, Debaryomyces hansenii, Kluyveromyces lactis and Saccharomyces cerevisiae have been encountered in foods such as high sugar products, fruit juices, wine, mayonnaise, chocolate and soft drinks. The demand for new methods of preservations has increased because of the negative association attached to chemical preservatives. The sequence of a novel short peptide (KKFFRAWWAPRFLK-NH2) was modified to generate three versions of this original peptide. These peptides were tested for the inhibition of the yeasts mentioned above, allowing for the better understanding of their residue modifications. The range of the minimum inhibitory concentration was between 25 and 200⯵g/mL. Zygosaccharomyces bailii was the most sensitive strain to the peptides, while Zygosaccharomyces rouxii was the most resistant. Membrane permeabilisation was found to be responsible for yeast inhibition at a level which was a two-fold increase of the MIC (400⯵g/mL). The possibility of the production of reactive oxygen species was also assessed but was not recognised as a factor involved for the peptides' mode of action. Their stability in different environments was also tested, focusing on high salt, pH and thermal stability. The newly designed peptides showed good antifungal activity against some common food spoilage yeasts and has been proven effective in the application in Fanta Orange. These efficient novel peptides represent a new source of food preservation that can be used as an alternative for current controversial preservatives used in the food industry.
Assuntos
Microbiologia de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Peptídeos/farmacologia , Leveduras/efeitos dos fármacos , Antifúngicos/farmacologia , Indústria de Processamento de Alimentos , Sucos de Frutas e Vegetais/microbiologia , Kluyveromyces/efeitos dos fármacos , Kluyveromyces/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/crescimento & desenvolvimento , Leveduras/crescimento & desenvolvimento , Zygosaccharomyces/crescimento & desenvolvimentoRESUMO
A marketing study revealed that commercially available burger buns can contain up to 10% (w/w) of added sugar. In order to reduce sugar and maintaining the product quality at the same time, functional ingredients and alternative sweetening agents have to be incorporated. In this study, the sourdough lactic acid bacteria Leuconostoc citreum TR116, selected for its ability to produce high amounts of mannitol, was used to produce wheat sourdough and its biochemical characteristics (cell count, pH, TTA, sugar- and acid profile, as well as mannitol production) were monitored over 48â¯h. The so produced sourdough was then incorporated, as a functional ingredient, into a sugar reduced burger bun system and the quality characteristics of the dough and the final product were determined. Sourdough incorporation counteract the negative effects of sugar reduction on dough properties and resulted in the same viscoelastic properties (0.423⯱â¯0.008) and gluten-network-development (PMT: 160⯱â¯12.6â¯s; TM: 44.0⯱â¯2.6 BU) as the full-sugar control dough. Furthermore, the investigation of specific volume, crumb hardness and chewiness revealed no significant differences between sugar reduced sourdough burger buns and its control. It is noteworthy that sourdough contributed to browning reaction resulting in darker crumb and crust colour (-8.2%; -9.6%) and it extended microbial shelf life of the burger buns significantly (+3.5â¯days). Sensory evaluation showed no significant differences in sweetness and sourness between sugar reduced buns containing sourdough and the full-sugar control. In conclusion, the incorporation of mannitol-rich sourdough fermented by Leuconostoc citreum TR116 represents a novel technological approach in the field of sugar reduction and showed high potential as a functional ingredient to ameliorate the losses of important quality parameters. Especially sourdough containing higher amounts of mannitol and lower amounts of lactate improved significantly the dough and burger bun quality.
Assuntos
Pão/análise , Leuconostoc/metabolismo , Manitol/metabolismo , Açúcares/análise , Triticum/microbiologia , Pão/microbiologia , Fermentação , Glutens/análise , Glutens/metabolismo , Ácido Láctico/análise , Ácido Láctico/metabolismo , Açúcares/metabolismo , Triticum/químicaRESUMO
Sugar reduction in sweet baked goods is one of the most popular trends on the food market. However, reducing sugar without lowering the product quality with respect to sweetness, texture and microbial shelf life is challenging. Sugar alcohols are one group of sugar replacers which maintain the bulk and contribute to sweetness. Nevertheless, alternative approaches, particularly those that are seen as 'clean label', are highly demanded. Hence, the natural, in situ production of mannitol in a sourdough system was performed and its potential as a functional ingredient to improve the product quality of a sugar-reduced cake was investigated. A full sugar cake (C1), a 50% sugar-reduced cake with wheat starch (C2) or with commercially available mannitol (C3) were considered as controls. The substitution of sugar by wheat starch or mannitol caused lower specific volume (-15.5%; -10.7%), a harder crumb (+17.1 N; +4.4 N), less browning, a shorter microbial shelf life (-5.7 days; -4.3 days) and poorer sensory properties. The incorporation of sourdough in C2 improved the pasting properties by decreasing the peak viscosity. Moreover, it resulted in a similar specific volume to the full-sugar control, contributed to significantly softer crumb (-8.6 N) and increased browning compared to C2. Sensory evaluation revealed an increased sweetness perception (+93%), aroma (+30%) and flavour (+25.5%) by the incorporation of sourdough. Although sourdough incorporation improved sugar-reduced cakes, the quality characteristics of the full-sugar control could not be achieved in this study. In conclusion, the addition of sourdough in amounts lower than 10% can be considered a useful tool to improve specific volume, crumb structure, colour, taste and flavour, as well as shelf life of sugar-reduced cakes.
Assuntos
Pão/análise , Açúcares/análise , Paladar , Adulto , Pão/microbiologia , Feminino , Fermentação , Manipulação de Alimentos , Humanos , Leuconostoc/metabolismo , Masculino , Manitol/análise , Controle de Qualidade , Amido/química , Triticum/química , Triticum/microbiologia , Viscosidade , Adulto JovemRESUMO
The challenge remains for the baking industry to reduce salt levels in yeasted bread as directed by governments, retailers and consumers around the world. The two main problems associated with the reduction of salt are a lack of salty taste and the reduction in shelf-life. Both of these issues are addressed in the presented work. A range of breads containing different levels of salt (0.0%, 0.3% and 1.2% of NaCl) in combination with various levels of sourdough (0%, 6%, 12%, 18%, 24%) was produced. The different doughs were analysed for their rheological behaviour. The bread quality characteristics such as loaf volume, crumb structure, staling rate and microbial shelf life were also determined. The sourdoughs were analysed for their different metabolites: organic acids, sugars, exopolysaccharides (EPS), and antifungal compounds. A trained sensory panel was used to perform descriptive analysis of the bread samples. The object of this paper is to use functional sourdoughs, containing Lactobacillus amylovorus DSM 19280 and Weisella cibaria MG1 to compensate for the quality problems that occur when salt is reduced in yeasted bread. The application of functional sourdoughs containing exopolysaccharides and/or antifungal substances in salt reduced breads significantly improved the quality. The application of functional sourdoughs allows the reduction of salt to a level of 0.3%.
Assuntos
Pão/microbiologia , Microbiologia de Alimentos , Lactobacillus acidophilus/metabolismo , Leuconostocaceae/metabolismo , Antifúngicos/farmacologia , Lactobacillus acidophilus/efeitos dos fármacos , Leuconostocaceae/efeitos dos fármacos , Cloreto de Sódio/farmacologia , Paladar , Fatores de TempoRESUMO
Exopolysaccharides produced by lactic acid bacteria are typically high molecular weight polymers that display physiochemical properties similar to commercial hydrocolloids or gums i.e. ability to form a network and bind water. Such properties, coupled with their production in-situ, mean these exopolysaccharides represent a natural alternative to commercial hydrocolloids for the enhancement of both gluten-containing and gluten-free cereal products. Research in the past decade has shown the potential of these lactic acid bacteria exopolysaccharides, in combination with sourdough technology, to enhance the quality of gluten-containing (primarily wheat) products, particularly with respect to loaf volume, shelf-life and staling rate. Such techno-functional properties can be exploited in the gluten-free area and shows promise in helping to overcome the challenge of producing gluten-free products of the same quality and acceptability as their gluten-containing counterparts. The aim of this review is to present an overview of our current knowledge of exopolysaccharides produced by lactic acid bacteria, and how they can be exploited in the area of cereal science and gluten-free.
Assuntos
Pão/microbiologia , Dieta Livre de Glúten/métodos , Microbiologia de Alimentos/métodos , Lactobacillales/metabolismo , Polissacarídeos Bacterianos/metabolismo , FermentaçãoRESUMO
The interest for plant-based dairy substitutes is expanding rapidly and consumers are opting for nutritious and healthy dairy alternatives. The reduction of sugar using different exogenous enzymes in combination with lactic acid fermentation in a quinoa-based milk substitute was explored in this study. Different amylolytic enzymes were used to release sugar from the raw material, which were further metabolised to mannitol, due to fermentation with two heterofermentative lactic acid bacteria. Using these two biotechnological techniques enables the reduction of sugar, while also preserving some of the sweetness. Leuconostoc citreum TR116, and Lactobacillus brevis TR055 were isolated from sourdough. Both strains showed high viable cell counts with L. citreum TR116â¯>â¯8.4 and L. brevis TR055â¯>â¯9.3â¯logâ¯cfu/mL, and a reduction in pH to 3.7 and 3.5 respectively. When fructose was available, mannitol was produced in conjunction with acetic acid in addition to lactic acid. Due to these processes, the original glucose value was reduced from 50â¯mmol/100â¯g to approximately 30â¯mmol/100â¯g, which equates to a glucose reduction of 40%. In respect to mannitol production, both strains performed well: L. citreum TR116 showed a conversion factor of 1:1 from fructose to mannitol, while L. brevis TR055 showed a lower yield, with a conversion factor of 1:0.8. Glycaemic load was reduced by more than a third, bringing it down to the low range with a value of about 10. Overall, enzymatic modification in conjunction with mannitol-producing lactic acid bacteria shows great potential for further possible application in the development of nutritious and sugar reduced plant-based milk substitutes.
Assuntos
Chenopodium quinoa/metabolismo , Leuconostoc/metabolismo , Levilactobacillus brevis/metabolismo , Manitol/metabolismo , Substitutos do Leite/química , Polímeros/metabolismo , Açúcares/metabolismo , Ácido Acético/metabolismo , Biotecnologia , Fermentação , Frutose/metabolismo , Glucose/metabolismo , Ácido Láctico/metabolismo , Levilactobacillus brevis/isolamento & purificação , Leuconostoc/isolamento & purificaçãoRESUMO
Exopolysaccharides produced by lactic acid bacteria are a diverse group of polysaccharides produced by many species. They vary widely in their molecular, compositional, and structural characteristics, including mechanisms of synthesis. The physiochemical properties of these polymers mean that they can be exploited for the sensorial and textural enhancement of a variety of food and beverage products. Traditionally, lactic acid bacteria exopolysaccharides have an important role in fermented dairy products and more recently are being applied for the improvement of bakery products. The health benefits that are continually being associated with these polysaccharides enable the development of dual function, added-value, and clean-label products. To fully exploit and understand the functionality of these exopolysaccharides, their isolation, purification, and thorough characterization are of great importance. This review considers each of the above factors and presents the current knowledge on the importance of lactic acid bacteria exopolysaccharides in the food and beverage industry.
Assuntos
Bebidas , Microbiologia de Alimentos , Alimentos , Lactobacillales/metabolismo , Polissacarídeos Bacterianos/metabolismo , Coloides , Fermentação , Tecnologia de Alimentos , Humanos , PrebióticosRESUMO
The aim of this study was to develop a novel beverage fermented with Weissella cibaria MG1 based on aqueous extracts of wholemeal quinoa flour. The protein digestibility of quinoa based-milk was improved by applying complex proteolytic enzymes able to increase protein solubility by 54.58%. The growth and fermentation characteristics of Weissella cibaria MG1, including EPS production at the end of fermentation, were investigated. Fermented wholemeal quinoa milk using MG1 showed high viable cell counts (>109cfu/ml), a pH of 5.16, and significantly higher water holding capacity (WHC, 100%), viscosity (0.57mPas) and exopolysaccharide (EPS) amount (40mg/l) than the chemical acidified control. High EPS (dextran) concentration in quinoa milk caused earlier aggregation because more EPS occupy more space, and the chenopodin were forced to interact with each other. Microstructure observation indicated that the network structures of EPS-protein improve the texture of fermented quinoa milk. Overall, Weissella cibaria MG1 showed satisfactory technology properties and great potential for further possible application in the development of high viscosity fermented quinoa milk.
Assuntos
Chenopodium quinoa/metabolismo , Dextranos/metabolismo , Substitutos do Leite/métodos , Weissella/metabolismo , Iogurte/microbiologia , Reatores Biológicos , Chenopodium quinoa/microbiologia , Fermentação , Farinha/análise , Proteínas de Plantas/metabolismoRESUMO
The increasing prevalence of coeliac disease (CD) and gluten-related disorders has led to increasing consumer demand for gluten-free products with quality characteristics similar to wheat bread. The replacement of gluten in cereal-based products remains a challenge for scientists, due to its unique role in network formation, which entraps air bubbles. When gluten is removed from a flour, starch is the main component left. Starch is used as gelling, thickening, adhesion, moisture-retention, stabilizing, film forming, texturizing and anti-staling ingredient. The extent of these properties varies depending on the starch source. The starches can additionally be modified increasing or decreasing certain properties of the starch, depending on the application. Starch plays an important role in the formulation of bakery products and has an even more important role in gluten-free products. In gluten-free products, starch is incorporated into the food formulation to improve baking characteristics such as the specific volume, colour and crumb structure and texture. This review covers a number of topics relating to starch; including; an overview of common and lesser researched starches; chemical composition; morphology; digestibility; functionality and methods of modification. The emphasis of this review is on starch and its properties with respect to the quality of gluten-free products.
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Puff pastry is a major contributor of fat and sodium intake in many countries. The objective of this research was to determine the impact of salt (0-8.4g/100g flour) on the structure and quality characteristics of puff pastry with full and reduced (-40%) fat content as well as the rheological properties of the resulting dough. Therefore, empirical rheological tests were carried out including dough extensibility, dough stickiness and GlutoPeak test. The quality of the puff pastry was characterized with the VolScan, Texture Analyzer and C-Cell. NaCl reduction significantly changed rheological properties of the basic dough as well as a number of major quality characteristics of the puff pastry. Significant differences due to NaCl addition were found in particular for dough resistance, dough stickiness, Peak Maximum Time and Maximum Torque (p<0.05). Peak firmness and total firmness decreased significantly (p<0.05) with increasing salt levels for puff pastry containing full fat. Likewise, maximal lift, specific volume, number of cells and slice brightness increased with increasing NaCl at both fat levels. Although a sensorial comparison of puff pastries revealed that salt reduction (30%) was perceptible, no significant differences were found for all other investigated attributes. Nevertheless, a reduction of 30% salt and 40% fat in puff pastry is achievable as neither the perception and visual impression nor attributes such as volume, firmness and flavour of the final products were significantly affected.