The group of Gram-negative bacteria capable of oxidising ethanol to acetic acid is called acetic acid bacteria (AAB). They are widespread in nature and play an important role in the production of ...food and beverages, such as vinegar and kombucha. The ability to oxidise ethanol to acetic acid also allows the unwanted growth of AAB in other fermented beverages, such as wine, cider, beer and functional and soft beverages, causing an undesirable sour taste. These bacteria are also used in the production of other metabolic products, for example, gluconic acid, l-sorbose and bacterial cellulose, with potential applications in the food and biomedical industries. The classification of AAB into distinct genera has undergone several modifications over the last years, based on morphological, physiological and genetic characteristics. Therefore, this review focuses on the history of taxonomy, biochemical aspects and methods of isolation, identification and quantification of AAB, mainly related to those with important biotechnological applications.
Acetic acid bacteria (AAB) are microorganisms widely distributed in nature. Although this group is involved in the spoilage of some foods, AAB are of great industrial interest, and their ...functionality is still poorly understood. AAB convert ethanol, sugars and polyols into various organic acids, aldehydes and ketones
oxidative fermentation. These metabolites are produced during a succession of biochemical reactions in various fermented foods and beverages, such as vinegar, kombucha, water kefir, lambic and cocoa. Furthermore, important products such as gluconic acid and ascorbic acid precursors can be produced industrially from their metabolism. The development of new AAB-fermented fruit drinks with healthy and functional properties is an interesting niche for research and the food industry to explore, as it can meet the needs of a wide range of consumers. Exopolysaccharides such as levan and bacterial cellulose have unique properties, but they need to be produced on a larger scale to expand their applications in this area. This work emphasizes the importance and applications of AAB during the fermentation of various foods, their role in the development of new beverages as well as numerous applications of levan and bacterial cellulose.
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•First study to classify vinegar by agronomic method of raw material cultivation.•Vinegar classification by type of raw materials and aging time.•NMR with PLS-DA had the best ...performance, followed by FT-IR with UV–vis and NIR.•Vinegar classification according to the agronomic cultivation mode is more complex.•Spectralprint techniques with chemometrics were useful for vinegar quality control.
Vinegar is a versatile product used for food preservation, cooking, healthcare, and cleaning. In this study, 80 vinegar of different raw materials, aging time, and for the first time by the agronomic method of raw material cultivation were classified by spectralprint techniques with chemometrics. Datasets were obtained by proton nuclear magnetic resonance (1H NMR), Fourier transforms mid-infrared (FT-IR), near-infrared (NIR), and ultraviolet–visible (UV–vis); then evaluated by common dimension (ComDim) and partial least squares-discriminant analysis (PLS-DA). NMR with PLS-DA had the best prediction performance compared to other techniques, with accuracy values between 92.3 and 100 %, followed by FT-IR and UV–vis of 80.8 and 96.0 % and NIR between 69.2 and 84.0 %. The results indicated that the classification of vinegar according to the agronomic cultivation method is more complex than aging time or raw material. However, any of these spectralprint techniques have demonstrated that they can be used in the classification of vinegar.
Despite the great properties of bacterial cellulose, its manufacture is still limited due to difficulties in large-scale production. These problems are mainly related to low production yields and ...high overall costs of the conventional culture media normally used. To surpass these problems, it is necessary to identify new cheap and sustainable carbon sources. Thus, this work aims to isolate and select a high cellulose-producing
strain from vinegar industry, and study its potential for bacterial cellulose synthesis in an industrial soybean co-product, known as soybean molasses, used as fermentation medium.
One isolated strain was able to produce high amount of cellulose in the standard Hestrin-Schramm medium, so we tested its ability to produce this biopolymer in a soybean molasses medium. The characteristics and properties of the produced bacterial cellulose membranes were analyzed by thermogravimetric analysis, X-ray diffraction, infrared spectroscopy, water-holding capacity and rehydration ratio. Genetic analysis of the selected strain served to determine its genus and species.
An isolated strain that produced the highest amount of cellulose in Hestrin-Schramm medium (3.7 g/L) was genetically identified as
V-05. This strain produced 10.0 g/L of cellulose in soybean molasses medium. Membranes from both substrates had similar chemical structure, crystallinity and thermal degradation. Soybean molasses proved to be a suitable alternative medium for biosynthesis of cellulose in comparison with the standard medium. In addition to providing higher production yield, the membranes showed great structural characteristics, similar to those obtained from standard medium.
In this research, we have isolated and identified a
strain which exhibits a high capacity for cellulose production in soybean molasses. The isolation and selection of strains with high capacity for microbial metabolite production is important for decreasing bioprocess costs. Furthermore, as there is a necessity today to find cheaper carbon sources to obtain microbial products at a lower cost, soybean molasses represents an interesting alternative medium to produce bacterial cellulose for its industrial application.
Açaí berry is rich in antioxidant compounds and is therefore closely associated with beneficial health effects. In this study, we aim to investigate the potential of using
HN001 as a probiotic ...culture on açaí flan.
The chemical composition, physicochemical and microbiological characteristics, and sensory acceptance during refrigerated storage (5 °C for 42 days) of flan were investigated. In addition, the consumer perception of the product was evaluated using word association when consumers were shown a photo of the product with or without the added ingredients accompanied with a brief description of the product.
The flan had a suitable chemical composition, mainly carbohydrates and proteins, probiotic viability reached 8 log CFU/g in the product and 4 log CFU/g after gastrointestinal simulation, typical açaí coloration, significant antioxidant activity and high sensory acceptability. The information about the ingredients and properties of the products increased the health value and positive feelings of the consumers towards the product.
Açaí flan has proven to be a suitable carrier for
HN001 as a probiotic culture, further enhancing the characteristic beneficial properties of the fruit. Therefore, combining this information with marketing strategies that inform consumers about the benefits of the product can further improve its acceptance. As far as we know, this is the first study on açaí flan with added probiotic culture.
ABSTRACT Water kefir is considered to be a functional food with probiotic characteristics. It can be improved with addition of organic brown sugar and fruits native to Brazil, such as jaboticaba. The ...objective of this study was to evaluate the effects of brown sugar type: organic and conventional and the presence or absence of jaboticaba pulp in water kefir fermentation, based on the carbohydrate, organic acid, mineral composition and color profile. The fermentation process was carried out in two stages: with kefir grains, for 24 hours, at 25 °C and after filtration, maintained for 24 h at 25 °C in hermetic bottles, followed by a period of 8h refrigeration, and monitored every 8 h. Scanning electron microscopy of the kefir grains was performed after 24 h. The major changes in physicochemical patterns occurred up to 40 h. The final beverages presented acidic characteristics as a result of the production of lactic, acetic and succinic acids. The total sugar content had a reduction of around 50%. The sucrose content was reduced and the glucose and fructose increased. The use of organic sugar influenced the composition of the minerals. The characteristics related to color showed a tendency to increase over the evaluated times. It was concluded that it is possible to produce beverages fermented by water kefir grains, using organic or conventional brown sugar and jabuticaba pulp, being an alternative for the substitution of soft drinks, since it has no preservatives or food colorings, presents lower content of sugars and can be handcrafted.
RESUMO O kefir de água é considerado um alimento funcional com características probióticas. Pode ser melhorado com adição de açúcar mascavo orgânico e frutas nativas do Brasil, como a jabuticaba. Objetivou-se avaliar os efeitos do tipo de açúcar mascavo: orgânico e convencional e da presença ou ausência de polpa de jabuticaba na fermentação de kefir de água, baseada no perfil de carboidratos, ácidos orgânicos, composição de minerais e cor. O processo fermentativo foi conduzido em duas etapas: com grãos de kefir, por 24 horas, a 25 °C e após filtragem, mantido por 24 h a 25 °C em garrafas herméticas, seguida de um período de 8h de refrigeração, e monitorado a cada 8 h. Foi realizada microscopia eletrônica de varredura dos grãos de kefir decorridas 24 h. As principais mudanças nos padrões físico-químicos ocorreram até 40h. As bebidas finais apresentaram característica ácida em decorrência da produção dos ácidos lático, acético e succínico. Os teores de açúcares totais tiveram uma redução em torno de 50%. O teor de sacarose foi reduzido e os teores de glicose e frutose aumentaram. A utilização de açúcar orgânico influenciou a composição dos minerais. As características relacionadas à cor apresentaram tendência de aumento ao longo dos tempos avaliados. Concluiu-se que é possível produzir bebidas fermentadas por grãos de kefir de água, utilizando-se como substrato açúcar mascavo orgânico ou convencional e polpa de jabuticaba, sendo alternativa para a substituição de refrigerantes, pois não tem conservantes nem corantes alimentares, apresenta menor teor de açúcares e pode ser produzido artesanalmente.
•Zygosaccharomyces sp. are the main active microorganism in Uruçú-Amarela honey.•Glucose and fructose are consumed over the maturation of stingless bee honey.•Ethanol is the major metabolite produced ...during maturation of Melipona mondury honey.•Maturation do not prevent degradation of flavonoids and phenolic acids.•Antioxidant activity of honey is higher when maturation is performed at 30 °C.
The objective of this study was to characterize the microbiota biodiversity of Uruçú-Amarela honey through metagenomics. Furthermore, the impact of maturation temperatures (20 and 30 °C) and time (0–180 days) on the physicochemical and antioxidant properties was investigated. 1H NMR was performed to verify metabolites formed during maturation. Uruçú-Amarela honey was mainly composed by lactic acid bacteria and osmophilic yeasts of genus Zygosaccharomyces. Maturation at 30 °C led to a higher fermentation activity, resulting in greater carbohydrate consumption, ethanol formation (0.0–0.6 %) and increased acidity (34.78–45.74 meq/kg) over the 180 days. It also resulted in honey with higher brown color (a* 0.7 to 3.89, b* 17.50–25.29) and antioxidant capacity, corroborating that the maturation is a suitable preservation technique for stingless bee honey, because it does not cause negative changes as it extends the shelf life of the stingless bee honey.
Soybean molasses is a by-product from the production of protein concentrate from soybean meal that predominantly contains sugars, with sucrose as the major component. In Brazil, soybean molasses is ...used for animal feed or it is discarded, although some industries use it to produce ethanol. This study aims to evaluate the parameters required for the acetic acid fermentation of soybean molasses, and characterise the resultant vinegar. To study the most suitable parameters for the acetic acid fermentation, vinegar was produced from the alcoholic fermentation of soybean molasses through eight fermentation cycles: five for adaptation and three for production. The average acidity of the acetic acid fermentation product was 50.60 g/L, with an acetic acid fermentation yield, total yield of acetic acid in broth and productivity 65.01 %, 92.76 % and 0.033 g/(L·h), respectively. The vinegar produced from soybean molasses had an acidity of 5.07 % (m/V), residual ethanol content 0.17 % (m/V), sugars 7.86 % (m/V), dry extract 14.67 % (m/V), ash 2.27 % (m/V) and a density of 1.023 g/cm3. The contents of total phenolics and isoflavone decreased after the alcohol and acetic acid fermentations. Moreover, the isoflavone profile of the fermented product comprised only three forms: daidzein, glycitin and genistin. According to our results, 3460 L of vinegar can be produced for every tonne of soy molasses, with an acetic acid concentration of 40 g/L, the minimum required by the legislation on vinegar production. Thus, these findings demonstrate that soy molasses represents a useful raw material for the production of vinegar.
A meliponicultura ou criação de abelhas-sem-ferrão possibilita aos agricultores familiares a extração e a comercialização de mel como fonte de alimentação e renda. Este artigo tem como objetivo ...relatar o desenvolvimento de uma barra de cereais com mel de abelha-sem-ferrão, de fácil execução, e a transferência desse produto inovador aos meliponicultores da região de Londrina/PR. Um convênio entre instituições oportunizou a oferta de um curso teórico e de uma oficina de elaboração de barra de cereais aos produtores de mel. Como resultado, os professores e alunos se sentiram valorizados por atenderem demandas reais da comunidade externa, ampliando seus conhecimentos técnicos e sua interação social. Os meliponicultores, por sua vez, conheceram uma nova forma de diversificação de produtos e geração de renda.http://dx.doi.org/10.35700/ca.2021.ano8n15.p33-41.2986
A face-centered factorial design was used to study the influence of temperature, cellulase, and pectinase concentration on the production of
Saccharomyces boulardii
cells during simultaneous ...saccharification and fermentation of organic and conventional apple substrate pulp. The effects of the variables fermentation temperature (25–35 °C), pectinase concentration (5–25 μL/100 g), and cellulase concentration (4–8 μL/100 g) were analyzed by multiple regression and polynomial models of second order, providing the ideal conditions for yeast cultivation. Cellular production of apple substrates was expressed in log CFU/mL. The optimum condition for temperature was 27.5 °C, and 20 and 5 μL/100 g for pectinase and 8 and 7 μL/100 g for cellulase concentrations for organic and conventional apple pulp, respectively. The observed viability values were in agreement with the predicted values of 8.352 log CFU/mL (organic) and 8.317 log CFU/mL (conventional) apple pulps, thus proving the effectiveness of the models.
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