Microbiological, biochemical, and functional aspects of sugary kefir fermentation - A review.

Sugary kefir beverage is produce by fermenting raw sugar solution with kefir grains, the latter consisting of polysaccharide and microorganisms. This beverage, with great consumption in countries such as USA, Japan, France, and Brazil, represents a promising market to functional cultured drinks. This paper reviews the microbial diversity and interaction, kinetics, safety, and bioactivities of sugary kefir fermentation. The literature reviewed here demonstrates that sugary kefir possesses a similar microbial association relative to traditional milk kefir fermentation, especially among lactic acid bacteria and yeast species, such as Lactobacillus, Leuconostoc, Kluyveromyces, Pichia, and Saccharomyces. However, a selective pressure at species level is generally observed, as, for example, the stimulation of Saccharomyces species metabolism, leading to a high content of alcohol in the final product. This also seems to stimulate the growth of acetic acid bacteria that benefit of increased ethanol production to acetic acid metabolism. Existing reports have suggested important bioactivities associated with sugary kefir beverage consumption, such as antimicrobial, antiedematogenic, anti-inflammatory, antioxidant, cicatrizing, and healing activities. Other alternative non-dairy substrates, such as fruits, vegetables, and molasses, have also been tested for adaptation of kefir grains and production of functional beverages with distinct sensory characteristics. This diversification is of crucial importance for the production of new probiotic products to provide people with special needs (lactose intolerance) and vegan consumers.

Exploring Microbial Influence on Flavor Development during Coffee Processing in Humid Subtropical Climate through Metagenetic-Metabolomics Analysis.

Research into microbial interactions during coffee processing is essential for developing new methods that adapt to climate change and improve flavor, thus enhancing the resilience and quality of global coffee production. This study aimed to investigate how microbial communities interact and contribute to flavor development in coffee processing within humid subtropical climates. Employing Illumina sequencing for microbial dynamics analysis, and high-performance liquid chromatography (HPLC) integrated with gas chromatography-mass spectrometry (GC-MS) for metabolite assessment, the study revealed intricate microbial diversity and associated metabolic activities. Throughout the fermentation process, dominant microbial species included Enterobacter, Erwinia, Kluyvera, and Pantoea from the prokaryotic group, and Fusarium, Cladosporium, Kurtzmaniella, Leptosphaerulina, Neonectria, and Penicillium from the eukaryotic group. The key metabolites identified were ethanol, and lactic, acetic, and citric acids. Notably, the bacterial community plays a crucial role in flavor development by utilizing metabolic versatility to produce esters and alcohols, while plant-derived metabolites such as caffeine and linalool remain stable throughout the fermentation process. The undirected network analysis revealed 321 interactions among microbial species and key substances during the fermentation process, with Enterobacter, Kluyvera, and Serratia showing strong connections with sugar and various volatile compounds, such as hexanal, benzaldehyde, 3-methylbenzaldehyde, 2-butenal, and 4-heptenal. These interactions, including inhibitory effects by Fusarium and Cladosporium, suggest microbial adaptability to subtropical conditions, potentially influencing fermentation and coffee quality. The sensory analysis showed that the final beverage obtained a score of 80.83 ± 0.39, being classified as a specialty coffee by the Specialty Coffee Association (SCA) metrics. Nonetheless, further enhancements in acidity, body, and aftertaste could lead to a more balanced flavor profile. The findings of this research hold substantial implications for the coffee industry in humid subtropical regions, offering potential strategies to enhance flavor quality and consistency through controlled fermentation practices. Furthermore, this study contributes to the broader understanding of how microbial ecology interplays with environmental factors to influence food and beverage fermentation, a topic of growing interest in the context of climate change and sustainable agriculture.

Chitooligosaccharides antagonize the cytotoxic effect of glucosamine.

Chitooligosaccharides (COS) are partially hydrolyzed compounds derived from chitosan that exhibit a number of biological activities, including antitumor, antibacterial and antifungal properties. In this work, we examined the cytotoxicity of pure COS and oligomers A, B and C (solutions composed of different amounts of COS) produced by enzymatic hydrolysis using a crude enzyme extract produced by the fungus Metarhrizium anisopliae. The antiproliferative effect of these molecules was analyzed using tumor cell lines (HepG2 and HeLa cells) and in a normal cell line (3T3). The antioxidant activity was analyzed in several in vitro experiments. Glucosamine showed higher toxicity (approximately 92%) to all cell lines studied. However, the oligomers obtained after hydrolysis demonstrated no toxic effects on the normal cells (3T3). Furthermore, we showed that a small amount of other COS can decrease the cytotoxic effect of glucosamine against 3T3 cells, indicating that glucosamine could be used as an antitumor drug in the presence of other COS. In addition, different effects were found in antiproliferative assays, which depended on the COS composition in the oligomers (A, B and C), showing that a combination of them may be essential for developing antineoplastic drugs. Superoxide anion scavenging was the main antioxidant activity demonstrated by the COS and oligomers. This activity was also dependent on the oligomer composition of the chitosan hydrolysates. Further work will identify the ideal proportions of COS and glucosamine for maximizing the effects of these biological activities.

Fermented Soy Products and Their Potential Health Benefits: A Review.

In the growing search for therapeutic strategies, there is an interest in foods containing natural antioxidants and other bioactive compounds capable of preventing or reversing pathogenic processes associated with metabolic disease. Fermentation has been used as a potent way of improving the properties of soybean and their components. Microbial metabolism is responsible for producing the ß-glucosidase enzyme that converts glycosidic isoflavones into aglycones with higher biological activity in fermented soy products, in addition to several end-metabolites associated with human health development, including peptides, phenolic acids, fatty acids, vitamins, flavonoids, minerals, and organic acids. Thus, several products have emerged from soybean fermentation by fungi, bacteria, or a combination of both. This review covers the key biological characteristics of soy and fermented soy products, including natto, miso, tofu, douchi, sufu, cheonggukjang, doenjang, kanjang, meju, tempeh, thua-nao, kinema, hawaijar, and tungrymbai. The inclusion of these foods in the diet has been associated with the reduction of chronic diseases, with potential anticancer, anti-obesity, antidiabetic, anticholesterol, anti-inflammatory, and neuroprotective effects. These biological activities and the recently studied potential of fermented soybean molecules against SARS-CoV-2 are discussed. Finally, a patent landscape is presented to provide the state-of-the-art of the transfer of knowledge from the scientific sphere to the industrial application.

Enhancing the Recovery of Bioactive Compounds of Soybean Fermented with Rhizopus oligosporus Using Supercritical CO2: Antioxidant, Anti-Inflammatory, and Oxidative Proprieties of the Resulting Extract.

The aim of the present study was to evaluate the use of supercritical CO2 combined with cosolvent for the recovery of bioactive compounds of soybean fermented with Rhizopus oligosporus NRRL 2710. Soxhlet extractions using seven different organic solvents (n-hexane, petroleum ether, ethyl acetate, acetone, ethanol, methanol, and water) were initially performed for comparative purposes. The extracts obtained were characterized by physicochemical, antioxidant, total phenolic, and oxidative proprieties. For the Soxhlet extractions, the highest and lowest yields obtained were 45.24% and 15.56%, using methanol and hexane, respectively. The extraction using supercritical CO2 combined with ethanol as a static modifier (scCO2 + EtOH) presented, at a high pressure (25 MPa) and temperature (80 °C), a phenolic compound content of 1391.9 µg GAE g-1 and scavenging of 0.17 g, reaching a 42.87% yield. The extracts obtained by sCO2 + EtOH were characterized by high contents of essential fatty acids (linoleic acid and oleic acid) and bioactive compounds (gallic acid, trans-cinnamic acid, daidzein, and genistein). These extracts also showed a great potential for inhibiting hyaluronidase enzymes (i.e., anti-inflammatory activity). Thermogravimetric analyses of the samples showed similar profiles, with oil degradation values in the range from 145 to 540 °C, indicating progressive oil decomposition with a mass loss ranging from 93 to 98.7%. In summary, this study demonstrated the flexibility of scCO2 + EtOH as a green technology that can be used to obtain high-value-added products from fermented soybean.

Chitooligosaccharides enzymatic production by Metarhizium anisopliae.

The products of chitosan hydrolysis are chitooligosaccharides and are used mainly for medical applications due to their specific biological activities. The objective of this study was to detect and identify the products of enzymatic hydrolysis of chitosan (dimers to hexamers) using a crude extract of chitosanolytic enzymes produced by the fungus Metarhizium anisopliae. These fungus was able to produce, during 48 h cultivation in a medium containing chitosan, chitooligosaccharides ranging from dimers, trimers, tetramers and pentamers at concentrations 0.2, 0.19, 0.06, 0.04 mg/mL, respectively, and the enzymatic activity was 2.5 U/L. Using the crude enzyme extract for chitosan hydrolysis, we detected the presence of dimers to hexamers at hydrolysis times of 10, 20, 30, 40, 50 and 60 min of enzymatic reaction, but the yields were higher at 10 min (54%). The hexamers was obtained only with 30 min of reaction with concentration of 0.004 mg/mL.

Single-step purification of chitosanases from Bacillus cereus using expanded bed chromatography.

A chitosanase-producing strain was isolated and identified as Bacillus cereus C-01. The purification and characterization of two chitosanases were studied. The purification assay was accomplished by ion exchange expanded-bed chromatography. Experiments were carried out in the presence and in the absence of cells through different expansion degree to evaluate the process performance. The adsorption experiments demonstrated that the biomass does not affect substantially the adsorption capacity of the matrix. The enzyme bound to the resin with the same extent using clarified and unclarified broth (0.32 and 0.30 U/g adsorbent, respectively). The fraction recovered exhibited 31% of the yield with a 1.26-fold increase on the specific activity concerned to the initial broth. Two chitosanases from different elution steps were recovery. Chit A and Chit B were stable at 30-60°C, pH 5.5-8.0 and 5.5-7.5, respectively. The highest activity was found at 55°C, pH 5.5 to Chit A and 50°C, pH 6.5 to Chit B. The ions Cu(2+), Fe(2+) and Zn(2+) indicated inhibitory effect on chitosanases activities that were significantly activated by Mn(2+). The methodology applied in this study enables the partial purification of a stable chitosanase using a feedstock without any pre-treatment using a single-step purification.

Production of enzymes by Paenibacillus chitinolyticus and Paenibacillus ehimensis to obtain chitooligosaccharides.

Obtaining oligosaccharides from chitosan has been the focus of several studies in the pharmaceutical, chemical, food, and medical areas, due to their functional properties. Here, we evaluated the production potential of biologically functional chitooligosaccharides using enzymes extracts produced by Paenibacillus chitinolyticus and Paenibacillus ehimensis. After 48 h of fermentation, these microorganisms were able to produce chitosanases, which generated oligomers with a degree of polymerization between dimers and hexamers. The maximum conversion of chitosan to oligomers was 99.2 %, achieved after 12 h incubation of chitosan with enzymes produced by P. ehimensis. The chitooligosaccharides generated were capable of scavenging the 2,2-diphenyl-1-picrylhydrazyl radical, reaching a maximum scavenging rate of 61 and 39 % when produced with P. ehimensis and P. chitinolyticus enzymes, respectively. The use of these enzymes in the crude form could facilitate their use in industrial applications.

Chitosanase production by Paenibacillus ehimensis and its application for chitosan hydrolysis

The chitosanase production by Paenibacillus ehimensis was studied in submerged cultures and the chitosan hydrolysis was evaluated by using these enzymes without purification. The bacterium produced inducibles enzymes after 12 h of growth in a culture medium containing 0.2 percent (w/v) of soluble chitosan as carbon source. The enzyme production was strongly repressed by the presence of glucose. The production started as soon as the available sugars finished in the culture medium. The maximum level of chitosanase activity was 500 U.L-1 at 36°C after 36 h incubation. The crude enzyme was optimally active at pH 6.0 and 55°C and in these conditions, the enzyme presented good stability (6 days). The enzyme without purification was used to hydrolyze the chitosan which resulted chitooligosaccharides between 20 and 30 min of reaction.

A produção de quitosanases pelo Paenibacillus ehimensis foi estudada em culturas submersas e a hidrólise da quitosana foi realizada utilizando essas enzimas sem purificação. As enzimas foram obtidas após 12 horas de crescimento desta bactéria em meio de cultivo contendo 0,2 por cento (p/v) de quitosana solúvel como fonte de carbono. A produção das enzimas foi fortemente reprimida na presença de glicose, sendo obtida após o consumo total dos açúcares disponibilizados no referido meio de cultivo. A máxima atividade quitosanolítica foi obtida após 36 horas de cultivo a 36ºC, atingindo valores de 500 U.L-1. As enzimas utilizadas no extrato bruto apresentaram melhores atividades quando submetidas a condições de pH e temperatura de 6,0 e 55ºC, respectivamente, e nessas condições permaneceram estáveis durante 6 dias. Essas enzimas sem serem submetidas aos processos de purificação foram utilizadas para hidrolisar a quitosana, obtendo os quito-oligossacarídeos entre 20 e 30 minutos de reação.

Analysis of advertisements of infant food commercialized in the city of Natal, Rio Grande do Norte, Brazil / Análise das propagandas de alimentos infantis comercializados na cidade de Natal, Rio Grande do Norte, Brasil

The advertising about maternal milk substitutes has been pointed as one of the factors responsible for the breastfeeding low rates. In this way, legal support was created to assure that the use of such products would not interfere on the healthy breastfeeding habit of the population. This study, developed between June 2006 and May 2008 in the city of Natal, state of Rio Grande do Norte, analyzed the food advertisements divulged under the validity of Law # 11.265/2006, which controls in Brazil the food commercialization and the publicity addressed to parents or keepers of nursling and children in the first childhood. 220 advertisements, being 141 of technical-scientific nature, and 79 for strictly commercial promotion, were collected and evaluated according to legal requirements. The results from this analysis showed that 100 percent of the advertisements of technical-scientific nature overstepped the clause V; 18.4 percent the clause IV and 14.2 percent the clauses I, II and III of article 19th of Law # 11265/2006. In 42 percent of the advertisements strictly for commercial promotion, the mandatory information mentioned at clauses I and II of the article 5th were not shown. In 8.7 percent of the advertisements containing such information, it was placed in an area that embarrassed its identification and reading, due to used fonts size and/or color; similarly as occurred with the information required by article 19th, in the advertisements of technical-scientific nature.

A propaganda de substitutos do leite materno tem sido apontada como um dos fatores responsáveis pelos baixos índices da amamentação. Neste sentido, dispositivos legais foram criados para assegurar o uso desses produtos, sem que haja interferência no aleitamento materno. Este estudo objetivou analisar propagandas de alimentos abrangidos pela Lei nº 11.265/2006, que regulamenta a comercialização e publicidade de alimentos para lactentes e crianças de primeira infância no Brasil, no período de junho 2006 a maio de 2008, na cidade de Natal/RN. Foram coletadas 220 propagandas, sendo 141 de material técnico-científico e 79 de promoção comercial que foram avaliadas quanto às exigências legais. O resultado desta análise demonstrou que 100 por cento das propagandas veiculadas em material técnico-científico infringiram o inciso V; 18,4 por cento o inciso IV e 14,2 por cento os incisos I, II e III do artigo 19 da Lei nº 11.265/2006. Em 42 por cento das promoções comerciais não foram veiculadas as informações obrigatórias constantes dos incisos I e II do artigo 5º. Em 8,7 por cento das que continham essas informações, estas estavam postas em local que dificultava sua identificação e leitura devido ao tamanho e cor das letras, semelhantemente ao ocorrido com as informações exigidas pelo artigo 19 nas propagandas veiculadas em material técnico-científico.