Background The food industry uses artificial sweeteners in a wide range of foods and beverages as alternatives to added sugars, for which deleterious effects on several chronic diseases are now well established. The safety of these food additives is debated, with conflicting findings regarding their role in the aetiology of various diseases. In particular, their carcinogenicity has been suggested by several experimental studies, but robust epidemiological evidence is lacking. Thus, our objective was to investigate the associations between artificial sweetener intakes (total from all dietary sources, and most frequently consumed ones: aspartame [E951], acesulfame-K [E950], and sucralose [E955]) and cancer risk (overall and by site). Methods and findings Overall, 102,865 adults from the French population-based cohort NutriNet-Santé (2009–2021) were included (median follow-up time = 7.8 years). Dietary intakes and consumption of sweeteners were obtained by repeated 24-hour dietary records including brand names of industrial products. Associations between sweeteners and cancer incidence were assessed by Cox proportional hazards models, adjusted for age, sex, education, physical activity, smoking, body mass index, height, weight gain during follow-up, diabetes, family history of cancer, number of 24-hour dietary records, and baseline intakes of energy, alcohol, sodium, saturated fatty acids, fibre, sugar, fruit and vegetables, whole-grain foods, and dairy products. Compared to non-consumers, higher consumers of total artificial sweeteners (i.e., above the median exposure in consumers) had higher risk of overall cancer (n = 3,358 cases, hazard ratio [HR] = 1.13 [95% CI 1.03 to 1.25], P-trend = 0.002). In particular, aspartame (HR = 1.15 [95% CI 1.03 to 1.28], P = 0.002) and acesulfame-K (HR = 1.13 [95% CI 1.01 to 1.26], P = 0.007) were associated with increased cancer risk. Higher risks were also observed for breast cancer (n = 979 cases, HR = 1.22 [95% CI 1.01 to 1.48], P = 0.036, for aspartame) and obesity-related cancers (n = 2,023 cases, HR = 1.13 [95% CI 1.00 to 1.28], P = 0.036, for total artificial sweeteners, and HR = 1.15 [95% CI 1.01 to 1.32], P = 0.026, for aspartame). Limitations of this study include potential selection bias, residual confounding, and reverse causality, though sensitivity analyses were performed to address these concerns. Conclusions In this large cohort study, artificial sweeteners (especially aspartame and acesulfame-K), which are used in many food and beverage brands worldwide, were associated with increased cancer risk. These findings provide important and novel insights for the ongoing re-evaluation of food additive sweeteners by the European Food Safety Authority and other health agencies globally. Trial registration ClinicalTrials.gov NCT03335644.
Microbial fermentation is a primary method by which a variety of foods and beverages are produced. The term refers to the use of microbes such as bacteria, yeasts, and molds to transform carbohydrates into different substances. Fermentation is important for preserving, enhancing flavor, and improving the nutritional quality of various perishable foods. Historical records clearly show that fermented foods and drinks, such as wine, beer, and bread, have been consumed for more than 7000 years. The main microorganisms employed were Saccharomyces cerevisiae, which are predominantly used in alcohol fermentation, and Lactobacillus in dairy and vegetable fermentation. Typical fermented foods and drinks made from yogurt, cheese, beer, wine, cider, and pickles from vegetables are examples. Although there are risks of contamination and spoilage by pathogenic and undesirable microorganisms, advanced technologies and proper control procedures can mitigate these risks. This review addresses microbial fermentation and clarifies its past importance and contribution to food preservation, flavoring, and nutrition. It systematically separates yeasts, molds, and bacteria and explains how they are used in food products such as bread, yogurt, beer, and pickles. Larger producers employ primary production methods such as the artisanal approach, which are explored along with future trends such as solid-state fermentation, the potential of biotechnology in developing new products, and sustainability in new product development. Future research and development strategies can lead to innovations in methods that improve efficiency, product range, and sustainability.
The development of non-alcoholic beer (NAB) with health benefits, using non-conventional potential probiotic yeasts, offers an interesting alternative to standard NAB brewing strategies. In this study, potential probiotic non-Saccharomyces yeasts Pichia manshurica, Kluyveromyces lactis, and Kluyveromyces marxianus, along with commercial probiotic yeast Saccharomyces boulardii, were characterised and tested for functional NAB production, whereas P. manshurica was used in NAB production for the first time. Growth and viability were assessed across a range of temperatures, pH, and iso-α-bitter acids. The tested yeasts withstood conditions typical of the beer matrix and human digestive tract and had a positive phenolic off-flavour phenotype. Two strains, K. lactis and K. marxianus, showed strong β-glucosidase activity, which may enhance beverage aroma complexity. Ethanol levels in beers fermented with non-Saccharomyces yeasts remained below the NAB limit (≤0.5% v/v). An analysis of volatile organic compound profiles revealed the potential of these yeasts to produce higher alcohols and esters valuable from a brewer’s perspective. This study provides valuable insight into novel probiotic fermentations and the potential application of unconventional yeasts in functional, aromatic, and health-oriented non-alcoholic beverages.
Kombucha is a fermented beverage traditionally made from the leaves of Camelia sinensis. The market has drastically expanded recently, and the beverage has become more elaborated with new, healthy food materials and flavors. Pruning and harvesting during coffee production may generate tons of coffee leaves that are discarded although they contain substantial amounts of bioactive compounds, including those found in maté tea and coffee seeds. This study characterized the changes in volatilome, microbial, and sensory profiles of pure and blended arabica coffee leaf tea kombuchas between 3–9 days of fermentation. Acceptance was also evaluated by consumers from Rio de Janeiro (n = 103). Kombuchas (K) were prepared using black tea kombucha starter (BTKS) (10%), sucrose (10%), a symbiotic culture of Bacteria and Yeasts (SCOBY) (2.5%), and a pure coffee leaf infusion (CL) or a 50:50 blend with toasted maté infusion (CL-TM) at 2.5%. The RATA test was chosen for sensory profile characterization. One hundred volatile organic compounds were identified when all infusions and kombucha samples were considered. The potential impact compounds identified in CL K and CL-TM K were: methyl salicylate, benzaldehyde, hexanal, nonanal, pentadecanal, phenylethyl-alcohol, cedrol, 3,5-octadien-2-one, β-damascenone, α-ionone, β-ionone, acetic acid, caproic acid, octanoic acid, nonanoic acid, decanoic acid, isovaleric acid, linalool, (S)-dihydroactinidiolide, isoamyl alcohol, ethyl hexanoate, and geranyl acetone. Aroma and flavor descriptors with higher intensities in CL K included fruity, peach, sweet, and herbal, while CL-TM K included additional toasted mate notes. The highest mean acceptance score was given to CL-TM K and CL K on day 3 (6.6 and 6.4, respectively, on a nine-point scale). Arabica coffee leaf can be a co-product with similar fingerprinting to maté and black tea, which can be explored for the elaboration of potentially healthy fermented beverages in food industries.
The use of whole-cell biocatalysts in microbial cell factories is of great interest to produce added-value compounds. Through large-scale fermentative processes, which use secondary raw materials as substrates, it is possible to recycle and upgrade agro-industrial by-products. This review addresses the main fermentative processes and bioreactors currently used for the valorization of orange peel, a by-product of the <i>Citrus</i> processing industry. Among the main added-value products, bioethanol, organic acids, enzymes, single cell proteins (SCPs), dyes and aromatic compounds have been industrially produced using orange peel via solid state fermentation and submerged fermentation. This approach fits within the circular economy goals in terms of clean technology and renewable energy, valorization and recycling, upgrade of industrial by-products and sustainability.
Morena Senna Saito, Wilton Amaral dos Santos, Maria Eugênia de Oliveira Mamede
Considering the health benefits of kombucha, already widely studied, the objective of this study was to develop kombucha beverages with the addition of an infusion of specialty arabica coffee from the first fermentation, varying the proportion of specialty coffee (2% to 13%), and evaluate their pH, volatile acidity, degree of alcohol, centesimal composition, sodium contents, and colour parameters to determine the acceptability of the beverages. Concerning the pH, all of the formulations conformed with the kombucha identity standard, but K3 (11% coffee) and K4 (13% coffee) were below the established minimum for volatile acidity. Except for K4, all of the other formulations were classified as alcoholic kombuchas, although their values were very close to the limit for non-alcoholic beverages. The formulations presented low sugar and sodium contents, which corroborated their low caloric value. Therefore, coffee-flavoured kombucha fermented for 18 days becomes an option for consumers looking for low-calorie, refreshing, and healthy drinks. The luminosity of the beverages decreased as the proportion of coffee increased, and consequently, the values for a* and b* increased, indicating a strong tendency for a yellowish-red colour. Sensorially, the formulations K4 and K3 were the most well accepted in all respects and can therefore be considered formulations with high commercialisation potential.
Svetoslav Dimitrov Todorov, Wilhelm Heinrich Holzapfel, John Robert Tagg
Strain ST182Gu, isolated from fresh guava fruit, was identified as <i>Enterococcus casseliflavus</i> on the basis of biochemical tests, sugar fermentation reactions (API20Strip), PCR with genus-specific primers, and 16S rRNA sequencing. This appears to be the first documentation of the presence of this species in guava. <i>E. casseliflavus</i> ST182Gu was shown to produce a 4.8 kDa class IIa bacteriocin, active against various lactic acid bacteria including <i>Enterococcus</i> spp. and <i>Streptococcus</i> spp., and <i>Staphylococcus aureus,</i> and different serotypes of <i>Listeria</i> spp. The activity of the peptide was reduced by treatment with 0.1 mg/mL proteolytic enzymes, but not by α-amylase, catalase, lipase, and 1% (<i>w/v</i>) sodium dodecyl sulphate (SDS), Tween-20, Tween-80, urea, NaCl, and EDTA. No change in activity was recorded after adjustment to pH values of between 2.0 and 12.0 for 2 h, and after treatment at 100 °C for 120 min or 121°C for 20 min, compared with non-treated antimicrobial peptide. The mode of action against representative susceptible bacteria was shown to be bactericidal and associated with cell lysis and enzyme- and DNA-leakage. These susceptible bacteria, <i>Listeria ivanovii</i> subsp. <i>ivanovii</i> ATCC 19119, <i>Listeria monocytogenes</i> ATCC 15313, and <i>Enterococcus faecalis</i> ATCC 19443 differed however in their sensitivity to bacteriocin ST182Gu (6,553,600 AU/mL, 102,400 AU/mL, and 51,200 AU/mL, respectively). No significant differences were detected in cell growth and bacteriocin production when strain ST182Gu was grown in MRS broth at 26 °C, 30 °C, and 37 °C for 24 h. Bacteriocin ST182Gu recovery from the surface of the producer cells showed different activity, dependent of the applied test organisms (3200, 800 and 400 AU/mL, evaluated versus <i>L. ivanovii</i> subsp. <i>ivanovii</i> ATCC 19119, <i>L. monocytogenes</i> ATCC 15313 and <i>E. faecalis</i> ATCC 19443, respectively), however, with proportional values with the activity recorded in cell free supernatant versus same test microorganisms. When bacteriocin ST182Gu was combined with sublethal doses of ciprofloxacin, synergistic inhibition of <i>L. ivanovii</i> subsp. <i>ivanovii</i> ATCC 19119 was demonstrated. This increase in ciprofloxacin sensitivity may be due to the dissipation of the proton gradient in the cell membrane of the target organism associated with exposure to bacteriocin ST182Gu. Apart from reducing the MIC of classical therapeutic antibiotics, bacteriocins such as ST182Gu may also play an important role in the treatment of multidrug resistant strains.
The current investigation briefly reviews previous studies about the fate of pesticides used in wine grape production during the alcoholic fermentation process, and how these could affect the correct functioning of yeast. The present review discusses the fact that yeasts could be used as a biological tool for pesticide dissipation, diminishing the concentration present in the grapes during the production process. The previous have never been directly boarded by other authors. The first part explores the influences of pesticides on yeasts and elucidates their effect on the fermentation process; also, some examples are analyzed of molecular studies involving the effect of pesticides on yeast. The second part discusses the effect of yeast on pesticide residues and their capacity to reduce its concentration during the alcoholic fermentation process, which varies among the different pesticides. In addition, this review discusses the mechanism by which yeast cells adsorb and/or degrade pesticides. In the last part, some examples of using yeasts as a possible remediation tool in wine and how the industry could use this to ensure consumers that a product is without pesticide residues are also discussed. This review shows that there is a natural capacity for the reduction of pesticide residue concentration by yeasts, and the effects of pesticides on yeast development is a variable phenomenon. This information guides advancement in pesticide removal from wine.
Jhunior Marcia, Ricardo Santos Aleman, Ismael Montero-Fernández
et al.
This study aimed to examine the prebiotic effect of <i>Carao</i> (<i>Cassia grandis</i>) pulp powder on the probiotic characteristics of <i>Lactobacillus acidophilus</i> regarding the viability, enzymatic activity, lysozyme resistance, bile and acid tolerances, and tolerance to gastric juices. <i>Carao</i> powder was used at 0% (control), 1%, 2%, and 3% (<i>w</i>/<i>v</i>). Acid and lysozyme tolerance were determined at 0, 30, 60, 90, and 120 min of incubation, whereas bile tolerance was analyzed at 0, 4, and 8 h. The gastric juice tolerance was determined at pH 2, 3, 4, 5, and 7 during 0 and 30 min of incubation. The protease was evaluated at 0, 12, and 24 h of incubation. The bacterial viability experiment was carried out for 10 h, taking readings every hour. Low-acidity conditions were used, and no significant differences were found between the control and the different <i>Carao</i> concentrations added to the <i>L. acidophilus</i> viability study. The <i>Carao</i> samples at 2% and 3% had significantly (<i>p</i> < 0.05) higher counts for bile and lysozyme resistance and higher protease activity when compared to control samples. On the other hand, <i>Carao</i> addition did not impact bacterial viability, acid tolerance, and gastric juice resistance. Thus, <i>Carao</i> pulp powder at different concentrations could act as a prebiotic source to enhance the development of <i>L. acidophilus</i> during gastrointestinal digestion.
The aroma of vanilla pods is mainly derived from vanillin. Microbial biotransformation reactions of vanillin precursors yield “natural” vanillin-related aroma metabolites. In this study, we coated vanilla pods with three edible microorganisms and observed the changes in tissues with a laser scanning microscope during early curing. In addition, the conducted volatile components analysis using gas chromatography-mass spectrometry (GC-MS) with ethanol extracts to investigate the differences in the aroma components of coated and uncoated microbial vanilla pods and to identify the correlation between processing and the oily luster of pods. The results demonstrate that the oily luster on the surface of vanilla pods coated with <i>Bacillus subtilis subsp. subtilis</i> is one of the necessary conditions for a high-quality vanilla product. Eight categories of compounds were found in the ethanol extract of vanilla pods. A total of 69 volatile components were analyzed. Different microbial species significantly influenced the volatile components, with 31 compounds not found in the control group. Furthermore, 30 odor and aroma compounds were identified. This study reveals the role of edible microbial coatings in enhancing the natural aroma of vanilla pods and offers possibilities for the development of new and unique vanilla aroma profiles.
Glycoproteins are involved in various significant biological processes and have critical biological functions in physiology and pathology by regulating biological activities and molecular signaling pathways. The variety of enzymes used in protein glycosylation and the wide range of diversity in the resulting glycoproteins pose a challenging task when attempting to simulate these processes in silico. This study aimed to establish and define the necessary structures to simulate the process of N-glycosylation in silico. In this article, we represent the process of glycosylation in the Golgi structure in an agent-based model with defined movement patterns and reaction rules between the associated proteins and enzymes acting as agents. The Golgi structure is converted into a grid consisting of 150 × 400 patches representing four compartments which contain a specific distribution of the fundamental enzymes contributing to the process of glycosylation. The interacting glycoproteins and membrane-bound enzymes are perceived as agents, with their own rules for movement, complex formation, biochemical reaction and dissociation. The resulting structures were saved into an XML-format, a mass spectrometry file and a GlycoWorkbench2-compatible file for visualization.
Pin Chanjula, Juraithip Wungsintaweekul, Rawee Chiarawipa
et al.
The objectives of the present study were to examine the influence of supplementation with dried kratom leaf (DKTL) on the performance, hematology, and nitrogen balance in goats. Four 12-month-old male crossbred (Thai Native x Anglo Nubian) goats with an initial body weight (BW) of 24.63 ± 0.95 kg were allocated randomly to receive four different levels of DKTL using a 4 × 4 Latin square design. The DKTL was added to a total mixed ration (TMR) diet with doses of 0, 2.22, 4.44, and 6.66 g/day to investigate the treatment’s efficacy. The DKTL was high in secondary metabolites, including mitragynine, total phenolics, total tannins, flavonoids, and saponins. There were quadratic effects on total DMI in terms of kg/day (<i>p</i> = 0.04), %BW (<i>p</i> = 0.05), and g/kg BW.75 (<i>p</i> = 0.02). DKTL increased apparent digestibility with quadratic effects (DM; <i>p</i> = 0.01, OM; <i>p</i> = 0.01, CP; <i>p</i> = 0.04, NDF; <i>p</i> = 0.01, and ADF; <i>p</i> = 0.01). The pH value was within the rumen’s normal pH range, whereas NH<sub>3</sub>-N and BUN concentrations were lower with DKTL supplementation, and also reduced cholesterol (CHOL, <i>p</i> = 0.05) and low-density lipoprotein (LDL, <i>p</i> = 0.01). The protozoa population decreased linearly as DKTL levels increased (<i>p</i> < 0.01), whereas <i>Fibrobacter succinogenes</i> increased quadratically at 0 h (<i>p</i> = 0.02), and mean values increased linearly (<i>p</i> < 0.01). The average value of acetic acid (C2) and methane production (CH4) decreased linearly (<i>p</i> < 0.05) when DKLT was added to the diet, whereas the quantity of propionic acid (C3) increased linearly (<i>p</i> = 0.01). Our results indicate that DKTL could be a great alternative supplement for goat feed. We believe that DKTL could provide opportunities to assist the goat meat industry in fulfilling the demands of health-conscious consumers.
Karel Krofta, Gabriela Fritschová, Alexandr Mikyška
et al.
From the brewing and commercial point of view, the content of alpha acids is one of the most important quality parameter of hops, which is subject to significant annual fluctuations. The established system for evaluating the content of alpha acids in Czech hops consists of pre-harvest and harvest predictions and a detailed analysis of reality based on the analysis of all purchasing lots of raw hops. It is differentiated according to varieties and hop growing areas. This article presents the results of the 2021 harvest, discusses the influence of weather conditions, the age of hop gardens and virus-free seedlings on the harvest results, and the relationship of predictions to reality. The average content of alpha acids in the majority Saaz variety in the Žatec, Úštěk and Tršice areas was 4.45, 4.20 and 3.36% by weight in the original respectively. In all areas, the alpha acids content has been significantly affected by the age of the hop growths. The total production of alpha acids in hops harvested in the Czech Republic in 2021 was 414.5 tons. The harvest is the highest in the last 25 years; the result is due to the combination of two factors, both high yield per hectare and high alpha acids content.
Kamran Jawed, Victor Uhunoma Irorere, Rajesh Reddy Bommareddy
et al.
The facultative chemolithoautotroph <i>Cupriavidus necator</i> H16 is able to grow aerobically either with organic substrates or H<sub>2</sub> and CO<sub>2</sub> s and it can accumulate large amounts of (up to 90%) poly (3-hydroxybutyrate), a polyhydroxyalkanoate (PHA) biopolymer. The ability of this organism to co-utilize volatile fatty acids (VFAs) and CO<sub>2</sub> as sources of carbon under mixotrophic growth conditions was investigated and PHA production was monitored. PHA accumulation was assessed under aerobic conditions, with either individual VFAs or in mixtures, under three different conditions—with CO<sub>2</sub> as additional carbon source, without CO<sub>2</sub> and with CO<sub>2</sub> and H<sub>2</sub> as additional sources of carbon and energy. VFAs utilisation rates were slower in the presence of CO<sub>2</sub>. PHA production was significantly higher when cultures were grown mixotrophically and with H<sub>2</sub> as an additional energy source compared to heterotrophic or mixotrophic growth conditions, without H<sub>2</sub>. Furthermore, a two-step VFA feeding regime was found to be the most effective method for PHA accumulation. It was used for PHA production mixotrophically using CO<sub>2</sub>, H<sub>2</sub> and VFA mixture derived from an anaerobic digestor (AD). The data obtained demonstrated that process parameters need to be carefully monitored to avoid VFA toxicity and low product accumulation.
During coffee processing, lactic acid bacteria (LAB) from multiple ecosystems (water, native soil, air, and plant) find in the cherry pulp a rich environment for their development. They utilize pulp substrate as a source of carbon and nitrogen to produce significant amounts of lactic acid. This natural fermentation is purposely used by coffee growers to promote an efficient removal of the mucilage layer adhering to the fruits, before storage and transport of the coffee beans. Besides lactic acid, LAB metabolism produces a variety of compounds from the utilization of citrate and the catabolism of amino acids. Recent studies have demonstrated that these metabolites have a complementary function in the formation of taste and flavor precursors of coffee beverages. However, the possibility of improving coffee quality by the use of LAB has largely been ignored. This review considers the importance of LAB associated with coffee processing, exploring their diversity and metabolism and influences on coffee quality. The selection of appropriate LAB strains, alone or in combination with yeasts, is a promising research line in a near future, leading to new perspectives on coffee quality.
R. Kozłowski, Marcin Dziedziński, B. Stachowiak
et al.
Beer is one of the most popular alcoholic beverages around the world. Currently, there is a noticeable increase in the consumption of beer, especially non- and low-alcoholic beers. The sensory characteristics of these beers are very similar to their alcoholic counterparts, while a lack of alcohol or a low alcohol content reduces their psychoactive character. In addition, their high nutritional and low caloric values make these types of drinks an excellent alternative to soft drinks (for adults), primarily sweetened carbonated beverages. The aim of this study was to characterize the non- and low-alcoholic beer market and the techniques for manufacturing these products. In general, reducing alcohol content is possible through the use of biological methods (limiting fermentation processes) and physical methods (dealcoholization processes). An example of a biological method is the modification of the mashing program in order to reduce the level of fermentable sugars in wort, e.g., inactivation of β-amylase, or the use of unconventional yeasts with limited ability or inability to convert fermentable sugars into alcohol. The group of physical methods includes modern thermal and membrane separation techniques which enable the efficient removal of ethanol from beer to the desired level. This paper also presents the nutritional value of regular and non-alcoholic beers and their antioxidant potential. The prohealth properties of beer were pointed out, emphasizing the negative influence of alcohol on the human body. The collected information shows that the market of non-alcohol and low-alcohol beers will continue to grow. The main directions of its development will concern the production of functional beers.
Margarita García, Braulio Esteve-Zarzoso, Juan Mariano Cabellos
et al.
Over the last decades, the average alcohol content of wine has increased due to climate change and consumer preferences for particular wine styles that resulted in increased grape sugar levels at harvest. Therefore, alcohol reduction is a current challenge in the winemaking industry. Among several strategies under study, the use of non-conventional yeasts in combination with Saccharomyces cerevisiae plays an important role for lowering ethanol production in wines nowadays. In the present work, 33 native non-Saccharomyces strains were assayed in sequential culture with a S. cerevisiae wine strain to determine their potential for reducing the alcohol content in Malvar white wines. Four of the non-Saccharomyces strains (Wickerhamomyces anomalus 21A-5C, Meyerozyma guilliermondii CLI 1217, and two Metschnikowia pulcherrima (CLI 68 and CLI 460)) studied in sequential combination with S. cerevisiae CLI 889 were best able to produce dry wines with decreased alcohol proportion in comparison with one that was inoculated only with S. cerevisiae. These sequential fermentations produced wines with between 0.8% (v/v) and 1.3% (v/v) lower ethanol concentrations in Malvar wines, showing significant differences compared with the control. In addition, these combinations provided favorable oenological characteristics to wines such as high glycerol proportion, volatile higher alcohols, and esters with fruity and sweet character.
Honey mead is a well-known conventional alcoholic beverage made by microbial fermentation of diluted honey. The selection of prospective yeasts for inoculation of honey-must with regard to honey mead quality determines the quality of mead production. The yeast consortium tolerant to ethanol stress was selected for this study using an enrichment technique. The activity of the invertase enzyme and the level of ethanol tolerance have been investigated. Thai stingless bee honey was used as a substrate, and the selected ethanol tolerant yeast consortium was used for mead fermentation. The results revealed that the PP03 had the highest invertase activity of 75.13±9.16 U/mL and the highest ethanol tolerance level of 12%. This is the first study using an ethanol tolerant yeast consortium to ferment honey mead from Thai stingless bee honey.