Co-culture submerged fermentation by lactobacillus and yeast more effectively improved the profiles and bioaccessibility of phenolics in extruded brown rice than single-culture fermentation

Grain bound polyphenols: Molecular interactions, release characteristics, and regulation mechanisms of postprandial hyperglycemia

Frequent postprandial hyperglycemia causes many chronic diseases. Grain polyphenols are widely recognized as natural active ingredients with high potential to treat chronic diseases due to their excellent postprandial hyperglycemic regulating effects. However, previous studies on polyphenols in grains mainly focused on the functional properties of free polyphenols and the extraction and physicochemical properties of bound polyphenols, ignoring the functional properties of bound polyphenols. Comprehensively understanding the binding properties of grain bound polyphenols (GBPs) and their mechanisms in regulating blood glucose levels is essential for developing and applying grain resources. This review summarizes the molecular interactions between GBPs and grain components and their effects on release characteristics and bioavailability at various stages. Meanwhile, the review focuses on elucidating the regulatory mechanism of post-release GBPs on postprandial hyperglycemia levels, incorporating insights from molecular docking, the gastrointestinal-brain axis, and gut flora. GBPs slow food digestion by occupying the active site of digestive enzymes and altering the secondary structure of enzymes and the hydrophobic environment of amino acid residues to inhibit enzyme activity. They modulate intestinal epithelial transport proteins (SGLT1, GLUT2, and GLUT4) to limit glucose absorption and increase glucose consumption. They also stimulate the release of short-term satiety hormones (CKK, GLP-1, and PYY) through the gastrointestinal-brain axis to decrease post-meal food intake. Furthermore, they optimize gut microbiota composition, promoting short-chain fatty acid production and bile acid metabolism. Therefore, developing functional foods with glucose-modulating properties based on GBPs is crucial for obesity prevention, diabetes management, and low-GI food development.

Identification of phenols and their formation network during the brewing process of Shanxi aged vinegar

Phenols are important functional compounds present in vineagr, however, their composition and formation pathways remain uncertain. Herein, non-targeted metabolomics and macrotranscriptomics methods were applied to identify phenols and analyze their formation network during the brewing process of Shanxi aged vinegar. A total of 82 phenols were detected from the raw material and the brewing process. Results indicated that phenolic acids were the major phenols and were mainly formed during acetic acid fermentation stages. Water, reducing sugars, lactic acid, and 7 amino acids influenced the formation and transformation of phenols, as shown through Spearman analysis. Furthermore, 16 genera and 38 enzymes were involved in substrates decomposition and phenols formation according to the metabolic pathway analysis, with Xenobiotics biodegradation and metabolism identified as the main pathway for phenols formation. Lactobacillus and Acetobacter were the key genera responsible for the phenols transformation. This study provides new insights into the phenols formation mechanisms in cereal vinegars and it is helpful for isolating the functional strains to reinforce the phenols formation.

The bioaccessibility and bioactivity of polyphenols from tsampa prepared from roasted highland barley flour solid-fermented by autochthonous lactic acid bacteria

Tsampa, which is abundant in polyphenols, demonstrates significant bioactivity and potential health benefit. However, the bioaccessibility and potential bioactivity of polyphenols derived from tsampa prepared from autochthonous lactic acid bacteria solid-fermented roasted highland barley flour (F-RHBF) have not been investigated. This study aimed to evaluate the bioaccessibility and bioactivity of polyphenols from tsampa prepared from F-RHBF through in vitro digestion model, and additionally, to explore the protective effects of digested tsampa extract against oxidative stress damage by establishing H2O2 -induced oxidative stress injury model of HepG2 cells. The results indicated that tsampa prepared from F-RHBF exhibited excellent bioaccessibility and bioactivity of polyphenols, including antioxidant and digestive enzymes inhibitory activity, compared to tsampa prepared from unfermented RHBF (UF-RHBF). Furthermore, the digested extract of tsampa prepared from F-RHBF was more effective in protecting HepG2 cells from oxidative damage by reducing the level of reactive oxygen species (ROS) and malondialdehyde (MDA), while enhancing the activity of superoxide dismutase (SOD), glutathione (GSH), catalase (CAT), glutathione peroxidase (GPx), and total antioxidant capacity (T-AOC). These findings suggested that fermentation and in vitro digestion can improve the bioaccessibility and bioactivity of polyphenols from tsampa. Present findings pave the way toward applying fermented highland barley flour to design tsampa and novel functional foods.

Regulation of the phenolic release and conversion in oats (Avena sativa L.) by co-microbiological fermentation with Monascus anka, Saccharomyces cerevisiae and Bacillus subtilis

Microbial fermentation is an effective method to improve the functional activity of oats (Avena sativa L.), while there are some limitations to the advantages of single microbial fermentation. In this study, a microbial co-culture fermentation system with Monascus anka, Saccharomyces cerevisiae and Bacillus subtilis to release and conversion oat phenolics was established. Results showed that the optimal microbial co-fermentation system was obtained by adding Saccharomyces cerevisiae on the fourth day and Bacillus subtilis on the eighth day during Monascus anka fermentation (MF + 4S + 8B). The phenolic content was reached 26.93 mg GAE/g DW, which increased 41.08 times compared to un-fermented oats (UF). In the process of co-fermentation systems, cellulase and β-glucosidase (r2 = 0.97, p < 0.01) had a positive correlation with the release of phenolics. SEM combined with HPLC showed that the complex enzyme system produced by microbial co-fermentation enhanced the disruption of oat cell structure, as well as altered the phenolics fractions and facilitated the conversion of bound phenolics to free phenolics, especially the content of chlorogenic acid and vanillic acid in the free forms was increased 31.42 and 14.15 times, respectively. Additionally, the phenolic contents were increased and the components were changed with the microbial co-fermentation of crude enzyme solution further added, which validated the positive influence of complex enzyme system of MF + 4S + 8B in the phenolic release and transformation of oats. Therefore, this study systematically investigated the phenolic mobilization in oats during the co-fermentation period, which provides a viable option for improving the functional properties of cereal products, as well as the application of microbial cell factories.

Functional microbiome assembly in food environments: addressing sustainable development challenges

The global food system faces numerous challenges, creating an urgent need for sustainable reform. Functional microbiome assemblies offer transformative potential by endowing microbial foods with diverse, beneficial characteristics. These assemblies can dynamically influence specific food systems, positioning them as a promising approach for reshaping food production. However, the current applications and types of microbiome assemblies in foods remain limited, with a lack of effective screening and regulatory methods. This review introduces the functions and practical approaches for implementing microbiome assemblies in food systems alongside future directions for enhancing their applications. Several ecological studies evaluated how to regulate functional output and revealed that environmental conditions, which shape the niche for species survival, significantly influenced the functional output of microbiomes. Building on this theoretical foundation, this review presents a model for functional output comprising niche conditions, functional gene codes, and corresponding functional outputs. This model is illustrated with examples to explore sustainable applications and regulatory mechanisms for functional microbiome assemblies. By highlighting the roles of functional outputs in food systems and examining the potential for food environments to induce and modulate microbiome functions, this review provides a roadmap to address emerging challenges in food sustainability.

Saccharomyces cerevisiae strains L7 contribute to flavor and deacidification in Suanyu, a Chinese traditional fermented fish

Saccharomyces cerevisiae L7 was found to be an excellent starter and biological deacidification strain for Suanyu, however, the underlying mechanisms remain poorly understood. This study aimed to investigate the acid inhibition mechanism of S. cerevisiae L7. The strain enhances the sensory and flavor characteristics of Suanyu. The growth of Lactiplantibacillus plantarum is inhibited due to competition for carbon sources, resulting in a decrease in cell count from 9.00 Lg CFU/mL at 48 h to 7.70 Lg CFU/mL in co-culture. The addition of yeast reduces acidity, decreasing it from 5.83 g/kg to 0.82 g/kg at 48 h, while increasing sugar utilization to 94.52%. We found that cell contact was the main method of inhibition between the two microbials. Transcriptome analysis revealed that multiple pathways were affected under co-culture, ultimately leading to a decrease in lactic acid production. These findings provide valuable insights into the microbial interactions involved in biological deacidification.

Recent Advances in the Health Benefits of Phenolic Acids in Whole Grains and the Impact of Processing Techniques on Phenolic Acids: A Comprehensive Review

Phenolic acids, essential compounds in whole grains, are renowned for their health-enhancing antioxidant and anti-inflammatory properties. Variations in concentration, particularly of hydroxybenzoic and hydroxycinnamic acids, are observed among grain types. Their antiobesity and antidiabetes effects are linked to their modulation of key signaling pathways like AMPK and PI3K, crucial for metabolic regulation and the body's response to inflammation and oxidative stress. Processing methods significantly influence phenolic acid content and bioavailability in whole grains. Thermal techniques like boiling, baking, or roasting can degrade these compounds, with loss influenced by processing conditions. Nonthermal methods such as germination, fermentation, or their combination, can protect or enhance phenolic acid content under ideal conditions. Novel nonthermal approaches like ultrahigh pressure (UHP), irradiation, and pulsed electric fields (PEF) show promise in preserving these compounds. Further research is needed to fully comprehend the impact mechanisms of these innovative methods on the nutritional and sensory attributes of cereals.

Unveiling biotransformation of free flavonoids into phenolic acids and Chromones alongside dynamic migration of bound Phenolics in Lactobacillus-fermented lychee pulp

Lactobacillus strains have emerged as promising probiotics for enhancing the bioactivities of plant-based foods associated with flavonoid biotransformation. Employing microbial fermentation and mass spectrometry, we explored flavonoid metabolism in lychee pulp fermented separately by Lactiplantibacillus plantarum and Limosilactobacillus fermentum. Two novel metabolites, 3,5,7-trihydroxychromone and catechol, were exclusively identified in L. plantarum-fermented pulp. Concomitant with consumption of catechin and quercetin glycosides, dihydroquercetin glycosides, 2,4-dihydroxybenzoic acid and p-hydroxyphenyllactic acid were synthesized by two strains through hydrogenation and fission of C-ring. Quantitative analysis revealed that bound phenolics were primarily located in water-insoluble polysaccharides in lychee pulp. Quercetin 3-O-rutinoside was partially liberated from water-insoluble polysaccharides and migrated to water-soluble polysaccharides during fermentation. Meanwhile, substantial accumulations in short-chain fatty acids (increased 1.45 to 3.08-fold) and viable strains (increased by 1.97 to 2.00 Log10 CFU/mL) were observed in fermentative pulp. These findings provide broader insight into microbial biotransformation of phenolics and possible guidance for personalized nutrition.

Valorization of Date By-Products: Enhancement of Antioxidant and Antimicrobial Potentials through Fermentation

The by-products from three varieties of dates-Mozafati, Sayer, and Kabkab-were subjected to solid-state fermentation using Aspergillus niger alone or in co-culture with Lactiplantibacillus plantarum or Limosilactobacillus reuteri to enhance their phenolic and flavonoid content, along with antioxidant and antimicrobial activities. Solid-state fermentation, being environmentally friendly and cost-effective, is particularly suitable for agricultural residues. Significant increases (p < 0.05) in total polyphenol content (TPC), total flavonoid content (TFC), and antioxidant power were observed post-fermentation, especially under co-culture conditions. The highest TPC (12.98 ± 0.29 mg GA/g) and TFC (1.83 ± 0.07 mg QE/g) were recorded in the co-culture fermentation of by-products from the Mozafati and Sayer varieties, respectively. HPLC analysis revealed changes in polyphenol profiles post-fermentation, with reductions in gallic and ferulic acids and increases in caffeic acid, p-coumaric acid, rutin, quercetin, and kaempferol. FT-IR analysis confirmed significant alterations in polyphenolic functional groups. Enhanced antimicrobial activity was also observed, with inhibition zones ranging from 8.26 ± 0.06 mm for Kabkab to 17.73 ± 0.09 mm for Mozafati. These results suggest that co-culture solid-state fermentation is a promising strategy for valorizing date by-products, with potential applications in nutraceuticals and/or pharmaceutical products and as valuable additives in the food industry.

Co-culture fermentation by Saccharomycopsis fibuligera and lactic acid bacteria improves bioactivity and aroma profile of wheat bran and the bran-containing Chinese steamed bread

Co-culture fermentation with yeast and lactic acid bacteria (LAB) exhibits advantages in improving the bioactivity and flavor of wheat bran compared to single-culture fermentation, showing application potentials in bran-containing Chinese steamed bread (CSB). To explore the effects of combination of yeast and different LAB on the bioactivity and flavor of fermented wheat bran, this study analyzed the physicochemical properties, phytate degradation capacity, antioxidant activities, and aroma profile of wheat bran treated with co-culture fermentation by Saccharomycopsis fibuligera and eight different species of LAB. Further, the phenolic acid composition, antioxidant activities, texture properties, aroma profile, and sensory quality of CSB containing fermented wheat bran were evaluated. The results revealed that co-culture fermentation brought about three types of volatile characteristics for wheat bran, including ester-feature, alcohol and acid-feature, and phenol-feature, and the representative strain combinations for these characteristics were S. fibuligera with Limosilactobacillus fermentum, Pediococcus pentosaceus, and Latilactobacillus curvatus, respectively. Co-culture fermentation by S. fibuligera and L. fermentum for 36 h promoted acidification with a phytate degradation rate reaching 51.70 %, and improved the production of volatile ethyl esters with a relative content of 58.47 % in wheat bran. Wheat bran treated with co-culture fermentation by S. fibuligera and L. curvatus for 36 h had high relative content of 4-ethylguaiacol at 52.81 %, and exhibited strong antioxidant activities, with ABTS•+ and DPPH• scavenging rates at 65.87 % and 69.41 %, respectively, and ferric reducing antioxidant power (FRAP) at 37.91 μmol/g. In addition, CSB containing wheat bran treated with co-culture fermentation by S. fibuligera and L. fermentum showed a large specific volume, soft texture, and pleasant aroma, and received high sensory scores. CSB containing wheat bran treated with co-culture fermentation by S. fibuligera and L. curvatus, with high contents of 4-ethylguaiacol, 4-vinylguaiacol, ferulic acid, vanillin, syringaldehyde, and protocatechualdehyde, demonstrated strong antioxidant activities. This study is beneficial to the comprehensive utilization of wheat bran resources and provides novel insights into the enhancement of functions and quality for CSB.

Technological and health properties and main challenges in the production of vegetable beverages and dairy analogs

Lactose intolerance affects about 68-70% of the world population and bovine whey protein is associated with allergic reactions, especially in children. Furthermore, many people do not consume dairy-based foods due to the presence of cholesterol and ethical, philosophical and environmental factors, lifestyle choices, and social and religious beliefs. In this context, the market for beverages based on pulses, oilseeds, cereals, pseudocereals and seeds and products that mimic dairy foods showed a significant increase over the years. However, there are still many sensory, nutritional, and technological limitations regarding producing and consuming these products. Thus, to overcome these negative aspects, relatively simple technologies such as germination and fermentation, the addition of ingredients/nutrients and emerging technologies such as ultra-high pressure, pulsed electric field, microwave and ultrasound can be used to improve the product quality. Moreover, consuming plant-based beverages is linked to health benefits, including antioxidant properties and support in the prevention and treatment of disorders and common diseases like hypertension, diabetes, anxiety, and depression. Thus, vegetable-based beverages and their derivatives are viable alternatives and low-cost for replacing dairy foods in most cases.

Polyphenols—Ensured Accessibility from Food to the Human Metabolism by Chemical and Biotechnological Treatments

Polyphenols are plant-based compounds famous for their positive impact on both human health and the quality of food products. The benefits of polyphenols are related to reducing cardiovascular diseases, cholesterol management, cancers, and neurological disorders in humans and increasing the shelf life, management of oxidation, and anti-microbial activity in food products. The bioavailability and bio-accessibility of polyphenols are of the highest importance to secure their impact on human and food health. This paper summarizes the current state-of-the-art approaches on how polyphenols can be made more accessible in food products to contribute to human health. For example, by using food processing methods including various technologies, such as chemical and biotechnological treatments. Food matrix design and simulation procedures, in combination with encapsulation of fractionated polyphenols utilizing enzymatic and fermentation methodology, may be the future technologies to tailor specific food products with the ability to ensure polyphenol release and availability in the most suitable parts of the human body (bowl, intestine, etc.). The development of such new procedures for utilizing polyphenols, combining novel methodologies with traditional food processing technologies, has the potential to contribute enormous benefits to the food industry and health sector, not only reducing food waste and food-borne illnesses but also to sustain human health.

A Novel Strategy to Enhance Antioxidant Content in Saccharomyces Cerevisiae Based on Oxygen Pressure

Antioxidant foods represent a potent lever to improve diets while creating value. Yet, their cultivation is often tied to a specific area and climate, limiting availability and increasing market cost. Therefore, microorganism-based antioxidant production emerges as a promising technology to solve these problems. In this view, a novel process was investigated for antioxidant accumulation in yeast culture. S. cerevisiae cells were exposed to various hyperbaric air conditions from 1 to 9 bar (A). Yeast cultures exhibited an increased reactive oxygen species content, which induced oxidative defense expression. After a few hours, reactive oxygen species levels decreased while antioxidant contents remained high, leading to a net increase in antioxidant power. At 6 bar (A), yeast achieved the highest net antioxidant power (phenolics content +48.3 ± 18.6 %, reducing power +120 ± 11.4 %) with an acceptable growth rate (0.27 h^-1). Regarding time evolution, a 2 h exposure seems to be the optimum: cells have the lowest reactive oxygen species level while their antioxidant power is increased. From a biotechnological perspective, this finding highlights air pressure as an antioxidant-manipulating stress strategy. Moreover, the proposed process led to a patent that could potentially reduce energy and chemical consumption in such antioxidant accumulation processes.

Application of Cellulase for Contributing Phenolic Release and Conversion in Oats (Avena sativa L.) During Microbial Fermentation

In this work, Monascus fermentation and cellulase hydrolysis (MCF) of oats (Avena sativa L.) to release and convert phenolic fraction was investigated. Results showed the fungus Monascus grew well with a biomass of 27.03 mg/g glucosamine equivalent in MCF, following the destruction of oat cellular structures. SDS-PAGE revealed lots of enzymes were regulated with the α-amylase and FPase activity achieved 139.25 U/g and 1.84 U/g in MCF, respectively. Compared with unfermented oats, content of the total phenolic fractions was increased by 19.2 times in MCF, suggesting a phenolic release process occurred during fermentation. Moreover, the soluble-free chlorogenic acid upregulated to 510.00 mg/kg whereas the insoluble-bound ferulic acid downregulated to 193.36 mg/kg in MCF, indicating a transformation process of chlorogenic acid from ferulic acid in oats was enhanced. Based on this, a possible pathway of phenolic release and conversion in oats during fermentation with Monascus spp. was revealed. This study was helpful to enrich the theory of microbial metabolism and transformation in grain materials.

The Existing Recovery Approaches of the Huangjiu Lees and the Future Prospects: A Mini Review

Huangjiu lees (HL) is a byproduct in Chinese Huangjiu production with various nutrient and biological functional components. Without efficient treatment, it could cause environmental issues and bioresource wasting. Existing dominant recovery approaches focus on large-scale disposal, but they ignore the application of high-value components. This study discusses the advantages and limitations of existing resourcing approaches, such as feed, food and biogas biological production, considering the efficiency and value of HL resourcing. The extraction of functional components as a suggestion for HL cascade utilization is pointed out. This study is expected to promote the application of HL resourcing.

Novel processing strategies to enhance the bioaccessibility and bioavailability of functional components in wheat bran

Dietary fiber, polysaccharides and phenols are the representative functional components in wheat bran, which have important nutritional properties and pharmacological effects. However, the most functional components in wheat bran exist in bound form with low bioaccessibility. This paper reviews these functional components, analyzes modification methods, and focuses on novel solid-state fermentation (SSF) strategies in the release of functional components. Mining efficient microbial resources from traditional fermented foods, exploring the law of material exchange between cell populations, and building a stable self-regulation co-culture system are expected to strengthen the SSF process. In addition, emerging biotechnology such as synthetic biology and genome editing are used to transform the mixed fermentation system. Furthermore, combined with the emerging physical-field pretreatment coupled with SSF strategies applied to the modification of wheat bran, which provides a theoretical basis for the high-value utilization of wheat bran and the development of related functional foods and drugs.

Performance of Thermoplastic Extrusion, Germination, Fermentation, and Hydrolysis Techniques on Phenolic Compounds in Cereals and Pseudocereals

Bioactive compounds, such as phenolic compounds, are phytochemicals found in significant amounts in cereals and pseudocereals and are usually evaluated by spectrophotometric (UV-VIS), HPLC, and LC-MS techniques. However, their bioavailability in grains is quite limited. This restriction on bioavailability and bioaccessibility occurs because they are in conjugated polymeric forms. Additionally, they can be linked through chemical esterification and etherification to macro components. Techniques such as thermoplastic extrusion, germination, fermentation, and hydrolysis have been widely studied to release phenolic compounds in favor of their bioavailability and bioaccessibility, minimizing the loss of these thermosensitive components during processing. The increased availability of phenolic compounds increases the antioxidant capacity and favor their documented health promoting.

Food Processing Technologies to Develop Functional Foods With Enriched Bioactive Phenolic Compounds in Cereals

Cereal grains and products provide calories globally. The health benefits of cereals attributed to their diverse phenolic constituents have not been systematically explored. Post-harvest processing, such as drying, storing, and milling cereals, can alter the phenolic concentration and influence the antioxidant activity. Furthermore, cooking has been shown to degrade thermo-labile compounds. This review covers several methods for retaining and enhancing the phenolic content of cereals to develop functional foods. These include using bioprocesses such as germination, enzymatic, and fermentation treatments designed to enhance the phenolics in cereals. In addition, physical processes like extrusion, nixtamalization, and parboiling are discussed to improve the bioavailability of phenolics. Recent technologies utilizing ultrasound, micro- or nano-capsule polymers, and infrared utilizing processes are also evaluated for their effectiveness in improving the phenolics content and bio-accessibility. We also present contemporary products made from pigmented cereals that contain phenolics.

Harnessing lactic acid bacteria in synthetic microbial consortia

Lactic acid bacteria (LAB) are important members in synthetic microbial consortia due to their 'generally recognized as safe' status and diverse metabolic activities. Defined communities with LAB show great potential in elucidating metabolic interactions that drive their assembly and demonstrating power to address sustainability challenges in food, environment, and health.

Effects of Dietary Yucca Schidigera Extract and Oral Candida utilis on Growth Performance and Intestinal Health of Weaned Piglets

Weaning piglets experienced the transformation from breast milk to solid feed and present the proliferation of pathogens, the presence of diarrhea, poor growth performance and even death. Plant extracts and probiotics have certain potential in improving animal growth performance, antioxidant capacity and immune function. The purpose of this study was to explore the effects of dietary yucca schidigera extract (YSE) and oral Candida utilis (CU) on growth performance and intestinal health weaned piglets. According to a 2 × 2 factorial design with the main factors being CU (orally administered 1 mL of 0.85% saline with or without CU; fed basal diet with or without 120 mg/kg YSE), forty 28 d healthy weaned piglets were randomly allocated into four groups of 10 barrows each: (1) piglets fed basal diet and orally administered 1 mL of 0.85% saline (CON); (2) piglets fed basal diet and orally administered 1 mL 1 × 10⁹ cfu/mL C. utilis in 0.85% saline (CU); (3) piglets fed the basal diet containing YSE (120 mg/kg) and orally administered 1 mL of 0.85% saline (YSE); (4) Piglets fed the basal diet containing 120 mg/kg YSE and 1 mL 1 × 10⁹ cfu/mL C. utilis in 0.85% saline (YSE+CU). This study lasted 28 days and evaluated the effects of dietary YSE and oral CU on growth performance, immunity, antioxidant function, ileal morphology, and intestinal microflora in weaned piglets. Dietary YSE increased ADG, the spleen and lymph node indexes, serum GLU, BUN, T-SOD, T-AOC, CAT concentrations, ileal villus height and villus height/crypt depth, jejunal occludin, and β-definsin-2 concentrations and ileal occludin concentration in weaned piglets (P < 0.05); decreased the diarrhea rate and mortality, rectal pH and urine pH, the BUN and MDA concentrations, crypt depth (P < 0.05); improved the diversity of cecal microflora. Orally CU increased ADG, and ADFI, the T-SOD, T-AOC, and CAT activity, ileal villus height, villus height/crypt depth, jejunum occludin, and β-definsin-2 concentrations (P < 0.05); reduced the diarrhea rate and mortality, urine pH, the BUN and MDA concentrations, crypt depth (P < 0.05); improved the diversity of cecal microflora. Dietary YSE and orally CU increased the T-SOD, T-AOC, and CAT activity, villus height/crypt depth, jejunal occludin concentration; reduced the diarrhea rate of weaned piglets by 28%, gastric pH, ileal pH, cecal pH and urine pH, MDA, crypt depth; improved the diversity of cecal microflora. YSE and CU could improve the growth performance, reduce the diarrhea rate, improve intestinal health, and increase the diversity and abundance of cecal microflora in weaned piglets and expected to be used as antibiotics alternative feed additives in the production of weaned piglets.

Fermentation transforms the phenolic profiles and bioactivities of plant-based foods

Phenolics are a group of compounds derived from plants that have displayed potent biological activities and health-promoting effects. Fermentation is one of the most conventional but still prevalent bioprocessing methods in the food industry, with the potential to increase phenolic content and enhance its nutritive value. This review details the biotransformation of different classes of phenolics (hydroxycinnamic and hydroxybenzoic acids, flavonoids, tannins, stilbenoids, lignans, alkylresorcinols) by various microorganisms (lactic acid bacteria, yeast, filamentous fungi) throughout the fermentation process in plant-based foods. Several researchers have commenced the use of metabolic engineering, as in recombinant Saccharomyces cerevisiae yeast and Escherichia coli, to enhance the production of this transformation. The impact of phenolics on the metabolism of microorganisms and fermentation process, although complex, is reviewed for the first time. Moreover, this paper highlights the general effect of fermentation on the food's phenolic content, and its bioaccessibility, bioavailability and bioactivities including antioxidant capacity, anti-cancer, anti-diabetic, anti-inflammation, anti-obesity properties. Phenolics of different classes are converted into compounds that are often more bioactive than the parent compounds, and fermentation generally leads to a higher phenolic content and antioxidant activity in most studies. However, biotransformation of several phenolic classes is less studied due to its low concentration and apparent insignificance to the food system. Therefore, there is potential for application of metabolic engineering to further enhance the content of different phenolic classes and bioactivities in food.

Effects of simultaneous and sequential cofermentation of Wickerhamomyces anomalus and Saccharomyces cerevisiae on physicochemical and flavor properties of rice wine

Microorganism species and inoculation fermentation methods have great influence on physicochemical and flavor properties of rice wine. Thus, this work investigated microbial interactions and physicochemical and aroma changes of rice wine through different inoculation strategies of Wickerhamomyces anomalus (W. anomalus) and Saccharomyces cerevisiae (S. cerevisiae). The results underlined that inoculation strategies and non-Saccharomyces yeasts all affected the volatile acidity, total acidity, and alcohol content of rice wine. The sequential cofermentation consumed relatively more sugar and resulted in the higher ethanol content, causing reduced thiols and increased alcohols, esters, phenylethyls, and terpenes, which was more conducive to improve rice wine flavor than simultaneous cofermentation. Moreover, simultaneous cofermentation increased fatty aroma of rice wine, while sequential cofermentation increased mellow and cereal-like flavor. These results confirmed that sequential cofermentation of S. cerevisiae and W. anomalus was a choice for the future production of rice wine with good flavor and quality.