Yeast mannan: A comprehensive functional analysis from structural characteristics to biological activity.

Influence of autolyzed whole yeast and yeast components on broiler chickens challenged with salmonella lipopolysaccharide

Liposomes play a significant role in encapsulation of various bioactive compounds (BACs), including functional food ingredients to improve the stability of core. This technology can be used for promoting an effective application in functional food and nutraceuticals. Incorporation of traditional and emerging methods for the developments of liposome for loading BACs resulted in viable and stable liposome formulations for industrial applications. Thus, the advance technologies such as supercritical fluidic methods, microfluidization, ultrasonication with traditional methods are revisited. Liposomes loaded with plant and animal BACs have been introduced for functional food and nutraceutical applications. In general, application of liposome systems improves stability, delivery, and bioavailability of BACs in functional food systems and nutraceuticals. This review covers the current techniques and methodologies developed and practiced in liposomal preparation and application in functional foods.

Observations on cell walls of yeasts and some other fungi by X-ray diffraction and solubility tests

Zymolyase B decreased the turbidity of a yeast cell wall suspension by about 50% and caused release of peptide-mannan from the cell walls. However cell walls treated with the enzyme still maintained the cell shape. The effect of the enzyme on the cell walls was inhibited by yeast mannan and completely counteracted by treatment of the enzyme with DFP. The activity was not affected by pH, but was considerably reduced by incubation of the enzyme at 55°C for 15 min, a treatment that did not affect the proteolytic activity. Heat-treatment decreased the molecular weight of the enzyme from 29,000 to 22,500 and its sensitivity to yeast mannan. Yeast mannan caused noncompetitive inhibition of the proteolytic activity of the native enzyme and competitive inhibition of that of the heat-treated enzyme. Modification of tryptophan residues of Zymolyase B resulted in decreased sensitivity to yeast mannan and a decrease in the activity of the enzyme on yeast cell walls as well as heat-treatment. On the basis of these res...

Zymolyase B decreased the turbidity of a yeast cell wall suspension by about 50% and caused release of peptide-mannan from the cell walls. However cell walls treated with the enzyme still maintained the cell shape. The effect of the enzyme on the cell walls was inhibited by yeast mannan and completely counteracted by treatment of the enzyme with DFP. The activity was not affected by pH, but was considerably reduced by incubation of the enzyme at 55°C for 15 min, a treatment that did not affect the proteolytic activity. Heat-treatment decreased the molecular weight of the enzyme from 29,000 to 22,500 and its sensitivity to yeast mannan. Yeast mannan caused noncompetitive inhibition of the proteolytic activity of the native enzyme and competitive inhibition of that of the heat-treated enzyme. Modification of tryptophan residues of Zymolyase B resulted in decreased sensitivity to yeast mannan and a decrease in the activity of the enzyme on yeast cell walls as well as heat-treatment. On the basis of these res...

Yeast mannan (YM) is an indigestible water-soluble polysaccharide of the yeast cell wall, with a notable prebiotic effect on the intestinal microbiota. We previously reported that YM increased Bacteroides thetaiotaomicron abundance in in vitro rat faeces fermentation, concluding that its effects on human colonic microbiota should be investigated. In this study, we show the effects of YM on human colonic microbiota and its metabolites using an in vitro human faeces fermentation system. Bacterial 16S rRNA gene sequence analysis showed that YM administration did not change the microbial diversity or composition. Quantitative real-time PCR analysis revealed that YM administration significantly increased the relative abundance of Bacteroides ovatus and B. thetaiotaomicron. Moreover, a positive correlation was observed between the relative ratio (with or without YM administration) of B. thetaiotaomicron and B. ovatus (r = 0.92), suggesting that these bacteria utilise YM in a coordinated manner. In addition, YM administration increased the production of acetate, propionate, and total short-chain fatty acids. These results demonstrate the potential of YM as a novel prebiotic that selectively increases B. thetaiotaomicron and B. ovatus and improves the intestinal environment. The findings also provide insights that might be useful for the development of novel functional foods.

A soil microorganism has been isolated which will grow on yeast mannan as the sole carbon source. The organism secretes into the cultural medium an α-mannosidase which appears to act as an exoglycosidase and removes the short α-1,2′- and α-1,3′-linked mannose side chains of the mannan molecule to leave a resistant core composed of a linear α-1,6′-linked mannose polymer. This provides the first direct proof that yeast mannan contains such a backbone structure. While the mannosidase does not appear to degrade the 1,6′-linked backbone, it does hydrolyze α-1,6′-mannobiose as well as the α-1,2′ and α-1,3′-linked oligosaccharides obtained from yeast mannan by acetolysis. It is not yet known whether this reflects a broad substrate specificity or the presence of several different proteins in the preparation. The enzyme may be useful for studies on the yeast cell wall and on mannose-containing glycoproteins.

Comprehensive characterization of Rubus idaeus L. Polysaccharides: Extraction, purification, structural diversity, biological efficacy, and structure-activity relationships.

Bioactive compounds from natural sources are gaining significant attention due to their potential health benefits. Caffeoylquinic Acids (CQAs), isolated from the leaves of sweetpotato (Ipomoea batatas L.), represent a promising class of polyphenolic compounds. This review offers a comprehensive analysis of CQAs and their derivatives, focusing on their extraction, characterization, and therapeutic applications. Sweet potato leaves, an abundant agricultural byproduct, are particularly rich in these compounds, which exhibit potent antioxidant, anti- inflammatory, anticancer, and antimicrobial properties. The review explores the structural diversity of CQAs, including mono-, di-, and tri-caffeoyl derivatives, and examines their bioactivity and stability. Extraction techniques, mainly green synthesis methods, have enhanced the efficiency and sustainability of isolating these bioactives, paving the way for their broader application in nutraceuticals, pharmaceuticals, and functional foods. Furthermore, the review delves into the mechanisms underlying the health-promoting effects of CQAs, emphasizing their roles in free radical scavenging, modulation of inflammatory pathways, and inhibition of cancer cell proliferation. Emerging studies suggest that CQAs may regulate metabolic disorders, such as diabetes and hyperlipidemia, by influencing glucose and lipid metabolism. Despite promising findings, challenges remain, such as limited bioavailability and a lack of clinical studies confirming efficacy in human populations. CQAs from sweet potato leaves present a natural and sustainable source of bioactive compounds with considerable therapeutic potential.

Prickly pear (Opuntia ficus-indica L. Miller) is a natural source of antioxidant compounds that have gained significant attention due to their potential health benefits. This study aims to investigate the effectiveness of pressurized liquid extraction (PLE) and Ultrasound-Assisted Extraction (UAE), combined with water–ethanol mixtures from 0 to 60%, at moderate temperatures between 50 °C to 70 °C to improve the recovery of antioxidant compounds from red peel prickly pear. The recovery of these compounds was affected by solvent composition and temperature for both extraction techniques. Interestingly, the use of pure water at 70 °C during the PLE process allowed the recovery of high concentrations of antioxidant compounds (12.96 mg GAE/g dw, IC5O: 2.03 mg/mL, ORAC: 625 µmol TE/g dw). On the contrary, when the UAE process was combined with 30% ethanol at 50 °C, the extractability of these compounds (10.52 mg GAE/g dw, IC5O: 3.09 mg/mL, ORAC: 561.26 µmol TE/g dw) was improved. In addition, different solvent compositions were identified to improve the recovery of specific polyphenols. For PLE, pure water at 70 °C was effective in recovering phenolic acids, flavanols, and flavonols, while the highest concentrations of stilbenes were obtained with 60% ethanol at 70 °C. For UAE, the use of 30% ethanol at 50 °C was more effective in extracting phenolic acids and stilbenes, whereas pure water at 50 °C provided high concentrations of flavanols and flavonols. These results contribute to the development of sustainable and efficient extraction strategies for obtaining antioxidant-rich extracts from prickly pear peel with important applications in functional foods, nutraceuticals, and pharmaceutical industries.

Mastitis is the most important bovine disease, causing dramatic economic losses to the dairy industry, worldwide. This study explores the valorization of whey from cows affected by mastitis, through a novel separation approach. Surface Active Maghemite Nanoparticles (SAMNs) were used as magnetic baits to selectively bind bioactive peptides with potential health benefits. Advanced techniques such as HPLC and LC-MS/MS highlighted SAMN capability of isolating a restricted group of peptides, drastically diverging from the control profile (Solid Phase Extraction, SPE) and characterized by a peculiar acidic residue distribution. Most importantly, both magnetically purified and nano-immobilized peptides (SAMN@peptides) showed protective activity against oxidative stress and inflammation, when tested on Caco-2 cells; with SAMN@peptides being associated with the strongest biological effect. SAMNs exhibited excellent characteristics, they are environmentally sustainable, and their synthesis is cost-effective prompting at a scalable and selective tool for capturing bioactive peptides, with potential applications in functional foods and nutraceuticals.

Bioactive peptides derived from insect proteins: Preparation, biological activities, potential applications, and safety issues

Ganoderma polysaccharides (GPs), derived from various species of the Ganoderma genus, exhibit diverse bioactivities, including immune modulation, anti-tumor effects, and gut microbiota regulation. These properties position GPs as dual-purpose agents for medicinal and functional food development. This review comprehensively explores the structural complexity of six key GPs and their specific mechanisms of action, such as TLR signaling in immune modulation, apoptosis pathways in anti-tumor activity, and their prebiotic effects on gut microbiota. Additionally, the structure–activity relationships (SARs) of GPs are highlighted to elucidate their biological efficacy. Advances in green extraction techniques, including ultrasonic-assisted and enzymatic methods, are discussed for their roles in enhancing yield and aligning with sustainable production principles. Furthermore, the review addresses biotechnological innovations in polysaccharide biosynthesis, improving production efficiency and making large-scale production feasible. These insights, combined with ongoing research into their bioactivity, provide a solid foundation for developing health-promoting functional food products that incorporate GPs. Furthermore, future research directions are suggested to optimize biosynthesis pathways and fully harness the health benefits of these polysaccharides.Graphical abstract

Brown algae have gained significant attention due to their abundance of bioactive compounds with promising bioactivities. This review comprehensively examines the primary bioactive compounds found in brown algae, including fucoidan, laminarin, alginates, phlorotannins, phenolic acids, flavonoids, fucoxanthin, fatty acids, fucosterol, and various vitamins and minerals. The bioactivities of these compounds are explored, focusing on their antioxidant, anti‐inflammatory, anticancer, and antimicrobial properties. By analyzing studies conducted between 2014 and 2024, this review provides a current and comprehensive understanding of these compounds’ effects and potential health benefits. Additionally, it discusses their present and future applications in pharmaceuticals, nutraceuticals, and functional foods, highlighting their market potential. This review also addresses key challenges such as regulatory compliance and chemical composition variability. Additionally, future perspectives are presented to guide upcoming research and development efforts to overcome these challenges and fully exploit these marine resources.

The linear (1 --> 6)-beta-d-glucans pustulan and luteose were effective competitive inhibitors of killer toxin action. Affinity chromatography of killer toxin on a pustulan-Sepharose column showed that toxin bound directly to a (1 --> 6)-beta-linked polysaccharide. Other polysaccharides found in yeast cell walls, including (1 --> 3)-beta-d-glucan, mannan, chitin, and glycogen, were not effective as inhibitors of toxin. Fractionation of yeast cell walls was attempted to identify the toxin receptor in sensitive Saccharomyces cerevisiae. The receptor activity was retained among the insoluble glucans in alkali-washed cells; yeast mannan and alkali-soluble glucan had little receptor activity. A minor fraction of receptor activity was removed from alkali-washed cells by hot acetic acid extraction, a procedure which solubilized some (1 --> 6)-beta-d-glucan and glycogen. The major fraction (>70%) of receptor activity remained with the acid-insoluble (1 --> 6)-beta-and (1 --> 3)-beta-glucans. Zymolyase, an endo-(1 --> 3)-beta-d-glucanase, solubilized a substantial fraction of the receptor activity in the acid-insoluble glucans. The receptor activity in yeast cell walls was periodate and (1 --> 6)-beta-d-glucanase sensitive, but was resistant to (1 --> 3)-beta-d-glucanase and alpha-amylase. The acid-soluble glucan fractions of a sensitive strain and a krel-l receptor-defective toxin-resistant mutant were examined. The krel-l strain had a reduced amount (ca. 50%) of (1 --> 6)-beta-d-glucan compared with the sensitive parent strain. A sensitive revertant of the krel-l strain regained the parental level of glucan. These results implicate (1 --> 6)-beta-d-glucan as a component of the yeast cell wall receptor for killer toxin.