Effects of Monascus purpureus-fermented tartary buckwheat extract on the blood lipid profile, glucose tolerance and antioxidant enzyme activities in KM mice

Evaluation of differences in volatile flavor compounds between liquid-state and solid-state fermented Tartary buckwheat by Monascus purpureus

The differences in volatile flavor compounds (VFCs) between Monascus-solid-state fermented Tartary buckwheat (MSFTB) and Monascus-liquid-state fermented Tartary buckwheat (MLFTB) were investigated using electronic nose and gas chromatography-ion mobility spectrometry (GC-IMS) analysis. The study revealed several significant differences in the composition and abundance of VFCs between the two states. Compared to MSFTB, MLFTB exhibited notable increases in various elements including protein, crude fat, total flavonoids, total polyphenols, Monacolin K, Monascus pigments. Principal component analysis demonstrated significant increases in the production of specific VFCs in MLFTB compared to MSFTB. A total of 25 VFCs were identified through GC-IMS, including 9 esters, 7 alcohols, 5 ketones, and 4 aldehydes. The content of pleasant VFCs in MLFTB was significantly higher than in MSFTB. These compounds served as both VFCs and key aroma components during fermentation. In conclusion, the Monascus fermentation state played a crucial role in enhancing the flavor quality of Tartary buckwheat.

Enhancement of bioactive compounds, antioxidant capacity, and inhibitory effects on mushroom tyrosinase, α-glucosidase, and nitric oxide production in sorghum (Sorghum bicolor L.) via solid-state fermentation with Monascus purpureus

Sorghum (Sorghum bicolor) is a gluten-free supercrop with a high content of phenolic compounds, along with anti-nutrient factors such as tannin that limit its use in food. In this study, we conducted solid-state fermentation for sorghum with Monascus purpureus to reduce the tannin content and value-added sorghum by enhancing biological properties. The results showed that fermented sorghum had 1.39- and 240 times higher total flavonoid and l-carnitine contents than non-fermented sorghum, while the tannin content was reduced by 2.26 times. Gallic acid and vanillic acid were newly detected, while catechin, caffeic acid, ferulic acid, vanillin, and protocatechuic acid contents of sorghum were enriched 2.73-14.42 times after fermentation. The antioxidant activities of sorghum increased by 1.45-1.98 times compared to non-fermented sorghum. The inhibition of α-glucosidase and mushroom tyrosinase of fermented sorghum was enhanced 2.0- and 1.42 times, while the inhibition of nitric oxide was maintained in LPS-stimulated RAW264.7 murine macrophage cells.

Monascus-fermented quinoa alleviates hyperlipidemia in mice by regulating the amino acid metabolism pathway

Monascus has the ability to produce secondary metabolites, such as monacolin K (MK), known for its physiological functions, including lipid-lowering effects. Widely utilized in industries such as health food and medicine, MK is a significant compound derived from Monascus. Quinoa, recognized by the Food and Agriculture Organization of the United Nations as "the only plant food that can meet human basic nutritional needs by itself", possesses dual advantages of high nutritional value and medicinal food homology. This study employed animal experiments to investigate the hypolipidemic activity of Monascus-fermented quinoa (MFQ) and explored the molecular mechanism underlying the lipid-lowering effect of MFQ on hyperlipidemic mice through transcriptomic and metabolomic analyses. The results demonstrated that high-dose MFQ intervention (1600 mg kg-1 d-1) effectively decreased weight gain in hyperlipidemic mice without significant changes in cardiac index, renal index, or spleen index. Moreover, hepatic steatosis in mice was significantly improved. Serum levels of total cholesterol, triglycerides, and low-density lipoprotein cholesterol were markedly reduced, demonstrating that the lipid-lowering effect of MFQ was comparable to the drug control lovastatin. Conversely, both low-dose MFQ (400 mg kg-1 d-1) and unfermented quinoa exhibited no significant lipid-lowering effect. Integrated analysis of the transcriptome and metabolome suggested that MFQ may regulate amino acid levels in hyperlipidemic mice by influencing metabolic pathways such as phenylalanine, tyrosine, and tryptophan metabolism. This regulation alleviates hyperlipidemia induced by a high-fat diet, resulting in a significant reduction in blood lipid levels in mice.

Antioxidant properties and changes in vitro digestion of the fermented kiwifruit extract prepared by lactic acid bacteria and yeasts

The health benefits of fermented fruits have attracted consumers' attention. High levels of antioxidant ability in the fermented kiwifruit extract were found at the early stage of fermentation. The co-fermention with Lactobacillus paracasei LG0260 and Kluyveromyces marxianus J2853 showed the highest ABTS radical scavenging ability (ABTS⋅+-SA) and superoxide dismutase (SOD) activity. Also, the typical antioxidant components of SOD activity, vitamin C concentration and total phenol content were highly correlated with ABTS⋅+-SA. Obviously, polyphenols in the fermented kiwifruit extract evolved into monophenols during fermentation. Compared to undigested samples, the activity of ABTS⋅+-SA and reducing power capacity (RP-CA) after the final intestinal digestion decreased and ranged 387.44-531.89 VCμg/mL, 650.95-981.63 VCμg/mL, respectively (P < 0.05). Meanwhile, SOD activity on the 10th day of fermentation were still remained 222.82 U/mL, 206.98 U/mL and 217.23 U/mL, respectively. These results suggested that the fermented kiwifruit extract could exhibit antioxidant activity through tolerance to the digestive environment.

Effect of Pleurotus eryngii mycelial fermentation on the composition and antioxidant properties of tartary buckwheat

In this study, we investigated the effect of solid-state fermentation of Pleurotus eryngii on the composition and antioxidant activity of Tartary buckwheat (TB). Firstly, the solid-state fermentation of P. eryngii mycelium with buckwheat was carried out, and the fermentation process was explored. The results of the extraction process and method selection experiments showed that the percolation extraction method was superior to the other two methods. The results of extraction rate, active components and antioxidant activity measurements before and after fermentation of TB extract showed that the extraction rate increased about 1.7 times after fermentation. Total flavonoids, rutin and triterpene contents were increased after fermentation compared to control. Meanwhile, LC-MS results showed an increase in the content of the most important substances in the fermented TB extract and the incorporation of new components, such as oleanolic acid, ursolic acid, amino acids, and D-chiral inositol. The fermented TB extract showed stronger antioxidant activity, while the protein and amino acid contents increased by 1.93-fold and 1.94-fold, respectively. This research was the first to use P. eryngii to ferment TB and prepared a lyophilized powder that could be used directly using vacuum freeze-drying technology. Not only the use of solid-state fermentation technology advantages of edible fungi to achieve value-added buckwheat, but also to broaden the scope of TB applications. This study will provide ideas and directions for the development and application of edible mushroom fermentation technology and TB.

Effects of extracted oil of fermented Tartary buckwheat on lipid-lowering, inflammation modulation, and gut microbial regulation in mice

This study investigated the composition of Tartary buckwheat oil fermented by Monascus purpureus and extracted under supercritical CO2 conditions (FTBO) and evaluated its effects on lipid-lowering, inflammation modulation, and gut microbial regulation in mice that were fed a high-fat diet (MOD). Compared with the raw oil (TBO), the γ-oryzanol content reached 27.09 mg g-1; the monounsaturated fatty acid (MUFA) content (such as oleic acid and palmitic acid) was elevated; and the antioxidant capacities of DPPH, ABTS, and hydroxyl were improved in FTBO (p < 0.0001). Then, supplementation with FTBO had a remarkable effect on reducing the body weight and visceral obesity as well as alleviating hyperglycemia, dyslipidemia, inflammatory reactions, and liver damage. The TC, TG, and LDL-C levels in the liver and plasma were reduced, and the HDL-C levels in the liver were increased (p < 0.05). In particular, the high-dose group (FTBOH) exhibited the most significant effect on reducing the pro-inflammatory cytokines ET, TNF-α, IL-1β, and IL-6 in the liver, which were 18.85, 570.12, 50.47, and 26.22 pg mL-1, respectively (p < 0.05). Moreover, FTBO reversed intestinal disorders and increased the intestinal microbial diversity and richness. The relative abundance of beneficial bacteria, such as Bifidobacterium, Lactobacillus, Limosilactobacillus, and Lachnospiraceae_UCG-006, were increased, and the relative abundance of the harmful bacteria Staphylococcus and Lachnoclostridium were reduced. In summary, FTBO has potential applications as a dietary supplement or dietary modifier in lowering blood lipids, modulating immune activity, and reversing intestinal disorders. This study provides reference guidance for the subsequent industrialization and development of Tartary buckwheat, the extension of the industrial chain, the development of new products, and the extraction of functional components.

Performance and mechanism of co-culture of Monascus purpureus, Lacticaseibacillus casei, and Saccharomyces cerevisiae to enhance lovastatin production and lipid-lowering effects

To facilitate lipid-lowering effects, a lovastatin-producing microbial co-culture system (LPMCS) was constituted with a novel strain Monascus purpureus R5 in combination with Lacticaseibacillus casei S5 and Saccharomyces cerevisiae J7, which increased lovastatin production by 54.21% compared with the single strain R5. Response Surface Methodology (RSM) optimization indicated lovastatin yield peaked at 7.43 mg/g with a fermentation time of 13.88 d, water content of 50.5%, and inoculum ratio of 10.27%. Meanwhile, lovastatin in LPMCS co-fermentation extracts (LFE) was qualitatively and quantitatively analyzed by Thin-Layer Chromatography (TLC) and High-Performance Liquid Chromatography (HPLC). Cellular experiments demonstrated that LFE exhibited no obvious cytotoxicity to L-02 cells and exhibited excellent biosafety. Most notably, high-dose LFE (100 mg/L) exhibited the highest reduction of lipid accumulation, total cholesterol, and triglycerides simultaneously in oleic acid-induced L-02 cells, which decreased by 71.59%, 38.64%, and 58.85% than untreated cells, respectively. Overall, LPMCS provides a potential approach to upgrade the lipid-lowering activity of Monascus-fermented products with higher health-beneficial effects.

Effect of enzymatic hydrolysis on volatile flavor compounds of Monascus-fermented tartary buckwheat based on headspace gas chromatography-ion mobility spectrometry

Tartary buckwheat was hydrolyzed with α-amylase, pullulanase, α-amylase and pullulanase double enzymes and fermented by Monascus. The fermentation products were named as enzymolysis-Monascus-fermented tartary buckwheat (EMFTB). The composition and content of volatile flavor compounds in EMFTB were investigated. The results showed that α-amylase and pullulanase hydrolysis reduced starch content and raised protein, flavonoids, Monacolin K and Monascus pigments content of EMFTB. Meanwhile, double enzyme hydrolysis significantly changed the principal components of volatile substances and affected the varieties and content of volatile organic substances in EMFTB using electronic nose and headspace gas chromatography-ion mobility chromatography (HS-GC-IMS). The volatile organic substances and main aroma components increased significantly in EMFTB, including 2-heptanone, 3-methyl-1-butanol, butan-1-ol, 2-methyl-1-propanol and other substances. These results indicate that the amylase hydrolysis plays an important role in improving the flavor quality of EMFTB.

Phytochemistry, Bioactivities of Metabolites, and Traditional Uses of Fagopyrum tataricum

In Tartary buckwheat (Fagopyrum tataricum), the edible parts are mainly grain and sprouts. Tartary buckwheat contains protecting substances, which make it possible for plants to survive on high altitudes and under strong natural ultraviolet radiation. The diversity and high content of phenolic substances are important for Tartary buckwheat to grow and reproduce under unfriendly environmental effects, diseases, and grazing. These substances are mainly flavonoids (rutin, quercetin, quercitrin, vitexin, catechin, epicatechin and epicatechin gallate), phenolic acids, fagopyrins, and emodin. Synthesis of protecting substances depends on genetic layout and on the environmental conditions, mainly UV radiation and temperature. Flavonoids and their glycosides are among Tartary buckwheat plants bioactive metabolites. Flavonoids are compounds of special interest due to their antioxidant properties and potential in preventing tiredness, diabetes mellitus, oxidative stress, and neurodegenerative disorders such as Parkinson's disease. During the processing and production of food items, Tartary buckwheat metabolites are subjected to molecular transformations. The main Tartary buckwheat traditional food products are bread, groats, and sprouts.