Taste peptides derived from Stropharia rugosoannulata fermentation mycelium and molecular docking to the taste receptor T1R1/T1R3

Nutritional, Bioactive, and Flavor Components of Giant Stropharia (Stropharia rugoso-annulata): A Review

Giant Stropharia (S. rugoso-annulata) is an edible mushroom recommended for consumption by the Food and Agriculture Organization of the United Nations. It possesses significant culinary and medicinal functionalities. The characteristics of this mushroom include high protein content, abundant bioactive compounds, delicious and sweet taste, and pleasant aroma. In recent years, the S. rugoso-annulata industry has seen strong growth, especially in China. This article presents the first comprehensive and systematic review of the nutritional, bioactive, and flavor components of S. rugoso-annulata, as well as their influencing factors. This article provides scientific evidence for the production of high-quality S. rugoso-annulata mushrooms, the extraction of bioactive components, post-harvest storage, and culinary processing, aiming to promote the consumption of S. rugoso-annulata and the health of consumers.

Difference in Volatile Aroma Components of Stropharia rugosoannulata under Two Cultivated Environments Investigated by SPME-GC-MS

In order to study the effect of both greenhouse and forest cultivating environments on Stropharia rugosoannulata, its volatile aroma compounds were measured by a headspace solid phase micro extractions-gas chromatograph-mass spectrometer (SPME-GC-MS). The optimal adsorption temperature was 75 °C and the optimal adsorption time was 40 min. A total of 36 volatile aroma compounds were identified by GC-MS, including 8 aldehydes, 2 ketones, 4 alcohols, 15 alkenes, and 4 alkanes. Hexanal, 3-Octanone, 2-Undecanone, (E)-Nerolidol, and (Z)-β-Farnesene made great aromatic contributions. Among them, Hexanal, 3-Octanone, 2-Undecanone were the key aroma compounds for which odor activity values (OAVs) were more than 1. (E)-Nerolidol showed odor modification in the forest samples and showed a key aroma effect in greenhouse samples. (Z)-β-Farnesene showed odor modification in greenhouse samples. 3-Octanone was the largest contributing compound for which the OAV was more than 60. The total content of volatile aroma compounds first increased and then decreased with growth time; it reached the highest level at 48 h: 2203.7 ± 115.2 μg/kg for the forest environment and 4516.6 ± 228.5 μg/kg for the greenhouse environment. The aroma was the most abundant at this time. All samples opened their umbrella at 84 h and become inedible. Principal component analysis (PCA), hierarchical cluster analysis (HCA), and orthogonal partial least squares discriminant analysis (OPLS-DA) were combined to analyze the aroma difference of S. rugosoannulata under two cultivation modes. PCA and HCA could effectively distinguish the aroma difference in different growth stages. Under different culturing methods, the aroma substances and their changes were different. The samples were divided into two groups for forest cultivation, while the samples were divided into three groups for greenhouse cultivation. At the end of growth, the aroma of S. rugosoannulata with the two cultivation modes was very similar. OPLS-DA clearly distinguished the differences between the two cultivation methods; 17 key aroma difference factors with variable importance projection (VIP) > 1 were obtained from SPLS-DA analysis.

A Review on Edible Fungi-Derived Bioactive Peptides: Preparation, Purification and Bioactivities

Edible fungi bioactive peptides (BAPs) are extracted from fruiting bodies and the mycelium of edible fungus. They have various physiological functions such as antioxidant activity, antihypertensive activity, and antibacterial activity. In this paper, the preparation and purification methods of edible fungus BAPs were reviewed, their common biological activities and structure-activity relationships were analyzed, and their application prospects were discussed.

Study on the relationship between structure and taste activity of the umami peptide of Stropharia rugosoannulata prepared by ultrasound

Through virtual screening, electronic tongue verification, and molecular docking technology, the structure-taste activity relationship of 47 kinds of umami peptides (octapeptide - undecapeptide) from Stropharia rugosoannulata prepared by simultaneous ultrasonic-assisted directional enzymatic hydrolysis was analyzed. The umami peptides of S.rugosoannulata can form hydrogen bond interaction and electrostatic interaction with umami receptors T1R1/T1R3. The amino acid residues at the peptides' N-terminal and C-terminal play a vital role in binding with the receptors to form a stable complex. D, E, and R are the primary amino acids in the peptides that easily bind to T1R1/T1R3. The basic amino acid in the peptides is more easily bound to T1R1, and the acidic amino acid is more easily bound to T1R3. The active amino acid sites of the receptors to which the peptides bind account for 42%-65% of the total active amino acid residues in the receptors. ASP147 and ASP219 are the critical amino acid residues for T1R1 to recognize the umami peptides, and ARG64, GLU45, and GLU48 are the critical amino acid residues for T1R3 to recognize the umami peptides. The increase in the variety and quantity of umami peptides is the main reason for improving the umami taste of the substrate prepared by synchronous ultrasound-assisted directional enzymatic hydrolysis. This study provides a theoretical basis for understanding simultaneous ultrasound-assisted directional enzymatic hydrolysis for preparing umami peptides from S.rugosoannulata, enhancing the flavor of umami, and the relationship between peptide structure and taste activity.