Exploration of Processing Applications Based on Differences in the Composition and Functional Properties of Lentinula edodes Polyphenol Extracts

To address industry challenges, such as low added value and poor processability of deep-processed Lentinula edodes products caused by regional variations, the major cultivar ‘Shenxiang 1513’ from two primary production regions in China, including Qingyuan (Zhejiang) and Suizhou (Hubei), was selected as research object. Based on the unique occurrence forms and health benefits of L. edodes polyphenols, this study systematically compared the composition and functional properties of polyphenol extracts obtained using different extraction methods. The goal was to identify their potential processing and application directions for these extracts (LEPs), and to provide a theoretical basis for the targeted development of high-value-added L. edodes products.

LEPs were prepared using three techniques: hot water extraction (H), microwave-assisted extraction (M), and ultrasonic-assisted extraction (U). Their microstructure and chemical composition were analyzed using scanning electron microscopy (SEM) and liquid chromatography-mass spectrometry (LC-MS), respectively, along with analysis of their physicochemical properties. In vitro antioxidant capacity was evaluated through radical scavenging and reducing power assays. Hypoglycemic and hypolipidemic potential were assessed by measuring inhibition of major digestive enzymes, intrinsic fluorescence quenching, and glycolipid adsorption capacity, enabling a multidimensional quality evaluation of LEPs.

The total polyphenol content of LEPs ranged from 2.82 to 5.51 mg GAE·g^-1, and total flavonoid content ranged from 5.69 to 6.81 mg RE·g^-1. LC-MS analysis showed that the polyphenol extract from Qingyuan contained higher levels of rutin, benzoic acid, 3,4-dihydroxybenzoic acid, and 4-hydroxybenzoic acid, whereas the polyphenol extract from Suizhou was mainly composed of 3,4-dihydroxybenzoic acid, vanillic acid, and benzoic acid. Basic physicochemical characterization indicated that LEPs had good solubility and oil-holding capacity. In antioxidant assays, Qingyuan-H exhibited the strongest scavenging capacity against ABTS⁺ radicals and hydroxyl radicals, with IC₅₀ (half-maximal inhibitory concentration) values of 0.18 and 3.25 mg·mL^-1, respectively. Qingyuan-M showed higher activity in DPPH radical scavenging and reducing power, with a half-inhibitory concentration of 1.49 mg·mL^-1 for DPPH, and a reducing power of 5.20 mg AAE·(g DW)^-1 at 6 mg·mL^-1. In vitro hypoglycemic assays confirmed that L. edodes polyphenol extracted from Qingyuan had a stronger glucose-lowering effect than that from Suizhou. The IC₅₀ of Qingyuan-M against α-glucosidase was 1.63 mg·mL^-1, and the fluorescence quenching mechanism was determined to be static quenching. Its glucose-binding capacity was 211.64 µmol·g^-1. The polyphenol extract from Suizhou showed higher pancreatic lipase inhibition than that from Qingyuan. Suizhou-M achieved 66.63% inhibition, with binding rates of 28.93% and 48.74% for sodium glycocholate and sodium taurocholate, respectively.

This study indicated that regional differences influenced the functional properties of L. edodes polyphenols and could guide processing strategies. Qingyuan sources mushrooms were more suitable for targeted development of natural antioxidant products. Polyphenols extracted from Qingyuan L. edodes via microwave-assisted extraction (Qingyuan-M) demonstrated outstanding glucose-lowering efficacy and were promising raw materials for hypoglycemic functional products. In contrast, polyphenols extracted from Suizhou L. edodes using the same method were more suitable for lipid-lowering product development.