In this study, a delicious mixed mushroom sauce was developed using the rare mushroom Oudemansiella raphanipes and the common oyster mushroom Pleurotus ostreatus as raw materials. Using principal component analysis (PCA) and partial least squares-discrimination analysis (PLS-DA), the flavor changes of mixed mushroom sauces with different mixing ratios were examined as a function of cooking time. The results showed that at a cooking time of 4 min and a 4:6 mixing ratio between oyster mushroom and O. raphanipies, the umami taste of the mushroom sauce was the strongest (m/m). At a cooking time of 4-5 min and a 4:6 ratio, the aroma quality was the best. Fourteen compounds, including glutamate and geraniyl acetone, resulted in significant differences in the umami and aroma of the product at different cooking times. This study will provide a theoretical basis for improving the flavor quality of mixed mushroom sauce, and, more broadly, promote the development of the edible mushroom processing industry.

Oudemansiella raphanipes is a rare edible mushroom with high nutritional value, which is loved by more and more consumers. However, its fruiting body has high water content and no epidermal protection, so it is very easy to decay and deteriorate during storage at normal temperature. Low-temperature cold chain conditions and harvesting methods can affect the storage quality of Oudemansiella raphanipes. In this study, Oudemansiella raphanipes harvested by cutting or pulling under the condition of cold chain temperature (10 ℃) was evaluated for changes in its sensory, nutritional, physiological and flavor attributes during storage. The results demonstrated different harvesting methods had significant effects on the quality of Oudemansiella raphanipes. The texture, color and electronic tongue taste value of Oudemansiella raphanipes harvested by pulling were better than those of Oudemansiella raphanipes harvested by cutting, while the latter effectively inhibited ethylene release in the early stage and superior to the former in terms of equivalent umami concentration (EUC) and the contents of polyphenols, flavonoids, soluble proteins, soluble sugars (in the late stage), total flavor nucleotides, flavor amino acids, and volatile C₈ compounds. In conclusion, under the condition of cold chain temperature, Oudemansiella raphanipes harvested by pulling has relatively better sensory quality, while Oudemansiella raphanipes harvested by cutting has better nutritional flavor, which is suitable for the production of instant food products. This study provides a theoretical basis for solving the problem of quality deterioration of Oudemansiella raphanipes during storage.

The volatile organic compounds (VOCs) in Lentinus edodes at different maturity stages were identified by optimized headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (GC-MS) and analyzed by odor activity value (OAV) and partial least squares discriminant analysis (PLS-DA). The results showed that the optimal extraction conditions were as follows: 1.0 g of sample was extracted at 50 ℃ for 25 min and then the analytes adsorbed on the fiber were desorbed in the GC-MS injection port for 3 min. A total of 71 VOCs were identified in L. edodes, and there were significant differences in the types and contents of volatile compounds at different maturity stages (P < 0.05). Out of these, 18 VOCs that could be used as biomarkers to distinguish L. edodes at different maturation stages were selected by PLS-DA and variable importance in projection (VIP). Besides, 16 volatile compounds with OAV ≥ 1 were identified. Among these compounds, 1-octen-3-ol, 3-octanol, 1-octen-3-one, 3-octanone, benzeneacetaldehyde, dimethyl disulphide, dimethyl trisulphide, 2,3,5-trithiohexane, and 1,2,4-trithiohexane showed VIP greater than 1, thus making them the most significant differential volatile compounds among different maturity stages of L. edodes. This study provides a theoretical foundation for understanding the mechanism of aroma formation during the maturation process of L. edodes.

Edible mushroom sexual spores have been gaining more interest due to their bioactive components and functions. Spore discharge (SD) is an important factor affecting the quality of edible mushrooms.In this review, the bioactive nutrients of sexual spores of edible mushrooms were summarized, the SD mechanism was described, and the relationship between postharvest SD and the quality of edible mushrooms was analyzed.Spores contain various bioactive nutrients that are beneficial to the human body. Mature mushrooms can actively discharge spores in a process affected by light, relative humidity, and temperature. During storage, the physiological metabolism of spore-bearing gill tissue is vigorous, promoting the release of postharvest spores and changing the nutritional value of fruiting bodies. The flavor of the fruiting bodies also varied significantly during SD. Edible mushroom sexual spores have the potential to become new raw materials for functional food and medical resources. Research on the effect of the mechanism of SD on the quality of edible mushrooms and the development of SD regulation technology may be a new trend in the quality control of edible mushrooms, which will promote the development of the edible mushroom industry.

The molecular mechanisms of energy status related to the umami taste of postharvest shiitake mushrooms during spore release remain poorly understood. In this study, the variations of energy status and umami taste of mushrooms were measured at 25 ℃. At 24 h storage, slight spore prints of mushrooms were first pictured, respiration peaked. Significant ATP decrease and ADP increase were also observed as the initiation of postharvest senescence (P < 0.05). Meanwhile, the activities of phosphohexose isomerase, succinate dehydrogenase, glucose-6-phosphate dehydrogenase and cytochrome c oxidase and the contents of umami nucleotides and amino acids were maintained at higher levels in mushrooms with spore release. Notably, the equivalent umami concentration (EUC) was strongly correlated with energy levels (R = 0.80). Fifteen related gene expression levels in the energy metabolism pathway were downregulated. LecpdP1 and LeAK were significantly expressed in the conversion of ATP into AMP and played key roles in connecting the energy state and umami level. These results provided valuable insights on the umami taste associated with energy metabolism mechanism during postharvest mushroom spore release.

Actinidia arguta is a berry fruit with high nutritional values. To evaluate the comprehensive quality, the fruit weight, titratable acid (TAC), soluble solids (SSC), vitamin C, mineral elements, and taste value of 67 accessions of A. arguta were measured, and sensory attributes including olfactive intensity, juiciness, sweetness, sourness, and astringency were assessed. Cluster analysis was carried out based on mineral elements, and principal component analysis (PCA) was used for comprehensive score ranking. The result demonstrated that fruit weight ranged from 3.5 g to 24.2 g, SSC ranged from 11.94% to 20.56%, TAC ranged from 0.15% to 1.20%, and vitamin C ranged from 3.51 g/kg to 230.76 g/kg (fresh weight) among the tested samples. There were significant differences in sourness, sweetness, bitterness, and umami among the 67 accessions based on electronic tongue analysis, and this result was rapidly and objectively characterized by the sensory assessment. The dendrogram was obtained and clustered the accessions into two major clusters, and five principal components were extracted by PCA. Overall, the information provided by this study identified the 10 best germplasm resources for fresh-eating and processing fruits. It can provide theoretical reference for nutritional efficacy evaluation and food development of A. arguta.

Suillus granulatus is a valuable wild edible mushroom with a strong umami taste. Different grades of S. granulatus were dried by different methods, including natural air drying (ND), hot air drying (HAD), vacuum drying (VD), and freeze drying (FD). Results showed that VD samples of all grades had the highest equivalent umami concentration (EUC) value (P < 0.05). The second grade of ND samples showed the highest EUC value (P < 0.05). The first grade of HAD samples showed the highest EUC value (P < 0.05). The third grade of FD samples showed the highest EUC value (P < 0.05). The third grade of VD samples had a higher EUC value than the other grades of samples dried by VD. Electronic tongue results indicated no significant differences between samples of all grades dried by all methods. Thus, umami taste components are affected by drying method and grade. VD is an appropriate drying method for all sample grades. ND, HAD, and FD are suitable for second-, first-, and third-grade samples, respectively.