Effect of Thymus vulgaris post‐extraction waste and spent coffee grounds on the quality of cultivated Pleurotus eryngii

Abstract

The study demonstrated that Pleurotus eryngii cultivation on substrate enriched with thymus (Thymus vulgaris) post‐extraction waste (TPEW) and spent coffee grounds (SCG) can beneficially affect yield and modify the mineral composition, profile of phenolic compounds, organic acids, and antioxidant activity. Cultivation with TPEW and SCG did not result in any significant differences in the contents of K, Mg, P, and S in fruiting bodies. The highest content of Ca and Na was recorded in cultivation with TPEW. The use of TPEW and SCG increased the total phenolic content, while in the phenolic profile changes were observed in the variants of 50% and 100% TPEW and 50% SCG. Cultivation with TPEW increased the sum of the organic acids and quinic, malonic, malic, acetic, and succinic acids, while addition of SCG resulted in their significant decrease. Practical applications The use of different additives to growing substrate is a possible way to improve the harvest yield. Moreover, this modification of cultivation allows to manage some waste materials. However, the application of waste materials can carry the risk to introduce substances potentially dangerous for human health into substrate. Additionally, the supplementation allows to modify the content of bioactive compounds. In this context, the monitoring of the quality of fruiting bodies seems to be necessary. Therefore, the study evaluated the content of elements (especially toxic trace elements), some bioactive compounds and antioxidant activity was examined. The results pointed, how the waste materials added to the substrate affect the quality of the final product. These findings could lead to improvements in the commercial production of P. eryngii and increase the quality of the final product.

A Possibility to Use Selected Crop Post-Extraction Wastes to Improve the Composition of Cultivated Mushroom Pleurotus citrinopileatus

“…However, the addition of 20% PPEW, 25 and 50% TPWE significantly contributed to the increase in LMWOAs contents in P. citrinopileatus. A confirmation of the influence of TPEW addition was provided by a study by G ąsecka et al [56], where P. eryngi was cultivated on spent coffee grounds (SCG) and TPEW. The authors showed that the addition of SCG inhibited the formation of LMWOAs in P. eryngi, but the addition of TPEW significantly increased acid contents in fruit bodies, similar to the results obtained now for P. citrinopileatus.…”

“…Each of them caused an increase in the sum of the detected LMWOAs as compared to the control variant. This is highly valuable information indicating that the type of post-extraction waste added to the growing medium may have a significant impact on the decreasing or increasing contents of LMWOAs [56]. In the case of the LMWOAs increase in fruit bodies, it is a highly beneficial aspect because the determined acids constitute important molecules in mushrooms.…”

“…Prepared extracts before UPLC analysis were dissolved in 1 mL of deionized water for analysis of LMWOAs (Mili-Q, Millipore, Molsheim, France) and in 80% methanol for analysis of phenolic compounds, then centrifuged (at 3425× g) and filtered through filters (0.22 µm cellulose membrane) (MilliporeSigma Filtration, Burlington, MA, USA) immediately prior to chromatographic analysis. For the determination of LMWOAs and phenolic compounds 5 µL of liquor was injected onto UPLC (Acquity UPLC HSS T3 C18 column (150 mm × 2.1 mm, 1.8 µm particle size) (Waters, Dublin, Ireland) and photodiode array detector (PDA) eλ (Waters Corporation, Milford, MA, USA) and analysed as was described above for phenolic compounds [56]. A gradient program was applied with the mobile phase composed of A (water, containing 0.10% formic acid) and B (acetonitrile, containing 0.10% formic acid).…”

“…A gradient program was applied with the mobile phase composed of A (water, containing 0.10% formic acid) and B (acetonitrile, containing 0.10% formic acid). External standards were used to quantify LMWOAs at λ = 280 nm wavelength, while phenolic acids were determined at λ = 280 nm and λ = 320 nm [56].…”

The importance of Cu × Pb interactions to Lentinula edodes yield, major/trace elements accumulation and antioxidants

“…The gradient program was applied. The concentration of phenolic compounds was determined using an external standard at wavelengths λ = 280 nm and λ = 320 nm [21].…”