The use of sensory analysis in biotechnology of the cultivation of macromycetes

Abstract

Sensory analysis is the most ancient and inexpensive method of assessing the quality of food products. Consumer demand for the fruit bodies of mushrooms is due to their unique taste and aroma. Profile methods of sensory analysis are used in quality control, for characterising the differences between food products and for determining the impact of various factors on the quality of the test product. The aim of this research is to study the influence of different types of substrates on the character and intensity of arom a of the dried fruit bodies of Pleurotus ostreatus (Jacq.: Fr.) Kumm. IBK–1535 using the sensory profile method. The substrates for the cultivation of mushrooms were selected from waste from the agricultural and wood processing industries: sunflower husks, wheat straw, waste from the cleaning of seed corn, and sawdust of deciduous trees and oak bark. The preparation and sterilization of substrates was performed according to standard techniques. During the process of cultivation we determined the culture-morphological indices of development of the mycelium: the duration of growth in the substrate, time of appearance of the primordia, the number of formed fruiting bodies of mushrooms, the average biomass of the fruiting bodies. We did not detect any significant differences between substrates in the growth rate of mycelia. The best culture-morphological indices of growth and development of mycelia were identified for the corn waste substrate. This substrate had the greatest number of primordia, while the lowest was for wheat straw. The mycelium of P. ostreatus IBK-1535 was white, fluffy, and denser on substrates of corn waste, sunflower husks and oak bark. The sensory profile analysis was performed according to ISO 6564:1885.1 g of dried fruiting bodies was crushed, placed in glass vials with stoppers and heated to +35…+40 °C for a better emission of volatile compounds. A five person degustation commission was trained to undertake the sensory analysis. First, using sensory analysis, the degustation commission determined the following descriptors of odour for the fruiting bodies of the fungi: mushroom, woody, grassy, sweet, sour. Then the intensity of the aroma of each sample was assessed on a five-point scale. The most characteristic mushroom aroma of the dried fruit bodies was obtained when oak bark was the substrate for cultivation. The samples of mushroom grown on sawdust and waste corn had a similar aroma. The samples obtained for sunflower husk and wheat straw had a slight mushroom aroma with grassy and sour notes. Thus, the use of the sensory profile method of analysis makes it possible to assess the degree of intensity of aroma of fruit bodies of higher edible mushrooms in relation to the conditions of their cultivation without having to use complicated instrumental methods of analysis. Moreover, sensory profile analysis can be used to monitor the odours and aromas of mushrooms, which are cultivated in artificial conditions, for the adjustment of the cultivation process and for conducting a rapid appraisal of the quality of mushroom products.