Writing in the International Journal of Food Science & Technology the team of scientists from China and the USA reported a fermentation technique that produces meaty flavour compounds from the oyster mushroom (Pleurotus ostreatus) mycelium.
Led by Dr Ramesh Yettella from the University of Arkansas, USA, the authors reported that the meaty flavour compounds were formed from the submerged liquid culture of P. ostreatus mycelium with 1% cysteine and 2% ribose after heat treatment.
“The utilisation of edible mushroom mycelia for the production of natural flavour compounds can have great benefits to consumers and food and flavour industry. Mushroom mycelia produce various enzymes in the submerged liquid culture media and play an important role for the production of various flavour compounds,” wrote the researchers.
“This research shows that P. ostreatuscan be utilised effectively to produce meaty flavour compounds by fermentation which are not available in the market,” they added.
The research team said that attaining the correct flavour in foods is extremely important for the acceptability of foods to consumers. They noted that there is a growing market share of flavoured and fragranced products – including convenience foods, beverages, cosmetics, and detergents – that require novel strategies for aroma chemicals.
“Nearly 80% of the flavours and fragrances used world-wide are produced chemically ... However, the increasing health and nutrition-conscious lifestyle trend globally, warrant the use of natural flavours in foods,” said Yettella and his team.
“Consumers prefer natural flavours to synthesised flavours,” they added.
They said that although plants are an important source of natural flavours, the active flavour compounds are often present in minor quantities or in bound form, “making isolation difficult and products expensive.”
“Several researchers reported the formation of volatile compounds from edible mushrooms. However, the production of meaty flavour compounds from the submerged liquid culture of mushroom mycelia has never been reported,” wrote the researchers.
As a result Yettella and his team investigated the formation of such meaty flavour compounds from a submerged liquid culture of P. ostreatus in the presence of amino acids and sugars.
Fifteen samples of oyster mushroom were prepared by the research team. After sterilisation, the team added amino acids and sugars to the base medium and inoculated with P. Ostreatus, heated, and then tested for flavour compound production.
The heat treated cultured samples were reported to have six major flavour attributes: meaty, sweet, earthy, musty, sulphuric pungent and burnt sugar.
The researchers reported that most of the samples produced sweet and musty flavour however sample 6, which contained P. ostreatus and with 1% cysteine and 2% ribose, produced a strong meaty flavour.
The meaty flavour compounds were then isolated and identified by the team, finding that sulphur containing heterocyclic compounds including 2,5-diethylthiophene, 2-formyl-5-methylthiophene, 3-ethyl-2-formylthiophene, and dimethylformyl thiophene were responsible for meaty flavour.
“These compounds were formed by non-enzymatic browning reaction between ribose and cysteine during heat treatment,” they added.
Source: International Journal of Food Science & Technology
Published online ahead of print, doi: 10.1111/j.1365-2621.2011.02778.x
“Meaty flavour compounds formation from the submerged liquid culture ofPleurotus ostreatus”
Authors: Y.R. Kim, R.R. Yettella, Y.S. Kim, C.K. Hah, C.W. Park, et a