CHANGES IN THE NUCLEOSTATUS OF MUSHROOMS DURING STORAGE AND THERMAL-PROCESSING

Changes in the nucleostatus of mushrooms were examined under different storage and processing conditions. The three examined conditions were: storage at 4-degrees-C, at room temperature, as well as the nucleostatus after thermal processing. The amount of nucleic acid decreased during both storage conditions, this was quite noticeable in the reduction of RNA content. This is a first order reaction. The amount of nucleotides increased in cold storage, whereas the amount at room temperature initially increased followed by a decrease. A strong increase in 3'-Mono-nucleotides content is the cause for this incline. The dominant fraction of nucleosides are adenosine, guanosine and uridine. The free bases increase during storage, however at room temperature one can detect a decrease at the storage halflife. The purine-N-content of the higher molecular nucleic material (nucleic acids) in mushrooms, strongly decreases during storage. The purine-N-content of the lower molecular nucleic material (nucleotides, nucleosides and free bases) at the same time increases. An increase in lower molecular nucleic material in mushrooms which were stored over a longer period of time can cause an increase in the blood serum concentration after consumption. Thermal processing causes a definit decrease in the RNA content of mushrooms. During cooking the nucleotides, nucleosides and bases are leached into the water. After examination there was no difference detectable in the nucleostatus of cooked or canned mushrooms. Dried mushrooms contained however a higher purine-N-content then the thermally treated ones. Half the purin bases are however to be found in lower molecular forms, whereas the cooked and canned mushrooms contained a definit lower amount of lower molecular nucleic material.