MUSHROOMS 9 



In order to obtain information on commercial ainned mushrooms, samples were 

 obtained from six different commercial canners. Each canner supplied samples 

 of (1) button mushrooms, (2) sliced mushrooms, and (3) stems and pieces in 5.5 

 ounce cans. Three to six months after they were canned the mushrooms were 

 analyzed for riboflavin, nicotinic acid, pantothenic acid, and biotin. For each 

 vitamin determination a composite sample from six cans was taken. The results 

 obtained, as shown in table 5, confirm the laboratory tests in showing that 

 commercially canned mushrooms are excellent sources of the four vitamins under 

 consideration. 



The canned button and sliced mushrooms were a better source of the B vita- 

 mins studied than the canned mushroom stems and pieces. It is of interest that 

 the vitamin content of commercially canned mushrooms obtained from different 

 amners was more uniform than the vitamin content of many other kinds of 

 canned foods as reported b>- Thompson, Cunningham and Snell (24) and Ives, 

 Wagner, Elvehjem and Strong (11). This is undoubtedly attributable, at least 

 in part, to the uniforni cultural conditions employed in raising mushrooms. 



Effect of Drying and Freezing on Vitamin Content of Mushrooms 



In an investigation on the dehydration and freezing of mushrooms Brunell, 

 Esselen, and Griffiths (3) obtained data on the stability of thiamin, riboflavin, 

 and nicotinic acid during these operations. Their data are summarized in table 6. 



During steam blanching and dehydration, the loss of thiamin was approxi- 

 mateh- 18 percent and that of nicotinic acid about 12 percent. It is probable that 

 most of these losses occurred in the blanching process. There was little or no 

 loss of riboflavin. All three of these vitamins were quite stable during storage 

 for five months at room temperature (75°-80°F.). 



With frozen mushrooms there was a slight loss of riboflavin and some loss of 

 thiamin during blanching prior to freezing, but all of these vitamins were quite 

 stable in the frozen product. 



Table 6. — Effect of Dehydration and Freezing on the Stability of 

 Thiamin, Riboflavin, and Nicotinic Acid in Mushrooms. 



