 Various authors regard Suillus collinitus as edible with a sour odor and nondescript taste . It is advisable , as for all species of Suillus , to pick only young specimens and to peel the cuticle before preparation . The mushroom contains several tocopherols , a class of chemical compounds collectively known as vitamin E , and which confer antioxidant activity . They also contain several organic acids , most predominantly the pairs malic and <unk> acids , and citric and <unk> acid , which respectively make up 42 % and 30 % of total organic acids . The composition and concentration of organic acids in mushrooms are major factors in influencing their flavour ; some organic acids contribute to antioxidant activity . 
