the effect of ascorbic acid, citric acids and sodium metabisulphite on colour and foaming properties of mushroom purees (agaricus bisporus)

enzymatic browning and formation of brown pigments are some of the most important problems in preparation of mushroom purees. in this study, the effect of some anti browning agents including sodium metabisulphite, ascorbic acid, and citric acid on the whiteness and foaming properties of mushroom purees was investigated. the results showed that soaking with acids and sodium metabisulphite significantly (p<0.05) reduced the browning in mushroom purees after crushing process. there was no significant difference (p<0.05) between whiteness, bi and δe at the start of the process and after 1 hour in the mushrooms soaked in metabisulphite solutions, where whiteness ,bi and δe changed significantly (p<0.05) after soaking mushrooms in acid solutions. soaking mushrooms in sodium metabisulphite solution had no effect on foaming properties. as a result, soaking of mushrooms in 0.5 gr/ml sodium metabisulphite solution for 10 minutes was found to be sufficient for maintaining whiteness and foaming properties in mushroom purees.