EFFECT OF RIPENING STAGE ON ORGANIC ACID PROFILES AND ANTINUTRIENT CONTENTS OF THREE SPECIES OF WILD EDIBLE MUSHROOM RUSSULA SSP.

Abstract

The present study was aimed at investigating the antinutrient and organic acid contents of three wild edible mushrooms from Russula genus as a function of their ripening stage. Fresh mushrooms Russula lepida, Russula mustelina and Russula delica were harvested from their natural habit in Brobo area’s (7°43'0" N and 4°42'0" W) in center Côte d’Ivoire. The fresh mushrooms were oven dried and ground to obtain the crude flour. Phytate and oxalate contents were investigated using standard colorimetric methods, while organic acid profiles were performed by using HPLC analytical methods. The antinutrient composition showed that the greatest content in phytates (1.60±0.10 mg/100 g) and oxalates (5.17±0.01 mg/ 100 g) were observed respectively, in R. lepida and R. mustelina immature fruiting bodies. These values are much lower than the standard safe limits. As regards organic acid profiles, they revealed the presence of at least fourteen organic acids namely benzoic, oxalic, fumaric, succinic, malic, tartaric, ascorbic, citric, lactic, adipic, propionic, formic, shikimic and acetic acids. The main organic acids in R. lepida were lactic (49.70 mg/ 100 g DW, for post-mature stage), fumaric (36.00 and 31.22 mg/ 100 g DW, respectively for immature and mature stage), citric (21.60 and 31.60 mg/ 100 g DW, respectively for immature and mature stage) and succinic (21.00 mg/ 100 g DW for post-mature stage) acids. Lactic acid (47.90 mg/ 100 g DW) was the dominating organic acid in R. mustelina at immature stage, whereas citric (30.20 mg/ 100 g DW at post-mature stage) and ascorbic acids (21.80 mg/ 100 g DW at post-mature stage) were major in R. delica. R. lepida showed the higher total organic acid contents (ranging from 113.13 mg/ 100 g in immature stage to 103.31 mg/ 100 g in post-mature stage) whatever the ripening stage. As for R. mustelina, the immature stage was better (100.02 mg/ 100 g DW), while R. delica showed better total organic acid content (83.33 mg/ 100 g DW) at post-mature stage.