Enzymatic hydrolysis of edible Passiflora fruit glycosides

The combined action of Hemicellulase REG 2 and sweet almond glucosidase containing beta-D-glucopyranosidase, alpha-L-rhamnopyranosidase, alpha-L-arabinopyranosidase and alpha-L-arabinfuranosidase activities allowed release of most of the volatile compounds bound as aglycones in edible Passiflora fruits. Great variability between the four species studied, P. edulis, P. edulis f falvicarpa, P. ligularis, P. molissima, was noticed. 2,5-Dimethyl-4-hydroxy-3-(2H) furanone (furaneol) was identified for the first time in bound form in purple and yellow passion fruit. Only geraniol was identified as the aglycone in P. molissima. and no terpenol is present in the hydrolysate obtained from P. ligularis. Several terpene diols: 2,6-dimethyl-1,8-octanediol, (E)- and (Z)-2,6-dimethylocta-2,7diene-1,6-diol, 2,6-dimethylocta-3,7-dien-2,6-diol and 2,6-dimethylocta-1,7-dien-3,6-diol have been identified in both purple and yellow passion fruit and small amounts of (Z)-2,6-dimethylocta-2,7-diene-1,6-diol are present in P. molissima. alpha-Ionol derivatives oxygenated in position 3 seem to be characteristic of purple passion fruit whereas p-ionol compounds oxygenated in position 3 are the major norisoprenoids identified as the aglycone in yellow passion fruit. The bound norisoprenoid content of P, ligularis and P. molissima is low. Important concentrations of bound aromatic alcohols are found in purple and yellow passion fruit whereas phenolics can be considered as characteristic of purple varieties. (C) 1999 Elsevier Science Ltd. All rights reserved.