EFFECT OF FUNGAL PHYTASE ON DEGRADATION OF THE PHYTIC ACID DURING FALAFEL PREPARATION

Document Type : Original Article

Author

Department of Food Science and Technology, Faculty of Agriculture, Damanhour Branch, Alexandria University, Damanhour, 22516, Egypt.

Abstract

The present study aimed to investigate the enzymatic degradation of phytic
acid in faba bean cotyledons to be used in Falafel preparation. Phytase was used in
soaking water at a rate of 10 g I kg cotyledons. The volume of soaking water was
previously adjusted to be equal to the hydration coefficient of cotyledons in order to
overcome the effect of leaching out phenomenon during soaking for 12 hr 120°C.
Moreover. such an effect was investigated for fermentation step ( 180 min/37°C )
followed by frying of Falafel patties.
Data indicated that phytic acid contents (and phytate phosphorus) were
declined by 6% and 23% (untreated sample) and by 17 % and 65 %
( phytase - treated sample) after soaking and after soaking followed by fermentation,
respectively. The inorganic phosphorus increased sharply while the organic
phosphorus other than phytate phosphorus seemed to be unaffected. The dialyzed
portion of phytate on which phytase mainly acted on was 60% in raw cotyledons.
Frying process had a slight effect on the aforementioned constituents. The in vitro
protein digestibility increased si~nificantly specially for phytase- treated samples. The
sensorical properties were not deteriorated due to addition of fungal phytase. The
natural fermentation significantly affected the flavour character and overall
acceptability . The fermentation of Falafel paste up to 120 min didn't deteriorate the
quality of Falafel . Addition of such a commercial preparation of phytase during the
processing of Falafel should be taken into consideration. It may overcome the risk of
the phytic acid as an antinutritional factor and thereby increase the bioavai!ability of
phosphorus.

Keywords