Kesan Perencatan Fitat Terhadap Bioavailabiliti Kalsium, Ferum dan Zink dalam Produk Kacang Soya Tempatan

Abstract

This study was carried out to determine the inhibitory effects of phytate on the bioavalaibility of calcium (Ca), ferum (Fe) dan zink (Zn) in selected soy-based products. Phytate exerts its inhibitory effects on the absorption of minerals such as Ca, Fe and Zn by forming insoluble and undigestible complexes. The inhibitory effect of phytate on the bioavailability of minerals like Ca, Fe and Zn was estimated by measuring their molar ratios. Phytate content was determined by using anion-exchange method while mineral contents were determined by Atomic Absorption Spectrophotometer (AAS). Soybased products were bought from the night markets and food stall located at Cheras and Sri Rampai, Kuala Lumpur. Each samples from both location was analysed in duplicates. Results from this study showed that soy cake and all dishes containing tempe did not contain phytate content. This may due to the presence of R. oligosporus that produces phytase and hydrolysed the phytate content during the fermentation process of tempe. There were five food samples that have a phytate/Ca molar ratio > 0.24, ten food samples with a phytate/ Fe molar ratio > 1, eight food samples have a phytate/Zn molar ratio >15 and one food sample has a [phytate x Ca]/ Zn molar ratio > 200. The result of molar ratio phytate/mineral in this study estimated the low bioavailability of Ca, Fe and Zn. In conclusion, soy cake and all dishes containing tempe contained high bioavailability of minerals, while tau-hoo pok contained low bioavailability of minerals.