Phytic Acid in Brown Rice Can Be Reduced by Increasing Soaking Temperature

Area of Science:

• Agricultural Science
• Food Science
• Biochemistry

Background:

• Phytic acid (PA) in seeds inhibits mineral absorption by chelating essential minerals.
• Degradation of phytic acid is crucial for enhancing mineral bioavailability, particularly in rice.
• Germinated brown rice (GBR) is recognized for improved nutrient availability and health benefits.

Purpose of the Study:

• To investigate the effect of soaking temperature on phytase activity and phytic acid content in germinated brown rice (GBR).
• To determine the impact of germination conditions on zinc (Zn) bioavailability in brown rice.

Main Methods:

• Rice seeds were soaked at different temperatures (30°C and 50°C) for 36 hours.
• Phytase activity and phytic acid content were measured.
• Zinc (Zn) content and total daily absorbed Zn (TAZ) were analyzed.

Main Results:

• Rice phytase exhibited thermostability, with optimal activity at 50°C.
• Soaking at 50°C for 36 hours significantly increased phytase activity and decreased phytic acid content compared to 30°C.
• Germination at 50°C resulted in higher TAZ values for zinc compared to 30°C, although total Zn content did not differ.

Conclusions:

• Seed germination and soaking at elevated temperatures effectively reduce phytic acid in brown rice.
• Optimizing germination temperature is a promising strategy to enhance mineral bioavailability in brown rice.
• GBR produced under optimized conditions offers improved mineral absorption and potential health advantages.