Ca2+-selective electrode: A simple method to measure the phytase-aided release of bound calcium in soymilk

Fang Yang, Conglan Zhang, Qi Liu, Can Xu, Youling L. Xiong

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

Soymilk is a nutritious beverage widely consumed worldwide. However, the presence of phytic acid hinders the bioavailability of minerals, such as calcium, underscoring the necessity for dephosphorylation. The aim of the study was to develop a quick and simple method to measure the phytase-aided release of bound calcium in soymilk. Freed calcium ion (Ca2+) by the phytase treatment (maximum activity of 48U/L) at different temperatures (45-65°C) and pH (4.8-5.6) was analyzed using a calcium ion-selective electrode (ISE) that produced almost a perfect linear relationship between the enzyme activity and the concentration of free calcium (r=0.98-0.99). The free calcium concentration in untreated soymilk (31mmol/L) increased up to 77mmol/L (p<0.05) with phytase treatment. The entire range of Ca2+ liberation was sensitively quantified with the ISE indicating the feasibility of this simple method for the assessment of the efficacy of phytase to improve the bioavailability of calcium, hence, nutritional value, of soymilk.

Original languageEnglish
Pages (from-to)43-47
Number of pages5
JournalJournal of Food Composition and Analysis
Volume39
DOIs
StatePublished - May 1 2015

Bibliographical note

Publisher Copyright:
© 2014 Elsevier Inc.

Keywords

  • Atomic absorption spectrophotometry
  • Calcium
  • Electromotive force
  • Food analysis
  • Food composition
  • Ion-selective electrode
  • Phytase
  • Phytic acid
  • Soymilk

ASJC Scopus subject areas

  • Food Science

Fingerprint

Dive into the research topics of 'Ca2+-selective electrode: A simple method to measure the phytase-aided release of bound calcium in soymilk'. Together they form a unique fingerprint.

Cite this