Nixtamalization Effects on the Contents of Phytic Acid in the Varieties of Maize and the Bioavailability of Iron in Nixtamalized Maize to Young Pigs

Abstract

The present study was conducted to investigate the effect of nixtamalization process on the phytic acid loss of maize and the subsequent influence on iron bioavailability of the iron-deficient piglets. Two experiments were conducted to achieve the objective: in the first step, three types of maize varying in phytic acid contents were processed by five lime concentrations treatment (0, 0.6, 1.2, 1.8 and 2.4%), four cooking duration (0, 45, 60 and 75 min) and thereafter soaking for five periods (0, 2, 4, 6 and 8 h) to optimize the best nixtamalization process parameter based on the maximum loss of phytic acid. In the second study, weaning piglets suffered iron-deficient were fed two diets: either lime-cooked maize produced by optimal parameter (NTM) or non-nixtamalized maize as control (CON), to examine the effects of the nixtamalization on the iron bioavailability, iron status and growth performance. The results showed that: (1)The greatest phytic acid loss of three types of maize and their processing parameters (lime concentration, cooking duration and steeping duration) were 17.4% (1.2%, 75 min and 4 h), 14.9% (1.8%, 75 min and 4 h) and 27.5% (1.8%, 75 min and 4 h), respectively. (2) The hemoglobin concentration (Hb), Packed Cell Volume (PCV), Red Blood Cell count (RBC) and Hemoglobin-Fe (Hb-Fe) content were improved in the NTM piglets compared with CON piglets (p<0.05). (3) The Average Daily Gain (ADG) and Average Daily Feed Intake (ADFI) at D 14 and D 28 were higher in NTM than CON group (p<0.05). These results demonstrated that nixtamalization process parameter should be varying according to the phytic acid contents of the maize to break down the maize phytic acid effectively. Above all, the lime-cooked maize could enhance the iron status and the growth performance of weaning piglets suffered iron-deficiency anemia, thus could be considered as an effective intervention protecting the consumer (including human and animal) from suffering iron deficiency.