Effect of calcium hydroxide on pasting, thermal, and wateradsorption behavior, and the flow properties of nixtamalized corn flour

摘要

Nixtamalized corn flour (NCF) has gained favor worldwide due to the growing popularityof Mexican cuisine. This research evaluates the effect of the amount of calciumhydroxide (Ca(OH)_2) employed during the nixtamalization on the water-adsorption,thermodynamic, and flow properties of NCF. In addition, NCF pasting and thermalproperties were evaluated to relate bulk-powder properties to wet-dispersion conditions.Ca(OH)_2 amounts of 1.5 and 2.0% induced higher ash and calcium content aswell as lower fat and protein content. Also, pasting properties and gelatinizationenthalpy (ΔH_(gel)) values, in addition to yellowish NCF, were related to Ca(OH)_2 concentration.With the independence of the Ca(OH)_2 amounts employed, no importantdifferences in the equilibrium's moisture content, as well as a negligible effect of temperatureon adsorption behavior, were observed. For prepared NCF, the moisturecontent corresponding to minimum integral entropy was not observed within therange of the aw analyzed; thus, GAB parameters are more reliable for suggesting thestorage conditions. NCF with a low amount of Ca(OH)_2 exhibited higher values ofmean caking strength (≈1.81 N) and cohesiveness index (≈13.99 × 10~（-5） N m g~（-1）), inaddition to higher resistance to flow. Therefore, the amount of Ca(OH)2 positivelyinfluenced flow properties, whereas wet-dispersion properties such as lower maximalpeak viscosity and ΔHgel values were obtained.