Water Absorption Characteristics of Obatanpa and Mamaba Maize Hybrids (Zea mays)

Abstract

Water absorption characteristics of two newly-released maize hybrids, Obatanpa and Mamaba, during soaking were measured at four temperatures of 30, 40, 50 and 60ºC. The absorption kinetics followed the Fick's law of diffusion during the first hours of soaking. The values determined for water diffusion coefficients varied from 7.31 x 10 -12 to 9.33 x 10 -12 m 2 /s and from 6.30 x 10 -12 to 8.25 x 10 -12 m 2 /s for Obatanpa and Mamaba respectively. An Arrhenius-type equation was used to relate the diffusion coefficient of Obatanpa and Mamaba to temperature, and the energy of activation for Obatanpa and Mamaba was estimated. The values determined were 6.54 kJ/mol and 6.82 kJ/mol for Obatanpa and Mamaba respectively.

Modelling the Water Absorption Characteristics of Different Maize (Zea Mays L.) Types during Soaking

“…The water absorption rate increased with increase in soaking temperature as this is due to increased water diffusion rate. Similar observations have been reported (Sopade and Obekpa, 1990;Lu et al, 1994;Sanni et al, 2003;Shittu et al, 2004;Addo et al, 2006;Addo and Bart-Plange, 2009;Tunde-Akintunde, 2010;Agu et al, 2013;Udoro et al, 2014). However, the rates of increment between the initial and final soaking temperatures were not the same for the different maize types.…”

“…1(a -f). The maize samples exhibited the typical water absorption characteristic as previously described for other food materials (Shittu et al, 2004;Addo et al, 2006;Peleg, 1988;Sopade et al, 1992;Hung et al, 1993;Maharaj and Sankat, 2000). There is an initial very rapid rate of water absorption which was later followed by a slower rate in the later stages as the saturation moisture content (SMC) was approached at all four temperatures.…”

“…Addo et al (2006) made similar observation when they studied the water absorption characteristics of maize (Obatanpa and Mamaba) as well as Shittu et al (2004), and Ali et al (1974) when they studied the water absorption characteristics of rice. The soaking water temperature and concentration of starch in food material determines starch behaviour in water (Addo et al, 2006;Tunde-Akintunde, 2010). Generally, starch grains have very little uptake of water at room temperature and their swelling power is also small.…”

“…Researchers have demonstrated that increasing the temperature of the soaking medium is an effective way to accelerate water uptake by various seeds and hence, shorten the soaking time (Quast and da Silva, 1997;Abu-Ghannam and Mckenna, 1997). Also, many studies have reported the influence of temperature on moisture diffusivity into soybean, amaranth grains and maize kernels, respectively (Hsu, 1983;Calzetta-Resio et al, 2003;Addo et al, 2006). However, effects of varietal variations and processing variables on the rate of water uptake and moisture diffusivity in some cereals grown in Nigeria, such as maize and its processed form have not been clearly established.…”

Análise da hidratação do arroz na parboilização

“…Muitos pesquisadores têm verificado que a dependência do coeficiente efetivo de difusão com a temperatura pode ser expressa por meio da representação de Arrhenius (RESIO; AGUERRE; SUAREZ, 2003; ADDO; BART-PLANGE; DZISI, 2006;SUAREZ, 2007;GINER, 2007;SANTALLA, 2007).…”