Search

The ultrasonic (US)-treated batter mixtures of commercial methylcellulose (MC) as the fried potato strips' coating layer were demonstrated. The layer formed a rapid gel that absorbs the substrate's water content and related functional groups that contribute to acrylamide formation reduction. Different concentrations of MC (0.5-2.0 w/v %) mixtures were subjected to US at 20 W to evaluate coating layers' effect prior to the deep-frying process. At 1% w/v concentration batter mixture, the USMC layer reduced the highest acrylamide value. For comparison purposes, the differences in the acrylamide content of the USMC, the non-USMC and the uncoated samples were 64.7 ± 5.04, 156.4 ± 7.44 and 344.1 ± 5.39 ng g-1, respectively. The results were supported with lower oil uptake and water retention of the USMC compared with the non-USMC with the values of 2.2 g/100g and 28.6 g/100g with 5.1 g/100g and 47 g/100g, respectively.

Food hydrocolloids, i.e., hydrolyzed methylcellulose, with thermal gelation properties, are widely used as batter mixtures to coat the fried food prior to the frying process. Properties of hydrocolloids able to satisfy population’s food demand by introducing health-benefits food in conjunction with public health concerns worldwide such as obesity. To study the coating mechanism's advantages, the hydrolyzed Methylcellulose (MC) that, possessed with thermal-reversible properties, was coated onto a potato substrate and investigated along the frying process. Different MC concentration samples between 0.5-2.0 w/v% were subjected to ultrasound treatment (UT) at 20 W to improve the prepared batter mixtures' rheological behaviour and physiochemical properties of fried food. Application of UT to methylcellulose (UTMC) clearly showed a phase transition from fluid- to gel-like between 20 °C and 65 °C with the increase in the oscillation frequency and temperature ramp test. UTMC method also showed lower sol-gel transition occurrence than non-UTMC at 25 °C and 30 °C respectively, within the linear viscoelastic region. When the MC concentrations were varied, the most effective concentration for coating purposes was noticed to occur at 1.0 (w/v%) UTMC, whereby the water retention and oil uptake was reduced to 39.3% and 56.9 %, respectively, as compared to 1.0 w/v% non-UTMC formulation. The batter-coated fried food also showed a significant decrease in the acrylamide concentration. The amount of acrylamide in 1.0 w/v% MC was reduced from 156.40±7.44 ng/g to 64.8 ±5.05 ng/g in 1.0 w/v% UTMC. In conclusion, this work's findings provide further insights into the influence of hydrocolloids as an effective layer to improve the quality of the fried products.

Ultrasonic treatment (UT) effects on methylcellulose (MC) for the food coating purpose prior to deep-fat frying process of potato strips were demonstrated. Different concentration of MC (0.5–2.0 wt/vol%) solutions were subjected to UT at 20 W to evaluate the effect of UT treated coatings on rheological behavior of the coated samples and their efficiency in minimizing the oil uptake. Application of UT to methylcellulose (UTMC) clearly showed a phase transition from fluid- to gel-like between 20 and 65°C with the increasing in the oscillatory frequency and temperature ramp test of UTMC showed the sol–gel transition occurrence is lower than non-UTMC at 20 and 29°C, respectively, within the linear viscoelastic region. When the MC concentrations were varied, the most effective concentration was noticed to occur at 1.0 (wt/vol%) UTMC whereby the relative variation of water retention and oil uptake were reduced to about 49.9 and 31.0%, respectively, as compared to 1.0 wt/vol% non-UTMC formulation. Experimental results affirm that UTMC coating application can be used successively to improve rheological properties of MC by minimizing oil uptake on fried food.