The effects of ingredients and water content on the rheological properties of batters and physical properties of crusts in fried foods

This study investigated the effect of ingredients and flour/water ratio on the rheological properties of batter. Replacing part of the wheat flour present in a weak composition (W-pattern) batter with gluten yielded a higher protein concentration that renders a strong composition (S-pattern) batter. This study also tested the effects of adding HPMC to S-pattern (SH-pattern) batter and crisping agents to W-pattern (WC-pattern) batter. The S- and SH-pattern batter exhibited Bingham-pseudoplastic fluid properties in a temperature range of 5–35 °C. W-pattern batters with a flour/water ratio of 1/1.5 and WC-pattern batters with flour/water ratio of 1/1 exhibited pseudoplastic fluid properties. Adding HPMC increased the fluid consistency index (b) of batter, revealing a higher viscosity and diminished fluidity. This batter showed a higher thermal solidification temperature and increased shear modulus (G′, G″), complex viscosity and further raised the batter pick-up. The addition of crisping agents to W-pattern batter shifted solidification temperature to a lower range. In fried mackerel nuggets, the S- and SH-pattern crusts exhibited a texture that was firm and brittle, while W- and WC-pattern crusts exhibited a texture that was significantly more crisp.