Preparation and characterization of low oil absorption corn starch by ultrasonic combined with freeze–thaw treatment

•

Combined ultrasonic and freeze–thaw pretreatment significantly reduced oil absorption of corn starch.

•

The combined treatment increased the density of corn starch granules.

•

The combined treatment increased the short-range order of cornstarch.

•

Modified starch could be used in low-fat fried food processing industry.

This study investigated the effects of ultrasonic, freeze–thaw, and combined pretreatments on corn starch oil absorption. Low-field nuclear magnetic resonance (LF NMR) was used to study the oil absorption changes after frying of corn starch (CS) subjected to different treatments. The structural characteristics of samples were evaluated using various techniques. Scanning electron microscopy, contact angle, and particle size analysis showed that corn starch subjected to combined ultrasonic and freeze–thaw treatment generated larger, coarser particles with a denser structure. Furthermore, X-ray diffraction, Fourier transform infrared spectroscopy, and differential scanning calorimetry showed that combined treatment improved the order and thermal stability of CS molecules, thereby inhibiting oil absorption during frying. The results showed that combined ultrasonic and freeze–thaw pretreatment significantly reduced the oil absorption of corn starch before and after frying.

Effects of beer-battering on the frying properties of rice and wheat batters and their coated foods

BACKGROUND

Beer in batter formulation or beer-battering has been popular in fried food recipes, but the topic is rarely reported in scientific journals or the claims substantiated with reliable studies. In this research, we prepared and characterized rice and wheat batters with and without using beer to replace water in the formulation. We studied and provided data on the effect of beer on the frying properties of batter and its coated foods.

RESULTS

With beer in the formulation, oil uptake of fried batters generally increased by up to 18%. Instrumental textural analyses indicate that beer-battering treatment generally decreased the hardness, increased the fracturability and improved the crispness of the fried batters. Sensory evaluations show similar trends, though to a lesser extent, that fish and onion rings coated with batters were softer but crispier with beer than without.

CONCLUSION

In general, beer-battering caused an increase in the oil uptake of the batter during frying. It also made the texture of fried batters slightly softer and crispier. The effects are more pronounced for rice batters than wheat batters.