Rheology of Muffin Batters by Line Spread Test and Viscosity Measurements
This work was aimed to quantify the flow properties of muffin batters by Line Spread Test (LST) and to establish a valid correlation between their line spread distance and viscosity. LST is a quick and inexpensive method for comparing relative viscosities of food slurries or a solid-liquid suspension type of food materials, like muffin batters. The rheological proper ties of muffin batters formulated using gluten free flours were studied. Five different combinations of rice flour and quinoa flour were studied as gluten free flour combinations. Control muffin batters were formulated using 100% wheat flour, which is a gluten positive flour. Density, pH, line spread distance and viscosity were measured for all six batter formulations including control. All tests were performed in triplicate and all data were analyzed statistically. In general, gluten free flour reduced the density and increased the acidity of muffin batters. Whereas, line spread distance was increased and viscosity was decreased with replacement of quinoa flour to rice flour in the muffin batters. A valid correlation between line spread distance and viscosity was observed. The inverse of LST in cm/sec was observed to be close to the viscosity in poise for muffin batters in this study.
Development of reduced-fat muffins by the application of jet-impingement microwave (JIM) technology
Abstract This work aimed to study the impact of air jet impingement and microwave combined (JIM) technology to produce full-fat (FF) and reduced-fat (RF) muffins, compared to conventional oven (CO). Batters and muffins were physicochemically (rheology, height, weight loss, moisture content, colour (crumb, crust), texture and visual analysis) and sensorially characterised. Results showed that JIM technology can produce muffins with similar heights to those of CO, even after reducing fat. Regarding the toasting level, the application of different JIM processes allows to control the toasting level in FF and RF samples, which is also perceived by the trained panel. JIM RF muffins were also more humid and elastic. However, JIM is not able to improve the oil taste or the velvety perception of RF muffins. According to these results, JIM stands as a promising technology to obtain high quality FF and RF muffins while saving time and avoiding the use of fat substitutes.
Super-resolution of overlapped waves in time and frequency domain in a directional borehole radar measurement
The Multiple Signal Classification (MUSIC) algorithm is modified in order to resolve multiple waves and to estimate reflection points in 3-D space. This algorithm is suitable for directional borehole radar with a circular dipole array antenna. Making use of the spatial frequency difference of acquired array signals, the signals are decorrelated, and the 3-D MUSIC algorithm is applied. The time domain signals of the singlehole array-type borehole radar are used in order to form a measurement vector in the MUSIC algorithm. A computer simulation confirms that the proposed algorithm may estimate the directions of arrival (DOA) for three signals. Applying the proposed algorithm to field experiment data successfully estimates the DOA of a reflected wave from a fracture in rock.