Crispness is one of the most important and desirable textural characteristics that signify freshness and high quality in breaded fried foods. Though many approaches to instrumental measurement of crispness have been made, the best measurements are still inconclusive. There is no reliable method available that can accurately measure and quantify crispness in breaded fried foods. In this study, the mechanical and ultrasonic techniques were used to determine crispness in breaded fried chicken nuggets under different storage conditions. The mechanical measurements have been made, using an Instron universal testing machine. An ultrasonic non-destructive evaluation system was used to measure ultrasonic properties of breaded friend chicken nuggets. A pair of dry-coupling 250-kHz ultrasonic transducers was used to perform the ultrasonic transmission through the breaded fried chicken nugget. The equipment set up was in the through-transmission mode because breaded fried chicken nugget is highly attenuative material. A sensory panel of eight members was trained to evaluate crispness in breaded fried foods. Panelists rated crispness on a nine-point category scale (1 = not crisp/soggy, 9 = very crisp). Sensory crispness values for breaded fried foods under different storage conditions were obtained. Ultrasonic velocity, transmission loss, peak frequencies and its energies, peak force and total energy were determined for each tested product. Correlation between sensory crispness and instrumental parameters suggests that the ultrasonic method can be used to evaluate crispness. The ultrasonic velocity had high correlation with sensory crispness (R2 = 0.83). This indicates that sensory crispness could be reasonably well predicted by the ultrasonic velocity. / Master of Science

Fried foods are delicious and enjoyed by almost everyone. However, they are not the healthiest foods to eat because of the amount of oil they contain. This thesis, sponsored by Moaero Company founder, Mr. Harrish Bhutani, intends to determine whether a simply designed centrifuge system can remove a reasonable amount of oil from fried foods after it has been deep fried without adversely affecting the texture of the fried food. Due to a large variety in the texture as well as the type of fried foods, and in order to keep the scope of this thesis more focused and feasible, the focus of this investigation will be French fries. Three variables are tested: the type of fry, the angular velocity of the centrifuge, and the time spent in the centrifuge. Multiple designs for the centrifuge system were made on SolidWorks. Engineer Equation Solver (EES) was used to aid steady state and transient heat transfer calculations. Minitab was used for statistical analysis. The impact of various parameters on the change in mass of the French fries, as a measure for evaluating the oil content, were studied. The results indicate whether a centrifuge will remove a reasonable amount of oil while also considering the integrity of the fries. The study concludes that centrifugation is be a cost-effective method for removing oil from fried foods.