Examinando por Autor "Takhar, Pawan"

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  • Miniatura
    Ítem
    Effect of Microwave Frying on Moisture Transport and Oil Uptake in Fried Foods
    (Zamorano: Escuela Agrícola Panamericana, 2019., 2019) Luna M., Efrain E.; Acosta, Adela; Takhar, Pawan
    The process of deep-frying potatoes dates from years around 1700 A.D. Despite being the most important method of preparations, deep-frying has remained the same since its origins. In the following study, microwave frying was compared against conventional frying at 177, 185 and 191 °C, furthermore, the addition of microwave energy after 1 minute of conventional frying was tested as well. Two different parameters were analyzed for each treatment: Oil Uptake and Moisture Transport. The effects of microwave energy in oil uptake were analyzed by measuring final fat content through Soxhlet extraction. Moisture transport was analyzed by measuring initial and final moisture content by freezing the samples in liquid nitrogen and then heating samples at 105 Celsius, with a posterior measurement weight loss. Microwave energy was found to increment moisture loss and oil uptake in the process of deep frying. It is speculated that microwave energy increases the energy inputted into the system, and thus it boosts water loss and therefore oil uptake after the frying finished. Temperature showed to have an impact in water loss but not in oil uptake. Said phenomenon can be explained by the fact that most of the oil absorbed by potatoes is absorbed after the frying process has been done. Further studies need to be done in order to give a deep and clear explanation of the effects of microwave energy on the complex process of deep frying.
  • Miniatura
    Ítem
    Microstructural Mechanical Texture Evaluation of Food Materials Using Nanoindentation as a Function of Drying Time (Case Study: Baking of Cookies)
    (Zamorano: Escuela Agrícola Panamericana, 2023) Cisneros M., Karla C.; Takhar, Pawan; Acosta, Adela
    The baking process alters food product mechanical properties due to phase movement and the application of heat. This leads to the formation of solid wall and porous channel networks at a microscale which have an impact on the final product’s macroscale quality. In fact, microstructure cell wall strength is closely related to the micromechanical properties and texture within the range of 0.1-100 µm. Despite this, limited research has been conducted on the micromechanical properties of baked goods. The aim of this study was therefore to investigate the microscale behavior of the mechanical properties of cookies using nanoindentation during baking time. Based on the loading and unloading curves of the nanoindentation test, as well as the Oliver and Pharr equations, the micromechanical properties of hardness, stiffness, and Young’s modulus were calculated along with the determination of the samples’ moisture content. All properties increased during baking compared to the early stages of the process. The lowest values were found in the 10-minute sample for all micromechanical properties. Subsequently, there was an increase at 15 minutes that remained without significant differences for the rest of the baking process. Moisture content showed significant differences from 10 to 30 minutes, followed by stabilization until the 60 minutes, where there was a significant reduction. Considering the present trends, the potential relations of the micromechanical properties, moisture content and ingredients interactions were explored. This reveals that baking process is a dynamic system with continuous changes, driven by the intricate interplay among the diverse ingredients.