DEVELOPMENT OF A MULTIFUNCTIONAL COOKING APPLIANCE: EVALUATION OF FOOD QUALITY INDEXES AND COOKING FUNCTIONS.

Household appliances are essential to modern living, simplifying daily tasks and enhancing quality of life. This PhD project addresses evolving consumer demands for multifunctional cooking appliances that optimize time, space, and energy consumption while delivering high sensory and nutritional food quality. The research aimed to design and develop a versatile appliance capable of performing wide-ranging cooking methods, replacing multiple standalone devices, and supporting sustainable cooking practices. The study adopted a multidisciplinary approach, combining expertise in food technology and engineering to evaluate and optimize cooking methods. Key physical, chemical, sensory, and nutritional parameters were identified and standardized to assess food quality across different cooking techniques. Experimental work was structured into three main work packages (WPs), focusing on distinct cooking methods and representative food matrices. WP1 investigated high-temperature pizza cooking, comparing the prototype multifunctional oven to conventional ovens and dedicated pizza ovens. An automated image analysis method was developed to objectively measure colour changes, enabling precise monitoring of pizza quality during baking. Results showed that high-temperature cooking (450°C) achieved pizzeria-style quality with optimal moisture retention and crust browning. Medium-temperature cooking (310°C), developed for the prototype oven, yielded similar moisture levels with reduced thermal damage, while low-temperature cooking (250°C) resulted in suboptimal crust development. WP2 focused on air-frying, both in dedicated appliances and in a prototype oven, evaluating the crispness of breaded foods (chicken nuggets) using a mechanical-acoustic analysis method. This approach combined auditory and mechanical measurements to closely approximate sensory perception. Findings demonstrated that both air frying and oven air-frying cooking could achieve the desired sensory and physicochemical properties of chicken nuggets, with low levels of thermal damage byproducts. WP3 explored the feasibility of low-temperature long-time (LTLT) cooking using convection air in prototype oven versus water bath methods and traditional cooking techniques. Quality attributes of animal products (tenderloin beef and salmon) and vegetable products (carrots) were assessed. LTLT air cooking of animal products showed potential for achieving tenderness and oxidative stability comparable to water bath methods, with reduced weight loss. Carrots exhibited better moisture retention and nutrient preservation in water baths, while air method maintained firmer textures. However, extended cooking times remain a limitation, particularly for air-based methods. The project included the optimization of operating algorithms and the integration of intelligent control systems to ensure precise temperature regulation and cooking efficiency. By addressing consumer preferences for convenience, health, and sustainability, the multifunctional appliance is designed to reduce energy consumption, minimize food waste, and eliminates the need for multiple devices in modern kitchens. This research findings provide valuable insights into the development of innovative cooking technologies, contributing to a sustainable and efficient approach to home cooking.