Different methods for improving texture profile and water retention of scrambled egg patties after high-pressure high-temperature (HPHT) treatment were evaluated as part of a feasibility study for the development of shelf-stable egg products. Four formulations, a basic one, 2 with xanthan gum, 1 with cheese, were compared after HPHT treatment by analyzing texture profile and degree of syneresis. The effects of water addition of 0% to 15%, 3 levels of vacuum packaging, 4 preheating rates, and 2 HPHT conditions (700 MPa/105 °C/5 min and 700 MPa/121 °C/3 min) on texture and water retention of egg patties were also compared for selected formulations. Patties reformulated with xanthan gum and cheese resulted in at least a 30% reduction in hardness, cohesiveness, and water loss. Use of low vacuum packaging in less porous patties modified with xanthan gum maintained original texture values after 700 MPa/105 °C/5 min. Addition of water into the defrosted structure increased water holding capacity and maintained hardness within its standard value after pressurization at 105 °C and 121 °C. Most texture descriptors and syneresis did not change significantly with preheating rates after HPHT treatment. Tested mechanisms for texture and water retention improvement of HPHT treated patties can contribute to meeting quality requirements not fulfilled by conventional thermal processing for the development of shelf-stable scrambled egg products.