Development of a Quinoa-Fortified Kale Soup and Optimized Retort Sterilization Process for Elderly Nutrition

Thailand’s transition toward a super-aged society is increasing the demand for ready-to-eat (RTE) foods that meet the nutritional and texture needs of elderly consumers. This study developed a quinoa-fortified kale soup and evaluated the effects of formulation and retort sterilization on its physical, chemical, microbial, and sensory properties. Three kale-to-quinoa ratios (35:5, 30:10, and 25:15) were analyzed for protein content, chlorophyll retention, viscosity, CIE Lab* color, and total soluble solids. The 30:10 ratio was selected for sterilization at 121°C for 10, 15, and 20 min. All treatments achieved commercial sterility (F₀ = 4.43–15.22 min;