Formulation and characterisation of fruit- and vegetable-based gel/paste for potential application in food 3D printing

One of the major barriers to developing food three-dimensional (3D) printing for personalised nutrition applications is the lack of food materials that can maintain structural integrity, nutritional adaptability, and sustainability. The present work addressed these challenges by creating and evaluating the gel paste from selected fruit and vegetable ingredients for food 3D printing applications. The main ingredients included high-fat avocado, fermented black garlic, lemon juice, celery, potato starch (PS), and xanthan gum (XG), which were used as thickeners. Optimal paste formulations offered robustness for 3D shape and form while maintaining desired nutritional content. The present work then developed four different paste types, containing different hydrocolloid compositions for 3D printing via a 0.5 mm syringe for quick extrusion testing. Analysis involved physicochemical parameters such as water content (WC), texture, antioxidant activity, carbohydrates, and vitamin C. Results indicated that moisture content played a crucial role in the structural stability of the paste, with the type 3 formulation (5% PS and 2% XG) demonstrating optimal moisture balance and structural integrity. Texture analysis indicated that type I pastes, which were composed of 3% PS and 1% XG, exhibited optimal hardness (7.427 N) and adhesiveness (-5.341 N), alongside adequate WC (83.37%) for effective extrusion and 3D shaping. Nutritional analysis indicated that the avocado-rich paste (type IV) had the highest antioxidant concentration, whereas the black garlic-rich paste (type I) exhibited the highest sugar content. The paste rich in lemon juice (type II) offered the highest vitamin C concentration, an important enhancement to nutritional value. The present work demonstrated the possibility of designing nutrient profiles for food 3D printing that enable novel culinary use and personalised nutrition. The findings would contribute to the field of food technology, with an emphasis on personalised nutrition.