Food texture is defined as a group of physical properties derived from food structure that can be sensed by elements of the oral and pharyngeal cavities (Paik & Nam-Jong, 2020).

Viscosity refers to the thickness or the “resistance to flow” of a substance. Foods and fluids that are thinner have lower viscosity, and those that are thicker have higher viscosity. Looking at liquids, for instance, water has a low viscosity, and olive oil has a high viscosity.

Food-extrinsic factors are influences on how people perceive and evaluate a food item that come from outside the food itself. Food-extrinsic factors include food packaging, labelling, branding, price of the food item, cultural associations and meaning of the food item, background music, temperature, the overall context or the environment in which the food is consumed, and many others (Wang et al., 2019).

Food-intrinsic sensory factors are characteristics of a food item that human senses can perceive. These include the color of the food product, its texture, viscosity, etc. The taste and smell of the food item are the core food-intrinsic factors in most cases.

Free radicals are reactive molecules with unpaired electrons, causing them to seek stability by taking electrons from other molecules. This process, called oxidative stress, can damage cells and is linked to aging and diseases. Antioxidants neutralize free radicals by donating electrons, preventing harm.

Fullness hormones induce a feeling of satiety and reduce the desire to eat. Cholecystokinin (CCK) and leptin are examples of fullness hormones.