SACE Stage 2 Nutrition Basics Practice Exam

The process of lipid digestion begins in the mouth with the action of lingual lipase. Lingual lipase is an enzyme secreted by the salivary glands, specifically the von Ebner's glands, and is responsible for initiating the breakdown of triglycerides into diglycerides and free fatty acids. Although the primary digestion of fats occurs in the small intestine, lingual lipase plays a crucial role in the early stages of lipid digestion, especially for infants who rely on this enzyme to digest milk fats.

In contrast, other options like salivary amylase primarily focus on carbohydrate digestion, while bile salts and gastric juices are involved in lipid breakdown further along in the digestive process, specifically in the stomach and small intestine. Thus, lingual lipase is the key enzyme that starts the process of fat digestion right at the beginning of the digestive tract in the mouth.