Question

Olestra^®is a fat-based fat substitute that became available in snack foods such as potato chips in 1998. Previous fat substitutes were carbohydrate-based or protein-based mixtures that did not give as good a sensation in the mouth and are not suitable for frying. With Olestra^®, the glycerol molecule of a fat is replaced by sucrose (p. 1237). In Olestra^®, the sucrose molecule has six, seven, or (most commonly) eight fatty acids esterified to its hydroxy groups. The fatty acids come from hydrolysis of vegetable oils such as soybean, corn, palm, coconut, and cottonseed oils. This unnaturally bulky, fat-like molecule does not pass through the intestinal walls, and digestive enzymes cannot get close to the sucrose center to bind it to their active sites. Olestra^® passes through the digestive system unchanged, and it provides zero calories.Draw a typical Olestra^® molecule, using any fatty acids that are commonly found in vegetable oils.

Short answer

Olestra^® is a fat-based fat substitute that became available in snack foods such as potato chips in 1998. Previous fat substitutes were carbohydrate-based or protein-based mixtures that did not give as good a sensation in the mouth and are not suitable for frying. In Olestra^®, the sucrose molecule has six, seven, or (most commonly) eight fatty acids esterified to its hydroxy groups. The fatty acids come from hydrolysis of vegetable oils such as soybean, corn, palm, coconut, and cottonseed oils. This unnaturally bulky, fat-like molecule does not pass through the intestinal walls, and digestive enzymes cannot get close to the sucrose center to bind it to their active sites. Olestra^® passes through the digestive system unchanged, and it provides zero calories.

Step-by-step solution

Step-1. Olestra®:

Olestra^® is a fat-based fat substitute that became available in snack foods such as potato chips in 1998. Previous fat substitutes were carbohydrate-based or protein-based mixtures that did not give as good a sensation in the mouth and are not suitable for frying. In Olestra^®, the sucrose molecule has six, seven, or (most commonly) eight fatty acids esterified to its hydroxy groups. The fatty acids come from hydrolysis of vegetable oils such as soybean, corn, palm, coconut, and cottonseed oils. This unnaturally bulky, fat-like molecule does not pass through the intestinal walls, and digestive enzymes cannot get close to the sucrose center to bind it to their active sites. Olestra^® passes through the digestive system unchanged, and it provides zero calories.

Step-2. Structure of olestra:

The structure of olestra is analogous to that of triglycerides, but olestra differs from triglycerides in that it consists of a core of sucrose, rather than of glycerol, esterified with six to eight rather than three, fatty acid chains. Fatty acids used to make olestra can be derived from any vegetable oil. Oleic, lauric, myristic, linoleic, linolenic fatty acid chains are involved in the structure of olestra.