Effects of tea polyphenol ester with different fatty acid chain length on camellia oil-based oleogels preparation and its effects on cookies properties.

Oleogels were prepared by emulsion template method through 3.0% tea polyphenol ester (Tp-ester) particles with four fatty acid chain length (Tp-laurate [C12], Tp-myristate [C14], Tp-palmitate [C16], and Tp-stearate [C18]) and 2.5% citrus pectin, and then were used in cookie production as fat replacer. Effects of the fatty acid chain length on the hydrophilicity/hydrophobicity of Tp-ester, on the appearance, microstructure, and firmness of dried products, on rheological features of oleogels, on the dynamic viscoelasticity and textural characteristics of cookies dough, and on cookies qualities were revealed. With the increase in the fatty acid chain length, the θo and θw values of four Tp-esters increased, the firmness of dried products with smaller oil droplets got larger, and the gel intensity of oleogels increased, but the quality scores, spread ratio, and break strength of the cookies did not change significantly. With the increase in the replacement levels of butter with oleogels, the harder cookie dough with weaker gel strength and the softer cookies with lower hedonic scores and crispness were found. At 25% and 50% replacement levels, cookies prepared with oleogels using Tp-palmitate or Tp-stearate particles exhibited similar hedonic scores, break strength, spread ratio, and storage stabilities to that of butter cookies. PRACTICAL APPLICATION: Cookies are relished by all age groups due to their taste and crispness, but include high content of saturated fatty acids that are harmful to people's health. The result of this study will help the industry to better design cookies through oleogels with tea polyphenols ester and pectin, and will provide healthy cookies with little or no butter for consumers.