Youtiao: Effect of ingredients and processing on quality attributes

Abstract

Background and ObjectivesYoutiao (oil stick), a popular food product in East and Southeast Asia, is a deep‐fried stick of wheat flour dough. The basic ingredients include wheat flour, water, leavening agent, and frying oil. The ingredients are mixed to form a dough, which is proofed and shaped before deep‐frying. There have been variations in the quality of youtiao from the market as the production is upscaling toward the industrial level. Consumers demand healthier formulations of youtiao. A better understanding of property–quality relationships of youtiao components is essential to meet these demands. This mini‐review summarizes the sensory quality and flavor attributes of youtiao. The effects of basic and optional ingredients, chemical components, and processing on the quality of youtiao are presented. Quality evaluation of youtiao and the occurrence of chemical toxins are also described. The property–quality relationships of youtiao components are discussed. Future research directions on how to improve the youtiao quality are suggested.FindingsYoutiao contains a range of chemical toxins including polycyclic aromatic hydrocarbons, acrylamide, 5‐hydroxymethylfurfural, 3‐monochloropropane‐1,2‐diol fatty acid esters, and aluminum. The textural, sensory, and chemical properties of youtiao are affected by the interactions between basic ingredients, optional ingredients, and processing operations. Suitable wheat varieties and frying oils should be chosen to make youtiao with desirable sensory properties. Optional ingredients, such as starch‐based nonwheat flours, hydrocolloids, and antioxidants, showed potential to improve various aspects of youtiao quality. Frozen dough technology is promising for industrial‐scale production of youtiao.ConclusionsVariation in the quality of youtiao from different manufacturers is large. There are many research opportunities to improve the quality of youtiao.Significance and NoveltyYoutiao represents a typical model system of deep‐fried cereal foods, which are under‐studied as compared with other cereal and grain‐based foods. This review systematically analyzed different aspects of youtiao quality for the first time, and may stimulate further interest in the studies of fried cereal and grain‐based foods.