An ISO-Protein Model Food System for Evaluating Food Texture Effects

Abstract

Perceptions of food quality, acceptability and satiety are often driven by food texture. It is hypothesized that food texture alters satiety by adjusting eating rate and enjoyment; however, few studies have evaluated wide ranges of food textures with standardized nutritional compositions. The goal of this study was to formulate and characterize a set of isocaloric, macronutrient-matched model foods with varying textures. Six distinct food textures were produced by varying the extent and type of aggregation of 11% whey protein isolate solutions. Textures were grouped into fluid-like (fluid, thin and thick semisolids) and solid-like (three soft solid gels) based on rheological and sensory properties. Increasing sample mechanical stiffness coincided with increasing cohesiveness in fluid-like textures and decreasing cohesiveness in solid textures; total oral manipulations increased with increasing stiffness. Trends in sensory cohesiveness reflected that solid textures are fractured with the molars while fluid-like textures are manipulated by tongue and jaw movements. These model foods demonstrated properties in the range of commercial food products. They are applicable to investigating structural mechanisms responsible for texture and satiety. A scheme was developed that outlines structural breakdown and coinciding perception of textural properties during oral processing. Practical Applications Understanding the multidisciplinary relationships among food structure, texture, sensory perception, satiety and nutrient availability are fundamental in the formulation of healthy and enjoyable food products. However, the selection of products to evaluate the role of food structure upon texture and health is often difficult due to variations in macronutrients, total calories, and sample volume. This research provides a nutritionally standardized model food system that spans a textural spectrum of fluids, semisolids, and soft solids. The basic model foods presented here can be used to establish fundamental relationships between food structure and physiological outcomes. Additionally, these model foods can easily be reformulated to represent more complex structures (e.g., mixed gels, emulsions) or to evaluate the effects of added flavor or color.