Abstract: Increasing the amount of protein in snack foods can add to their satiating ability, which aligns with many health-based trends currently seen in the food industry. Understanding the effect of adding high levels of protein in a food matrix is essential for product development. The objective for this research was to determine the effects of varying protein type and level on the sensory-related aspects of a model extruded snack food. Independent variables in the design of the snacks were the level of total protein and the protein type in the formulation. The level of protein ranged from 28% to 43% (w/w) in 5% increments. The protein type varied in the ratio of whey to soy protein ranging from 0: 100 to 100: 0, in 25% increments. Descriptive analysis was conducted on the samples to profile their sensory characteristics. Protein type was found to be the predominant variable in differentiating the sensory characteristics of the samples. Soy protein imparted nutty, grainy aromas-by-mouth, and increased expansion during processing, resulting in a lighter, crispier texture. Whey protein imparted dairy related aromas-by-mouth and inhibited expansion during processing, resulting in a more dense, crunchy texture. Separately, 100 consumers rated their acceptance of the samples using the 9-point hedonic scale. It was found that protein type was also the predominant variable in affecting acceptance, with some clusters of consumers preferring samples comprised of soy protein, and others preferring samples with whey. Food product developers can use these findings to predict changes in a similar food product by varying protein level or protein type.
Practical Application: This work shows how the perceivable appearance, aroma, and texture characteristics of puffed snack foods change when adding protein or changing the protein type. The type of protein incorporated was shown to have major effects on the characteristics of the snacks, partially because of their impact on how much the snacks puffed during processing. The findings from this research can help develop acceptable products that incorporate high levels of protein to be aligned with current health trends in the market.