Multi-Response Optimization of Formulation and Processing Parameters for a High-Protein Beef-Based Snack to Enhance Mechanical Crispiness, Acoustic Crispiness, and Protein Digestibility

This study aimed to optimize the formulation and processing parameters of beef-based chips to maximize textural properties and protein digestibility using response surface methodology (RSM) with a central composite design. Statistical models were developed to predict the effects of beef powder incorporation level (%), extruded sheet thickness (mm), and baking time (min) on the mechanical crispiness, acoustic crispiness, crispiness acceptability, and in vitro protein digestibility of the chips. Optimization predicted that formulations consisting of beef powder at 65.8%-67.7%, a baking time of 14.0-14.8 min, and an extruded sheet thickness of 1.0 mm would fall within the optimization criteria for the dependent variables. The predictive models' accuracy was validated. Validation data further indicated that the crispiness acceptability of the optimized beef chip (67.5 ± 1.3) was significantly higher than that of the non-optimized beef chip (60.8 ± 3.3). Micro-CT analysis was conducted as a post-optimization experiment to evaluate the microstructural attributes of the optimized beef chip compared with a non-optimal beef chip and a commercial potato-based chip. The micro-CT results further exhibited the impact of pore characteristics, matrix compaction and spatial distribution on textural characteristics. The 2D and 3D micro-CT images of the optimal beef chip show smaller, more connected pores than those of the non-optimal beef chip, and the optimal beef chip's pore connectivity more closely resembles that of a commercial potato-based chip. These optimization and post-optimization findings provide a scientifically validated strategy to enhance the textural properties and protein quality in innovative beef-based chips, offering a strong foundation for future functional snack innovations. PRACTICAL APPLICATIONS: This study optimized the formulation and processing parameters for a high-protein beef-based chip to enhance mechanical crispiness, acoustic crispiness, crispiness acceptability, and protein digestibility. The use of beef powder as the primary ingredient improves the protein intake while offering opportunities for value addition to underutilized raw materials. The integration of optimal processing parameters further ensures maximized textural quality while maintaining high protein digestibility, making the product competitive with commercially available potato-based chips. This optimized product can be positioned in the functional snack market, providing a nutritious, convenient and consumer-acceptable alternative to conventional starch-based chips, which the food industry can commercialize. However, before commercialization, further studies are required to evaluate the consumer acceptance, product safety, shelf-life testing and product cost.