Evaluation of novel-extruding ingredients to improve the physicochemical and expansion characteristics of a corn-puffed snack-containing pearled barley.

Extruded puffed snacks are usually a highly aerated and nutrient-deficient starchy snack. In this study, a control corn-based puffed snack-containing pearled barley was supplemented with different ingredients (spirulina, polydextrose, and psyllium husk), to aid in improving both the nutrition and physical properties (e.g., expansion) of the control snack. A response surface design (D-optimal design) encompassing 27 combinations was used to investigate and understand the effects of the three different ingredients individually and in combination. The screw speed of the extruder was also chosen as a variable in the design. It was found that spirulina (a highly proteinous ingredient) at extreme levels (5%) produced a snack with a reduced expansion ratio (2.2). Combinations that incorporated the medium levels of polydextrose gave favourable expansion results (2.5) compared with the other two ingredients (spirulina and psyllium husk), the addition of polydextrose reduced the hardness of the puffed snack. This finding was supported by the textural/acoustic results which illustrated that combinations that contained polydextrose resulted in a crispier snack, i.e., maximum sound peak, 101.4 dB (sound pressure level) compared to spirulina [105 dB (SPL)] and psyllium husk [104 dB (SPL)]. Based on the information attained on the effects of the ingredients on the snack properties, optimised snacks will be generated for further investigation. [ABSTRACT FROM AUTHOR]