PHYSICAL AND SENSORY EVALUATION OF CORNFLAKES CRISPNESS

Three compression systems were used to study the mechanical behavior of cereal flakes of 13 commercial cornflakes brands that were also evaluated by sensory analysis. A Kramer cell, on an Instron testing machine, allowed to simultaneously record force in the range 0-5 kN and sound in the frequency domain 0-22 kHz during the crushing of 20 mm thick beds of cereal flakes tested in bulk. It was shown to be the most reliable and efficient method for discrimination. Acoustic emission has been shown to correlate with crispness perception. Uncrispy-perceived products emitted signals with lower average amplitude and higher peaks, at low frequencies - less than 3 kHz - and opposed a high mechanical resistance to compression. On the opposite, the crispiest flakes emitted sounds with larger average amplitude, fewer high peaks and uniformly distributed in the frequency domain with a moderated mechanical resistance. Links between texture perception and structure were improved and results validated the developed system, which may be used for quality evaluation of particle solid foam foods.