Evaluation of the Crispness of Porous Foods Using the Acoustic Emission Technique

Abstract

The acoustic emission (AE) technique was used to develop a method for the objective evaluation of the crispness of porous foods. The crispness of six types of commercial porous foods was changed by controlling their moisture contents at six levels by varying the humidity (i.e., dry, 22, 43, 56, 68, and 81 % relative humidity) of the storage environment at 25 °C. As the crispness of a sample with high water activity (a w ) was expected to deteriorate, the physicochemical, mechanical, and acoustic characteristics of a w -controlled food samples were evaluated. The a w had no influence on the shape and porous structure of the foods. However, the number of force peaks in the uniaxial compression test appeared to be related to their a w . Moreover, the breaking characteristics of a sample at different a w values changed depending on the porous food type classified according to the degree of starch gelatinization. Among the AE characteristics, the number of AE events and AE count corresponded well with the a w of the porous food. Therefore, for an objective evaluation of the crispness of porous foods, the AE events and AE count, which are highly sensitive, can be suitable indicators, rather than the number of force peaks.

Correlation between acoustic characteristics and sensory evaluation of puffed‐grain food based on energy analysis

“…The correlation and reproducibility of the E max (−0.167) and t (0.165) of Senbei are poor, which may be due to the uneven pore distribution of Senbei leading to the uneven peak value of cavity rupture vibration. Miura et al (2023) conducted acoustic and mechanical measurements on six commodities after they were treated with different hygroscopic conditions and also found that high‐precision acoustic characteristics can better characterize the brittleness of porous foods than mechanical characteristics. The energy release was concentrated in a shorter period, as shown in the Hilbert graph (Figure S4).…”

Innovations in nondestructive assessment of baked products: Current trends and future prospects

“…In the case of baked goods, AE is specifically employed to evaluate textural attributes such as crispiness and crunchiness (Aboonajmi & Faridi, 2016). AE has been reported to measure the crispness of several baked products, including but not limited to cookies, biscuits, rice crackers, corn snacks, bread, extruded cereals, and snacks (Chanvrier et al, 2014;Hirte et al, 2010;Jakubczyk et al, 2017;Miura et al, 2023).…”