Evolution and modeling of texture changes and drying kinetics of bamboo shoots under high-humidity air-impingement blanching

This study investigated the effect of hot water blanching (HWB),high-humidity air-impingement blanching (HHAIB), different HHAIB blanch-ing times (2, 4, 6, 8, and 10 min), and different HHAIB blanching temperatures(80, 85, 90, and 95 degrees C) on texture quality, lignin content, weight loss, color,microstructure, and drying kinetics of bamboo shoots. After HWB treatment, thelignin content of bamboo shoots was apparently lower than that of HHAIB andthe samples obtained the highest weight loss value of 6.13%. Both the texture val-ues (brittleness and chewiness) and lignin content of bamboo shoots exhibitedan overall downward trend as the HHAIB blanching time and blanching tem-perature increased. Specifically, the lignin content of bamboo shoots decreasedfrom 5.59% to 4.58% with an increase in HHAIB blanching time from 2 to 10 minand dropped from 5.48% to 4.63% as HHAIB blanching temperature increasedfrom 80 to 85 degrees C, respectively. The lignin content was proved to be positively cor-related (p<0.05) with texture attributes (brittleness and chewiness). A secondpolynomial model was obtained for fitting the variation kinetics of lignin contentduring thermal processing. Reducing the HHAIB blanching time and blanchingtemperature would obtain a lower weight loss and a better color performance(Delta EandL*). Additionally, microstructure observation revealed that the distribu-tion density of microchannels initially increased and then decreased with theextension of blanching time, while it continuously became firmer as HHAIBblanching temperature increased. Overall, the optimal processing parameterswere achieved under the HHAIB blanching temperature of 85 degrees C for 6 min,ensuring a high-quality performance of bamboo shoot products.