Preparation of Heat-Sensitivity Proteins from Walnut Meal by Sweep Frequency Ultrasound-Assisted Alkali Extraction

Table 1

Secondary structures of walnut proteins extracted with and without ultrasound.

Sample	α-helix (%)	β-sheet (%)	β-turn (%)	Random coil (%)
Without ultrasound	4.5 ± 0.06^b	53.0 ± 0.23^a	18.6 ± 0.12^a	23.9 ± 0.28^a
With ultrasound	6.4 ± 0.04^a (↑42.2)	54.4 ± 0.26^a (↑2.6)	19.3 ± 0.14^a (↑3.8)	19.9 ± 0.17^b (↓16.7)

The different superscript letters of data under the same column indicate that they are significantly different . The values in parenthesis are the change percentage points of secondary structure content in walnut protein with ultrasound compared to that without ultrasound.