Stability and sensory analysis of walnut polypeptide liquid: response surface optimization

Figures & data

Table 1. Levels of test factors for the optimization stability of walnut polypeptide liquid

Level	Four-factor level table
	X1 -CMC-Na (%)	X2-SG (%)	X3-SE (%)	X4-Homogeneous pressure (MPa)
−1	0.01	0.02	0.02	30
0	0.02	0.03	0.03	35
1	0.03	0.04	0.04	40

Table 2. Test factor and level table for response surface methodology. Based on the Box–Benhnken Center combination, the ratio of material to liquid (X₁), protein sugar (X₂), citric acid (X₃) and walnut powder flavor (X₄) were selected, the sensory test was optimized using the formulated polypeptide solution (Y) as the response value

Level	Four-factor level table
	X1-Material liquid ratio (%)	X2-Protein sugar (%)	X3-Citric acid (%)	X4-9115 Walnut powder flavor (%)
−1	10	0.1	0.20	0.10
0	15	0.2	0.25	0.15
1	20	0.3	0.30	0.20

Table 3. Walnut peptide liquid taste rating standards according to the Chinese National standards

Category	First grade	Secondary grade	Third grade
Color (20)	Uniform color, white or milky white (16–20)	Rendered white gray (10–15)	Color shades are different, or have other colors (1–9)
Head fragrance (20)	With aroma of walnut oil, no other odor (16–20)	Lighter or heavier walnut flavor, no other odor (10–15)	There are other odors (1–9)
Sweetness (30)	Moderate sweetness, no other bad taste (20–30)	Sweet or sweet taste, no other bad taste (10–19)	A little sweet, with other flavors (1–9)
Taste (30)	Good taste, no bitter taste (20–30)	Slightly bitter and astringent, unpleasant (10–19)	Poor taste, bitter taste (1–9)

Table 4. Antioxidant capacity of walnut polypeptide liquid

Number	Molecular weight cut off	OH (%)	O2^−(%)
1	3 u	73.3	64.4
2	5 u	66.1	58.9
3	10 u	59.2	51.6
4	Liquid	44.4	36.8

Table 5. Test sample data and results using Box-Behnken design for walnut polypeptide liquid

Number	X1-CMC-Na (%)	X2-SG (%)	X3-SE (%)	X4-Homogeneous pressure (Mpa)	Y-Emulsification stability (%)
1	0.03	0.03	0.04	35	69.9
2	0.02	0.03	0.04	30	87.6
3	0.02	0.04	0.04	35	70.0
4	0.02	0.02	0.04	35	91.3
5	0.03	0.02	0.03	35	78.7
6	0.02	0.02	0.03	40	70.1
7	0.02	0.03	0.04	40	71.3
8	0.01	0.03	0.03	40	60.6
9	0.02	0.03	0.02	40	49.7
10	0.02	0.03	0.03	35	88.3
11	0.01	0.04	0.03	35	86.5
12	0.02	0.03	0.03	35	89.7
13	0.02	0.04	0.03	40	43.9
14	0.01	0.02	0.03	35	71.7
15	0.01	0.03	0.04	35	79.8
16	0.03	0.03	0.03	40	95.2
17	0.02	0.03	0.03	35	93.4
18	0.02	0.02	0.03	30	73.0
19	0.02	0.03	0.03	35	81.2
20	0.01	0.03	0.03	30	78.3
21	0.03	0.03	0.03	30	57.5
22	0.02	0.04	0.02	35	43.6
23	0.01	0.03	0.02	35	78.8
24	0.02	0.03	0.03	35	97.2
25	0.02	0.03	0.02	30	78.4
26	0.02	0.04	0.03	30	39.5
27	0.02	0.02	0.02	35	78.7
28	0.03	0.03	0.02	35	28.2
29	0.03	0.04	0.03	35	34.1