Comparative Studies of Combined Influence of Variables on the Esterification Degree of Pectin Extracted by Sulfuric Acid and Citric Acid

Table 1

Variable levels and the response of DE of pectin based on pH value, extraction temperature, and time.

Std.	Variable levels			DE (%)
	X 1 pH value	X 2 Extraction temperature (°C)	X 3 Extraction time (h)	DEc	DEs
1	1	90	2	26.98	28.13
2	2	90	1.5	33.97	34.13
3	2	90	1.5	33.97	34.13
4	1	80	1.5	33.46	38.01
5	2	90	1.5	33.97	34.13
6	1	90	1	40.35	39.95
7	2	90	1.5	33.97	34.13
8	2	80	1	42.61	43.02
9	2	100	2	23.56	28.32
10	2	100	1	41.73	38.88
11	3	90	1	43.78	41.44
12	3	80	1.5	37.94	41.56
13	2	90	1.5	33.97	34.13
14	3	100	1.5	31.97	33.95
15	3	90	2	31.4	31.3
16	2	80	2	32.08	34.1
17	1	100	1.5	30.64	32.16