Table 3 Results of 29 tests of CCD in response surface methodology

Tests	A	B	C	D	Tests	A	B	C	D
1	99.30	88.61	1,947	9.5	16	70.35	71.21	1,652	3.0
2	90.48	87.66	1,964	8.3	17	98.12	89.66	1,984	9.0
3	94.30	86.49	1,845	6.7	18	101.87	90.41	2,014	10.8
4	89.46	84.62	1,883	7.4	19	88.81	87.13	1,893	8.9
5	95.86	84.72	1,948	9.4	20	81.35	75.65	1,674	8.1
6	107.23	91.76	2,079	12.0	21	94.57	85.22	1,884	8.6
7	88.47	85.19	1,749	8.7	22	103.28	88.73	2,007	11.8
8	79.22	79.85	1,862	6.8	23	90.35	89.17	2,017	9.4
9	80.35	81.21	1,749	6.4	24	103.28	88.73	2,011	11.8
10	94.86	77.49	1,678	5.9	25	99.64	78.74	1,946	9.7
11	99.28	89.73	1,933	8.4	26	83.44	82.78	1,863	5.9
12	100.27	84.66	2,004	8.9	27	99.30	88.61	1,947	9.5
13	84.88	81.41	1,792	8.4	28	90.48	87.66	1,964	8.3
14	90.78	86.32	1,841	7.4	29	94.30	86.49	1,845	6.7
15	90.41	86.65	1,909	10.6

Tests of 19 combinations listed in Table 1 were performed and the results obtained were showed in Table 3 where A, B, C, and D represented total yield of polypeptide (mg/g), the obtaining rate of oligopeptide (%), ionic Ca²⁺ content (mg/100 mL) and viable counts of Lactobacillus helveticus (×10⁹ CFU/mL).