Optimizing the acceleration of Cheddar cheese ripening using response surface methodology by microbial protease without altering its quality features

AMB Express

Table 2 The significance of each independent variable effect indicated by using F-ratio and P-value in the final models

Variables	Independent variable	Main effects			Quadratic effects			Interaction effects
Variables	Independent variable	X1	X2	X3	X1²	X2²	X3²	X1X2	X1X3	X2X3
pH (Y1)	p-value	0.002^a	0.001^a	0.004^a	0.001^a	0.000^a	0.001^a	0.004^a	0.964	0.000^a
pH (Y1)	F-ratio	21.14	28.60	16.55	24.89	43.73	24.00	16.58	0.00	52.63
ADV (Y2)	p-value	0.011^a	0.078	0.006 ^a	0.020^a	0.792	0.230	0.007^a	0.180	0.183
ADV (Y2)	F-ratio	10.71	4.09	14.02	8.35	0.07	1.69	12.86	2.15	2.13
Moisture (Y3)	p-value	0.075	0.112	0.575	0.028^a	0.195	0.361	0.195	0.751	0.031^a
Moisture (Y3)	F-ratio	4.19	3.20	0.34	7.16	2.00	0.94	2.00	0.11	6.82
a_w (Y4)	p-value	0.001^a	0.044^a	0.136	0.000^a	0.781	0.006^a	0.019^a	0.123	0.107
a_w (Y4)	F-ratio	22.59	5.70	2.75	44.44	0.08	14.13	8.63	2.97	3.29
SN [(%), Y5]	p-value	0.007	0.003^a	0.007^a	0.002^a	0.001^a	0.756	0.372	0.005^a	0.724
SN [(%), Y5]	F-ratio	12.74	17.69	13.14	20.47	29.20	0.10	0.90	14.63	0.13
Fat [(%), Y6]	p-value	0.138	0.006^a	0.028^a	0.866	0.304	0.000^a	0.006^a	0.001^a	0.029^a
Fat [(%), Y6]	F-ratio	2.71	13.91	7.17	0.03	1.21	38.69	13.66	23.72	7.03
Overall acceptability (Y7)	p-value	0.216	0.003^a	0.001^a	0.680	0.000^a	0.090	0.766	0.003^a	0.048^a
Overall acceptability (Y7)	F-ratio	1.80	17.72	28.80	0.18	32.41	3.50	0.10	18.27	5.46

X1, X2 and X3: the main effect of protease purification factor, protease concentration and ripening time X1², X2² and X3²: the quadratic effect of protease purification factor, protease concentration and ripening time, respectively. X1X2: the interaction effect of protease purification factor and protease concentration, X1X3: the interaction effect of protease purification factor and ripening time, X2X3: the interaction effect of protease concentration and ripening time
^aSignificant (P ≤ 0.05)