. 2022 Apr 21;5:752–762. doi: 10.1016/j.crfs.2022.04.004

Table 4.

Changes in pH values and contents of short-chain fatty acids produced at different time points of fermentation.

Groups	Time (h)	pH	Short-chain fatty acids (mmol/L)
Groups	Time (h)	pH	Acetic acid	Propionic acid	i-Butyric acid	n-Butyric acid	i-Valeric acid	n-Valeric acid	Total
BLANK	0	8.95 ± 0.01 ^{a, B}	ND	ND	ND	ND	ND	ND	ND
	6	8.73 ± 0.02 ^{b, A}	5.189 ± 0.004 ^{d, B}	ND	ND	ND	ND	ND	5.189 ± 0.004 ^{c, C}
	12	8.60 ± 0.02 ^{c, A}	6.095 ± 0.094 ^{c, C}	1.502 ± 0.113 ^{a, B}	0.286 ± 0.016 ^{b, B}	0.687 ± 0.025 ^{c, B}	0.488 ± 0.026 ^{a, A}	0.786 ± 0.054 ^{b, B}	9.877 ± 0.064 ^{b, C}
	24	8.14 ± 0.02 ^{d, A}	6.453 ± 0.045 ^{b, C}	1.698 ± 0.065 ^{a, A}	0.280 ± 0.005 ^{b, B}	0.784 ± 0.002 ^{b, B}	0.524 ± 0.024 ^{a, A}	0.867 ± 0.059 ^{b, B}	10.605 ± 0.019 ^{a, B}
	48	7.86 ± 0.02 ^{e, A}	6.731 ± 0.027 ^{a, C}	1.723 ± 0.002 ^{a, B}	0.367 ± 0.022 ^{a, B}	0.857 ± 0.029 ^{a, B}	0.275 ± 0.003 ^{b, C}	1.020 ± 0.007 ^{a, B}	10.702 ± 0.033 ^{a, C}
INU	0	9.11 ± 0.03 ^{a, A}	ND	ND	ND	ND	ND	ND	ND
	6	7.46 ± 0.04 ^{b, B}	6.266 ± 0.156 ^{c, A}	1.701 ± 0.078 ^{c, A}	0.291 ± 0.006 ^{d, A}	0.802 ± 0.016 ^{bc, A}	0.371 ± 0.040 ^{a, A}	1.226 ± 0.083 ^{a, A}	10.657 ± 0.024 ^{d, A}
	12	6.82 ± 0.01 ^{c, B}	7.267 ± 0.030 ^{b, B}	1.621 ± 0.007 ^{c, AB}	0.368 ± 0.004 ^{c, A}	0.775 ± 0.009 ^{c, AB}	0.344 ± 0.009 ^{a, B}	1.233 ± 0.016 ^{a, A}	11.606 ± 0.021 ^{c, A}
	24	5.88 ± 0.04 ^{d, B}	7.973 ± 0.015 ^{b, B}	1.845 ± 0.027 ^{b, A}	0.429 ± 0.015 ^{b, A}	0.844 ± 0.014 ^{a, A}	0.312 ± 0.006 ^{a, B}	1.216 ± 0.125 ^{a, A}	12.619 ± 0.171 ^{b, A}
	48	5.19 ± 0.02 ^{e, B}	8.667 ± 0.031 ^{a, B}	2.356 ± 0.044 ^{a, A}	0.781 ± 0.037 ^{a, A}	0.809 ± 0.002 ^{b, B}	0.349 ± 0.010 ^{a, B}	1.134 ± 0.029 ^{a, A}	14.096 ± 0.141 ^{a, B}
LLPI	0	8.21 ± 0.02 ^{a, C}	ND	ND	ND	ND	ND	ND	ND
	6	7.16 ± 0.06 ^{b, C}	6.447 ± 0.042 ^{d, A}	1.716 ± 0.010 ^{b, A}	0.251 ± 0.014 ^{b, B}	0.746 ± 0.020 ^{b, B}	0.246 ± 0.003 ^{b, B}	0.683 ± 0.023 ^{a, B}	10.088 ± 0.028 ^{d, B}
	12	6.23 ± 0.03 ^{c, C}	7.845 ± 0.070 ^{c, A}	1.731 ± 0.032 ^{b, A}	0.246 ± 0.017 ^{b, B}	0.744 ± 0.022 ^{b, A}	0.257 ± 0.037 ^{b, C}	0.675 ± 0.004 ^{a, C}	11.499 ± 0.031 ^{c, B}
	24	5.47 ± 0.04 ^{d, C}	8.540 ± 0.404 ^{b, A}	1.805 ± 0.039 ^{b, A}	0.244 ± 0.012 ^{b, B}	0.759 ± 0.003 ^{b, B}	0.241 ± 0.008 ^{b, C}	0.677 ± 0.026 ^{a, B}	12.265 ± 0.321 ^{b, A}
	48	4.94 ± 0.01 ^{e, C}	9.940 ± 0.099 ^{a, A}	2.534 ± 0.202 ^{a, A}	0.662 ± 0.263 ^{a, A}	0.985 ± 0.027 ^{a, A}	0.379 ± 0.005 ^{a, A}	0.706 ± 0.021 ^{a, C}	15.206 ± 0.377 ^{a, A}

Sample codes were the same as in Fig. 3. Values represent mean ± standard deviation, and different capital letters (A-C) showed significant differences among different groups (p < 0.05) at the same time point, while lowercase letters (a-e) represented significant differences among different time (p < 0.05) in the same group; Statistical significances were carried out by ANOVA and Duncan's test. ND: not detected.