Enhanced enzymatic sugar production from corn stover by combination of water extraction and glycerol-assisted instant catapult steam explosion

Bioresources and Bioprocessing

Table 2 Equivalents of glucan and xylan determined in pretreatment hydrolysates and total equivalents of glucan and xylan

Water extraction prior to ICSE	G:W²	Pretreatment hydrolysates							Total equivalent (%)⁷
		Glucan equivalent (%)³			Xylan equivalent (%)⁵				Total equivalent (%)⁷
		Glucose	Gluco-oligoes⁴	Total	Xylose	Xylo-oligoes⁶	Furfural	Total	Glucan	Xylan
No	0:5	1.8 ± 0.0	5.4 ± 0.2	7.2 ± 0.2	4.4 ± 0.8	32.7 ± 1.2	0.6 ± 0.0	37.7 ± 2.0	82.3 ± 3.0	80.7 ± 2.3
	2:3	1.8 ± 0.2	6.6 ± 0.5	8.4 ± 0.7	6.4 ± 0.2	32.5 ± 0.3	1.1 ± 0.0	40.0 ± 0.5	89.0 ± 2.5	83.5 ± 1.2
	3:2	2.8 ± 0.1	5.1 ± 0.2	7.9 ± 0.3	6.8 ± 0.7	30.9 ± 0.4	1.1 ± 0.0	38.8 ± 1.1	88.4 ± 1.1	81.2 ± 1.5
	4:1	1.9 ± 0.2	5.5 ± 0.1	7.4 ± 0.3	6.7 ± 0.3	26.4 ± 0.3	1.1 ± 0.0	34.2 ± 0.6	85.9 ± 1.3	70.3 ± 1.3
	5:0	1.9 ± 0.2	5.7 ± 0.1	7.6 ± 0.3	6.0 ± 0.7	28.1 ± 0.6	0.6 ± 0.0	34.7 ± 1.3	87.9 ± 1.1	77.7 ± 1.6
Yes¹	0:5	3.0 ± 0.0	2.5 ± 0.1	5.5 ± 0.1	3.7 ± 0.1	34.7 ± 0.4	0.5 ± 0.0	38.9 ± 0.5	90.1 ± 0.5⁸	91.9 ± 0.8⁹
Yes¹	4:1	0.8 ± 0.1	4.6 ± 0.1	5.4 ± 0.2	2.1 ± 0.0	30.3 ± 0.2	0.9 ± 0.1	33.3 ± 0.3	87.0 ± 0.9⁸	78.7 ± 2.7⁹

1. For every 100 g corn stover, water extraction removed 2.6% glucan equivalent and 1.3% xylan equivalent; 2. G:W = glycerol:water (w/w); 3. glucan equivalent from HMF was negligible (≤ 0.03%); 4. gluco-oligoes included gluco-oligosaccharides and possible glyceryl glucosides; 5. xylan equivalent from furfural was not included (≤ 1.1%) as furfural could also generated from other C5 sugars; 6. xylo-oligoes included xylo-oligosaccharides and possible glyceryl xylosides; 7. total equivalent includes those both in solid residue (glucan or xylan recovery in Table 1) and pretreatment hydrolysate; 8. total glucan equivalent included those in solid residue, pretreatment hydrolysis and also glucan equivalent (sucrose, glucose and fructose) from water extractives; 9. total xylan equivalent also included those in solid residue, pretreatment hydrolysis and also xylan equivalent from water extractives