Effect of Tannin-Binding Agents (Polyethylene Glycol and Polyvinylpyrrolidone) Supplementation on In Vitro Gas Production Kinetics of Some Grape Yield Byproducts
Table 2
Total gas production volume of grape yield byproducts in incubation times (mL/g DM).
Treatments
Incubation times (h)
2
4
6
8
12
16
24
36
48
Grape pomace (GP)
Control
39.2a
89.1a
127.8a
157.7b
188.8b
206.3b
231.7b
260.3b
269.8b
GP + PEG
7.6b
56.2b
119.1b
166.7a
208.6a
242.0a
277.8a
312.5a
331.1a
GP + PVP
9.4b
51.3b
115.5b
163.6a
205.4a
239.8a
276.5a
310.5a
327.8a
SEM
1.59
1.59
1.49
1.25
1.83
2.36
2.45
2.39
2.54
Raisin waste (RW)
Control
33.1a
73.8a
101.0b
118.7b
141.8b
156.6b
180.9b
203.2b
208.7b
RW + PEG
12.7b
62.0b
109.6a
134.3a
158.4a
180.3a
204.4a
229.4a
247.1a
RW + PVP
9.8b
54.4c
104.6ab
132.8a
159.9a
182.3a
206.5a
229.7a
247.9a
SEM
1.41
1.49
1.85
2.51
3.51
3.74
3.87
3.64
3.54
Dried grape byproduct (DGB)
Control
32.7a
77.5a
112.7a
139.1a
161.6b
182.5b
209.2b
234.5b
243.4b
DGB + PEG
9.8b
58.4b
114.8a
146.9a
182.5a
212.3a
241.8a
269.2a
286.5a
DGB + PVP
6.9b
47.8c
103.3b
136.3a
165.6b
189.9b
218.3b
234.5b
264.1b
SEM
2.01
2.83
2.50
3.59
4.02
5.16
6.08
6.12
6.18
GP: grape pomace, RW: raisin waste, and DGB: dried grape pomace.
a,b,cWithin a column, means without a common superscript letter differ ().