Table 4. Free sugar composition of citrus, apple, and grape peel powders (unit: g/100 g)

Free sugar	Citrus	Apple	Grape	F-value
Sucrose	0.50±0.00a1)2)	0.53±0.06a	Traceb	321.00***3)
Cellobiose	Trace4)	Trace	ND5)	ND
Maltose	Trace	3.10±0.10	Trace	2,883.00***
Lactose	ND	ND	ND	ND
Rhamnose	Trace	Trace	Trace	ND
Ribose	Trace	0.10±0.00	Trace	ND
Mannose	Trace	Trace	Trace	ND
Fructose	7.53±0.15c	26.17±0.64a	8.63±0.25b	3,003.69***
Galactose	Trace	0.10±0.00	Trace	ND
Xylose	0.10±0.00	0.20±0.00	0.30±0.00	ND
Glucose	6.90±0.17b	12.80±0.26a	4.63±0.12c	2,996.12***
Total6)	15.03±0.33b	43.00±1.06a	13.57±0.37c	2,433.12***

All values are mean±SD (n=3).
Means within different superscript letters (^a-c) in the same row are significantly different at p<0.05 according to Duncan’s multiple range test.
^***p<0.001
Trace, detected at levels less than 0.01 g/100 g.
ND, not detected.
Total sugar content was calculated as the sum of all quantified sugars.