Table 6. Mineral composition of citrus, apple, and grape peel powders (unit: mg/100 g)

Minerals	Citrus	Apple	Grape	F-value
Na	3.04±0.091)b2)	3.17±0.08a	0.35±0.01c	2.84*3)
Ca	41.82±0.93a	4.21±0.09c	9.78±0.21b	72.07***
K	85.19±1.93b	72.51±1.56c	114.29±1.45a	191.58***
Mg	7.92±0.20b	3.63±0.12c	11.79±0.28a	89.72***
Cu	0.02±0.00b	Trace4)	0.20±0.01a	3.33*
Mn	0.17±0.01a	ND5)	0.13±0.01b	133.63***
Fe	0.28±0.01b	0.24±0.01c	1.40±0.03a	3.04*
Zn	0.04±0.00b	0.04±0.00b	0.09±0.01a	9.91**
Total6)	138.48±3.16a	83.80±1.84b	138.03±2.00a	9.50**

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 using Duncan’s multiple range test.
^**p<0.01, ^***p<0.001.
Trace, detected at levels less than 1 mg/100 g.
ND, not detected.
Total mineral content was calculated as the sum of all quantified mineral elements.