Effect of Cooking on Soluble and Insoluble Oxalate Contents in Selected Pakistani Vegetables and Beans

Figures & data

Figure 1 Peaks of HPLC. (a) Peaks of standards of oxalic acid and (b) peaks of oxalic acid in food samples.

Figure 2 Peak area of the standards of oxalic acid during HPLC analysis.

Table 1 Total, soluble and insoluble oxalate contents of raw and boiled vegetables and beans (mg/100 g of wet weight).*

Vegetables/Beans	Total oxalate			Soluble oxalate			Insoluble oxalate
	Raw	Boiled	% loss	Raw	Boiled	% loss	Raw	Boiled	% loss
Spinach	978 ± 5 ^a	477 ± 8 ^b	51.2	543 ± 2 ^a	184 ± 5 ^b	66.1	435 ± 3 ^a	293 ± 3 ^b	32.6
Carrot	49 ± 7 ^a	26 ± 9 ^b	46.9	28 ± 4 ^a	14 ± 5 ^b	50.0	21 ± 3 ^a	12 ± 4 ^b	42.8
Beet root	67 ± 12 ^a	52 ± 14 ^b	22.4	45 ± 7 ^a	38 ± 8 ^b	15.6	22 ± 5 ^a	15 ± 6 ^b	31.8
White bean	158 ± 16 ^a	47 ± 17 ^b	70.3	52 ± 8 ^a	12 ± 9 ^b	76.9	106 ± 8 ^a	34 ± 8 ^b	67.9
Red bean	113 ± 15 ^a	72 ± 17 ^b	36.3	37 ± 8 ^a	22 ± 9 ^b	40.5	76 ± 6 ^a	50 ± 8 ^b	34.2
Soybean	497 ± 22 ^a	224 ± 25 ^b	54.9	155 ± 13 ^a	64 ± 15 ^b	58.7	343 ± 8 ^a	162 ± 10 ^b	52.8
*n = 3 Extractions were done in triplicate for samples of raw and boiled vegetables and beans. Wet weight refers to the original store-purchased weight for raw and cooked weight (boiled, drained and dried) vegetables and beans.
a, b = Different alphabets in the same row for the data in coloumns on the total, soluble and insoluble oxalate contents of raw and boiled vegetables and beans differ signicantly (P < 0.05).