Effect

Type of produce Dehulled defatted cow pea flour (DDCF)	pH	Foam volume (ml) at room temperature (30% – 32 °C) after time min. (Fs)
	pH	5	10	15	20	30	40	50	60	90	120
	2	95^a	91^a	85^b	73^c	53^d	53^d	43^f	43^e	38^e	28^g
	4	47^m	44^h	45^j	37^j	34^h	35^h	34ⁱ	34^g	33^f	31^f
	7	84^d	50^g	42^k	39ⁱ	39^f	39^g	39^g	31^h	22^h	21ⁱ
	9	90^c	90^b	90^a	90^a	90^a	90^a	90^a	90^a	90^a	90^a
	12	78^f	43^h	32ⁿ	32^k	25^j	25^j	25^k	25^j	24^g	25^h
Cowpea protein isolate-A (CPIA)	2	76^j	64^e	58^f	56^e	47^e	44^f	38^h	38^f	38^e	38^e
	4	81^e	51^g	51^h	51^f	48^e	48^e	47^d	48^d	48^d	45^d
	7	72ⁱ	68^c	66^d	67^c	67^c	60^c	54^c	54^c	54^c	54^c
	9	92^h	92^a	82^c	82^b	75^b	75^b	65^b	62^b	62^b	61^b
	12	74^g	55^f	48ⁱ	42^h	33^h	31ⁱ	25^k	21ⁱ	21^h	19^j
Cowpea protein isolate-B (CPIB))	2	81^e	66^d	64^c	55^c	47^e	44^f	44^e	39^f	38^e	27^g
	4	76^g	69^c	53^g	48^g	38^g	34^h	30^j	26ⁱ	26^g	26^h
	7	49ⁱ	36^j	34^m	32^k	29ⁱ	25^j	25^k	23^k	15ⁱ	16^k
	9	50^k	41ⁱ	37ⁱ	29ⁱ	21^k	12^k	12ⁱ	8.0^m	8.0^j	7.0ⁱ
	12	0.0ⁿ	0.0^k	0.0^o	0.00^m	0.0ⁱ	0.0ⁱ	0.0^m	0.0ⁿ	0.0^k	0.0^m
SE.M±		0.334	0.455	0.395	0.475	0.431	0.4323	0.434	0.429	0.683	0.41
C.V(%)		1.49	1.88	1.55	2.41	2.25	2.27	2.57	7.03	7.03	2.68

Table 2: Effect of pH on foam capacity and stability of dehulled defatted cowpea flour (DDCF) and cowpea protein isolates (CPIA and CPIB) SEM ± is standard error mean. Means in the same column followed by the same letter (s) are not significantly different according to Duncan’s Multiple Range Test (DMRT) C.V % coefficient of variance.