Angiotensin I-converting enzyme inhibitory and hypocholesterolemic activities: Effects of protein hydrolysates prepared from Achatina fulica snail foot muscle

Figures & data

Figure 1. Degree of hydrolysis of SFMPH hydrolysed with papain, trypsin, and alcalase at various times. Within the same enzymatic action, values (mean ± SD of triplicates) with different letters (a–c, h–j, w–y) are significantly different (Duncan, P < 0.05). A control test (without proteases addition) for each enzymatic treatment was performed according to normalization protocol and its DH value was in the range of 11.8–12.0%.

Table 1. The distribution of molecular size fractions in the SFMPH hydrolysed with papain, trypsin, and alcalase.

Proteases	Hydrolysis time (min)	Molecular size^a distribution (%)^b
		>20,000	6511–20,000	686–6511	189–686	<189
Without proteases	15, 30, 60	5.1	8.9	28.0	41.1	16.9
Papain	15	1.1	4.0	18.5	42.2	34.2
	30	0.5	1.1	10.7	41.3	46.4
	60	0.1	1.5	10.4	43.6	44.4
Without proteases	15, 30, 60	5.2	8.9	28.2	41.3	16.7
Trypsin	15	1.0	1.6	14.6	47.1	35.7
	30	0.6	1.1	13.0	46.8	38.5
	60	0.3	1.3	11.0	46.3	41.1
Without proteases	15, 30, 60	5.5	8.8	27.8	41.0	17.0
Alcalase	15	0.3	0.7	6.8	59.3	32.9
	30	0.6	0.0	5.6	55.2	38.6
	60	0.1	0.0	4.4	56.4	39.1

^aMolecular weight (Da) of all hydrolysates was evaluated using standard proteins as described in the Materials and Methods.

^bFor determination of molecular size distribution (%), peak area in the HPLC chromatograms was integrated in reference to the peak area of the standard proteins. Each value represents the mean of triplicate determinations.

Table 2. Effect of SFMPH after treatment with papain, trypsin, and alcalase for 60 min on functional properties^a.

Proteases	Fat adsorption capacity (g oil/g hydrolysate)	Foam capacity (%)	Foam stability (%)			Emulsion capacity (mL oil/g hydrolysate)
			After 15 min	After 30 min	After 60 min
Without proteases	2.33 ± 0.02^w	57.3 ± 1.47^w	69.1 ± 3.4^w	40.0 ± 4.1^w	23.6 ± 2.0^w	10.5 ± 0.15^w
Papain	1.68 ± 0.05^x	54.1 ± 2.22^x	30.5 ± 2.9^x	21.4 ± 0.6^x	15.0 ± 2.0^x	8.0 ± 0.01^x
Trypsin	1.48 ± 0.08^y	54.8 ± 1.79^x	31.1 ± 1.9^x	18.4 ± 3.1^x	12.2 ± 1.5^x	7.5 ± 0.02^x
Alcalase	1.35 ± 0.01^z	32.3 ± 2.29^y	22.7 ± 1.9^y	9.5 ± 1.3^y	6.2 ± 0.4^y	4.5 ± 0.03^y

^aValues (means ± SD of triplicate) in the same column with different superscript letters (w–z) are significantly different (Duncan, P < 0.05).

Table 3. Effect of SFMPH after treatment with papain, trypsin, and alcalase for 60 min on disintegration of cholesterol micelles^a.

Proteases	Concentration (mg/mL)	Intact cholesterol-micelle (mM/h)	Percent decrease of cholesterol micelle (%)^b
Without proteases	10	0.93 ± 0.03	20.4 ± 1.8
	20	0.88 ± 0.01	23.9 ± 0.6*
Papain	10	0.89 ± 0.01	23.0 ± 0.6
	20	0.89 ± 0.00	22.6 ± 0.0*
Trypsin	10	0.83 ± 0.01	28.3 ± 0.6
	20	0.84 ± 0.01	27.4 ± 0.6*
Alcalase	10	0.80 ± 0.02	31.5 ± 0.8
	20	0.78 ± 0.02	33.3 ± 1.3*

^aMean value ± SD of the three replications.

^bPercent decrease of cholesterol micelle was determined by loss in the concentration of intact cholesterol micelle with hydrolysate addition over the control (without hydrolysate addition 1.17 ± 0.05 mM).

*Statistically different from the value obtained with 10 mg/mL of enzymatic hydrolysate (P < 0.05).

Table 4. ACE inhibitory activity (IC₅₀) of SFMPH hydrolysed with alcalase at various hydrolysis times.

Hydrolysis time (min)	IC50^a
0	0.192 mg/mL^v
15	0.073 mg/mL^w
30	0.031 mg/mL^x
60	0.024 mg/mL^y
Captopril	0.0019 μg/mL^z

^aValues (means ± SD of triplicate) in the same column with different superscript letters (v–z) are significantly different (Duncan, P < 0.05).