BRONTO / Processing lines / Soybean processing technology / Correlation between trypsin inhibitors and urease activity

Correlation between trypsin inhibitors and urease activity

Trypsin inhibitors are biologically active substances that reduce the nutritional value of protein in soybeans.

Food with an increased content of trypsin inhibitors leads to a decrease of hydrolysis of food proteins, decrease of protein assimilation and as a result hypertrophy of the pancreas, liver dysfunction, growth retardation

Urease:

is not a toxic protein
is not of much concern to domestic animals nutritionists

The only relationship because as heat is applied in the presence of adequate moisture trypsin inhibitors and urease are deactivated.

The urease activity unlike trypsin inhibitors is easy to measure. That’s why the urease activity is used as a “marker” of trypsin inhibitor activity.

As a result of the study of 104 samples of soybean meal analyzed by Nutrianalisis Ltd between 2008 and 2012, (Belalcazar and Otalora, 2012), there was discovered a correlation between the content of a trypsin inhibitor (x, mg /g) and urease activity (y, pH):

Y = 0,0738 x – 0,1224, with R2 = 0,947.

(R2) is a rather significant correlation between the content of inhibitors of trypsin and urease activity.

The correlation between the content of trypsin inhibitors and urease activity based on the analysis of 104 samples of soybean meal:

Trypsin Inhibitors, mg/g	Urease activity, pH	Trypsin Inhibitors, mg/g	Urease activity,pH
1,75	0,015	5,50	0,292
1,81	0,024	7,00	0,382
2,02	0,040	7,50	0,450
1,81	0,011	6,00	0,290
2,00	0,023	6,00	0,276
1,70	0,005	9,00	0,530
1,92	0,032	4,00	0,152
3,56	0,120	6,20	0,321
3,60	0,120	5,50	0,285
3,71	0,129	5,20	0,257
1,90	0,021	7,50	0,430
2,10	0,032	8,00	0,502
3,56	0,108	9,50	0,550
3,40	0,127	9,00	0,510
1,82	0,020	7,90	0,452
1,88	0,014	8,20	0,445
2,15	0,025	7,00	0,412
2,25	0,020	6,50	0,320
2,30	0,024	7,25	0,355
1,95	0,020	6,90	0,402
1,95	0,050	6,50	0,482
2,10	0,049	6,00	0,320
2,82	0,050	5,50	0,300
2,18	0,060	7,90	0,450
2,12	0,047	5,82	0,320
2,02	0,020	5,75	0,290
2,09	0,031	5,50	0,310
1,80	0,020	6,80	0,405
2,09	0,031	5,95	0,300
1,80	0,020	7,00	0,480
1,78	0,007	6,85	0,350
1,75	0,010	6,92	0,420
1,65	0,000	7,12	0,440
4,50	0,198	5,92	0,325
3,05	0,080	5,40	0,285
2,85	0,030	5,00	0,312
1,70	0,000	6,52	0,425
2,10	0,060	6,20	0,355
3,80	0,090	6,90	0,415
1,80	0,020	4,20	0,250
1,76	0,020	4,07	0,157
2,15	0,050	6,40	0,335
1,55	0,000	4,00	. 0,146
1,50	0,000	9,50	0,600
1,62	0,000	8,24	0,480
1,72	0,060	7,20	0,420
1,85	0,016	6,95	0,380
1,88	0,032	9,20	0,520
3,50	0,107	—	—
2,10	0,009	—	—
3,80	0,139	—	—
3,96	0,142	—	—
1,75	0,006	—	—
1,70	0,001	—	—
2,14	0,024	—	—
3,20	0,072	—	—

The source of information:

“NEW INSIGHTS ON THE UREASE ACTIVITY RANGE FOR SOYBEAN MEAL”. Nelson Ruiz, PhD. Nelson Ruiz Nutrition, LLC USA

Articles

Feed Soy Concentrates Based on Extruded Grain

One of the key limiting factors in improving compound feed quality is the deficit of protein raw materials, a replenishable source of which is the grain of leguminous crops. Legumes (lupines, vetches, field beans, field peas, soybeans, chickpeas) contain 25% to 40% protein, 37–45% starch, 1.5–4.5% fat, vitamins, and micronutrients. The proteins of leguminous crops are characterized by good solubility: water- and salt-soluble fractions account for 70% to 90% of the protein. The amino acid profile includes all essential amino acids, with methionine + cystine being the limiting amino acid. Seeds of vetch and field beans have lysine as their second limiting amino acid.

12.10.2026

Articles

Extrusion Preparation of Grain Raw Materials in Pet Food Production

The market for pet food (dogs and cats) is one of the most dynamic and profitable segments of the feed-milling industry. While the profitability of traditional compound feed for farm animals typically ranges from 5% to 15%, the production of dry pet food achieves a profitability of 50% to 250%.

12.10.2026