Acid Protease

Acid Protease (Aspergillus aspartic protease) is an endopeptidase active at low pH that hydrolyses internal peptide bonds in proteins. It is the principal protease for brewing, distilling, soy sauce production and acidic protein-hydrolysate manufacture.

Off-white to light tan free-flowing powder, or amber liquid. Activity is standardised in Acid Protease Units defined by the Folin-Ciocalteu method on hemoglobin or casein at pH 3.0.

We supply food-grade Acid Protease from manufacturers in China holding ISO 22000, Halal, Kosher and other certifications relevant to the product and production. Aspergillus niger and Aspergillus oryzae are the dominant source organisms.

Common market grades include 50,000 U/g standard brewing grade, 100,000 to 200,000 U/g concentrated for distilling and feed applications, 500,000 U/g high-activity grade, and clarification-tuned grades selected for narrow specificity on haze-forming proteins.

Bulk and reduced-MOQ shipments. Batch-level COA covering activity, pH optimum, temperature optimum, moisture, heavy metals and microbiology.

Acid Protease from Aspergillus species has been used in commercial food production for over a century, originally as a side activity of koji-mould fermentations in East Asian soy sauce and miso manufacture. The enzyme was commercially purified in the mid-20th century for brewing and distilling, and now serves a broad portfolio of acidic-pH food processing operations.

Industrial production is by submerged or solid-state fermentation of Aspergillus niger and Aspergillus oryzae strains. Solid-state fermentation on wheat bran remains a notable production route, particularly in Asia, where it delivers a koji-style enzyme profile favoured in traditional fermented foods.

The enzyme is Generally Recognized as Safe by the U.S. FDA from approved Aspergillus strains, listed in the JECFA enzyme compendium, and approved as a processing aid in the EU.

Mechanistically, Aspergillus acid protease is an aspartic endopeptidase with two catalytic aspartate residues at its active site. It hydrolyses internal peptide bonds with a broad specificity favouring hydrophobic residues in the P1 and P1' positions, and operates optimally at pH 2.5 to 4.0, which makes it ideal for low-pH processing where neutral and alkaline proteases would be inactive.

Strategic positioning is mature and broad across the global brewing, distilling and East Asian fermented-foods industries, and growing in plant-protein hydrolysate manufacture as the plant-protein segment scales.

• Beer brewing; chillproofing and haze-precursor hydrolysis at low wort pH
• Whisky and grain spirits distilling; supports yeast nutrition through free amino nitrogen release
• Soy sauce and fermented soy condiment production; classical koji-derived protease activity
• Acidic protein hydrolysate manufacture; soy and whey hydrolysates for flavour and clinical-nutrition use
• Yeast extract production; supports cell-wall disruption and peptide release at low pH
• Wine clarification; reduces protein-related haze in white wines
• Animal feed; pre-digestion of plant proteins for aquaculture and pet food
• Cheese making in selected traditional cheeses where acid-protease activity is part of the flavour profile