Bromelain (Protease from Pineapple)

Bromelain is a mixture of proteolytic enzymes (primarily cysteine‑type proteases) extracted from the stem and fruit of Ananas comosus (pineapple). In dietary supplements, it is used primarily for its ability to hydrolyze proteins, which underlies its anti‑inflammatory, digestive-support, and tissue-repair properties.

• Type: Bromelain is a cysteine protease.
• Molecular Weight: ~24 kDa (≈ 23,200 Da).
• Primary Structure: Consists of ~ 210 amino‑acid residues.
• Active Site: The catalytic triad Cys‑27, His‑159, and Asn‑175 (numbering varies by isoform) forms the active site.
• Enzyme Family: The enzyme belongs to the MEROPS family C1 (papain‑like).
• Glycosylation: The enzyme is glycosylated (≈ 10 % carbohydrate).
• pH Optimum: The enzyme has a pH optimum.

• Source: Commercial bromelain is extracted mainly from pineapple stem (≈ 70 % of total yield) because the stem contains higher protease activity than the fruit.
• Extraction Process:
  • Aqueous extraction
  • pH‑adjusted precipitation
  • Ultrafiltration to isolate the protein fraction
  • Freeze‑drying to produce a stable powder.
• Recombinant Expression: Some manufacturers use recombinant expression in Pichia pastoris or E. coli to achieve consistent enzyme activity, but most dietary supplements rely on vegetal extraction.
• Quality Considerations:
  • Activity units (e.g., 1,000 GDU/g – “gelatin‑digesting units”)
  • Protease activity per capsule
  • Third‑party testing for purity (absence of heavy metals, pesticide residues)
  • Standardized activity.
• GMP Facilities: Good‑manufacturing‑practice (GMP) facilities provide the most reliable products.