Juice debittering technology — industrial source of naringinase for citrus processing Which microorganism is the standard commercial source of naringinase used to remove the bitter compound naringin from citrus juices?

Microbiology Industrially Useful Microbial Processes Difficulty: Easy
Choose an option
  • A
    Aspergillus niger
  • B
    Aspergillus flavus
  • C
    Aspergillus oryzae
  • D
    Saccharomyces cerevisiae
  • E
    Penicillium roqueforti

Answer

Correct Answer: Aspergillus niger

Explanation

Introduction / Context:Naringinase (alpha-L-rhamnosidase plus beta-glucosidase activities) hydrolyzes naringin, a key bitter flavonoid in grapefruit and some orange varieties. Food technologists deploy microbial naringinase to debitter juice without compromising aroma or nutritional value.

Given Data / Assumptions:

  • We are selecting a safe, high-titer, industrial enzyme source.
  • The enzyme must be produced economically at scale and meet food-grade standards.
  • Aspergillus niger is a workhorse organism for food enzymes.

Concept / Approach:Aspergillus niger has a long history of safe use (GRAS) and produces robust extracellular glycosidases, including naringinase, pectinases, and cellulases. A. flavus is disqualified by aflatoxin risk; A. oryzae is used for other enzyme systems but is not the predominant commercial source of naringinase; S. cerevisiae is primarily a fermentative yeast with limited secretion of such glycosidases.

Step-by-Step Solution:Identify the enzyme (naringinase) and its debittering role.Match to industrial producer strains: A. niger aligns best.Exclude unsafe or non-productive organisms for this specific enzyme.

Verification / Alternative check:Supplier catalogs and applied microbiology literature list A. niger as the principal source of commercial naringinase preparations.

Why Other Options Are Wrong:A. flavus poses toxin risks; A. oryzae is useful but not the dominant naringinase source; S. cerevisiae and Penicillium roqueforti are not standard producers for this application.

Common Pitfalls:Confusing naringinase with pectinase; both may be used in juice processing, but they tackle different quality defects (bitterness vs. clarity/yield).

Final Answer:Aspergillus niger.

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