Beet molasses pretreatment in fermentation: to reduce problematic trace metals, beet molasses is commonly pretreated with which chemical agents?

Introduction / Context:
Beet molasses is a widely used, low-cost carbon source in industrial fermentations. However, trace metals present in molasses can inhibit microbial growth or distort product yields. Pretreatment strategies remove or complex these metals to stabilize fermentation performance.

Given Data / Assumptions:

• Target is reduction of trace metal bioavailability (for example, copper, iron, heavy metals).
• Industrial practice favors simple, scalable treatments compatible with downstream processing.
• We are comparing commonly cited chemical approaches.

Concept / Approach:
Ferrocyanide/ferricyanide treatments precipitate or complex certain metals, reducing their inhibitory effects. When applied under controlled conditions, they help clarify the feedstock without causing unacceptable cyanide release under process conditions. Strong mineral acids (HCl, H₂SO₄) adjust pH and can hydrolyze impurities but are not primarily metal-chelating solutions for this purpose. The misspelled “ethylenediamine tetrachloro acetic acid” is not the standard chelator (EDTA is ethylenediaminetetraacetic acid) and is inappropriate as written.

Step-by-Step Solution:

Verification / Alternative check:
Fermentation manuals and sugar industry practices note the use of ferrocyanide/ferricyanide clarifying steps to mitigate metal-related inhibition and color bodies.

Why Other Options Are Wrong:

• “Ethylenediamine tetrachloro acetic acid”: Incorrect chemical; even EDTA (correct name) is not the standard industrial choice here.
• Hydrochloric/sulphuric acid: Useful for pH adjustment or hydrolysis; not specific for complexing trace metals in this context.
• Sodium bicarbonate: Buffering/neutralization, not a metal-complexing pretreatment.

Common Pitfalls:
Overlooking safety controls for ferro/ferricyanide systems; assuming any acid wash solves metal inhibition; ignoring that chelation strategy must not impair downstream product recovery.

Final Answer:
ferrocyanide or ferricyanide