Thawing microbiology – At fairly low thawing temperatures, which groups predominate on vegetables like sweet corn and peas?

Introduction / Context:
When frozen vegetables are thawed at relatively low temperatures, the surviving microflora that resume activity can shift toward Gram-positive cocci with better cold tolerance and stress resistance.

Given Data / Assumptions:

• Commodity: sweet corn and peas.
• Condition: thawing at fairly low (near-refrigeration) temperatures.
• We compare Streptococcus and Micrococcus groups.

Concept / Approach:
Gram-positive cocci such as Micrococcus and some Streptococcus/enterococcal relatives are relatively resilient to freeze–thaw stress and osmotic shock. Under cool thawing, they can comprise a noticeable proportion of the recoverable microflora versus more injured Gram-negatives.

Step-by-Step Solution:
Consider freeze injury patterns → many Gram-negatives are sublethally injured. Cold-tolerant Gram-positive cocci survive better → Micrococcus and related streptococci increase in prevalence. Thus, both listed groups can be predominant under the stated condition.

Verification / Alternative check:
Historical food microbiology surveys of thawed vegetables frequently report recoveries of Micrococcus and Streptococcus at low thaw temperatures, aligning with stress-tolerance profiles.

Why Other Options Are Wrong:
Choosing only one group is incomplete; “none” contradicts observed recoveries; thermophiles do not prevail at low temperatures.

Common Pitfalls:
Assuming Enterobacteriaceae always dominate; temperature and stress history shift the flora.

Final Answer:
Both (a) and (b).