Osmotolerant spoilage in high-sugar foods: Which molds can grow in jellies and candied fruits up to about 67.5% sugar?

Introduction / Context:
Jellies and candied fruits rely on high sugar to lower water activity and inhibit many microbes. However, several osmotolerant or xerophilic molds still grow at sugar levels near 67.5%, causing surface colonies, off-flavors, and pigment defects.

Given Data / Assumptions:

• Sugar concentration up to about 67.5% (w/w).
• Candidate genera: Aspergillus, Penicillium, Citromyces (historic name used in food literature).
• Product types: jellies and candied fruits.

Concept / Approach:
Osmotolerant molds possess physiological mechanisms (compatible solutes, stress-responsive proteins) allowing growth at low water activity. Several species of Aspergillus and Penicillium tolerate high osmotic pressure; Citromyces appears in older texts for citric-acid related, osmotolerant fungi. Collectively, they represent common spoilers in high-sugar confections.

Step-by-Step Solution:
Match high sugar (low a_w) with xerophilic/osmotolerant molds.Recognize all three listed genera contain such species.Therefore, choose the comprehensive option covering all.

Verification / Alternative check:
Preservation guides for jams/jellies note surface mold growth despite high sugar, especially after seal failure or condensation during cooling.

Why Other Options Are Wrong:

• Any single genus only: Too narrow; several genera contain osmotolerant species.
• Rhizopus only: Less osmotolerant; prefers higher a_w and is not the typical spoiler at 60–70% sugar.

Common Pitfalls:
Overreliance on sugar without proper hermetic sealing; headspace condensation enables surface colonization.

Final Answer:
All of these.