Aflatoxin Production in Black Currant, Blueberry and Strawberry Jams

Area of Science:

• Food Microbiology
• Mycotoxicology
• Food Preservation

Background:

• Aspergillus parasiticus can produce aflatoxins, which are harmful mycotoxins.
• Fruit jams can be susceptible to fungal contamination and mycotoxin production.
• Factors like sugar content, pH, temperature, and atmosphere influence fungal growth and mycotoxin synthesis.

Purpose of the Study:

• To investigate the influence of jam composition (unsweetened, sweetened), storage conditions (temperature, atmosphere), and pH on aflatoxin production by Aspergillus parasiticus.
• To determine the distribution of aflatoxins in jam layers.
• To compare aflatoxin synthesis in jams versus a yeast extract sucrose broth.

Main Methods:

• Incubation of black currant, blueberry, and strawberry jams (unsweetened and sweetened) with Aspergillus parasiticus spores at various temperatures and atmospheres for up to 6 months.
• Measurement of hyphal dry weight, pH, and aflatoxin production.
• Analysis of aflatoxin distribution in jam layers under controlled and uncontrolled pH conditions.
• Incubation in yeast extract sucrose broth as a control.

Main Results:

• Aflatoxin was detected in black currant and strawberry jams at 22 and 30°C, but not in blueberry jam.
• Sugar addition inhibited detectable aflatoxin production but enhanced fungal growth.
• Storage at 4°C significantly reduced fungal growth.
• High CO2 atmosphere inhibited aflatoxin in black currant and blueberry jams but not strawberry jam.
• Increased initial pH led to higher aflatoxin synthesis but reduced fungal biomass.
• Aflatoxin synthesis was less efficient in jams compared to yeast extract sucrose broth.

Conclusions:

• Blueberry jam may contain inhibitory substances against aflatoxin production.
• Jam matrix components or limited nutrients may restrict aflatoxin synthesis.
• Storage temperature, pH, and atmospheric conditions are critical factors in controlling aflatoxin contamination in fruit jams.