Heat stability of Trichoderma asperelloides SKRU-01 culture filtrates: Potential applications for controlling fungal spoilage and AFB₁ production in peanuts

This study aimed to examine the heat stability of culture filtrates of Trichoderma asperelloides SKRU-01 (culture filtrates SKRU-01) over a temperatures range (40-121 degrees C) and the effects on the antifungal activity against two aflatoxin-producing strains (Aspergillus parasiticus TISTR 3276 and A. flavus PSRDC-4), aflatoxin B-1 (AFB(1)) degradation, and the role in mycotoxin control in peanuts. The impact of SKRU-01 culture age (2-12 day-old) on both pathogenic strains revealed that the culture age of 6-12 day-old cultures exhibited no significant difference (p > 0.05) of growth inhibition for strain TISTR 3276 (81.89-82.28 %) and 4-12 day-old cultures for strain PSRDC-4 (74.87-79.06 %). The heat-treated temperatures from 40 degrees C to 121 degrees C caused no significant (p > 0.05) reduction of mycelial growth for strain TISTR 3276 (82.61 % to 79.13 %) but significant (p < 0.05) deduction for strain PSRDC-4 (75.15 % to 59.17 %). Heat treatment of the culture filtrates SKRU-01 at 60-121 degrees C caused the reduction on spore germination inhibition (from about 68 % to 58.16 % for strain TISTR 3276 and 51.11 % for strain PSRDC-4). These results indicate that strain TISTR 3276 exhibited greater susceptibility to culture filtrates SKRU-01 compared to strain PSRDC-4. Furthermore, the culture filtrates SKRU-01 exhibited remarkable thermal stability at 121 degrees C, degrading AFB(1) to 63.91 %. Application of heat-stable culture filtrates SKRU-01 in peanuts demonstrated that the reduction in fungal population and AFB(1) production of both pathogenic strains depended significantly (p < 0.05) on the level of heat treatment. The non-treated and 40 degrees C treated culture filtrates SKRU-01 could reduce AFB(1) production to lower than the Standard Aflatoxin Limitation (<20 mu g/kg), ensuring food safety and mitigating the health risks associated with aflatoxin exposure.