Antagonistic Effect of Yeast, Acetic Acid Bacteria and Mangosteen Rind Extract on Aflatoxigenic Aspergillus flavus in Unfermented Cocoa Beans

Yeasts and bacteria are two of common biocontrol agents to control mycotoxigenic fungi. Meanwhile, the mangosteen rind extract contains xanthone and gartanin compounds for antioxidant, antiproliferation, antiinflammation, antimicrobial, and anticancer. The objectives of this research were to test the effects of yeasts, acetic acid bacteria (AAB), and mangosteen rind extract on the aflatoxigenic A.ybegillz1sj7av.w growth and aflatoxin production in unfermented cocoa beans. Four yeast isolates, i.e., I~satcbenkia orientalis (lo) BIO 211291, 286 and 288, and Endomyces fbulger (E! BIO 132219; one bacteria isolate of Acetobacter aceti (Aa) FNCC0016; and mangosteen rind extract (MRE) were tested for their capabilities in inhibiting an aflatoxigenic A.javus (Afj BIO 3361/747 growth using the well method (in vitro). Two types of yeast (10 BIO 211291 and 288) were combined with A a and MRE in cocoa beans (in vivo). Aflatoxin production was analyzed using Thin h y e r Cbromathograph_v (TLC). The results showed that interaction of l o BIO 211291 and 288, and EfBIO 132219 on aflatoxigenic Af were interaction with inhibition zone > 2 mm (type D), while the interaction type of l o BIO 211286 on Afwere mutual intermingling growth, where both fungi grew into each other without any macroscopic sign of interaction (type A). The best treatment in agar media (in vitro) was Io BIO 211288 + A a on Potato Dextrose Agar + 12 g/L MRE. The highest l o population was 5.88 log cfu/g on cocoa beans inoculated by I o BIO 211291 + MRE in 1 day after inoculation, while the highest A. aceti population was 4.74 log cfu/g on cocoa beans with l o BIO 21 1291 + BIO 211288 + A a in 3 days after inoculation. Two best treatments were I o BIO 211288 + A a + MRE and I o BIO 211291 + BIO 211288 + A a + MRE, because there were no A.j7avuspopulation since 3 until 11 days after inoculation. Aflatoxin in all samples treatment was lower than limit detection B1 (< 2.20 ppb), B2 (< 3.50 ppb), (GI < 0.54 ppb), dan (G2 < 1.00 ppb).