The efficacy of radio frequency treatment and its potential for control of storage fungi and
Pitipong Thobunluepop, Korrakitt Chaloeithoi, Suchada Vearasilp and Supasark Limpiti
Book of abstracts, APS2010 & SEAsia2010 & GMS2010, August 2-4, 2010, Radisson Hotel, Bangkok, Thailand
2010
บทคัดย่อ
The experiment was aimed to evaluate the efficacy of radio frequency (RF) heat treatment to eradicate storage fungi and control of alflatoxin 81 contamination. The experiment was designed in 5 x 5 Factorial in CRD with 10 replications. Treatments were RF heated temperatures; 50, 60, 70, 80°C and control (not treated), and RF treated time; 4, 5, 6, 7, and 8 minutes. Then, maize grain was sampled immediately after treatment and then for each 3 months. The experiment found that, after RF treatment, all species of storage fungi; Aspergillus flavus,Aspergillus niger, Rhizopus sp., and Penicillium sp. were eradicated while RF treating temperature and duration increased. The best RF treated condition was 80°C with 8 minutes that could eradicate those storage fungi for 94.20, 91.20, 91.20, and 92.80 %, respectively. The RF treated temperature was the main factor that could control aflatoxin 81 contamination. Afltoxin 81 contamination decreased significantly while RF treated temperature was 80°C (6.93 ppb) as compared with control (52.33 ppb). Additionally, the aflatoxin 81 contamination could be predicted by RF treatment as following y = 40.10 + 7.15a - 10.11b - 1.13c, while was aflatoxin 81 contamination, a was storage duration (1 = before storage, 2 = stored for 6 months, and 3 = stored for 12 months), b was RF treating temperature (1 = no RF treatment, 2 = RF treated at 50°C, 3 = RF treated at 60°C, 4 = RF treated at 70°C, and 5 = RF treated at 80°C ), and c was RF treating time (1 = RF treated for 4 mins, 2 = RF treated for 5 mins, 3 = RF treated for 6 mins, 4 = RF treated for 7 mins, and 5 = RF treated for 8 mins) (R-Squared = 0.689).