Effect of ultra-superheated steam on aflatoxin reduction and roasted peanut properties

BACKGROUNDAflatoxins are carcinogenic toxins produced by Aspergillus flavus and Aspergillus parasiticus that are found naturally in peanut. It requires extremely high temperatures to eliminate aflatoxins from the nuts. The aims of this study were to investigate the effect of ultra-superheated steam (USS) on the reduction of aflatoxin B-1 (AFB(1)) accompanying the roasting process and to determine roasted peanut qualities that affected consumer acceptance. RESULTSWhole peanut kernels were intentionally contaminated by AFB(1) standard solution at the level of 5010 mu g kg(-1) before subjecting to USS treatment at 300-400 degrees C between 10 and 80s. The high temperature of USS could significantly decrease AFB(1) level to 9.83 +/- 3.51, 15.33 +/- 2.23 and 8.95 +/- 2.32 mu g kg(-1) when 300 degrees C for 80s, 350 degrees C for 40s and 400 degrees C for 40s were employed, respectively. AFB(1) was reduced as much as 83.86 +/- 2.66% when 400 degrees C for 40s was applied. The moisture content of treated peanuts was decreased to less than 3% and browning index was developed from 30.96 +/- 1.59 to 95.76 +/- 7.23. CONCLUSIONHigher roasting degree was obtained according to the increase in browning index. Oil quality showed that peroxide values and acid values were greatly below the allowance level. USS could effectively decrease AFB(1) and render expectable roasting qualities of peanut. (c) 2017 Society of Chemical Industry