Abstract

Dry spices are at risk of microbial contamination because traditional drying processes fail to eliminate unwanted microorganisms. Radiofrequency (RF) has shown the potential for pasteurizing agricultural products. To control the natural microflora, we added a decontamination step before hot-air drying for preparing Sichuan pepper. Sichuan pepper kernels were heated by RF to 50 °C (cold spot), held for 10 min, and dried in a hot-air convection oven at 50 °C for 10 h. The total plate counts (TPCs) and quality loss were traced and compared with those following a 50 °C hot-air drying process as the control group. RF heating and holding processes achieved reductions of 0.68 ± 0.52 and 1.63 ± 0.35 log CFU/g (dry base, d.b), respectively, in Sichuan pepper TPCs. The final products treated by RF had 2.45 ± 0.19 log CFU/g (d.b), whereas the TPC in the control group remained as high as 2.95 ± 0.20 log CFU/g (d.b). Sichuan pepper kernels in the two groups showed similar drying rates; however, RF-treated Sichuan pepper lost most of its oil droplets, resulting in significant reductions in flavor and color. The results indicated that RF-assisted hot-air drying could efficiently control the natural microflora of Sichuan pepper, but with severe quality deterioration.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call