The Effect of Sanitizers on the Native Microflora of Mung Bean Seeds (Vigna radiata)

摘要

The ingredients of sanitizers varies from natural products such as botanical extracts (lemon and orange extract) and cleaning agents derived from natural plant oil to chemicals such as surfactant solutions, combinations of surfactants with organic or mineral acids and alkaline washes that can remove wax, soil, harmful substances including agricultural chemicals found on fruits and vegetables. Most companies do not make any claims about the microbial reduction in fruits and vegetables by using their sanitizers. This study was therefore conducted to evaluate the effect of five commercial sanitizers available in the local market (labeled as A, B, C, D and E) in reducing microbial population found on the mung bean seeds. About 10 g of mung bean seeds in a stomacher bag were treated with the test solutions for 10 min, shaken at 170 rpm and compared with untreated seeds and sterile deionised water. Microbial populations were enumerated by using Plate Count Agar (PCA) for total bacterial counts, Potato Dextrose Agar (PDA) for yeast and mould and E. coli/coliform Agar for E. coli and coliforms. All cleansers were tested at minimum concentration as recommended by the manufacturer. Among the 5 commercial sanitizers, A, C and D were effective in significantly reducing yeast and mould to an undetectable level compared to B and E. Sanitizers A, C and D also showed comparable results in reducing the total bacterial counts compared to the other sanitizers. Only sanitizers A and B were effective in significantly reducing the E. coli and coliforms. All the 5 sanitizers did not inhibit the seeds from sprouting although, sanitizer D germination percentage was statistically difference from untreated seeds or seeds treated with sterile deionised water.