SHELF-LIFE EXTENSION STUDIES OF DAUCUS CAROTA

ABSTRACT

Carrot (Daucus carota) is an important food crop with a low shelf life after harvesting. It has a very significantly high nutritional value. This study aimed at extending the shelf life of Daucus carota by inhibiting microbial growth using zinc oxide nanoparticles combined with aqueous extract of Phyllanthus niruri during storage at ambient conditions. Fresh carrot fruits were purchased from New Benin market, Benin City in Edo state. The parameters used in selecting carrot for this study include uniformity in colour, size, absence of physical damages and bacteria infection. They were kept in sterile polythene bags before transporting to the microbiology laboratory where they were then trimmed and washed with distilled water to remove dirt. After which appropriate microbiological analysis were carried out and the plant extract nanoparticles were prepared and the carrots where treated with it. In this study, it was observed that zinc oxide nanoparticles combined with Phyllanthus niruri extract has harmful effects under in vivo conditions on all tested carrots. The severity of disease quantifies the extent of disease damage to the carrot and was determined using the disease severity rating (0-5), with 0 showing no visible disease growth on the carrot and 5 indicating total rot. It is further challenging with nanoparticles as its toxicity has been linked with its size. From the results of these study, zinc oxide nanoparticles combined with Phyllanthus niruri extract did not demonstrate significant Antibacteria activity against the tested isolates promoting rot in carrot. Further studies should however be carried out to ascertain the effectiveness of these treatment in other systems.