Smart delivery of plant derived metabolites through nano encapsulation against insect pests of stored products

Abstract

newline Experiments were conducted to develop and evaluate the nanoformulations of sweet newlineflag (Acorus calamus Linn.), lemongrass (Cymbopogon flexuosus (Steud.) Wats), peppermint newline(Mentha piperita Linn. ), and#946;- asarone, citral, citronellal, geraniol and menthol on rice weevil, newlineSitophilus oryzae (Linn.) and pulse beetle, Callosobruchus maculatus (Fab.). The extraction newlineof A. calamus rhizome, C. flexuosus leaf and M. piperita leaf has yielded 4.17, 1.30 and newline1.50% w/v oil respectively. and#946;-asarone (91.54%), Geraniol (52.96%) and Levomenthol newline(30.77%) were found to be the principal compound of A. calamus rhizome, C. flexuosus leaf newlineand M. piperita leaf respectively. newlineBased on the results of the dermal toxicity of the three plant extracts against S. oryzae newlineand C. maculatus the coarse emulsions of Sweet flag 6 EC, Peppermint 5 EC (with newlinehydrophilic-lipophilic balance (HLB) value 10.0) and Lemongrass 5 EC (with HLB- 12.0) newlinewere developed. Nanoemulsions of plant extracts were developed by using ultrasonicator newline(high energy method), at a high frequency of 20 kHz and power output of 1500 W for 30 newlineminutes. The mean droplet size of the A. calamus, C. flexuosus and M. piperita newlinenanoemulsions were 68.2, 83.3 and 117.3 nm, respectively. In spontaneous emulsification newlinemethod (low energy method), nanoemulsions of A. calamus (AF), C. flexuosus (CF) and newlineM. piperita (MF) oils were developed with different ratios of oil and surfactant viz., 1: 0.5 newline(AF1, CF1 and MF1), 1:1 (AF2, CF2 and MF2), 1:1.5 (AF3, CF3 and MF3) and 1:2 v/v (AF4, newlineCF4 and MF4). In A. calamus nanoemulsion, the droplet size was found to be minimum in AF4 newline(17.9 nm) followed by AF3 (31.5 nm), AF2 (33.4 nm) and AF1 (51.2 nm). The droplet size newlinedecreased with increase in the surfactant concentration. The same trend was observed in C. newlineflexuosus nanoemulsion where the minimum droplet size was observed in CF4 (58.8 nm) newlinewhich contain higher surfactant (1:2) concentration. Similarly, in M. piperita nanoemulsion newlinethe smaller mean droplet size was observed in MF4 (52.9 nm). Furt