The Fatty Acid Compositions, Irritation Properties, and Potential Applications of Teleogryllus mitratus Oil in Nanoemulsion Development

Abstract

This study aimed to characterize and investigate the potential of the oils from Gryllus bimaculatus, Teleogryllus mitratus, and Acheta domesticus to be used in nanoemulsions. The oils were extracted by a cold press method and characterized for their fatty acid profiles. Their irritation effects on the chorioallantoic membrane (CAM) were evaluated, along with investigations of solubility and the required hydrophilic-lipophilic balance (RHLB). Various parameters impacting nanoemulsion generation using high-pressure homogenization were investigated. The findings revealed that G. bimaculatus yielded the highest oil content (24.58% w/w), followed by T. mitratus (20.96% w/w) and A. domesticus (15.46% w/w). Their major fatty acids were palmitic, oleic, and linoleic acids. All oils showed no irritation, suggesting safety for topical use. The RHLB values of each oil were around six-seven. However, they could be successfully developed into nanoemulsions using various surfactants. All cricket oils could be used for the nanoemulsion preparation, but T. mitratus yielded the smallest internal droplet size with acceptable PDI and zeta potential. Nanoemulsion was found to significantly enhance the antioxidant and anti-skin wrinkle of the T. mitratus oil. These findings pointed to the possible use of cricket oils in nanoemulsions, which could be used in various applications, including topical and cosmetic formulations.

Keywords: Acheta domesticus; Fourier transform infrared spectrometer; Gryllus bimaculatus; Teleogryllus mitratus; cricket; fatty acid; nanoemulsion; required hydrophilic–lipophilic balance.

Figure 1

External appearance of G. bimaculatus (a), T. mitratus (b), A. domesticus (c), and the oils extracted from G. bimaculatus (d), T. mitratus (e), and A. domesticus (f).

Figure 2

FR-IR spectra of the oils derived from G. bimaculatus (a), T. mitratus (b), and A. domesticus (c).

Figure 3

Photographs from the HET-CAM test illustrate the CAM before exposure to the test sample (0 min) and after exposure to a positive control (1% w/v sodium lauryl sulfate aqueous solution), negative control (normal saline solution), and oils extracted from G. bimaculatus, T. mitratus, and A. domesticus for 5 min and 60 min. The letter “H” represents vascular hemorrhage, “L” represents vascular lysis, and “C” represents vascular coagulation.

Figure 4

Photographs from the solubility test illustrate the lowest amount of ethanol, dimethyl sulfoxide (DMSO), mineral oil, and olive oil that completely solubilized the oils extracted from G. bimaculatus (a), T. mitratus (b), and A. domesticus (c).

Figure 5

The external appearance of emulsions, composed of a mixed emulsifier with HLB values ranging from 4.3 to 15.0, water, and varying cricket oils, including G. bimaculatus (a), T. mitratus (b), and A. domesticus (c), observed at 0, 1, 12, and 24 h after preparation. Additionally, the size of internal droplets and the percentage of phase separation in each emulsion derived from G. bimaculatus (d), T. mitratus (e), and A. domesticus (f), were evaluated after 24 h.

Figure 6

External appearance of nanoemulsions containing oils derived from G. bimaculatus (GB), T. mitratus (TM), and A. domesticus (AD) before (a) and after (b) centrifugation at 5000 rpm for 15 min, internal droplet size (☐) and polydispersity index (PDI, ●) (c), zeta potential (d), and viscosity (e) of each nanoemulsions. The letters a, b and c, as well as the symbols α and β, denote statistically significant differences among nanoemulsion formulations.

Figure 7

External appearance of nanoemulsions containing oils derived from T. mitratus at the concentrations ranging from 1 to 5% w/w before (a) and after (b) centrifugation at 5000 rpm for 15 min, internal droplet size (☐) and polydispersity index (PDI, ●) (c), zeta potential (d), and viscosity (e) of each nanoemulsions. The letters a, b, and c, as well as the symbols α, β, and γ, denote statistically significant differences among nanoemulsion formulations.

Figure 8

External appearance of nanoemulsions containing oils derived from T. mitratus and various surfactant types, including Tween^® 20 (T20), Tween^® 80 (T80), Tween^® 85 (T85), and lecithin (LC), before (a) and after (b) centrifugation at 5000 rpm for 15 min, internal droplet size (☐) and polydispersity index (PDI, ●) (c), zeta potential (d), and viscosity (e) of each nanoemulsion. The letters a, b, c, and d, as well as the symbols α and β, denote statistically significant differences among nanoemulsion formulations.

Figure 9

External appearance of nanoemulsions containing oils derived from T. mitratus and various concentrations of Tween^® 85, ranging from 3 to 5% w/w, before (a) and after (b) centrifugation at 5000 rpm for 15 min, internal droplet size (☐) and polydispersity index (PDI, ●) (c), zeta potential (d), and viscosity (e) of each nanoemulsion. The letters a and b, as well as the symbols α and β, denote statistically significant differences among nanoemulsion formulations.

Figure 10

External appearance of nanoemulsions containing oils derived from T. mitratus without (CON) and with various types of humectants, including glycerin (GLY), propylene glycol (PG), butylene glycol (BG), and sorbitol (SOR), before (a) and after (b) centrifugation at 5000 rpm for 15 min, internal droplet size (☐) and polydispersity index (PDI, ●) (c), zeta potential (d), and viscosity (e) of each nanoemulsion. The letters a, b, and c, as well as the symbols α, β, γ, and δ, denote statistically significant differences among nanoemulsion formulations.

Figure 11

Ferric reducing antioxidant power (a) and dose response curves on the inhibition of DPPH radical (b) and collagenase activities (c) of T. mitratus oil and nanoemulsion containing 5% w/w T. mitratus oil. The asterisk symbol (*) denotes statistically significant differences between T. mitratus oil and nanoemulsion containing 5% w/w T. mitratus oil formulations (p < 0.05).