Thermo-Oxidative Stability Evaluation of Bullfrog (Rana catesbeiana Shaw) Oil

Abstract

Bullfrog oil (BO), a natural product obtained from recycling of adipose tissue from the amphibian Rana catesbeiana Shaw, has been recently evaluated as a therapeutic activity ingredient. This work aimed to evaluate the long-term and accelerated thermal oxidative stabilities of this product, which is a promising raw material for emulsion technology development. BO was extracted from amphibian adipose tissue at 70 °C with a yield of 60% ± 0.9%. Its main fatty acid compounds were oleic (30.0%) and eicosapentaenoic (17.6%) acids. Using titration techniques, BO showed peroxide, acid, iodine and saponification indices of 1.92 mEq·O2/kg, 2.95 mg·KOH/g oil, 104.2 g I2/100 g oil and 171.2 mg·KOH/g oil, respectively. In order to improve the accelerated oxidative stability of BO, synthetic antioxidants butylhydroxytoluene (BHT) and buthylhydroxyanisole (BHA) were used. The addition of BHT increased the oxidation induction time compared to the pure oil, or the oil containing BHA. From the results, the best oil-antioxidant mixture and concentration to increase the oxidative stability and allow the oil to be a stable raw material for formulation purposes was derived.

Oil Extraction from Rana catesbeiana by Supercritical Carbon Dioxide and Mechanical Pressing

“…The mean AV and the maximum PV were 4.90 ± 0.40 mg KOH g −1 and 1.26 ± 0.25 mEq kg −1 , respectively. The AV and PV of the FBB oil obtained in the investigated temperatures (40 to 90 °C) are similar to the values (2.95–4.08 mg KOH g −1 and 1.93 mEq kg −1 ) reported in the literature by Rutckeviski et al () and Lopes et al ().…”

“…Based on the total amount of 400 ton year −1 of bullfrog meat produced and that the FBB corresponds to 2 wt.% of this quantity, 4.8 ton year −1 of FBB oil can be obtained. Similar yields (60–62 wt.%) are reported by Amaral‐Machado et al (), Méndez et al (), and Rutckeviski et al (), using cooking as extraction method at temperatures of 80, 98, and 70 °C for 40, 30, and 30 min, respectively. Utilizing the same method, with an extraction time of 40 min, Lopes et al () reported yields within the range of 10 to 85 wt.% for temperatures of 35 to 200 °C, respectively.…”

“…The studies reported in the literature about oil extraction from the FB of the R. catesbeiana (Amaral‐Machado et al, ; Méndez et al, ; Rutckeviski et al, ) have only evaluated methods such as solvent extraction and cooking extraction. Taking this into account, the study of fat body of bullfrog (FBB) oil obtained from the conventional ME and unconventional SFE methods can become an opportunity to increase the competitiveness of the bullfrog industry.…”

Bullfrog Oil Reduces the Carrageenan-induced Edema in Wistar Rats by <i>in vitro</i> Reduction of Inflammatory Mediators

“…6 fatty acids, in addition to cholesterol 9. 5 and ethyl-iso allocholate 3.5 6,9,10 . However, despite its broad popular use, especially against inflammatory conditions, there is a lack of scientific evidence supporting such therapeutic property.…”

Use of Natural Products in Asthma Treatment

“…is oil has been used by the traditional medicine to treat inflammatory disorders, especially asthma [223]. is oil is composed of a mixture of monoand polyunsaturated fatty acids and bile-derived steroid compound (ethyl iso-allocholate) [81,224], which are responsible for its therapeutic properties [81].…”