Optimizing Preparation of Fish Scale Collagen Peptide/Sacha Inchi (Plukenetia volubilis L.) Seed Oil Nanoemulsion

Abstract This study presents results of extracting hydrolyzed collagen peptide from fresh‐water fish scale and using it to prepare a nanoemulsion based on Sacha inchi ( Plukenetia volubilis L.) seed oil and collagen peptide. The sacha inchi seed oil is extracted from the seeds of Sacha Inchi (abbreviated as sachi) plant and contains approximate 45 % triple omega 3–6‐9 (ω‐3, ω‐6, ω‐9) content. Pseudo‐ternary phase diagrams of three components: aqueous collagen solution, sachi seed oil, and surfactant/co‐surfactant (S mix ) have been constructed. The parameters including the composition of S mix , sachi seed oil, and aqueous collagen solution have been selected to optimize the technology factors for the emulsion process. A quadratic regression equation was chosen, and experimental planning following the Box‐Behnken model using response surface methodology was used to optimize the preparation conditions for the nanoemulsion. The average droplet size of the emulsion systems is the object function for optimization. The S mix is a mixture of surfactant (Tween80) and propylene glycol (PG) with different ratios of Tween80/PG of 1/1, 2/1, 3/1, and 4/1, corresponding to the formation of four emulsion systems, code 1, 2, 3, 4, respectively. The optimal parameters for each emulsion system are different, however, the aqueous collagen solution contains a higher proportion in emulsions. Under the optimal conditions, the predicted values of the objective function of emulsions code 1–code 4 ranged from 95.62 to 185.14 nm, increasing together with the Tween80 ratio in S mix . The experiment values of the objective function of emulsions code 1–code 4 prepared under the optimal conditions are 104.22, 133.70, 159.27, and 207.87 nm, respectively. These values are close to the predicted values, suggesting that the suitability of the experiment and theory. Additionally, the stability of the nanoemulsion prepared under the optimal conditions is also evaluated. A stable nanoemulsion is potentially for loading nutraceuticals and vitamins for applications in personal health care and medicinal fields.