Preparation and Characterization of Camelina sativa Protein Isolates and Mucilage

Abstract

Processes for the production of protein isolates from camerlina Camelina sativa were developed by modifying the procedure used for other seeds from the Brassicaceae family, such as rapeseed and mustard. The procedure consisted of defatting the seed followed by alkaline extraction at pH 11, ultra‐ and diafiltration using a 5‐kDa membrane, isolelectric precipitation of the proteins at pH 5 and recovery of the acid soluble protein isolates (SPI) after further filtration and drying. Protein yields as precipitated protein isolate and SPI were 10.7 and 11.4%, containing 67 and 42%, respectively. Due to the high concentration of mucilage in camelina, a water‐to‐seed ratio of 30 had to be used for protein extraction from the hexane‐defatted seed and most of the mucilage had to be removed prior to the defatting process. A rapid mucilage extraction process using water at 55 °C was developed. Camelina mucilage absorbs water and oil. Viscosity measurements of dried and redissolved mucilage showed the highest values at natural pH, and the viscosity increased rapidly above 1% solids concentration. It may be a useful product in the food and pharmaceutical industries.

Camelina sativaComposition, Attributes, and Applications: A Review

“…Protein yields were low at 11.4% for the soluble proteins and 10.7% for the precipitated proteins, while the protein contents were 67% and 42%, respectively. Precipitated protein yield reported by Boyle et al [11] was almost four times higher than the one reported by Sarv et al [66] One possible explanation is the higher alkaline pH that was used for the extraction and the addition of ammonium sulfate (pH 12 for Boyle et al [11] vs pH 11 for Sarv et al [66] ). Li et al [65] studied the impact of the pH on the solubilization of glutelin, the main protein present in camelina meal, and they found that the solubility of glutelin was ≈1.75 times higher at pH 12 than at pH 11.…”

“…For the spring cultivars (66), the total concentration of flavonoids varied from 404 ± 38.5 to 429.9 ± 13.8 mg kg −1 , which was significantly lower than for the winter cultivars (9) (507.3 ± 51.4 to 526.4 ± 10.4 mg kg −1 ). Similar results were reported for the phenolic acids, with the concentration ranging from 2043.6 ± 62.5 to 2174.0 ± 145.2 mg kg −1 in the spring cultivars and from 3936.0 ± 210.8 to 3704.7 ± 195.4 mg kg −1 in the winter cultivars.…”

“…From these results, we may conclude that the salt precipitation process applied on CPDC meal is the most interesting process in terms of protein yield and protein purity. In their work, Sarv et al [66] used defatted camelina seeds as the starting material to isolate camelina proteins. Due to the high concentration of mucilage in camelina seeds, the mucilage had to be removed prior to the defatting step using water at 55 °C for 1 h. Camelina proteins were isolated by alkaline extraction at pH 11, followed by ultrafiltration and diafiltration using a 5 kDa membrane, and isoelectric precipitation of the proteins at pH 5 and recovery of the acid soluble proteins and of the precipitated proteins, before drying.…”

“…When compared to a soy protein isolate (92% protein), camelina concentrates showed good functional properties, except for solubility at pH 7 and emulsification stability, where the soy protein isolate showed significantly better properties. In their work, Sarv et al [66] characterized the water and oil absorption ca-pacities of their camelina protein concentrate obtained after isoelectric precipitation. They reported values of 158% ± 5.2% and 107% ± 4.7%, respectively.…”

“…The extraction of camelina protein is a challenge, owing to the presence of mucilage in the camelina meal, which complicates wet extraction processes, due to its high water-binding capacity. [66] In future works, it would be of interest to develop an integrated process that would consist of a degumming step to extract the mucilage from the whole camelina seeds, followed by an oil extraction step, and finally by a protein extraction step (Figure 2). A similar approach has already been successfully applied for flaxseed, which also has a high mucilage content.…”