Characterization of Flaxseed Oil Bimodal Emulsions Prepared with Flaxseed Oil Cake Extract Applied as a Natural Emulsifying Agent

Abstract

Currently, a majority of oilseeds plants are converted into byproducts and waste materials during processing. Press cakes are rich in valuable biopolymers, such as proteins and polysaccharides (fiber, lignans, etc.). In this study flaxseed oil cake extract (FOCE) was used to stabilize flaxseed oil-in-water emulsions. The effect of FOCE with various flaxseed oil concentrations (10–50% v/v) on several physicochemical properties of emulsions, such as stability, rheology, color and particle size was investigated. The rheological parameters suggested that all samples were non-Newtonian fluids, whereas particle size measurements and calculation SPAN index provided information about the broadness of emulsions particle size distribution. FOCE was able to efficiently stabilize oil/water interfaces with a high oil content. Results obtained for FOCE were compared with effects for synthetic emulsifier (Tween 80) and separated FOCE compounds (flaxseed gum and flaxseed protein). FOCE emulsifying activity is a result of different water-holding and oil-binding capacities of flaxseed gum and protein. This result is an intriguing conclusion regarding the necessity for using pure emulsifiers, showing the possibility of using a bio-based extract containing biopolymers, which is part of the principles of circular economy and the idea of zero-waste. The results give the opportunity to use FOCE as an ingredient in efficient flaxseed oil emulsions stabilizer for food applications.

Formulation and Evaluation of Spray-Dried Reconstituted Flaxseed Oil-in-Water Emulsions Based on Flaxseed Oil Cake Extract as Emulsifying and Stabilizing Agent

“…The droplet size was essential for the stability of the emulsion, as emulsions with a controlled particle size exhibited greater stability. Moreover, it was suggested that the smaller the droplets, the higher was the emulsion stability [5]. In fact, the lowest D 4,3 (2.693 ± 0.00 µm) and D 3,2 (2.166 ± 0.01 µm) after reconstitution were observed for the sample FOCE-MS-20%.…”

“…This might be an explanation for the decreased yield in this study, which is observed for samples with FOCE. The dry matter content of FOCE was reported at approximately 3% and consists of flaxseed proteins, polysaccharides (flaxseed gum), and another extractable compounds [5]. In the presented study, FOCE was used as a liquid phase and its components played the role of emulsifying agents, but should also be calculated for the total solids concentration.…”

“…The processing of FOC into Flaxseed Oil Cake Extract (FOCE) (used as a liquid phase) was carried out following the procedure described elsewhere [5]. Starch Capsul ® and maltodextrin were used as a wall material in the ratio 1:1 (8.5 g of each per 100 mL of FOCE).…”

“…The scale according to Reddy et al (presented in Table 2) was used to characterize the powders' flowability (C) and cohesiveness (HR) [21]. The indices were calculated from the bulk (ρ b ) and tapped (ρ t ) densities, according to the Formulas (5) and 6:…”

“…The optical properties of the sample were defined as follows-refractive index 1500 and absorption 1.00. Droplet size measurements were described as the volume-weighted mean diameter d 4,3 = ∑n i d 4i /∑n i d i3 and d 3,2 = ∑n i d 3i /∑n i d i2 , where n i is the number of droplets of diameter d i [5].…”