High resistance to heating treatments is a prerequisite for ready-to-eat (RTE) surimi products. In this study, emulsion-formulated surimi gels were prepared, and the effects of oil types and emulsification degrees on the thermal stability of surimi gel were investigated. The results showed the gel properties of surimi gels were modulated by oil types and emulsification degrees. In detail, the rising pre-emulsification ratio caused the increase of the emulsifying activity index (EAI) and decrease of emulsifying stability index (ESI) for both emulsions. The larger droplet sizes of perilla seed oil than soybean oil may be responsible for their emulsifying stability difference. The gel strength, water retention, dynamic modulus and texture properties of both kinds of surimi gels displayed a firstly increased and then decreased tendency with the rising pre-emulsification ratios. The peak values were obtained as perilla seed oil emulsion with emulsification ratio of 20% group (P1) and soybean oil emulsion with emulsification ratio of 40% group (S2), respectively. Anyway, all emulsion gels showed higher thermal stability than the control group regardless of oil types. Similar curves were also obtained for the changes of hydrogen bond, ionic bond and hydrophobic interactions. Overall, perilla seed oil emulsion with emulsification ratio of 20% (P1 group) contributed to the improved thermal stability of surimi gels.
Polylactides (PLAs) are a class of polymers that are very appealing in biomedical applications due to their degradability in nontoxic products, tunable structural, and mechanical properties. However, they have some drawbacks related to their high hydrophobicity, lack of functional groups able to graft bioactive molecules, and solubility in unsafe solvents. To circumvent these shortcomings, porous scaffolds for tissue engineering were prepared by vigorously mixing a solution of isotactic and atactic PLA in nontoxic ethyl acetate at 70 °C with a water solution of choline taurinate. The partial aminolysis of the polymer ester bonds by taurine -NH2 brought about the formation of PLA oligomers with surfactant activity that stabilized the water-in-oil emulsion. Upon drying, a negligible shrinking occurred, and mechanically stable porous scaffolds were obtained. By varying the polymer composition and choline taurinate concentration, it was possible to modulate the pore dimensions (30–50 µm) and mechanical properties (Young’s moduli: 1–6 MPa) of the samples. Furthermore, the grafted choline taurinate made the surface of the PLA films hydrophilic, as observed by contact angle measurements (advancing contact angle: 76°; receding contact angle: 40°–13°). The preparation method was very simple because it was based on a one-pot mild reaction that did not require an additional purification step, as all the employed chemicals were nontoxic.
The behavior of a water-in-oil emulsion stabilized with asphaltenes under the action of an inhomogeneous alternating electric field has been studied. The experimental technique is based on the use of microfluidics, optical microscopy, and high-speed video filming. Quantitative estimates of the parameters characterizing the dynamics of the destruction of the emulsion, depending on the frequency and amplitude of the applied field, are obtained. The method will be useful in the development of effective methods for breaking emulsions and modifying existing technologies for separating oil emulsions into phases.
Effects of essential oils, namely Cinnamon, Citronella, Peppermint, Eucalyptus, Lavender, Thyme, Rosemary, Basil oil enriched coconut oil emulsion on shelf life and quality of ambient stored mango cv. Rangkuai were evaluated. Citronella oil (Cymbopogon nardus) @ 0.5% (v/v) was found to maintain low weight loss (5.14%), high fruit firmness (52.85 N/cm2), ascorbic acid (33.62 mg/100 g), total phenol (89.67 mg/100 g) and least fruit decay (8.33%) at 12 days after storage (DAS) and had delayed accumulation of pulp colour (L: 91.06, a: -2.61, b : 24.03), β-carotene (3.85 mg/100 g) and total sugar (4.46%) for delayed ripening, thus found to extend the shelf life by 7 days compared with control (12.85 days).
Bangladesh J. Bot. 50(4): 1143-1149, 2021 (December)
Emulsion Surimi Gel with Tunable Gel Properties and Improved Thermal Stability by Modulating Oil Types and Emulsification Degree