نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 دانش آموخته بین المللی کارشناسی ارشد، گروه علوم و مهندسی صنایع غذایی، دانشکده کشاورزی، دانشگاه کردستان،
2 گروه علوم و مهندسی صنایع غذایی، دانشکده کشاورزی، دانشگاه کردستان
3 دانش آموخته دکتری، گروه علوم و صنایع غذایی، دانشگاه صنعتی اصفهان
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objective
Growing concerns regarding the safety of synthetic colorants, along with a rising trend toward natural compounds, have highlighted phycocyanin as a prominent natural pigment. Phycocyanin, primarily extracted from cyanobacteria such as Spirulina platensis, offers health-promoting properties—including antioxidant, anti-inflammatory, and immune-boosting effects—in addition to its brilliant blue color. However, its low stability against temperature, light, and pH poses significant challenges for its application. Therefore, this study aimed to develop an encapsulation system based on alginate ionic gelation and chitosan coating to entrap phycocyanin.
Materials and Methods
In this study, primary phycocyanin-alginate capsules (at concentrations of 1%, 2%, and 3% w/v) were first prepared using the ionic gelation method in the presence of calcium ions. The formulated capsules were then homogenized using an Ultra-Turrax at 12,000 rpm to reduce their size to the nanometer scale. Subsequently, the produced nanoparticles were immersed in a 0.5% (w/v) chitosan solution for 30 minutes to form a chitosan coating on their surface. Finally, to create a secondary coating and establish a multi-layered structure, the chitosan-coated particles were submerged in a 0.2% (w/v) sodium alginate solution for 10 minutes.
Results
Preliminary evaluations revealed that the maximum absorption wavelength (λmax) of the commercial phycocyanin used was 620 nm, with a purity ratio of 1.6. This value indicates an appropriate purity level for food-grade applications. The encapsulation efficiency (EE) results demonstrated that increasing the sodium alginate concentration from 1% to 3% (w/v) significantly enhanced the EE, reaching a maximum of 93.34% in the 3% treatment. Conversely, the loading capacity (LC) exhibited a decreasing trend (from 90% to 67%) due to the increased mass of the wall matrix.
Dynamic Light Scattering (DLS) analysis revealed a bimodal structure, where the dominant nanoparticle population ranged from 160 to 200 nm; moreover, higher polymer concentrations led to an increase in the particle size of phycocyanin-loaded formulations. Scanning Electron Microscopy (SEM) images confirmed a predominantly spherical morphology for the nanoparticles, alongside some aggregations induced by the freeze-drying process. X-ray Diffraction (XRD) phase analysis showed that the entirely amorphous phycocyanin and the semi-crystalline primary polymers transformed into an ordered nanocrystalline structure following encapsulation. This transformation—characterized by distinct peaks at 2θ angles of 27°, 32°, 45°, and 55°—was attributed to polyelectrolyte complex formation and the adoption of the calcium ion-alginate network model (egg-box model). Furthermore, Differential Scanning Calorimetry (DSC) thermograms indicated that encapsulation markedly increased the phase transition energy and enthalpy, which is ascribed to dense hydrogen bonding and the entrapment of structural water.
Conclusion
In conclusion, results of this study introduce the successful production of a multilayer nanocapsule as an efficient carrier to protect this bioactive pigment and exploit its functional properties in the food and pharmaceutical industries.
کلیدواژه‌ها [English]
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