Beeswax organogels: Influence of gelator concentration and oil type in the gelation process. (June 2016)

• Record Type: Journal Article
• Authors: Martins, Artur J.; Cerqueira, Miguel A.; Fasolin, Luiz H.; Cunha, Rosiane L.; Vicente, António A.
• Is Part Of: Food research international. Volume 84(2016:Jun.)
• Page Start: 170
• Page End: 179
• Publication Date: 2016-06
• Subjects: Oleogel -- Wax -- Rheology -- Small angle X-ray scattering (SAXS) -- Crystallinity -- Food science; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2016.03.035
• Languages: English
• ISSNs: 0963-9969

Abstract

Abstract: This work focused on how different types of oil phase, MCT (medium chain triglycerides) and LCT (long chain triglycerides), exert influence on the gelation process of beeswax and thus properties of the organogel produced thereof. Organogels were produced at different temperatures and qualitative phase diagrams were constructed to identify and classify the type of structure formed at various compositions. The microstructure of gelator crystals was studied by polarized light microscopy. Melting and crystallization were characterized by differential scanning calorimetry and rheology (flow and small amplitude oscillatory measurements) to understand organogels' behaviour under different mechanical and thermal conditions. Fourier transform infrared spectroscopy (FTIR) analysis was employed for a further understanding of oil-gelator chemical interactions. Results showed that the increase of beeswax concentration led to higher values of storage and loss moduli ( G ′, G ″) and complex modulus ( G *) of organogels, which is associated to the strong network formed between the crystalline gelator structure and the oil phase. Crystallization occurred in two steps (well evidenced for higher concentrations of gelator) during temperature decreasing. Thermal analysis showed the occurrence of hysteresis between melting and crystallization. Small angle X-ray scattering (SAXS) analysis allowed a better understanding in terms of how crystal conformations were disposed for each type of organogel. The structuring process supported by medium or long-chain triglycerides oils was an important exploit to apprehend the impact of different carbon chain-size on the gelation process and on gels' properties. Graphical abstract: Highlights: Organogels revealed important features such as thermo-reversibility and thixotropy. LCT-based organogels revealed stronger behaviour than MCT-based organogels; Different carbon-chain oil phases and gelator concentrations impact organogels' properties.