The Influence of Edible Oils’ Composition on the Properties of Beeswax-Based Oleogels

This study aimed to find relationships between the properties of beeswax-based oleogels and the type of oil used. The influence of linseed, sunflower, olive, and fish oils was studied. For these oils, the fatty acid composition, the content of total polar components, and the iodine value were characterized. Textural and thermodynamic properties were determined for oleogels, the oil-binding capacity was estimated, and the morphology of crystals was studied. The concentration of beeswax in all oleogels was 6.0% w/w. It was shown that the type of oil has a significant influence on all characteristics of the oleogels. The use of different oils at the same technological treatment leads to the formation of crystals of diverse morphology—from platelets to spherulites. At the same time, it was revealed that some characteristics of oils have a varying contribution to the properties of oleogels. The content of total polar materials in oils is associated with a decrease in strength parameters (yield value and elastic modulus) and the oil-binding capacity of oleogels. In its turn, the iodine value of oils has a close positive correlation with the melting and crystallization temperatures of oleogels. The results obtained in this article indicate that the properties of beeswax-based oleogels can be directed by changing the oil composition.

Palm Olein Organogelation Using Mixtures of Soy Lecithin and Glyceryl Monostearate

The present work investigated the interaction between soy lecithin (SL), glyceryl monostearate (GMS), and water in structuring palm olein (PO) to create an organogel having similar mechanical properties to commercial spread. Extreme vertices mixture design was used to optimize the composition of PO-based organogel. The resulting model showed a good fit to the predicted data with R2 ≥ 0.89. The optimum composition was 8% SL, 22% GMS, 28% water, and 42% PO (w/w) to produce a mean firmness of 1.91 N, spreadability of 15.28 N s−1, and oil binding capacity (OBC) of 83.83%. The OBC of optimized organogel was 10% higher than commercial spread product, and no significant difference was observed in the mechanical properties (p > 0.05). The microstructure, as well as the rheological and thermal properties of the optimized organogel were characterized. Fourier transform infrared analysis indicated that hydrogen bonding and van der Waals interactions were the key driving forces for organogelation. The mixture of SL and GMS favored the formation of β′ + β form crystals with a predominance of the β′ form. These results have important implications for the development of PO-based organogel as a potential fat replacer in the production of low-fat spread.

Electrolysis soy protein isolate-based oleogels prepared with an emulsion-templated approach

This research focuses on the use of protein-polyphenol complex and protein-polyphenol: polysaccharide complexes to prepare oleogels through an emulsion-templated approach. Electrolysis soy protein isolate (ESPI) could be effectively adsorbed on the surface of a single-layer emulsion to increase the particle size. The order of the negative charges of the emulsion after adding polysaccharides was xanthan gum (XG)> pectin> carboxymethyl cellulose (CMC). Rheological behavior showed that the stability of the double-layer emulsions increased, and the viscoelasticity increased around one order of magnitude with the addition of polysaccharides. The oil binding capacity (OBC) of the oleogel prepared by adding polysaccharides increased to more than 97%. The peroxide value (PV) and anisidine value (AV) of XG oleogel were the minimum values in all samples. The AV and POV were within the regulatory limits of China after storage for 21 days. This provides a reference to design of ESPI-based oleogel for different applications.

Oleogels—Their Applicability and Methods of Characterization

Oleogels or, more precisely, non-triglyceride structured lipid phases have been researched excessively in the last decade. Yet, no comprehensive knowledge base has emerged, allowing technology elevation from the laboratory bench into the industrial food application. That is partly due to insufficient characterization of the structuring systems studied. Examining a single composition decided upon by arbitrary methods does not stimulate progress in the research and technology area. A framework that gives much better guidance to product applications can easily be derived. For example, the incremental structure contribution concept is advocated as a parameter to compare the potency of structuring systems. These can straightforwardly be determined by combining solubility data and structural measurements in the recommended manner. The current method to determine the oil-binding capacity suffers from reproducibility and relevance. A newly developed method is suggested to overcome these shortcomings. The recommended new characterization of oleogels should contribute to a more comprehensive knowledge base necessary for product innovations.

Formation of zinc oxalate from zinc white in various oil binding media: the influence of atmospheric carbon dioxide by reaction with 13CO2

The formation of metal oxalates in paintings has recently gained a great deal of interest within the field of heritage science as several types of oxalate compounds have been identified in oil paintings. The present work investigates the formation of metal oxalates in linseed oil in the presence of the artists’ pigments zinc white, calcite, lead white, zinc yellow, chrome yellow, cadmium yellow, cobalt violet, and verdigris. The oil paint films were artificially photo-aged by exposure to UVA light at low and high relative humidity, and afterwards analysed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The results showed that, compared to the other pigments investigated, zinc white is especially prone to metal oxalate formation and that high humidity is a crucial factor in this process. Consequently, the reactivity and photo-aging of ZnO in various oil binding media was investigated further under simulated solar radiation and at high relative humidity levels. ATR-FTIR showed that zinc oxalate is formed in all oil binding media while X-ray powder diffraction (PXRD) revealed it was mainly present in an amorphous state. To examine whether atmospheric CO2(g) has any influence on the formation of zinc oxalate, experiments with isotopically enriched 13CO2(g) were performed. Based on ATR-FTIR measurements, neither Zn13C2O4 nor Zn13CO3 were formed which suggests that the carbon source for the oxalate formation is most likely the paint itself (and its oil component) and not the surrounding atmosphere.

Effect of Blanching Plus Fermentation on Selected Functional Properties of Mealworm (Tenebrio molitor) Powders

The aim of this study was to determine the effect of blanching followed by fermentation of mealworms (Tenebrio molitor) with commercial meat starter cultures on the functional properties of powders produced from the larvae. Full fat and defatted powder samples were prepared from non-fermented and fermented mealworm pastes. Then the crude protein, crude fat, and dry matter contents, pH, bulk density, colour, water and oil binding capacity, foaming capacity and stability, emulsion capacity and stability, protein solubility, quantity of free amino groups, and protein composition of the powders were evaluated. Regardless of the starter culture used, the blanching plus fermentation process reduced the crude and soluble protein contents of the full fat powders and in general impaired their water and oil binding, foaming, and emulsifying properties. Defatting of the powders improved most functional properties studied. The o-phthaldialdehyde assay revealed that the amount of free amino groups was higher in the fermented powders while sodium dodecyl sulfate polyacrylamide gel electrophoresis demonstrated that the soluble proteins of the fermented powders were composed of molecules of lower molecular mass compared to non-fermented powders. As molecular sizes of the soluble proteins decreased, it was clear that the protein structure was also modified by the fermentation process, which in turn led to changes in functional properties. In general, it was concluded that fermentation of mealworms with blanching as a pre-treatment does not contribute to the functional properties studied in this work. Nevertheless, the results confirmed that the properties of non-fermented powders are comparable to other food protein sources.

Functional properties of powders produced from either or not fermented mealworm (Tenebrio molitor) paste

The aim of this study was to determine the effect of fermentation of mealworms (Tenebrio molitor) with commercial meat starters cultures on the functional properties of powders produced from the larvae. Full fat and defatted powder samples were prepared from non-fermented and fermented mealworm pastes. Then the crude protein, crude fat and dry matter contents, pH, bulk density, colour, water and oil binding capacity, foaming capacity and stability, emulsion capacity and stability, protein solubility, quantity of free amino groups and protein composition of the powders were evaluated. Regardless of the starter culture used, fermentation significantly (p < 0.05) reduced the crude and soluble protein content of the non-defatted mealworm powders and in general impaired their water and oil binding, foaming- and emulsifying properties. Defatting of the powders improved most functional properties studied, except the protein solubility, water binding capacity, foaming capacity and emulsion stability. The o-phthaldialdehyd assay revealed that the amount of free amino groups increased during fermentation, which may be attributed to proteolysis of mealworm proteins by the starters. Sodium dodecyl sulfate polyacrylamide gel electrophoresis demonstrated that the soluble proteins of fermented powders were composed of molecules of lower molecular mass compared to non-fermented powders. As the molecular sizes of the soluble proteins decreased, it is clear that also the protein structure was modified by the fermentation process, which in turn led to changes in functional properties. It was concluded that fermentation of mealworms in general does not contribute to the functional properties studied in this work. Nevertheless, the results confirmed that the properties of non-fermented powders are comparable to other food protein sources.

Effectiveness of Toothpony (Gazza minuta) protein hydrolysate on reducing oil uptake upon deep-frying

Toothpony (Gazza minuta) is not typically used for human consumption due to its small size and low meat content, which is widely used as a fish meal. It is stated to be high in protein content and may be suitable for fish protein hydrolysate (FPH) production. Deepfat fried foods contain significant amounts of fat, in some cases up to one-third of the total food weight after frying. Toothpony FPH with low oil-binding ability may reduce the amount of oil consumed by deep-fried products. The objective of this research was to measure the physicochemical properties of Toothpony FPH and its utilisation in reducing the oil intake of deep-fried food. Toothpony FPH was obtained using the enzymatic method successfully. Batter formulations are prepared by adding 0%, 2%, 4%, 6% and 8% of Toothpony FPH into the sample mixtures. The present study indicates the degree of hydrolysis of Toothpony FPH determined by trichloroacetic acid (TCA) method was found to be 98.02%. Toothpony FPH's molecular weight distributions ranged from 7 to 175kDa and FTIR's transmission spectrum indicated the presence of amide I and amide II compounds (1654 and 1535cm-1 ). Oil binding capacity of Toothpony FPH was found to be low, which was 1.9 g oil/ g protein. This study indicated that 4% of Toothpony FPH produced the optimum amount to be incorporated in batter in order to best reduce oil uptake. In sensory evaluation, deep-fat-fried squid incorporated with 8% of Toothpony FPH showed the highest acceptance in all attributes, which were colour, crispness, oiliness, taste and overall acceptability. This approach offers the potentials use of Toothpony fish FPH for the production batter formulation which is efficient in the reduction of oil uptake.

Valorization of Flaxseed Oil Cake Residual from Cold-Press Oil Production as a Material for Preparation of Spray-Dried Functional Powders for Food Applications as Emulsion Stabilizers

Flaxseed oil cake extract (residual from cold-press oil production and rich in proteins and polysaccharides) was evaluated as a potential substrate for the preparation of spray-dried powders with emulsifying activity. Three variants of powders were obtained using different spray-drying process inlet temperatures: 160 °C, 180 °C, and 200 °C. The influence of temperature on physicochemical features (water holding capacity, oil binding capacity, water activity, solubility, color, chemical composition, antioxidant activity, and surface morphology) of the powders was estimated. Additionally, the emulsifying activity of the powders and the stability of oil-in-water emulsions prepared with their various content (0.5%, 1%, and 3%) were determined. Results showed that inlet temperature had significant influence on all physicochemical and functional properties of the powders. Increased inlet temperature decreased solubility and antioxidant activity but increased water-holding capacity, oil-binding capacity, and emulsifying activity. The emulsions prepared with the powder obtained at 200 °C showed the highest stability. SEM images showed the production of relatively spherical particles which were folded or wrinkled with a lot of dentures. This study could open a promising pathway for producing natural and plant-based spray-dried powders for food applications as emulsion stabilizers.