Tempering of cocoa butter and chocolate using minor lipidic components

Preparation of soybean protein isolate-ester emulsifier oleogels and comparative study of their structure and properties

In recent years, oleogel as a viscoelastic semi-solid to replace trans fatty acids and reduce saturated fatty acids in food has received more and more attention. Herein, an emulsion template method was used to produce soybean oil-based oleogels with seven different ester emulsifiers and soy protein isolate as oleogelators. The chemical and physical characteristics of oleogels produced via various crosslinking factors were comparatively examined. Results revealed that all oleogels generated β-type needle crystals and exhibited high oil-holding capacity (>80 %), among which glycerol monolaurate G2 and diacetyl tartaric acid ester of mono-diglycerides G6 exhibited the strongest oil-holding capacity (96.6 % and 96.2 %, respectively). Furthermore, all oleogels exhibited strong thixotropic recovery, high thermal stability, as well as high gel strength (G' > G''). Of these, G2 and G6 exhibited the highest thixotropic recovery rates at 74.54 % and 78.19 %, respectively. Additionally, in accelerated oxidation trials, the peroxide value and thiobarbituric acid reactive substances of all oleogels had low oxidation rates, indicating high oxidative stability. These results contribute to a better understanding of oleogels for formulating trans-free and low-saturated foodstuffs with desired physical and functional properties.

The relationship between nonlinear viscoelasticity and baking performance in low-saturated puff pastry margarine

The oil phase obtained by blending and oleogel methods has potential for the production of non‑hydrogenated and low-saturated puff pastry margarine, thereby reducing intakes of both types of dietary fat. The crystal form, microstructure, rheology, and baking applications of puff pastry margarines prepared with anhydrous milk fat (AMF)/palm stearin (POs), POs/palm oil (PO), beef tallow (BT)/PO, or AMF/POs/diacetyl tartaric acid ester of mono(di)glycerides (DATEM) oleogels were investigated using X-ray scattering, polarized light microscope, and rheometer, respectively. All margarines exhibited β'-form crystal and strongly viscoelastic at low strain. With the addition of DATEM oleogel, their crystal microstructure became more uniform and finer, and the croissants were less hard (1690) and chewiness (160). The chewiness of croissants produced using the margarines was significantly improved with POs content. The theoretical basis for preparation and application in non‑hydrogenated and low-saturated puff pastry margarine was provided in the present study.

Hard X-ray imaging and tomography at the Biomedical Imaging and Therapy beamlines of Canadian Light Source

The Biomedical Imaging and Therapy facility of the Canadian Light Source comprises two beamlines, which together cover a wide X-ray energy range from 13 keV up to 140 keV. The beamlines were designed with a focus on synchrotron applications in preclinical imaging and veterinary science as well as microbeam radiation therapy. While these remain a major part of the activities of both beamlines, a number of recent upgrades have enhanced the versatility and performance of the beamlines, particularly for high-resolution microtomography experiments. As a result, the user community has been quickly expanding to include researchers in advanced materials, batteries, fuel cells, agriculture, and environmental studies. This article summarizes the beam properties, describes the endstations together with the detector pool, and presents several application cases of the various X-ray imaging techniques available to users.

Chemical transesterification of coconut and corn oils using different metal hydroxides as catalysts to determine the chemical and physiochemical changes to the oils

BACKGROUND

The transesterification of butteroil has been shown to alter its lipid chemistry and thus alter the crystallization of the fat. The reaction kinetics and resulting crystallization of the butteroil differ depending on the nature of the catalyst used. Modeling the reaction with vegetable oils is a simpler method for the analysis of resulting products to understand the chemical and physiochemical changes that occur based on catalyst selection. The objective of this work is to perform a chemical transesterification of coconut and corn oil using monovalent and divalent catalysts to investigate the chemical and crystal changes that occur.

RESULTS

Coconut and corn oil were subjected to chemical transesterification using both Ca(OH)2 and KOH as catalysts. In both the coconut and corn oil samples, transesterification caused monoglycerides (MAGs) and diacylglycerides (DAGs) to form from the most abundant fatty acid found in each sample. Coconut oil's melting temperature, solid fat content (SFC), and storage modulus decreased as a result of the transesterification, and crystals began to form in the corn oil causing melting thermograms to be evident, higher SFC, and a more viscous oil as a result. Using Ca(OH)2 as a catalyst resulted in more MAG formation, and a higher SFC and melting temperature than when KOH was used as a catalyst.

CONCLUSION

The results demonstrate that the chemical changes that result from transesterification of plant-based oils change the crystallization behavior of the oils and can therefore be used for different applications in the food industry. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Nutri-cereal tissue-specific transcriptome atlas during development: Functional integration of gene expression to identify mineral uptake pathways in little millet (Panicum sumatrense)

Little millet (Panicum sumatrense Roth ex Roem. & Schult.) is an essential minor millet of southeast Asia and Africa's temperate and subtropical regions. The plant is stress-tolerant, has a short life cycle, and has a mineral-rich nutritional profile associated with unique health benefits. We report the developmental gene expression atlas of little millet (genotype JK-8) from ten tissues representing different stages of its life cycle, starting from seed germination and vegetative growth to panicle maturation. The developmental transcriptome atlas led to the identification of 342 827 transcripts. The BUSCO analysis and comparison with the transcriptomes of related species confirm that this study presents high-quality, in-depth coverage of the little millet transcriptome. In addition, the eFP browser generated here has a user-friendly interface, allowing interactive visualizations of tissue-specific gene expression. Using these data, we identified transcripts, the orthologs of which in Arabidopsis and rice are involved in nutrient acquisition, transport, and response pathways. The comparative analysis of the expression levels of these transcripts holds great potential for enhancing the mineral content in crops, particularly zinc and iron, to address the issue of "hidden hunger" and to attain nutritional security, making it a valuable asset for translational research.

Utilizing Synchrotron-Based X-ray Micro-Computed Tomography to Visualize the Microscopic Structure of Starch Hydrogels In Situ

This study aimed to visualize the microstructures of starch hydrogels using synchrotron-based X-ray micro-computed tomography (μCT). Waxy maize starch (WMS, 3.3% amylose, db), pea starch (PS, 40.3% amylose), and high-amylose maize starch (HMS, 63.6% amylose) were cooked at 95 and 140 °C to prepare starch hydrogels. WMS and HMS failed to form a gel after 95 °C cooking and storage, while PS developed a firm gel. At 140 °C cooking, HMS of a high amylose nature was fully gelatinized and generated a rigid gel with the highest strength. Both scanning electron microscopy (SEM) and μCT revealed the unique structural features of various starch hydrogels/pastes prepared at different temperatures, which were greatly affected by the degree of swelling and dispersity of the starches. As a nondestructive method, μCT showed certain advantages over SEM, including minimal shrinkage of the hydrogels, relatively simple sample preparation, and allowing for three-dimensional reconstruction of the hydrogel microstructure. This study indicated that synchrotron-based μCT could be a useful technique in visualizing biopolymer-based hydrogels.

Polymorphic phase transitions in triglycerides and their mixtures studied by SAXS/WAXS techniques: In bulk and in emulsions

Triacylglycerols (TAGs) exhibit a monotropic polymorphism, forming three main polymorphic forms upon crystallization: α, β' and β. The distinct physicochemical properties of these polymorphs, such as melting temperature, subcell lattice structure, mass density, etc., significantly impact the appearance, texture, and long-term stability of a wide range products in the food and cosmetics industries. Additionally, TAGs are also of special interest in the field of controlled drug delivery and sustained release in pharmaceuticals, being a key material in the preparation of solid lipid nanoparticles. The present article outlines our current understanding of TAG phase behavior in both bulk and emulsified systems. While our primary focus are investigations involving monoacid TAGs and their mixtures, we also include illustrative examples with natural TAG oils, highlighting the knowledge transfer from simple to intricate systems. Special attention is given to recent discoveries via X-ray scattering techniques. The main factors influencing TAG polymorphism are discussed, revealing that a higher occurrence of structural defects in the TAG structure always accelerates the rate of the α → β polymorphic transformation. Diverse approaches can be employed based on the specific system: incorporating foreign molecules or solid particles into bulk TAGs, reducing drop size in dispersed systems, or using surfactants that remain fluid during TAG particle crystallization, ensuring the necessary molecular mobility for the polymorphic transformation. Furthermore, we showcase the role of TAG polymorphism on a recently discovered phenomenon: the creation of nanoparticles as small as 20 nm from initial coarse emulsions without any mechanical energy input. This analysis underscores how the broader understanding of the TAG polymorphism can be effectively applied to comprehend and control previously unexplored processes of notable practical importance.

Synchrotron micro-computed tomography unveils the three-dimensional structure and origin of staminodes in the Plains Prickly Pear Cactus Opuntia polyacantha Haw. (Cactaceae)

Floral appendages display an array of shapes and sizes. Among these organs, staminodes are morphologically diverse structures that have lost the ability to produce pollen, but in some instances, they produce fertile pollen grains. In the family Cactaceae staminodes are uncommon and range from simple linear to flat to spatulate structures, but studies describing their structural attributes are scanty. This study highlights the advantages of synchrotron radiation for sample preparation and as a research tool for plant biology. It describes the internal morphology of floral parts, particularly stamen, tepal, and staminode in the Plains Prickly Pear Cactus, Opuntia polyacantha, using synchrotron radiation micro-computed tomography (SR-μCT). It also shows the different anatomical features in reconstructed three-dimensional imaging of reproductive parts and discuss the advantages of the segmentation method to detect and characterize the configuration and intricate patterns of vascular networks and associated structures of tepal and androecial parts applying SR-μCT. This powerful technology led to substantial improvements in terms of resolution allowing a more comprehensive understanding of the anatomical organization underlying the vasculature of floral parts and inception of staminodes in O. polyacantha. Tepal and androecial parts have uniseriate epidermis enclosing loose mesophyll with mucilage secretory ducts, lumen, and scattered vascular bundles. Cryptic underlying structural attributes provide evidence of a vascularized pseudo-anther conjoint with tepals. The undefined contours of staminodial appendages (pseudo-anther) amalgamated to the tepals' blurred boundaries suggest that staminodes originate from tepals, a developmental pattern supporting the fading border model of floral organ identity for angiosperms.

The Effects of Emulsifier Addition on the Functionalization of a High-Oleic Palm Oil-Based Oleogel

Alternatives to oils with high saturated fatty acid content are often liquid oils (high in unsaturated fatty acids) that have a modified structure created either through additives or processing. Emulsifiers are additives that can be used as structuring agents of liquid fats; this process results in products such as oleogels, which can broaden the applications of these oils. This study assessed and compared the effects of mono- and diglycerides at 3%, 5%, 7% and 10% w/w on the mechanical and thermal properties of high-oleic palm oil (HOPO) oleogels. HOPO was heated to 75 °C and mixed with mono- or diglycerides at those four concentrations. The thermomechanical properties of the melted oleogels were assessed using differential scanning calorimetry (DSC). The melted oleogels were cooled to final temperatures of 5 °C, 10 °C and 15 °C under identical cooling rates, after which a puncture test (via a texture analyzer) was used to assess their textures. Finally, polarized light microscopy was used to assess the mechanical changes induced through emulsifier addition. The results showed that the use of mono- and diglycerides significantly modified the thermal and mechanical properties of the oleogels. The addition of saturated monoglycerides promoted a higher-temperature nucleation stage that did not previously occur in HOPO. The onset crystallization temperature increased with the addition of diglycerides, promoting crystallization at higher temperatures of the high-melting fraction of HOPO. The hardness of the oleogel generally increased with emulsifier addition and a reduction of the temperature. The effect of the temperature on the hardness was significantly greater in the diglyceride oleogel than in the monoglyceride oleogel. This study shows that the addition of mono- and diglycerides allows companies to customize their formulations to achieve desired results that may not previously have been possible, thereby facilitating novel uses for these oils within the industry.

Nonlinear viscoelasticity and crystallization behavior of anhydrous milk fat/palm stearin/oleogel blends

The crystallization behavior of anhydrous milk fat (AMF)/palm stearin (POs)/diacetyl tartaric acid ester of mono(di)glycerides (DATEM) oleogel blends was investigated, moreover, the linear and nonlinear rheological behavior of systems was analyzed by small amplitude oscillatory shear (SAOS) and large amplitude oscillatory shear (LAOS). The addition of DATEM oleogels inhibited the growth rate of crystals of blends at 4 °C and reduced the average size of crystalline nanoplatelet. Moreover, the DATEM oleogels promoted the transition of blends to more stable β polymorphism. The nonlinear rheological response of blends was qualitatively analyzed by normalized Lissajous-Bowditch curves. The addition of DATEM oleogels made blends more resistant to large deformations and slowed down viscous losses while reducing the rearrangement behavior of the crystal microstructure under high strain. These findings could open up the possibility of developing low-saturated fat products and further broaden the application of oleogels.

Challenges and developments for the blue perovskite nanocrystal light-emitting diodes

Perovskite nanomaterials have been highly thought as next-generation light emitters after recent development owing to their benefits of simple synthesis, low-cost, large-area, and wide color gamut. Encouragingly, the external quantum efficiencies (EQEs) of green, red, and near-infrared perovskite light-emitting diodes (PeLEDs) have exceeded more than 20%. However, the performance of the blue PeLEDs is still lower than other analogs, which severely limits the applications of PeLEDs in future full-color displays. Herein, we have reviewed the advances in blue perovskite NCs and their applications in blue PeLEDs. Promising blue perovskite emitters and strategies for fabricating highly efficient blue PeLEDs based on perovskite NCs are investigated and highlighted. Moreover, we point out the main challenges in blue perovskite NC LEDs including low electroluminescence efficiency (EL), spectral instability, the difficulty of charge injection, and device optimization. The perspectives for the further development of blue PeLEDs are also presented.

Kinetics Crystallization and Polymorphism of Cocoa Butter throughout the Spontaneous Fermentation Process

The spontaneous fermentation process of Criollo cocoa is studied for its importance in the development of chocolate aroma precursors. This research supports the importance of spontaneous fermentation, which was studied through the crystallization behavior and polymorphisms of cocoa butter (CB), the most abundant component of chocolate that is responsible for its quality physical properties. The k-means technique was used with the CB crystallization kinetics parameters to observe the division of the process during the first stage (day 0–3). The experimental crystallization time was 15.78 min and the second stage (day 4–7) was 17.88 min. The Avrami index (1.2–2.94) showed that the CB crystallizes in the form of a rod/needle/fiber or plate throughout the process. CB produced metastable crystals of polyforms β1′ and β2′. Three days of fermentation are proposed to generate Criollo cocoa beans with acceptable CB crystallization times.