Controlled release of caffeine from tablets of spray-dried casein gels

Casein-based hydrogels: Advances and prospects

Casein-based hydrogels (Casein Gels) possess advantageous properties, including mechanical strength, stability, biocompatibility, and even adhesion, conductivity, sensing capabilities, as well as controlled-releasing behavior of drugs. These features are attributed to their gelation methods and functionalization with various polymers. Casein Gels is an important protein-based material in the food industry, in terms of dairy and functional foods, biological and medicine, in terms of carrier for bioactive and sensitive drugs, wound healing, and flexible sensors and wearable devices. Herein, this review aims to highlight the importance of the features mentioned above via a comprehensive investigation of Casein Gels through multiple directions and dimensional applications. Firstly, the composition, structure, and properties of casein, along with the gelation methods employed to create Casein Gels are elaborated, which serves as a foundation for further exploration. Then, the application progresses of Casein Gels in dairy products, functional foods, medicine, flexible sensors and wearable devices, are thoroughly discussed to provide insights into the diverse fields where Casein Gels have shown promise and utility. Lastly, the existing challenges and future research trends are highlighted from an interdisciplinary perspective. We present the latest research advances of Casein Gels and provide references for the development of multifunctional biomass-based hydrogels.

Use of dairy industry side-stream lactose for tablet manufacturing - proof of concept study

During recent years there have been shortages of certain drugs due to problems in raw material supply. These are often related to active ingredients but could also affect excipients. Lactose is one of the most used excipients in tableting and comes in two anomeric and several solid-state forms. The aim of this study was to utilize lactose from a dairy side-stream and compare it against a commercial reference in direct compression. This would be a sustainable option and would secure domestic availability during crises. Two types of lactose, spray-dried and freeze-dried, were evaluated. Lactose was mixed with microcrystalline cellulose in different ratios together with lubricant and glidant, and flowability and tabletability of the formulations was characterized. The fully amorphous and small particle-sized spray-dried lactose flowed inadequately but exhibited good tabletability. The larger particle-sized, freeze-dried lactose exhibited sufficient flow and better tabletability than the commercial reference. However, disintegration and drug release were slower when using the investigational lactose formulations. This was most likely due to remaining milk proteins, especially caseins, in the lactose. Overall, the investigational lactose provides promise for the use of such a side-stream product during crisis situations but enhancing their properties and/or purity would be needed.

The aggregation of casein micelles induced by Ca2+ during in vitro digestion: effects on the release of loaded anthocyanins

Colloidal calcium phosphate (CCP) confers a modifiable structure to micellar casein (MC), which endows it with potential advantages as a delivery carrier. However, it is difficult to achieve multipattern release of the core material in the intestine with MC as a single wall. In this study, we prepared an anthocyanin-casein-based delivery system utilizing MC with different freezing degrees as the wall material with the objective of achieving the controlled release of anthocyanin as the model core in the intestine. The results showed that freezing could significantly reduce the CCP level up to 50%. Static in vitro simulated digestion with the addition of exogenous Ca2+ showed that the designed delivery system exhibited low anthocyanin release (15%-35%) in the gastric tract. The pattern of release in the intestine depended on the CCP dissociation degree. High and low dissociation degrees corresponded to slow release (from 15% to 65% within 2 h) and burst release (from 35% to 90% within 5 min), respectively. WAXS/SAXS analysis revealed that exogenous serum Ca2+ inherent in simulated gastric fluid and endogenous serum Ca2+ induced by CCP dissociation was synergistically involved in the reconstitution of CCP-mediated nanoclusters and large aggregates. The freezing degree of MC determined the endogenous serum Ca2+ level, which influenced the gastric aggregation behavior of wall MC and ultimately led to a fairly different gastrointestinal release behavior of anthocyanins.

The Release Behavior of Anthraquinones Encapsulated into Casein Micelles during In Vitro Digestion

The degradation of anthraquinones extracted from aloe vera plants can be prevented by encapsulating them in casein micelles (CMs). The oral, gastric, and intestinal digestion behavior of spray-dried microcapsules of casein micelles loaded with aloe vera-extracted anthraquinone powder (CMAQP), freeze-dried powder (CMFDP), and whole-leaf aloe vera gel (CMWLAG) obtained through ultrasonication was investigated. The results found that CMAQP and CMFDP dissolved slowly and coagulated into large curds during gastric digestion, improving the retention of anthraquinones in the digestive tract. In contrast, CMWLAG structure was destroyed and increased amounts of anthraquinones were released during oral and gastric digestion phases, indicating increased amounts of surface anthraquinones instead of the encapsulation of anthraquinones in the interior of CMs. The strong hydrophobic interactions protected anthraquinones within the core of CM for CMAQP and delayed diffusion. However, during SIF digestion, both CMAQP and CMFDP released significant amounts of anthraquinones, although CMAQP showed a much more controlled release for both aloin and aloe-emodin over SIF digestion time. The release behavior of anthraquinones from CM microcapsules was a function of the type of anthraquinone that was used to encapsulate. The present study provides insight into the release behavior of loaded bioactive compounds using food-grade CMs as the wall material during in vitro digestion and highlights the importance of the type of bioactive component form that will be encapsulated.

Wall Materials for Encapsulating Bioactive Compounds via Spray-Drying: A Review

Spray-drying is a continuous encapsulation method that effectively preserves, stabilizes, and retards the degradation of bioactive compounds by encapsulating them within a wall material. The resulting capsules exhibit diverse characteristics influenced by factors such as operating conditions (e.g., air temperature and feed rate) and the interactions between the bioactive compounds and the wall material. This review aims to compile recent research (within the past 5 years) on spray-drying for bioactive compound encapsulation, emphasizing the significance of wall materials in spray-drying and their impact on encapsulation yield, efficiency, and capsule morphology.

Caffeine-loaded nano/micro-carriers: Techniques, bioavailability, and applications

Caffeine, as one of the most consumed bioactive compounds globally, has gained considerable attention during the last years. Considering the bitter taste and adverse effects of high levels of caffeine consumption, it is crucial to apply a strategy for masking the caffeine's bitter taste and facilitating its programmable deliverance within a long time. Other operational parameters such as food processing parameters, exposure to sunlight and oxygen, and gastrointestinal digestion could also degrade the phenolic compounds in general and caffeine in special. To overcome these challenges, various nano/micro-platforms have been fabricated, including lipid-based (e.g., nanoliposomal vehicles; nanoemulsions, double emulsions, Pickering emulsions; microemulsions; niosomal vehicles; solid lipid nanoparticles and nanostructured lipid carriers), as well as biopolymeric (e.g., nanoparticles; hydrogels, organogels, oleogels; nanofibers and nanotubes; protein-polysaccharide nanocomplexes, conjugates; cyclodextrin inclusion complexes) and inorganic (e.g., gold and silica nanoparticles) nano/micro-structures. In this review, the findings on various caffeine-loaded nano/micro-carriers and their potential applications in functional food products/supplements will be discussed. Also, the controlled release and bioavailability of encapsulated caffeine will be given, and finally, the toxicity and safety of encapsulated caffeine will be presented.

Serum IMA and LP-PLA2 Levels in Patients with Coronary Heart Disease and Their Correlation with the Degree of Myocardial Ischaemia and Their Diagnostic Value

Purpose

To measure serum levels of ischaemia-modified albumin (IMA) and lipoprotein-associated phospholipase A2 (LP-PLA2) in patients with coronary heart disease (CHD) and to analyse their correlation with the degree of myocardial ischaemia and their diagnostic value.

Methods

A sample of 150 patients diagnosed with CHD by coronary angiography in our hospital from March 2019 to September 2021 was taken as the CHD group. The patients were divided into acute myocardial infarction (AMI) group (n = 52), unstable angina pectoris (UAP) group (n = 54), and stable angina pectoris (SAP) group (n = 44) according to the degree of myocardial ischaemia, and then 50 healthy physical examination patients were selected as the health group during the same period. Serum C-reactive protein (CRP), interleukin-6 (IL-6), IMA, and LP-PLA2 levels were measured in each group separately. Multiple ordered logistic regression was used to analyse the factors influencing the degree of myocardial ischaemia in patients with CHD. Pearson correlation was used to analyse the correlation between serum IMA, LP-PLA2 levels and serum CRP, IL-6 levels in CHD patients. The diagnostic value of IMA alone, LP-PLA2 alone, and in combination for CHD was analysed using receiver operating characteristic (ROC) curves.

Results

In terms of serum CRP, IL-6, IMA, and LP-PLA2 levels, the CHD group was higher than the health group, the AMI and UAP groups were higher than the SAP and health groups, and the AMI group was higher than the UAP group (P < 0.05). Multiple ordered logistic regression analysis showed that serum CRP, IL-6, IMA, and LP-PLA2 levels were all independent influences on the degree of myocardial ischaemia in patients with CHD (P < 0.05). Pearson correlation analysis showed a positive correlation between serum IMA, LP-PLA2 levels and serum CRP, IL-6 levels in CHD patients (P < 0.001). The area under curve (AUC) for serum IMA levels to predict myocardial ischaemia in patients with CHD was 0.754 (95% CI: 0.684-0.825), with a sensitivity of 61.3% and specificity of 84.0% when the best cut-off value was 0.453; the AUC for serum LP-PLA2 levels to predict myocardial ischaemia in patients with CHD was 0.747 (95% CI: 0.681-0.813), with a sensitivity of 62.0% and specificity of 82.0% when the optimal cut-off value was 0.440; and the AUC of IMA + LP-PLA2 for predicting myocardial ischaemia in patients with CHD was 0.892 (95% CI: 0.847-0.938), with a sensitivity of 86.7% and specificity of 80.0% when the optimal cut-off value was 0.667. The specificity was 80.0%.

Conclusions

Serum IMA and LP-PLA2 levels are elevated in patients with CHD. Serum IMA and LP-PLA2 levels are closely related to the degree of myocardial ischaemia and its inflammatory level, and the combination of IMA + LP-PLA2 can improve the diagnosis efficacy of myocardial ischaemia in CHD patients.

Casein Micelles as an Emerging Delivery System for Bioactive Food Components

Bioactive food components have potential health benefits but are highly susceptible for degradation under adverse conditions such as light, pH, temperature and oxygen. Furthermore, they are known to have poor solubilities, low stabilities and low bioavailabilities in the gastrointestinal tract. Hence, technologies that can retain, protect and enable their targeted delivery are significant to the food industry. Amongst these, microencapsulation of bioactives has emerged as a promising technology. The present review evaluates the potential use of casein micelles (CMs) as a bioactive delivery system. The review discusses in depth how physicochemical and techno-functional properties of CMs can be modified by secondary processing parameters in making them a choice for the delivery of food bioactives in functional foods. CMs are an assembly of four types of caseins, (α_s1, α_s2, β and κ casein) with calcium phosphate. They possess hydrophobic and hydrophilic properties that make them ideal for encapsulation of food bioactives. In addition, CMs have a self-assembling nature to incorporate bioactives, remarkable surface activity to stabilise emulsions and the ability to bind hydrophobic components when heated. Moreover, CMs can act as natural hydrogels to encapsulate minerals, bind with polymers to form nano capsules and possess pH swelling behaviour for targeted and controlled release of bioactives in the GI tract. Although numerous novel advancements of employing CMs as an effective delivery have been reported in recent years, more comprehensive studies are required to increase the understanding of how variation in structural properties of CMs be utilised to deliver bioactives with different physical, chemical and structural properties.

Microstructures of encapsulates and their relations with encapsulation efficiency and controlled release of bioactive constituents: A review

Vitamins, peptides, essential oils, and probiotics are examples of health beneficial constituents, which are nevertheless heat-sensitive and possess poor chemical stability. Various encapsulation methods have been applied to protect these constituents against thermal and chemical degradations. Encapsulates prepared by different methods and/or at different conditions exhibit different microstructures, which in turn differently influence the encapsulation efficiency as well as retention of encapsulated core materials. This review provides a summary of various microstructures resulted from the use of selected encapsulation methods or systems, namely, spray coating; co-extrusion; emulsion-, micelle-, and liposome-based; coacervation; and ionic gelation encapsulation, at different conditions. Subsequent effects of the different microstructures on encapsulation efficiency and retention of encapsulated core materials are mentioned and discussed. Encapsulates having compact microstructures resulted from the use of low-surface tension and low-viscosity encapsulants, high-stability encapsulation systems, lower loads of core materials to total solids of encapsulants and appropriate solidification conditions have proved to exhibit higher encapsulation efficiencies and better retention of encapsulated core materials. Encapsulates with hollow, dent, shrunken microstructures or thinner walls resulted from inappropriate solidification conditions and higher loads of core materials, on the other hand, possess lower encapsulation efficiencies and protection capabilities. Encapsulates having crack, blow-hole or porous microstructures resulted from the use of high-viscosity encapsulants and inappropriate solidification conditions exhibit the lowest encapsulation efficiencies and poorest protection capabilities. Compact microstructures and structures formed between ionic biopolymers could be used to regulate the release of encapsulated cores.

Spray-Drying Microencapsulation of Bioactive Compounds from Lemon Verbena Green Extract

Lippia citriodora has been demonstrated to have a wide variety of phytochemicals which provide benefits to human health acting as antioxidants or anti-obesogenics. In this study, these phytochemicals were recovered using a microwave-assisted technology and applying optimal conditions and microencapsulated using spray drying. In this study, two different carbohydrates, maltodextrin (MD) and inulin (IN), were compared as carriers in the encapsulation procedure. The spray drying process was optimized by using a response surface methodology (RSM) based on a central composite design 2², where air inlet temperature and the sample:encapsulating agent ratio (S:EA) were selected as independent variables. Both designs were analyzed equally to evaluate differences between each carrying agent on polar compounds’ encapsulation (process yield (Y%), encapsulation efficiency (EE%) and recovery of compounds (R%)) during the spray drying. The EE% and R% of each polar compound was monitored by High Performance Liquid Chromatography coupled to Time-of-Flight mass spectrometer by electrospray interface (HPLC-ESI-TOF-MS). The results showed that the use of IN as a carrier increased the powder recovered and the recovery of polar compounds after the spray dry process, whereas MD achieved a higher encapsulation efficiency.

Effect of ultrasound on binding interaction between emodin and micellar casein and its microencapsulation at various temperatures

Emodin is a bioactive compound with strong anti-inflammatory and antioxidant properties. Micellar casein is casein concentrates close to the native state of casein micelles. The interaction of emodin and micellar casein under heat treatment in the absence and presence of ultrasound was investigated, and the properties of microencapsulated emodin in micellar casein were compared. Fluorescence experiments proved that the major interaction between emodin and micellar casein was through hydrophobic forces under heat treatment in the absence and presence of ultrasound. However, ΔH, ΔS and ΔG of emodin-casein complexation without sonication were higher than those with sonication, in contradiction to binding constants. The particle sizes of emodin-casein complexes in the presence of ultrasound were smaller than those without sonication, while the specific surface area showed an opposite trend. As to encapsulation, emodin-casein capsules under heat-sonication treatment showed higher antioxidant properties than those of heat treatment alone under similar experimental conditions. Interestingly, micellar casein-emodin encapsulation in the presence of ultrasound showed a lower release rate of emodin in gastrointestinal conditions than that without ultrasound at the emdoin concentration of 10 μmol per gram casein. Ultrasound has been shown to be a potential processing technology for customizing the release kinetics of bioactive compounds.

Casein-based hydrogels: A mini-review

Casein-based hydrogels are biocompatible, biodegradable, renewable, easy to obtain, inexpensive, and non-toxic. They exist in different physicochemical states, e.g. particle hydrogels, which can be dived in suspensions or emulsions and macro hydrogels that are gel colloid type. These biomaterials have drawn increasing attention in recent years due to their abilities to form networks of different tensile strengths and to encapsulate, protect and release biomolecules. This mini-review outlines the recent advances in casein-based hydrogel research and the uses of casein-based hydrogels as drug delivery system for both hydrophobic and hydrophilic molecules. The food and biomedical potential along with possible future uses of the casein-based hydrogels are discussed throughout the document.

Nutraceuticals' Novel Formulations: The Good, the Bad, the Unknown and Patents Involved

Traditional nutraceuticals and cosmeceuticals hold pragmatic nature with respect to their definitions, claims, purposes and marketing strategies. Their definitions are not well established worldwide. They also have different regulatory definitions and registration regulatory processes in different parts of the world. Global prevalence of nutraceuticals and cosmeceuticals is noticeably high with large market share with minimal regulation compared to traditional drugs. The global market is flooded with nutraceuticals and cosmeceuticals claiming to be of natural origin and sold with a therapeutic claim by major online retail stores such as Amazon and eBay. Apart from the traditional formulations, many manufacturers and researchers use novel formulation technologies in nutraceutical and cosmeceutical formulations for different reasons and objectives. Manufacturers tend to differentiate their products with novel formulations to increase market appeal and sales. On the other hand, researchers use novel strategies to enhance nutraceuticals and cosmeceuticals activity and safety. The objective of this review is to assess the current patents and research adopting novel formulation strategies in nutraceuticals and cosmeceuticals. Patents and research papers investigating nutraceutical and cosmeceutical novel formulations were surveyed for the past 15 years. Various nanosystems and advanced biotechnology systems have been introduced to improve the therapeutic efficacy, safety and market appeal of nutraceuticals and cosmeceuticals, including liposomes, polymeric micelles, quantum dots, nanoparticles, and dendrimers. This review provides an overview of nutraceuticals and cosmeceuticals current technologies, highlighting their pros, cons, misconceptions, regulatory definitions and market. This review also aims in separating the science from fiction in the nutraceuticals and cosmeceuticals development, research and marketing.