Nanostructured lipid carriers loaded with free phytosterols for food applications

Lipid Nanoparticles: Formulation, Production Methods and Characterization Protocols

Lipid nanoparticles (LNs) have emerged as advanced lipid-based delivery systems, offering an effective approach for encapsulating and protecting lipid-soluble bioactive compounds, increasing their bioavailability. Solid Lipid Nanoparticles (SLNs) and Nanostructured Lipid Carriers (NLCs) are particularly promising for bioactive compound entrapment. However, to fully exploit their potential, it is crucial to carefully select the appropriate lipid matrices and emulsifiers. This review offers a comprehensive, up-to-date examination, considering studies published in the last 15 years, of the chemical, physical, and structural characteristics of lipids employed in LN production, focusing on the key components of the formulations: lipid matrices, emulsifiers, and bioactive compounds. In addition, it provides an in-depth analysis of production methods, drawing on insights from the latest scientific literature, and emphasizes the most important characterization techniques for LNs. Key parameters, including particle size (PS), zeta potential (ZP), crystallinity, thermal behavior, morphology, entrapment efficiency (EE), load capacity (LC), and physical stability, are discussed. Ultimately, this review aims to identify critical factors for the successful production of stable LNs that efficiently encapsulate and deliver bioactive compounds, highlighting their significant potential for applications in food systems.

Hyaluronic acid-decorated lipid nanocarriers as novel vehicles for curcumin: Improved stability, cellular absorption, and anti-inflammatory effects

This study aimed to investigate how hyaluronic acid interfacial decoration affects the stability, cellular absorption, and anti-inflammatory effects of curcumin-loaded nanostructured lipid carriers. Nanocarriers were synthesized with an ovalbumin single layer and ovalbumin/hyaluronic acid double, mixed, or conjugated layers. All nanocarriers were spherical (200-300 nm diameter), and their encapsulation efficiency exceeded 95 %. Among the layers, the conjugated one exhibited the highest elastic surface dilatational modulus of approximately 40 mN/m, and the longest curcumin half-life of 186.07 days at 4 °C. Spearman's correlation analysis showed a negative correlation (r = -0.6698) between the recrystallization index and curcumin stability. The layer's mechanical strength improved curcumin stability by preventing crystal transition. Hyaluronic acid decoration enhanced the curcumin uptake of Caco-2 cells by 1.96-2.48 folds. Among the layers, the conjugate one was the most effective because of its strong binding constant with the receptor. Hyaluronic acid decoration improved the anti-inflammatory effects of curcumin.

Food nanotechnology: opportunities and challenges

Food nanotechnology, which applies nanotechnology to food systems ranging from food production to food processing, packaging, and transportation, provides tremendous opportunities for conventional food science and industry innovation and improvement. Although great progress and rapid growth have been achieved in food nanotechnology research owing to the unique food features rendered by nanotechnology, at a fundamental level, food nanotechnology is still in its initial stages and the potential adverse effects of nanomaterials are still a controversial problem that attract public attention. Food-derived nanomaterials, compared to some inorganic nanoparticles and synthetic organic macromolecules, can be digested rapidly and produce similar digestion products to those produced normally, which become the mainstream and trend for food nanotechnology in practical applications, and are expected to be a vital tool for addressing the security problem and easing public concerns. These food-derived materials enable the favourable characteristics of nanostructures to be combined with the safety, biocompatibility, and bioactivity of natural food. Very recently, diverse food-derived nanomaterials have been explored and widely applied in multiple fields. Herein, we thoroughly summarize the fabrication and development of nanomaterials for use in food technology, as well as the recent advances in the improvement of food quality, revolutionizing food supply, and boosting food industries based on foodborne nanomaterials. The current challenges in food nanotechnology are also discussed. We hope this review can provide a detailed reference for experts and food manufacturers and inspire researchers to participate in the development of food nanotechnology for highly efficient food industry growth.

Steam explosion pretreatment enhances free/combined phytosterol extraction and utilization in rapeseed (Brassica napus L.) and its processed products: Insights from SPE-GC approach

The study investigates the impact of steam explosion pretreatment on the distribution of free and combined phytosterols within rapeseed and its derived products. Utilizing solid phase extraction-gas chromatography (SPE-GC) analysis, we elucidated the composition and distribution of phytosterols in five rapeseed varieties and their corresponding processed oils and cakes. The results indicated that Zhongyou 516 and Xiwang 988 are richer in combined phytosterols, whereas Dadi 199, Zhongyouza 501, and Xiwang 291 have a greater concentration of free phytosterols. Steam explosion pretreatment significantly increased the extraction proportion of combined phytosterols in rapeseeds. Throughout the oil process, more than half of the total phytosterol content, specifically 57.0%, was transferred from the steam explosion-treated rapeseed into the rapeseed oil. The variety Xiwang 291 showed the highest efficiency in this transfer, achieving a rate of 61.7%. The study provides crucial data for the enhancement of rapeseed processing techniques and the efficient utilization of phytosterols. Moreover, the study highlights the potential use of the ratio of free to combined phytosterols as a discriminator for different rapeseed oil varieties, offering valuable insights for quality assurance and product differentiation in the industry.

Phytosterols: Physiological Functions and Potential Application

Dietary intake of natural substances to regulate physiological functions is currently regarded as a potential way of promoting health. As one of the recommended dietary ingredients, phytosterols that are natural bioactive compounds distributed in plants have received increasing attention for their health effects. Phytosterols have attracted great attention from scientists because of many physiological functions, for example, cholesterol-lowering, anticancer, anti-inflammatory, and immunomodulatory effects. In addition, the physiological functions of phytosterols, the purification, structure analysis, synthesis, and food application of phytosterols have been widely studied. Nowadays, many bioactivities of phytosterols have been assessed in vivo and in vitro. However, the mechanisms of their pharmacological activities are not yet fully understood, and in-depth investigation of the relationship between structure and function is crucial. Therefore, a contemporaneous overview of the extraction, beneficial properties, and the mechanisms, as well as the current states of phytosterol application, in the food field of phytosterols is provided in this review.

Development and characterization of nanostructured lipid carriers for cannabidiol delivery

This study evaluated the physicochemical characteristics of nanostructured lipid carriers (NLCs) as a potential vehicle for cannabidiol (CBD), a lipophilic molecule with great potential to promote health benefits. NLCs were produced using hemp seed oil and fully-hydrogenated soybean oil at different proportions. The emulsifiers evaluated were soybean lecithin (SL), Tween 80 (T80) and a mixture of SL:T80 (50:50). CBD was tested in the form of CBD-rich extract or isolate CBD, to verify if it affects the NLCs characteristics. Based on particle size and polydispersity, SL was considered the most suitable emulsifier to produce the NLCs. All lipid proportions evaluated had no remarkable effect on the physicochemical characteristics of NLCs, resulting in CBD-loaded NLCs with particle size below 250 nm, high CBD entrapment efficiency and CBD retention rate of 100% for 30 days, demonstrating that NLCs are a suitable vehicle for both CBD-rich extract or isolate CBD.

Current and New Insights on Delivery Systems for Plant Sterols in Food

Plant sterols are minor bioactive components of food lipids, which are often used for the formulation of functional foods due to their cholesterol-lowering properties. However, they have low solubility and tend to crystallize, which may affect their biological effects, the sensory profile of the sterol-enriched food, and its consumer acceptability. Moreover, due to the unsaturated structure of sterols, they are susceptible to oxidation, so different encapsulation systems have been developed to improve their dispersibility/solubility, stability, delivery, and bioaccessibility. This chapter provides an overview of the main encapsulation systems currently used for plant sterols and their application in model and food systems, with a particular focus on their efficiency and impact on sterol bioaccessibility.

Guar gum series affect nanostructured lipid carriers via electrostatic assembly or steric hindrance: Improving their oral delivery for phytosterols

Surface modification of nanostructured lipid carriers (NLCs) can be an effective way to improve their oral delivery for active ingredients. In this study, four type of guar gum series modified NLCs for the delivery of phytosterols (PS) were constructed and the effects of the polysaccharides on their structure and physicochemical properties were studied. DLS and AFM results revealed that positively charged polysaccharides could bind to PS-NLCs through electrostatic attraction and made the complexes finally take positive charges, while negatively charged polysaccharides were more likely to fill in the gaps of NLC systems to achieve a balance between electrostatic repulsion and intermolecular forces. Although all four polysaccharides exhibited good storage stability and controlled release of PS in simulated intestinal digestion, PS-NLCs modified with partially hydrolyzed cationic guar gum (PHCG) at medium or high concentrations exhibited better gastric stability, mucoadhesion, and cellular uptake, which had considerable significance for improving the oral bioavailability of PS. This might be related to the coating structure of PHCG-PS-NLCs confirmed by AFM, FTIR, and Raman characterization. This study provide a reference value for designing suitable PS-NLC complexes without synthetic surfactants.

Simultaneous Analysis of Free/Combined Phytosterols in Rapeseed and Their Dynamic Changes during Microwave Pretreatment and Oil Processing

Here, a simple, efficient, and rapid solid phase extraction-gas chromatography (SPE–GC) method was developed for the simultaneous analysis of free/combined phytosterols in rapeseed and their dynamic changes during microwave pretreatment and oil processing. First, by comparing different methods for extracting free/combined phytosterols from rapeseed and rapeseed cake, the Folch method was considered to be the optimal method and was selected in subsequent experiments. Subsequently, the extraction method was validated by determining the recoveries of standards (brassinosterol, campesterol, β-sitosterol and cholesteryl oleate) spiked in rapeseed and rapeseed oil samples, and the recoveries were in the range from 82.7% to 104.5% and 83.8% to 116.3%, respectively. The established method was applied to study the dynamic changes of the form and content of phytosterols in rapeseed and its products (rapeseed oil and cake) during rapeseed microwave pretreatment and the oil production process. Additionally, the results showed that more than 55% of the free/combined phytosterols in rapeseed were transferred to rapeseed oil during the oil processing, and this proportion will increase after microwave pretreatment of rapeseed. This work will provide analytical methods and data support for a comprehensive understanding of phytosterols in rapeseed and its products during oil processing.

Encapsulated Microstructures of Beneficial Functional Lipids and Their Applications in Foods and Biomedicines

Beneficial functional lipids are essential nutrients for the growth and development of humans and animals, which nevertheless possess poor chemical stability because of heat/light-sensitivity. Various encapsulation technologies have been developed to protect these nutrients against adverse factors. Different microstructures are exhibited through different encapsulation methods, which influence the encapsulation efficiency and release behavior at the same time. This review summarizes the effects of preparation methods and process parameters on the microstructures of capsules at first. The mechanisms of the different microstructures on encapsulation efficiency and controlled release behavior of core materials are analyzed. Next, a comprehensive overview on the beneficial functional lipids capsules in the latest food and biomedicine applications are provided as well as the matching relationship between the microstructures of the capsules and applications are discussed. Finally, the remaining challenges and future possible directions that have potential interest are outlined. The purpose of this review is to convey the construction of beneficial functional lipids capsules and the function mechanism, a critical analysis on its current status and challenges, and opinions on its future development. This review is believed to promote communication among the food, pharmacy, agronomy, engineering, and nutrition industries.

An efficient and robust continuous-flow bioreactor for the enzymatic preparation of phytosterol esters based on hollow lipase microarray

In this study, a continuous-flow bioreactor packed with well-organized lipase microarrays was developed for the sustainable synthesis of functional lipid-phytosterol esters (PEs). Hollow mesoporous silicon spheres with a suitable pore size were prepared for lipase immobilization, and the hydrophobic modification endowed the lipase with excellent catalytic activity and stability. The results showed that the condensely packed lipase microarrays offered large specific surface areas and guaranteed the thorough interaction between the lipase and substrates in the continuous-flow bioreactor. Meanwhile, the substrate could pass through the reactor at 1 mL/min with a high conversion of 93.6% due to the hollow structure of the packing spheres. Moreover, the reactors were able to produce 1564 g PEs/g catalyst in a continuous 30-day processing period, which set the highest records for PEs synthesis. This sustainable and highly-converting flow system provided a feasible path for scale-up production of PEs in the food processing area.

Microencapsulation by spray chilling in the food industry: Opportunities, challenges, and innovations

Background

The increasing demand for healthy eating habits and the emergence of the COVID-19 pandemic, which resulted in a health crisis and global economic slowdown, has led to the consumption of functional and practical foods. Bioactive ingredients can be an alternative for healthy food choices; however, most functional compounds are sensitive to the adverse conditions of processing and digestive tract, impairing its use in food matrices, and industrial-scale applications. Microencapsulation by spray chilling can be a viable alternative to reduce these barriers in food processing.

Scope and approach

This review discusses the use of spray chilling technique for microencapsulation of bioactive food ingredients. Although this technology is known in the pharmaceutical industry, it has been little exploited in the food sector. General aspects of spray chilling, the process parameters, advantages, and disadvantages are addressed. The feasibility and stability of encapsulated bioactive ingredients in food matrices and the bioavailability in vitro of solid lipid microparticles produced by spray chilling are also discussed.

Main findings and conclusions

Research on the microencapsulation of bioactive ingredients by spray chilling for use in foods has shown the effectiveness of this technique to encapsulate bioactive compounds for application in food matrices. Solid microparticles produced by spray chilling can improve the stability and bioavailability of bioactive ingredients. However, further studies are required, including the use of lipid-based encapsulating agents, process parameters, and novel formulations for application in food, beverages, and packaging, as well as in vivo studies to prove the effectiveness of the formulations.

Production and characterization of nanoemulsion with low-calorie structured lipids and its potential to modulate biomarkers associated with obesity and comorbidities

Structured lipids (SL) containing behenic acid have been produced in order to obtain low-calorie lipids for foods; however, the development of a high nutritional value and a stable nanoemulsion carrier system for these SL is an interesting breakthrough for this field of research, improving technologic and biological potential for food application. In this sense, the aim of this study was to evaluate the stability of a nanoemulsion containing SL NeSL (produced with olive oil, soybean oil and fully hydrogenated crambe oil), the behavior during in vitro digestion and the effects on biomarkers involved in the obesity in cell models. The samples showed good stability throughout storage (30 days) under refrigeration and room temperature and after the gastric digestion phase compared to the controls (nanoemulsion of olive and soybean oil). After the intestinal phase, there was an increase in oil droplet size and zeta potential, a characteristic of coalescence. In the lipid accumulation model in adipocytes, the highest concentration (50 µL/mL) of NeSL resulted in 42% less lipid accumulation, compared to the control. Furthermore, the sample was able to reduce inflammatory cytokines produced by macrophages provoked by LPS (lipopolysaccharide). The combination of the oils in NeSL resulted in a fatty acid profile with beneficial health properties, which may have contributed to less lipid accumulation and improved inflammatory parameters. This SL in the form of a nanoemulsion, may be used as a partial fat substitute in low-calorie food products.

Plant oils: From chemical composition to encapsulated form use

The last decade has witnessed a burgeoning global movement towards essential and vegetable oils in the food, agriculture, pharmaceutical, cosmetic, and textile industries thanks to their natural and safe status, broad acceptance by consumers, and versatile functional properties. However, efforts to develop new therapy or functional agents based on plant oils have met with challenges of limited stability and/or reduced efficacy. As a result, there has been increased research interest in the encapsulation of plant oils, whereby the nanocarriers serve as barrier between plant oils and the environment and control oil release leading to improved efficacy, reduced toxicity and enhanced patient compliance and convenience. In this review, special concern has been addressed to the encapsulation of essential and vegetable oils in three types of nanocarriers: polymeric nanoparticles, liposomes and solid lipid nanoparticles. First, the chemical composition of essential and vegetable oils was handled. Moreover, we gather together the research findings reported by the literature regarding the different techniques used to generate these nanocarriers with their significant findings. Finally, differences and similarities between these nanocarriers are discussed, along with current and future applications that are warranted by their structures and properties.

Rhamnolipids-based nanostructured lipid carriers: Effect of lipid phase on physicochemical properties and stability

In this work rhamnolipids were evaluated as surfactants for the production of nanostructured lipid carriers (NLCs). NLCs were produced by melt-emulsification using ultra-homogenisation followed by ultrasonication and different ratios of medium-chain-triglycerides and glycerol monostearate (lipid phase) were tested. NLCs presented sizes and polydispersity index values ranged between 97 and 120 nm and 0.20-0.26, respectively. Transmission electron microscopy observations confirmed the size and the spherical morphology of the NLCs. The thermal analysis and X-ray diffraction showed that the amount of solid lipid (glycerol monostearate) influences the melting, crystallisation and enthalpy of NLCs and their degree of crystallinity. Results showed that NLCs were more stable at 4 °C and the best formulation (1% of water phase, 0.05% of biosurfactant and solid:liquid ratio of 10:90) was stable for 30 days. This work showed the possibility of using rhamnolipids to produce NLCs and represent an important step for the development of lipid-based nanosystems using biosurfactants.