McClements, D. Julian

Job Title

Professor, Department of Food Science, College of Natural Sciences

Last Name

McClements

First Name

D. Julian

Discipline

Food Science

Expertise

Delivery systems
Food biopolymers and colloids
Physicochemical basis of digestion

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Search Results

Now showing 1 - 10 of 20

Open Access
Recent Advances in Encapsulation, Protection, and Oral Delivery of Bioactive Proteins and Peptides using Colloidal Systems
(2020) Perry, Sarah L.; McClements, David Julian
There are many areas in medicine and industry where it would be advantageous to orally deliver bioactive proteins and peptides (BPPs), including ACE inhibitors, antimicrobials, antioxidants, hormones, enzymes, and vaccines. A major challenge in this area is that many BPPs degrade during storage of the product or during passage through the human gut, thereby losing their activity. Moreover, many BPPs have undesirable taste profiles (such as bitterness or astringency), which makes them unpleasant to consume. These challenges can often be overcome by encapsulating them within colloidal particles that protect them from any adverse conditions in their environment, but then release them at the desired site-of-action, which may be inside the gut or body. This article begins with a discussion of BPP characteristics and the hurdles involved in their delivery. It then highlights the characteristics of colloidal particles that can be manipulated to create effective BPP-delivery systems, including particle composition, size, and interfacial properties. The factors impacting the functional performance of colloidal delivery systems are then highlighted, including their loading capacity, encapsulation efficiency, protective properties, retention/release properties, and stability. Different kinds of colloidal delivery systems suitable for encapsulation of BPPs are then reviewed, such as microemulsions, emulsions, solid lipid particles, liposomes, and microgels. Finally, some examples of the use of colloidal delivery systems for delivery of specific BPPs are given, including hormones, enzymes, vaccines, antimicrobials, and ACE inhibitors. An emphasis is on the development of food-grade colloidal delivery systems, which could be used in functional or medical food applications. The knowledge presented should facilitate the design of more effective vehicles for the oral delivery of bioactive proteins and peptides.
Open Access
Methods for Testing the Quality Attributes of Plant-Based Foods: Meat- and Processed-Meat Analogs
(2021) McClements, David Julian; Weiss, Jochen; Kinchla, Amanda J.; Nolden, Alissa A.; Grossmann, Lutz
The modern food system is seeing a change in consumption patterns provoked by several drivers—including ethical, health, and environmental concerns—that are increasing the sales of meat analog foods. This change is accompanied by increased research and development activities in the area of plant-based meats. The aim of the present review is to describe methods that are being employed by scientists to analyze and characterize the properties of meat alternatives and to propose standardized methods that could be utilized in the future. In particular, methods to determine the proximate composition, microstructure, appearance, textural properties, water-holding properties, cooking resilience, and sensory attributes, of plant-based meat are given. The principles behind these methods are presented, their utility is critically assessed, and practical examples will be discussed. This article will help to guide further studies and to choose appropriate methods to assess raw materials, processes, products, and consumption behavior of meat analogs
Open Access
Influence of Protein Type on the Antimicrobial Activity of LAE Alone or in Combination with Methylparaben
(2020) Loeffler, Myriam; Schwab, Verena; Terjung, Nino; Weiss, Jochen; McClements, David Julian
The cationic surfactant Lauric arginate (LAE) has gained approval for utilization in meat products (limit: 200 mg/kg). However, as for other antimicrobials, its activity is reduced when applied to complex food matrices. The current study therefore aims to better understand protein-antimicrobial agent-interactions and their influence on the antimicrobial activity of (i) LAE and (ii) methylparaben against Listeria innocua and Pseudomonas fluorescens in defined model systems (pH 6). Antimicrobials were utilized alone or in combination with nutrient broth containing either no protein or 2% bovine serum albumin, whey protein isolate, or soy protein hydrolysate. LAE was found to form complexes with all proteins due to electrostatic attraction, determined using microelectrophoretic and turbidity measurements. Minimal lethal concentrations of LAE were remarkably increased (4–13 fold) in the presence of proteins, with globular proteins having the strongest impact. Combinations of LAE (0–200 µg/mL) with the less structure-sensitive component methylparaben (approved concentration 0.1%) remarkably decreased the concentrations of LAE needed to strongly inhibit or even kill both, L. innocua and P. fluorescens in the presence of proteins. The study highlights the importance of ingredient interactions impacting microbial activity that are often not taken into account when examining antimicrobial components having different structure sensitivities
Open Access
Application of Nanotechnology to Improve the Performance of Biodegradable Biopolymer-Based Packaging Materials
(2021) Khezerlou, Arezou; Tavassoli, Milad; Sani, Mahmood Alizadeh; Mohammadi, Keyhan; Ehsani, Ali; McClements, David Julian
There is great interest in developing biodegradable biopolymer-based packaging materials whose functional performance is enhanced by incorporating active compounds into them, such as light blockers, plasticizers, crosslinkers, diffusion blockers, antimicrobials, antioxidants, and sensors. However, many of these compounds are volatile, chemically unstable, water-insoluble, matrix incompatible, or have adverse effects on film properties, which makes them difficult to directly incorporate into the packaging materials. These challenges can often be overcome by encapsulating the active compounds within food-grade nanoparticles, which are then introduced into the packaging materials. The presence of these nanoencapsulated active compounds in biopolymer-based coatings or films can greatly improve their functional performance. For example, anthocyanins can be used as light-blockers to retard oxidation reactions, or they can be used as pH/gas/temperature sensors to produce smart indicators to monitor the freshness of packaged foods. Encapsulated botanical extracts (like essential oils) can be used to increase the shelf life of foods due to their antimicrobial and antioxidant activities. The resistance of packaging materials to external factors can be improved by incorporating plasticizers (glycerol, sorbitol), crosslinkers (glutaraldehyde, tannic acid), and fillers (nanoparticles or nanofibers). Nanoenabled delivery systems can also be designed to control the release of active ingredients (such as antimicrobials or antioxidants) into the packaged food over time, which may extend their efficacy. This article reviews the different kinds of nanocarriers available for loading active compounds into these types of packaging materials and then discusses their impact on the optical, mechanical, thermal, barrier, antioxidant, and antimicrobial properties of the packaging materials. Furthermore, it highlights the different kinds of bioactive compounds that can be incorporated into biopolymer-based packaging.
Open Access
Formulation of More Efficacious Curcumin Delivery Systems Using Colloid Science: Enhanced Solubility, Stability, and Bioavailability
(2020) Zheng, Bingjing; McClements, David Julian
Curcumin is a bioactive constituent isolated from turmeric that has historically been used as a seasoning, pigment, and herbal medicine in food. Recently, it has become one of the most commonly studied nutraceuticals in the pharmaceutical, supplement, and food areas because of its myriad of potential health benefits. For instance, it is claimed to exhibit antioxidant, anti-inflammatory, antimicrobial, antiparasite, and anticancer activities when ingested as a drug, supplement, or food. Toxicity studies suggest that it is safe to consume, even at relatively high levels. Its broad-spectrum biological activities and low toxicity have meant that it has been widely explored as a nutraceutical ingredient for application in functional foods. However, there are several hurdles that formulators must overcome when incorporating curcumin into commercial products, such as its low water solubility (especially under acidic and neutral conditions), chemical instability (especially under neutral and alkaline conditions), rapid metabolism by enzymes in the human body, and limited bioavailability. As a result, only a small fraction of ingested curcumin is actually absorbed into the bloodstream. These hurdles can be at least partially overcome by using encapsulation technologies, which involve trapping the curcumin within small particles. Some of the most commonly used edible microparticles or nanoparticles utilized for this purpose are micelles, liposomes, emulsions, solid lipid particles, and biopolymer particles. Each of these encapsulation technologies has its own benefits and limitations for particular product applications and it is important to select the most appropriate one.
Open Access
Oil-in-water Pickering emulsions via microfluidization with cellulose nanocrystals: 1. Formation and Stability
(2019) Bai, Long; Lv, Shanshan; Huan, Siqi; McClements, David Julian; Rojas, Orlando J.
Oil-in-water Pickering emulsions were successfully prepared via high-energy microfluidization using cellulose nanocrystals (CNC) as interfacial stabilizers. The influence of microfluidization pressure, CNC concentration, and oil type on droplet size and emulsion stability was determined. Under optimized homogenization conditions, CNC formed and stabilized emulsions based on corn, fish, sunflower, flax, orange, and MCT oils. The droplet size decreased with increasing microfluidization pressure from 9 to 17 kpsi, but then increased slightly at 19 kpsi. The creaming stability of the emulsions increased with CNC concentration, which was mainly attributed to the decrease in droplet size (mean particle diameter < 1 μm at CNC-to-oil ratios greater than 1:10) and slightly increased viscosity. The Pickering emulsions were stable to droplet coalescence, presumably due to strong electrostatic and steric repulsions between the lipid droplets carrying adsorbed nanoparticles. The Pickering emulsions had good stability over a range of environmental stresses: pH 3 to 10; NaCl ≤ 100 mM; temperature from 30 to 90 °C. Droplet flocculation was, however, observed under more acidic conditions (pH 2) and at high ionic strength (200–500 mM NaCl), owing to electrostatic screening. Our results indicate that microfluidization is an effective method for forming CNC-stabilized Pickering emulsions suitable for utilization in the food industry.
Open Access
Utilization of Nanotechnology to Improve the Handling, Storage and Biocompatibility of Bioactive Lipids in Food Applications
(2021) McClements, David Julian; Öztürk, Bengü
Bioactive lipids, such as fat-soluble vitamins, omega-3 fatty acids, conjugated linoleic acids, carotenoids and phytosterols play an important role in boosting human health and wellbeing. These lipophilic substances cannot be synthesized within the human body, and so people must include them in their diet. There is increasing interest in incorporating these bioactive lipids into functional foods designed to produce certain health benefits, such as anti-inflammatory, antioxidant, anticancer and cholesterol-lowering properties. However, many of these lipids have poor compatibility with food matrices and low bioavailability because of their extremely low water solubility. Moreover, they may also chemically degrade during food storage or inside the human gut because they are exposed to certain stressors, such as high temperatures, oxygen, light, moisture, pH, and digestive/metabolic enzymes, which again reduces their bioavailability. Nanotechnology is a promising technology that can be used to overcome many of these limitations. The aim of this review is to highlight different kinds of nanoscale delivery systems that have been designed to encapsulate and protect bioactive lipids, thereby facilitating their handling, stability, food matrix compatibility, and bioavailability. These systems include nanoemulsions, solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), nanoliposomes, nanogels, and nano-particle stabilized Pickering emulsions.
Open Access
Development of Next-Generation Nutritionally Fortified Plant-Based Milk Substitutes: Structural Design Principles
(2020) McClements, David Julian
Consumers are increasingly interested in decreasing their dietary intake of animal-based food products, due to health, sustainability, and ethical concerns. For this reason, the food industry is creating new products from plant-based ingredients that simulate many of the physicochemical and sensory attributes associated with animal-derived foods, including milk, eggs, and meat. An understanding of how the ingredient type, amount, and organization influence the desirable physicochemical, sensory, and nutritional attributes of these plant-based foods is required to achieve this goal. A potential problem with plant-based diets is that they lack key micronutrients, such as vitamin B12, vitamin D, calcium, and ω-3 fatty acids. The aim of this review is to present the science behind the creation of next-generation nutritionally fortified plant-based milk substitutes. These milk-like products may be formed by mechanically breaking down certain plant materials (including nuts, seeds, and legumes) to produce a dispersion of oil bodies and other colloidal matter in water, or by forming oil-in-water emulsions by homogenizing plant-based oils and emulsifiers with water. A brief overview of the formulation and fabrication of plant-based milks is given. The relationship between the optical properties, rheology, and stability of plant-based milks and their composition and structure is then covered. Approaches to fortify these products with micronutrients that may be missing from a plant-based diet are also highlighted. In conclusion, this article highlights how the knowledge of structural design principles can be used to facilitate the creation of higher quality and more sustainable plant-based food products.
Open Access
Excipient Nanoemulsions for Improving Oral Bioavailability of Bioactives
(2016) Salvia-Trujillo, Laura; Martin-Belloso, Olga; McClements, David Julian
The oral bioavailability of many hydrophobic bioactive compounds found in natural food products (such as vitamins and nutraceuticals in fruits and vegetables) is relatively low due to their low bioaccessibility, chemical instability, or poor absorption. Most previous research has therefore focused on the design of delivery systems to incorporate isolated bioactive compounds into food products. However, a more sustainable and cost-effect approach to enhancing the functionality of bioactive compounds is to leave them within their natural environment, but specifically design excipient foods that enhance their bioavailability. Excipient foods typically do not have functionality themselves but they have the capacity to enhance the functionality of nutrients present in natural foods by altering their bioaccessibility, absorption, and/or chemical transformation. In this review article we present the use of excipient nanoemulsions for increasing the bioavailability of bioactive components from fruits and vegetables. Nanoemulsions present several advantages over other food systems for this application, such as the ability to incorporate hydrophilic, amphiphilic, and lipophilic excipient ingredients, high physical stability, and rapid gastrointestinal digestibility. The design, fabrication, and application of nanoemulsions as excipient foods will therefore be described in this article.
Open Access
Fermentation of tomato juice improves in vitro bioaccessibility of lycopene
(2020) Lu, Yuyan; McClements, David Julian; Liang, Xiuping; Liu, Xuebo; Liu, Fuguo
The impact of fermentation (Saccharomyces cerevisiae ATCC 9763) on the bioaccessibility of lycopene in a model tomato juice was examined. The physicochemical and structural properties of the tomato tissue were determined after fermentation and the bioaccessibility of lycopene was monitored using a simulated gastrointestinal tract. A lycopene concentration of 45.1 mg/100 g was obtained under optimal fermentation conditions. The cell walls of the tomato cells were hydrolyzed and disrupted by fermentation. Cell disruption decreased the pectin content and reduced the tissue fragment size, thereby reducing gravitational separation and facilitating lycopene release. The lycopene bioaccessibility in the tomato juices increased in the following order: unfermented (8.5%) < fermented (11.4%) < unfermented-emulsified (13.6%) < fermented-emulsified (22.7%). These effects were attributed to a combination of greater tomato tissue disruption and enhanced mixed micelle formation. Our results may be useful for the development of functional foods and beverages with improved health benefits.