Miguel Ângelo Parente Ribeiro Cerqueira

Nanoemulsions for Food Applications: Development and Characterization

The application of nanotechnology to food, medical and pharmaceutical industries has received great attention from the scientific community. Driven by the increasing consumers’ demand for healthier and safer food products and the need for edible systems able to encapsulate, protect, and release functional compounds, researchers are currently focusing their efforts in nanotechnology to address issues relevant to food and nutrition. Nanoemulsion technology is particularly suited for the fabrication of encapsulating systems for functional compounds as it prevents their degradation and improves their bioavailability. This review focuses on nanoemulsions and provides an overview of the production methods, materials used (solvents, emulsifiers, and functional ingredients) and of the current analytical techniques that can be used for the identification and characterization of nanoemulsions. Finally, nanotechnological applications in foods currently marketed are reported.

Active and Intelligent Packaging for Milk and Milk Products

8.1 Importance and Definition of Active and Intelligent Packaging 176 8.1.1 A Brief Historical Introduction of Package Evolution 176 8.1.2 More Consumer Demand, More Packaging Functions 177 8.1.3 Concepts and Application of Active Packaging 179 8.1.3.1 Antimicrobial Packaging 179 8.1.3.2 Edible Packages 180 8.1.3.3 Oxygen Absorber 182 8.1.3.4 Ethylene Absorber 183 8.1.3.5 Humidity Absorber 184 8.1.4 Concepts and Application of Intelligent Packaging 184 8.2 Development of Antimicrobial Packaging 185 8.2.1 Commonly Used Antimicrobial Substances 186 8.2.2 Antimicrobial Incorporation into Plastic Polymers 187 8.2.3 Antimicrobial Immobilization in Polymers 188 8.2.4 Surface Modification 189 8.2.5 Factors to Consider in the Production of Antimicrobial Films ........ 190 8.3 Nanotechnology—Applications in Food Packaging 190 8.4 Potential Use of Active and Intelligent Packaging in Milk and Milk Products 192 Acknowledgments 196 References 196

Effect of moderate electric fields in the properties of starch and chitosan films reinforced with microcrystalline cellulose

Microcrystalline cellulose (MCC) can provide improved properties when the aim is the development of biodegradable packaging materials. In this work the physicochemical properties of polysaccharide-based films (chitosan and starch) with the incorporation of MCC and the application of moderate electric field (MEF) and ultrasonic bath (UB) as treatments, were evaluated. For each treatment, the thickness, moisture content, solubility, water vapor permeability, contact angle, mechanical properties, along with its color and opacity were determined. The surface morphologies of the films were assessed by scanning electron microscopy (SEM). X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA) were also performed. It was observed that the addition of different concentrations of MCC as well as the application of MEF are responsible for changes in the properties of the films, being this effect dependent on the polysaccharide used. Chitosan-based films were slightly yellow, transparent and presented a more homogeneous structure. The use of MEF was efficient in decreasing the permeability to water vapor in chitosan based films without MCC, as well as in production of films with a more hydrophobic surface. The addition of MCC promoted more opaque, rigid, less flexible and less hydrophobic films. Starch-based films were whitish, with a more heterogeneous structure and the application of MEF generated more hydrophilic films with lower tensile strength and Youngs modulus. The films with MCC were more opaque, less flexible and less hydrophilic than the films without MCC. The composites presented good thermal properties, which increases their applicability as packaging materials. Therefore, the incorporation of MCC into polysaccharide-based films as well as the application of MEF can be an approach to change the properties of films.

Advances in Food Nanotechnology

Abstract The use of nanotechnology in the food industry offers many potential benefits for consumers and manufacturers. The dimension and physico-chemical properties of materials at the nanoscale allow their inclusion in several food processes and applications showing great advantages when compared with micro- and macroscale alternatives. The benefits of applying nanotechnology have been driving the development of new and high performance materials for the food sector in areas, such as: encapsulation of compounds (using bio-based nanostructures), food safety (i.e., detection of contaminants and microorganisms and removal of chemicals from foods), and food processing (i.e., nanofiltration and enzyme immobilization). The increasing number of publications and patents shows the fast growth of this topic in the agro-food industry, which is confirmed by the significant number of companies using nanotechnology in the development of their products. Also, the acceptance of the consumers for nanotechnology-based products is of utmost importance: this will dictate if they will/should be in the market or not. This chapter addresses these issues aiming at providing an integrated perspective to reader, foreseeing that, in the next few years, government organizations, academia, and industry will need to work together to increase the acceptance of nanotechnology-based products.

Use of edible films and coatings in cheese preservation: Opportunities and challenges

In the last years, there has been a growing interest in the use of edible materials in food packaging. The cheese industry is clearly one of the sectors where these materials have a good opportunity for application, as shown by the recent developments on edible coatings and films for cheese. Edible coatings and films, besides its edibility, can be used to reduce weight loss and prevent the microbiological spoilage through the control of oxygen and carbon dioxide exchange rate and as a carrier of antimicrobial compounds. This review summarizes the recent results on edible films and coatings for cheese, the main developments and the main future perspectives for the application of these materials in the cheese industry.

Physiological protection of probiotic microcapsules by coatings

ABSTRACT Nowadays, food and nutrition have a greater impact in peoples concerns, with the awareness that nutrition have a direct impact in health and wellbeing. Probiotics have an important role in this topic and consumers are starting to really understand their potential in health, leading to an increasing interest of the companies to their commercial use in foods. However, there are several limitations to the use of probiotics in foods and beverages, being one of them their efficiency (directly associated to their survival rate) upon ingestion. This work is focused in microencapsulation techniques that have been used to increase probiotics efficiency. More specifically, this work reviews the most recent and relevant research about the production and coating techniques of probiotic-loaded microcapsules, providing an insight in the effect of these coatings in probiotics survival during the gastrointestinal phase. This review shows that coatings with the better performances in probiotics protection, against the harsh conditions of digestion, are chitosan, alginate, poly-L-lysine, and whey protein. Chitosan presented an interesting performance in probiotics protection being able to maintain the initial concentration of viable probiotics during a digestive test. The analyses of different works also showed that the utilization of several coatings does not guarantee a better protection in comparison with monocoated microcapsules.

Development of an immobilization system for in situ micronutrients release

An immobilization system constituted by coated microcapsules was developed aiming at immobilizing probiotic bacteria capable of producing folate and release it in a sustained manner into the intestine. Despite no probiotic folate-producers have been immobilized so far, the system has been developed with this goal and this work reports its stability and ability to release folate under gastro-intestinal conditions. Microcapsules were made of alginate with three consecutive coatings of poly-l-lysine, sodium alginate and chitosan. Turbidity experiments showed a strong electrostatic interaction between these polymers. Fourier transform infrared spectroscopy (FTIR) and confocal analysis showed the stability of the coating materials when applied on the microcapsules, even after they were immersed in solutions simulating conditions in the stomach and small intestine (i.e. pH2, 60min and pH7.2, 120min, respectively). Coated microcapsules have an average diameter size ranged from 20 and 40μm, and swelled upon exposure to a neutral medium, without dissolution as showed by microscopy analyses. Release experiments proved the ability of the coated microcapsules to release folic acid, at different rates, depending on the applied coating. Release experiments showed that the first coating (Ɛ-PLL) is characterized by Fickian diffusion as the main release mechanism of folic acid. Fickian rate constant (kF) decreased with the number of consequent coatings, reflecting the decrease of predominance of Ficks behavior. Results showed that the developed coated microcapsules have suitable characteristics for encapsulation of folic acid aiming in situ release in the intestine.

Hydrogel as an alternative structure for food packaging systems

Hydrogels are three-dimensional, hydrophilic networks, comprising polymeric chains linked through physical or chemical bonds. In the area of food, hydrogels have great potential to be used in food packaging systems or as carriers of bioactive components. This paper reviews the nature of hydrogels, their 3D network conformation, their functional properties, and their potential applications in food packaging systems. Regarding their potential food packaging applications, hydrogels can present a conformation which allows their use as part of a packaging system to control the humidity generated by food products with high water content. Moreover, the incorporation of nanoparticles into hydrogels may grant them antimicrobial activity. Finally, although the current research in this field is still limited, the results obtained so far are promising for innovative and potential applications in the food field, which also include their integration into intelligent food packaging systems and their direct incorporation into food matrices as a flavor carrier system.

Use of Lignocellulosic Materials in Bio-based Packaging

This chapter presents the most recent studies on the use of lignocellulosic materials for the development of bio-based packaging materials. It is addressed the incorporation of cellulose and its derivatives, hemicellulose, and lignin in bio-based packaging, and some works where the lignocellulosic materials with few pretreatment are used as filler are also presented. Additionally, it is discussed some bio-based materials extracted from biomass, such as polysaccharides and proteins, but also the chemically synthesized polymers such as polylactic acid (PLA), or obtained through biotechnological routes such as polyhydroxyalkanoates.

Food Applications of Lignocellulosic-Based Packaging Materials

The use of current packaging materials on food products has as main objective to protect the product for the maintenance of food quality and safety during transportation and storage, but also to attract the attention of the consumers for a particular brand while giving information about the food product. The use of cellulose-based materials as secondary and tertiary packaging has been one of the main applications of lignocellulosic materials in food packaging. Nowadays, the use of lignocellulosic materials incorporated in bio-based materials showed to be a good possibility to reduce the use of petroleum-based materials and thus increase the sustainability. During this chapter are given some commercial examples and research studies of the application of lignocellulosic-based materials as food packaging.