Showing papers in "Trends in Food Science and Technology in 2016"

Industrial applications of crustacean by-products (chitin, chitosan, and chitooligosaccharides): A review

Abstract: Background Food processing produces large quantities of by-products. Disposal of waste can lead to environmental and human health problems, yet often they can be turned into high value, useful products. For example, crustacean shell wastes from shrimp, crab, lobster, and krill contain large amounts of chitin, a polysaccharide that may be extracted after deproteinisation and demineralization of the exoskeletons. Scope and approach This review summarizes the current state of knowledge of these crustacean shellfish wastes and the various ways to use chitin. This biopolymer and its derivatives, such as chitosan, have many biological activities (e.g., anti-cancer, antioxidant, and immune-enhancing) and can be used in various applications (e.g., medical, cosmetic, food, and textile). Key findings and conclusions Due to the huge waste produced each year by the shellfish processing industry and the absence of waste management which represent an environmental hazard, the extraction of chitin from crustaceans’ shells may be a solution to minimize the waste and to produce valuable compound which possess biological properties with application in many fields. As a food waste, it is important to also be aware of the non-food uses of these wastes.

Essential oils as additives in biodegradable films and coatings for active food packaging

Abstract: The authors acknowledge the financial support from the Spanish Ministerio de Educacion y Ciencia through Project AGL2010-20694, from Universidad Politecnica de Valencia through Project PAID-06-11-2013 and from Conselleria de Empresa, Universidad y Ciencia (Project GV/2013/152).

Green alternative methods for the extraction of antioxidant bioactive compounds from winery wastes and by-products: A review

Abstract: Background Wine production represents one of the major agricultural activities worldwide. This production is accompanied with the generation of tremendous amounts of wastes and by-products exceptionally rich in bioactive compounds (especially phenolics). Recovering these molecules constitutes a key point for the valorization of the wine-processed materials, making them on the verge of commercialization. Regarding the health related benefits of these molecules; they could be used as additives for food and cosmetic products. Scope and approach The current review is revising the potential of alternative extraction methodologies for the recovery of antioxidant bioactive compounds from winery wastes and by-products. Conventional (solid liquid extraction, heating, grinding, etc) and non-conventional (pulsed electric fields, high voltage electrical discharges, pulsed ohmic heating, ultrasounds, microwave-assisted extractions, sub- and supercritical fluid extractions, as well as pressurized liquid extraction) methods have been applied for the extraction of high-added value compounds from winery-processed materials. Key findings and conclusions Non-conventional technologies represent a promising tool to recover high-added value compounds from winery wastes and by-products. However, several parameters are influencing the choice of technology used to recover these compounds, such as the matrix being processed, the selectivity, the energy consumption, the equipment cost, and the value of the extract.

The biological activities, chemical stability, metabolism and delivery systems of quercetin: A review

Abstract: Background Quercetin, one of the most well-known flavonoids, has been included in human diet for a long history. The use of quercetin has been widely associated with a great number of health benefits, including antioxidant, anti-inflammatory, antiviral and anticancer as well as the function to ease some cardiovascular diseases (i.e., heart disease, hypertension, and high blood cholesterol). However, poor water solubility, chemical instability and low bioavailability of quercetin greatly limit its applications. Utilization of delivery systems can improve its stability, efficacy and bioavailability. Scope and approach In this review, biological activities, chemical stability, metabolism and toxicity of quercetin and different delivery systems for quercetin were discussed. Key findings and conclusions Quercetin digested in human body (e.g., mouth, small intestine, liver, kidneys) undergoes glucuronidation, sulfation or methylation. During the food processing and storage, many factors such as heat, pH, metal ions, could affect the chemical stability (including oxidation and degradation) of quercetin. Utilization of delivery systems including lipid-based carriers, nanoparticles, inclusion complexes, micelles and conjugates-based encapsulation has the potential to improve both the stability and bioavailability and thus health benefits of quercetin. Each delivery system has its unique advantages and shortcomings, and the specific selection should be based on the application domains. Moreover, the exploration of natural food-grade ingredients as main compositions of delivery systems for quercetin might be required in the future.

Development of biocontrol products for postharvest diseases of fruit: The importance of elucidating the mechanisms of action of yeast antagonists

Abstract: s Background Impressive progress was made in the last decade in development, registration and commercialization of biocontrol products based on yeast to manage postharvest pathogens of fruit. To successfully inhibit the pathogen infection and development, several possible mechanisms operate in a tritrophic host-pathogen-antagonist interaction system. Scope and Approach The current reviews focuses on the recent knowledge on the mechanisms by which yeast biocontrol agents (BCAs) interact with pathogens and fruit tissues. The main mechanisms of action explored include antibiosis, mycoparasitism, production of lytic enzymes, induced resistance, competition for limiting nutrients and space, and the role of oxidative stress. Omics techniques can provide a powerful tool to study complex fruit host-pathogen-antagonist-native microflora interactions. Key Findings and Conclusions Various aspects relevant to mechanisms of action of yeast antagonists have been discussed, including unique environment of surface wounds, iron competition, biofilm formation, cell wall degrading enzymes, and involvement of oxidative stress. Outstanding advancement in molecular and omics technologies revolutionized the research about the physiological status of BCAs and the global effect of the application of BCAs on the transcriptome and/or proteome of fruit. Microbial communities on plant surfaces could impact disease control through their interactions with host plants, pathogens, and BCAs, in a quadritrophic interaction system, hence microbiome research opens new research opportunities. The complex modes of action make antagonistic performance and efficacy more dependent on production, formulation, packing, application, and storage. A deep understanding of the mode of action is essential to develop appropriate formulation and methods of application.

Nano-encapsulation as a promising approach for targeted delivery and controlled release of vitamins

Abstract: Background Vitamins are bioactive molecules necessary for human health, which are sensible to degradation. During consumption, the bioavailability of these compounds might be limited due to structure break-down and low absorption. Today, nanoencapsulation can be a promising approach for targeted delivery of vitamins and protecting these bioactive components against destructive environment during processing and delivery. Regarding the benefits of utilizing nanotechnology in the food sector, safety aspects of these tiny carriers should also be clarified as this technology develops. Due to the possible negative effects of nanomaterials, several agencies have legislated regulatory policies to prevent potential harms to the consumers, which are underlined in this article. Scope and approach Nanoencapsulation-based technologies are a unique and novel field of investigation in the food and pharmaceutical industry with benefits, such as higher bioavailability, high shelf-stability and controlled release of active compounds. This review highlights recent works on these techniques and advances made in nanoencapsulation of lipophilic and hydrophilic vitamins, safety issues and health risks regarding the consumption of these products, which opens new horizons in food technology and nutrition with possibilities of commercialization in the near future. Key findings and conclusions Recently, considerable progresses are being carried out in the field of food nanoencapsulation involving novel nanovehicles to encapsulate vitamins. Nanofibers and nanohydrogels are some examples of efficient and modern nanocarriers. Overall, the vitamins encapsulated within nanovehicles are considered safe since they are mostly produced from food components, meanwhile more studies should be performed regarding the safety issues of nanodelivery of vitamins. In near future, it is assumed that nanoencapsulated vitamins will be broadly applied the in the food and beverage products.

Recent advances on food-grade particles stabilized Pickering emulsions: Fabrication, characterization and research trends

Abstract: Background Colloidal particles assembled from food grade materials with proper fabrication and/or modification can function as Pickering emulsion stabilizers. Scope and approach This paper summarized recent research practices in developing food-grade particles stabilized Pickering emulsions. Recent advances in methods for their fabrication and characterization were reviewed. Research progresses in clarifying their stabilization mechanisms based on interfacial microstructure observation as well as promising research trends in basic research and fields of applications were highlighted. Key findings and conclusions Food-grade materials can be used to engineer colloidal particles through five commonly used methods. Chemical modification, physical deposition and complex formation with surfactants were emerging strategies for improving their interfacial attachment efficiency. Current approaches and results in the study of food-grade particles stabilized Pickering emulsions, including contact angle and microstructure characterization, as well as stabilization mechanisms and rheological properties were summarized. Promising research trends in food-grade particles stabilized Pickering emulsions include: (1) to develop tunable interfacial structure, (2) to clarify their digestion profile under oral conditions, and (3) to expand their applications in fields like target delivery and double emulsions with enhanced stability.

An overview of the intelligent packaging technologies in the food sector

Abstract: Background Intelligent packaging is the newest technology within the food packaging field. Even though this technology is still growing and not fully commercially viable, it has enormous potential to improve the safety, quality, and traceability of food products, as well as its convenience for consumers. Scope and approach This paper first describes both the technical aspects and commercial applications of the most representative intelligent technologies—indicators, data carriers, and sensors—with special focus on systems and devices that are directly integrated into the package. Secondly, to provide useful guidelines for future research in the field, the paper discusses some important aspects that still hinder the full exploitation of intelligent technology within the food packaging industry. Key findings and conclusions Future research needs to consider some important aspects in order to make intelligent systems commercially viable, such as cost, consumers' acceptance and confidence, regulatory aspects (e.g., labeling), and multifunctionality.

Food colorants: Challenges, opportunities and current desires of agro-industries to ensure consumer expectations and regulatory practices

Abstract: Background Worldwide consumers seek most delightful and appealing foodstuffs, at the same time they require safer, more nutritious and healthier products. Color is one of the most important organoleptic attributes that directly affects consumers' acceptance and food selection. Scope and approach The present report aims to provide an extensive approach to the field of food (natural/synthetic) colorants, namely those who are currently allowed with established acceptable daily intake (ADI). It also describes the biotechnological and industrial techniques that have been used to optimize food attractiveness, shelf life and color stability, as well as the general trends and future perspectives of food science and technology in the topic of food colorants. Key findings and conclusions Synthetic food colorants were largely used, but have been progressively substituted by those obtained from natural origins. Numerous side effects and toxicity, at both medium and long-terms, allergic reactions, behavioral and neurocognitive effects have been related with their use. Otherwise, naturally-derived food colorants seem to provide high quality, efficiency and organoleptic properties, and also play a contributive role as health promoters. Anthocyanins, carotenoids, phenolic compounds, beet derivatives, annatto and some curcuminoids are among the most commonly used, while strict regulatory practices have been applied looking for food quality assurance.

Production of bioactive peptides during soybean fermentation and their potential health benefits

Abstract: Background Fermented soybean products are consumed in many Asian countries and are one of the potential sources of bioactive peptides. Soybean is fermented using bacteria (Bacillus subtilis and lactic acid bacteria) and fungi (Mucor spp., Aspergillus spp. and Rhizopus spp.), resulting in different types of fermented products. Scope and approach This review article is focused on production of bioactive peptides in fermented soybean products and their role in prevention and treatment of several metabolic diseases. Studies on novel bioactive peptides having specific health benefits can lead to their application in the development of functional foods and pharmaceuticals with the aim replace synthetic drugs that have several side effects. Key findings and conclusions Peptides in fermented soybean products are either released by the hydrolysis of soybean proteins during fermentation or produced by the microorganisms associated with fermentation. During soybean fermentation specific bioactive peptides are produced as a result of hydrolysis of soybean proteins (Glycinin and β-conglycinin). Individual microbial strains contribute in the formation of specific bioactive peptides with respective health benefits depending on the sequence and composition of amino acids. Such bioactive peptides may act like regulatory compounds and exhibit bioactive properties such as anti-hypertensive, antimicrobial, antioxidant, anti-diabetic and anticancer activities. Studies in future, on application of specific strains for soybean fermentation can lead in to the formation of novel bioactive peptides with potential health benefits.

Nanomaterials for products and application in agriculture, feed and food

Abstract: Background Nanotechnology applications can be found in agricultural production, animal feed, food processing, food additives and food contact materials (hereinafter referred to as agri/feed/food). A great diversity of nanomaterials is reported to be currently used in various applications, while new nanomaterials and applications are reported to be in development. Scope and approach It is expected that applications of nanomaterials in agri/feed/food will increase in the future and thereby increase the human and environmental exposure to such materials. To gain up-to-date knowledge we explored and reviewed the already marketed and in-development applications of nanomaterials in the agri/feed/food sectors upon the request of the European Food Safety Authority (EFSA). In this paper the results of the project are highlighted and discussed in more detail. Key findings and conclusions The majority of the applications of nanomaterials that we identified concerned application in food as food additives and food contact materials, while much fewer applications seem to be developed for agriculture and feed. Nano-encapsulates, silver, titanium dioxide and silica are the most often mentioned nanomaterials in the literature. About half of the identified applications are claimed to be already in use. In-development applications are found for nano-encapsulates and nano-composites in novel foods, food and feed additives, biocides, pesticides and food contact materials.

Functional and bioactive properties of fish protein hydolysates and peptides: A comprehensive review

Abstract: Global fish processing industries dispose of fish wastes that account for more than 60% of processed fish biomass. In lieu of environmental pollution and disposal problems, these wastes are used to produce fish silage, fishmeal and sauce. They are also utilized for the production of value added products such as proteins, hydrolysates, bioactive peptides, collagen and gelatin. Research on the production of fish protein hydroysates (FPHs) presently focuses on maximizing the industrial potential of fish wastes. Since bioactive peptides containing amino acids hold properties of great interest, this paper reviews current research on the functional and bioactive properties of FPHs with an additional focus on gaps between fish and other hydrolysates, as well as current and future trends for the productive utilization of FPHs.

Food-grade particles for emulsion stabilization

Abstract: The use of solid, food-grade particles as emulsion stabilizers is highly promising in the field of food science and technology. Food-grade particles (e.g. fat and wax crystals, protein particles, and protein-polysaccharide complexes) can form alternatives to inorganic particles (e.g. silica, alumina or clays), which are incompatible and mostly unserviceable when considering food and nutraceutical applications. This review provides a concise insight into the concept of Pickering stabilization with the emphasis on the available food-grade particles that have been researched in this field. The innovative food applications of particle-stabilized emulsions are also discussed.

Cold plasma interactions with enzymes in foods and model systems

Abstract: Background The past decade has seen an increased interest in the application of non-equilibrium plasma for food processing. An important aspect of the interaction of chemical species of plasma with foods is the effect on enzymes, which play an important role in retaining the food quality and often serve as markers for processing efficiency. Scope and approach The present review covers a critical analysis of the current status of the relationship between plasma parameters and enzyme functionality, with an emphasis on the translation of this knowledge for food applications. The review provides a brief introduction to plasma technology, a summary of the enzyme inactivation studies, followed by a discussion of the mechanism and kinetics of inactivation, and finally, points at the future research needs. Key findings and conclusion Cold plasma inactivation of enzymes is primarily dependent on power input of the discharge, degree of exposure to reactive species, the mass transfer between the plasma-liquid phases, structural complexity and stability of the enzymes in their local environment. The mechanism of inactivation is primarily due to the loss of secondary structure due to breakdown of specific bonds or chemical modifications of the side chains by the action of the myriad of chemically active species constituting the plasma. Further research is required to understand the interactions of chemical species in plasma with proteins at a molecular level, coupled with better tools to monitor and control the plasma chemistry.

Crosslinking in polysaccharide and protein films and coatings for food contact – A review

Abstract: Background Crosslinking is the process of forming tridimensional networks by linking polymer chains by covalent or noncovalent bonds. It is useful for polysaccharide- and protein-based films and coatings to be applied to food surfaces, enhancing their water resistance as well as mechanical and barrier properties. Crosslinkers intended to be used for food contact materials must present low toxicity. Scope and approach This review is a summary of the main crosslinking agents which have been used for protein and polysaccharide films and coatings, and which may be applied as food contact materials. The study emphasizes the mechanisms of crosslinking agents, the chemical groups involved, conditions for application, advantages and drawbacks, as well as examples of applications for food contact materials. Key findings and conclusions Crosslinking is a promising technique to improve the performance and applicability of protein- and polysaccharide-based food contact materials, especially concerning their water sensitivity, which hinders many of their potential applications as food contact materials. Some aldehydes are very effective as crosslinkers, but they have been avoided in food contact materials because of possible migration of aldehyde residues to food, and less toxic compounds have been studied for those applications, such as phenolic acids, oxidized polysaccharides, and enzymes. Crosslinking techniques may help make protein- and polysaccharide-based materials more suitable for large-scale processing and applications in the future.

Protein and lipid oxidation in meat: A review with emphasis on high-pressure treatments

Abstract: Background High-pressure (HP) treatment is considered a food safety process that can stabilize meat by inactivating microorganisms. However, HP treatment can induce modifications of components, such as lipids and proteins, and favor their oxidation by promoting the formation of radicals. Oxidation is one of the most important factors in the non-microbial degradation of meat. Lipid oxidation has been extensively investigated in meat because the products of the reaction can readily react with proteins, leading to organoleptic modifications and the loss of nutritional value. In contrast, the interest in protein oxidation is more recent. Scope and approach The objective of this work is to review the literature on the effect of HP treatment on lipid and protein oxidation in comparison with that of classical meat processing to identify a possible link between protein and lipid oxidation and the underlying mechanisms. Key findings and conclusions Microorganisms were efficiently inactivated after treatment at pressures above 400 MPa. This pressure seems to be critical for the initiation of lipid oxidation, which was probably related to the no hemic iron in the meat, rather than the hemic compounds. Lipid and protein oxidation are closely related, as shown by the observed pattern of each reaction, which depends on the type of meat, the treatment used, and the methods used to assess the reactions. As it was observed to be for cooked meat products, the impact of HP could be greater for meat products that underwent cold storage. Better control of the quality of meat products subjected to HP treatments requires that the entire process, extending from the raw product to its conservation and consumption, be considered.

Micro-scale vegetable production and the rise of microgreens

Abstract: Background Interest in fresh, functional foods is on the rise, compelled by the growing interest of consumers for diets that support health and longevity. Microgreens garner immense potential for adapting leafy vegetable production to a micro-scale and for improving nutritional value in human diet. Scope and approach Major preharvest factors of microgreens production, such as species selection, fertilization, biofortification, lighting and growth stage at harvest are addressed with respect to crop physiology and quality, as well as postharvest handling and applications, temperature, atmospheric composition, lighting and packaging technology which influence shelf-life and microbial safety. Key prospects for future research aiming to enhance quality and shelf-life of microgreens are highlighted. Key findings and conclusions Effective non-chemical treatments for seed surface sterilization and antimicrobial action, pre-sowing treatments to standardize and shorten the production cycle and crop-specific information on the interaction of sowing rate with yield and quality deserve further attention. Indigenous landraces, underutilized crops and wild edible plants constitute a vast repository for selection of genetic material for microgreens. Modular fertilization may fortify microgreens bioactive content and augment their sensorial attributes. Pre- and postharvest select-waveband, intensity and photoperiod combinations can elicit compound-specific improvements in functional quality and in shelf-life. Research is needed to identify effective sanitizers and drying methods non-abusive on quality and shelf-life for commercialization of ready-to-eat packaged microgreens. Genotypic variability in postharvest chilling sensitivity and the interactions of temperature, light conditions and packaging gas permeability should be further examined to establish environments suppressive on respiration but preventive of off-odor development.

Effect of processing on conformational changes of food proteins related to allergenicity

Abstract: Background Food allergy is one of the major health concerns worldwide that has been increasing at an alarming rate in recent times. Foods undergo various processing steps before consumption that could affect conformation of food proteins, their digestion and thereby allergenicity. Scope and approach This review summarizes the effect of various processing methods on structural changes of major food allergens and how these changes affect their digestibility as well as allergenicity. This information could be a base line for selecting suitable food processing parameters for management of food allergies. Key findings and conclusions Most physical processes (heat, pressure, radiation, and ultrasound) affect conformational epitopes (destroy, mask or expose) of food proteins by altering their secondary and tertiary structures whereas the linear/sequential epitopes are affected mainly through bio-chemical (fermentation and enzymatic hydrolysis) treatments. Processing may also influence the interaction of food proteins with other ingredients via Maillard reaction and give rise to formation of new allergenic compound (neo-allergens). Processing induced changes to food proteins can largely affect their susceptibility to gastrointestinal digestion, absorption kinetics and consequently their allergenic response to immune system. Therefore, allergenic potential of food proteins may be minimized by selecting appropriate parameters during processing. Allergenicity of certain food proteins can also be modulated through optimized formulation with other food matrices. However, depending on the method of processing, intensity of treatment and molecular characteristics of allergen food proteins, allergenicity can be increased, decreased or remain unaltered.

Paraprobiotics: Evidences on their ability to modify biological responses, inactivation methods and perspectives on their application in foods

Abstract: Background The classical definition of probiotics indicates “they are live microorganisms which, when ingested in adequate amounts can provide health benefits to the host”. These benefits are provided due to interactions between the probiotics and the gastrointestinal microbiota and immunological system. On the other hand, non-viable probiotics have been known as “ghost probiotics”, “postbiotics” and “inactivated probiotics”, but recently the term “paraprobiotics” has been coined. Scope and approach In this study, the main methods used to inactivate probiotics to produce paraprobiotics, their role as modifiers of biological responses as well as their potential application in foods are discussed. Key findings and conclusions A number of biological effects have been associated with paraprobiotics, highlighting that they could constitute an excellent option to improve health status and wellness. Although health benefits have been associated to paraprobiotics, most data in literature show these effects are linked to their direct consumption. Therefore, the use of foods as carriers for paraprobiotics seems to constitute a field to be explored with several opportunities and challenges. Among them, are of special importance the selection of probiotic species and strains to be used for paraprobiotics production, the use of appropriate methods for inactivation and delivery, the evaluation of their stability and activity in foods during shelf life, and the use of adequate methods to assess their biological effects.

Antioxidant phenolics and their microbial production by submerged and solid state fermentation process: A review

Abstract: Background Bioactive phenolic compounds have recently received great attention in the food and clinical sectors due to their antioxidant potential. Extensive studies have been carried out to explore antioxidant potential of different phenolics from various natural sources in order to replace the use of health hazard synthetic antioxidants in food products. Scope and approach The present review aims to provide an update of existing state-of-art and future prospect of both submerged fermentation (SmF) and solid-state fermentation (SSF) processes for the production/extraction of bioactive phenolics utilizing various substrates and microorganisms. Studies on enhancement of antioxidant potentials by increasing phenolics content of food materials including cereals and legumes by mainly SSF are reviewed and discussed thoroughly. Key findings and conclusions Microbial fermentation processes have been established as a potent tool for the production of antioxidant phenolic compounds due to their cost-effectiveness and environmental advantages. Extraction of phenolics through fermentation process is by far a more efficient process considering that conventional extraction methods using organic solvents do not allow complete release of bound phenolics from plant materials. During fermentation process, antioxidant phenolics are either produced by microorganisms through secondary metabolic pathway or released from the matrix of the substrate by extracellular enzymatic action. Fermentation technology is no doubt proving to be a boon for the food industry; however, extensive in vivo and toxicological researches are essential before the application of antioxidant-rich fermented foods for human health benefits.

In vivo antioxidant activity of phenolic compounds: facts and gaps

Abstract: Background Numerous diseases have been related with free radicals overproduction and oxidative stress. Botanical preparations possess a multitude of bioactive properties, including antioxidant potential, which has been mainly related with the presence of phenolic compounds. However, the mechanisms of action of these phytochemicals, in vivo effects, bioavailability and bio-efficacy still need research. Scope and approach The present report aims to provide a critical review on the aspects related with the in vivo antioxidant activity of phenolic extracts and compounds from plant origin. Key findings Biological functions beyond the human metabolism were discussed, comparing in vivo vs. in vitro studies, as also focusing the conditioning factors for phenolic compounds bioavailability and bio-efficacy. Furthermore, an upcoming perspective about the use of phytochemicals as life expectancy promoters and anti-aging factors in human individuals was provided. Conclusions Overall, and despite all of those advances, the study of the biological potential of numerous natural matrices still remains a hot topic among the scientific community. In fact, the available knowledge about the responsible phytochemicals for the biological potential, their mechanisms of action, the establishment of therapeutic and prophylactic doses, and even the occurrence of biochemical inter-relations, is considerable scarce.

Emulsion-based encapsulation and delivery systems for polyphenols

Abstract: Background Instability and low bioavailability of polyphenols greatly limit their potential health benefits in preventing ageing, cancer, inflammation and neurodegenerative diseases. Utilization of protected encapsulation and delivery system can improve the stability and bioavailability of polyphenols. A wide range of technologies have been developed to encapsulate polyphenols. Among these, emulsion-encapsulation is regarded as one of the most promising techniques for protection and delivery of polyphenols, due to its high-efficiency encapsulation, maintenance of chemical stability and controlled release. Scope and approach In this review, preparation, applications and limitations of emulsion-based encapsulation and delivery systems for polyphenols, including single, multiple and nano-emulsions, are discussed. Key findings and conclusions Utilization of encapsulated polyphenols instead of free molecules improves both the stability and bioavailability of the molecules in vitro and in vivo. Many emulsion-based delivery systems for polyphenols have been well established, including single, multiple and nano-emulsions. However, variations in composition and preparation technologies result in the formation of a range of emulsions of new properties with great potential in delivery of polyphenols or other bioactive nutrients, e.g., using unsaturated fatty acids as the oil phase, which can achieve the delivery of multiple nutrients at the same time. Furthermore, very few studies have been done on the in vivo absorption, transportation and release of polyphenols incorporated emulsions, which are essential to their deeper and wider applications. Hence, systematic and intensive investigation of metabolism and physiological effects of encapsulated polyphenols or other potential bioactive nutrients in vivo are required.

Gut microbiota role in dietary protein metabolism and health-related outcomes: The two sides of the coin

Abstract: Background Human gut bacteria can synthesize proteinogenic amino acids and produce a range of metabolites via protein fermentation, some known to exert beneficial or harmful physiological effects on the host. However, the effects of the type and amount of dietary protein consumed on these metabolic processes, as well as the effects of the microbiota-derived amino acids and related metabolites on the host health are still predominantly unknown. Scope and approach This review provides an up-to-date description of the dominant pathways/genes involved in amino acid metabolism in gut bacteria, and provides an inventory of metabolic intermediates derived from bacterial protein fermentation that may affect human health. Advances in understanding bacterial protein fermentation pathways and metabolites generated at a global level via the implementation of ‘omics’ technologies are reviewed. Finally, the impact of dietary protein intake and high-protein diets on human health is discussed. Key findings and conclusions The intestinal microbiota is able to synthesize amino acids, but the net result of amino acid production and utilization, according to dietary patterns still needs to be determined. The amount of ingested dietary protein appears to modify both the diversity and composition of the intestinal microbiota as well as the luminal environment of the intestinal epithelium and peripheral tissues. The understanding of the consequences of such changes on the host physiology and pathophysiology is still in an early stage but major progress is expected in the near future with the investigation of host-microbe omics profiles from well-controlled human intervention studies.

Electronic noses and tongues to assess food authenticity and adulteration

Abstract: Background There is a growing concern for the problem of food authenticity assessment (and hence the detection of food adulteration), since it cheats the consumer and can pose serious risk to health in some instances. Unfortunately, food safety/integrity incidents occur with worrying regularity, and therefore there is clearly a need for the development of new analytical techniques. Scope and approach In this review, after briefly commenting the principles behind the design of electronic noses and electronic tongues, the most relevant contributions of these sensor systems in food adulteration control and authenticity assessment over the past ten years are discussed. It is also remarked that future developments in the utilization of advanced sensors arrays will lead to superior electronic senses with more capabilities, thus making the authenticity and falsification assessment of food products a faster and more reliable process. Key findings and conclusions The use of both types of e-devices in this field has been steadily increasing along the present century, mainly due to the fact that their efficiency has been significantly improved as important developments are taking place in the area of data handling and multivariate data analysis methods.

Food contamination during food process

Abstract: Food contamination can come from different situations. A wide overview is presented in this paper, where the different steps applied to food, from the reception of raw materials to the final food intake by consumers, are shown. Among the sources involved in the food contamination processes the following ones can be highlighted: a) External raw food contamination due to environmental contamination; b) Transport of raw materials to the factory where they will be processed; c) Food conditioning, which involves the storage of raw materials, preheating, disinfection, cleaning and sterilization steps; d) Heating steps either by boiling, cooking, baking, frying or combining with other ingredients at high temperature in an oven or in a reactor; e) Food packaging; f) Transport of packaged food and g) Storage and distribution of packaged food. The problems related to each step as well as the resulting contaminants for the food are shown and discussed.

Sensory characteristics of wholegrain and bran-rich cereal foods: A review

Abstract: Background: Wholegrain foods are known to be health-beneficial but their sensory characteristics may be a limiting factor for consumption. The scientific literature of factors influencing sensory quality of wholegrain foods is rather scarce. Scope and approach: Many cereals like rye, oats, barley and sorghum are actually used mainly as wholegrain, whereas for wheat the situation is the opposite. This review deals with factors that differentiate the sensory properties of wholegrain and bran-rich foods from those of refined cereal foods. Key findings and conclusions: Wholegrain and bran contain flavour-active compounds, flavour precursors and resistant cell wall structures causing changes in flavour and texture during processing. In wholegrain foods, different chemical constituents contribute to bitterness. Increased knowledge on flavour formation has led to the possibility to not only measure but actually also design the flavour. Structure and texture are also important determinants underlying eating quality and stability of cereal foods. Hitherto established means of modulating sensory quality and thus improving acceptability of wholegrain foods are presented. © 2015 Elsevier Ltd.

X-ray micro-computed tomography (μCT) for non-destructive characterisation of food microstructure

Abstract: Background Food microstructure can be visualised by a wide range of microscopic techniques, however these methods are usually destructive and require sample preparation. X-ray micro-computed tomography (μCT) provides an alternative as it is non-invasive, non-destructive and requires no sample preparation. It characterises structures three-dimensionally, allowing evaluation of microstructural changes at resolutions as high as a few hundred nanometres. After the discovery of X-rays in 1895, X-ray computed tomography (CT) was developed and introduced into clinical practices in the 1970s. The first X-ray μCT food application, to detect the maturity of green tomatoes, followed in 1991. Scope and approach This review aims to provide an overview of the basic principles of X-ray μCT, the different systems, image processing and analysis as well as image texture analysis. Food applications are highlighted and the review concludes with future trends of X-ray μCT. Key findings and conclusions The controlled production and stability of microstructure is of great interest to the food industry. Both laboratory μCT and synchrotron systems are becoming more common and thus will lead to imaging in three dimensions at a micron scale playing a much bigger role in future food studies. Limitations include operator dependency, time and cost constraints and imaging artefacts. Technological and computational progress, however, encourages the growth of this technique in food science.

Role of food processing in food and nutrition security

Abstract: Background Food and nutrition security, a major global challenge, relies on the adequate supply of safe, affordable and nutritious fresh and processed foods to all people. The challenge of supplying healthy diets to 9 billion people in 2050 will in part be met through increase in food production. However, reducing food losses throughout the supply chain from production to consumption and sustainable enhancements in preservation, nutrient content, safety and shelf life of foods, enabled by food processing will also be essential. Scope and approach This review describes developments in primary food production systems and the role of food processing on population health and food and nutrition security. It emphasises the need to monitor the attitudes and values of consumers in order to better understand factors that may lead to negative perceptions about food processing. Key findings and conclusions For a resource constrained world, it is essential to have a balanced approach to both energy and nutrient content of foods. Environmental sustainability is critical and both the agrifood production and the food processing sectors will be challenged to use less resources to produce greater quantities of existing foods and develop innovative new foods that are nutritionally appropriate for the promotion of health and well-being, have long shelf lives and are conveniently transportable. Healthy diets which meet consumer expectations produced from resilient and sustainable agrifood systems need to be delivered in a changing world with diminishing natural resources. An integrated multi-sectoral approach across the whole food supply chain is required to address global food and nutrition insecurity.

Food drying enhancement by ultrasound – A review

Abstract: Background Drying is one of the most popular methods of preserving a wide variety of food and agricultural products. Unfortunately, this unit operation may negatively influence product quality. Moreover, due to the high heat capacity of water, drying is usually a long-lasting and energy-intensive process, thus new drying techniques are continuously being sought. Scope and approach This review presents the current state of art in ultrasonic-assisted drying. Despite immense knowledge on the principles of ultrasound generation and action, this technology has found no practical application in industrial drying yet. In this paper we tried to find the reasons for this state of affairs. Up-to-date designs of dryers using ultrasound to enhance the drying process and the various possible mechanisms of accelerating the drying process with the application of ultrasonic waves are discussed. The influence of ultrasound on the product's quality (dried food) is judged and described. Key findings and conclusions The analysis of the results presented by the researchers here allows to state that applying ultrasound to drying caused a shortening of the drying time and could reduce total energy consumption. Moreover, due to the small “temperature effect”, the quality of the obtained products was noticeably better as compared to the control processes (without ultrasound enhancement). The lack of an effective technology for generating power ultrasound in air was distinguished as the primary constraint for industrial application of this technology. The necessity of conducting detailed studies on ultrasound application in drying was emphasized.

Biovalorisation of okara (soybean residue) for food and nutrition

Abstract: Background Okara is the soybean residue that remains after the manufacture of soymilk or soybean curd. The high moisture content (70–80%) makes it susceptible to spoilage, and so it is often discarded. Yet, okara still holds many nutrients (on a dry weight basis, approximately 50% carbohydrates, 20–30% proteins and 10–20% lipids, as well as minerals and phytochemicals), making it a suitable substrate for biovalorisation. Scope and approach The composition of okara is assessed with respect to its potential for biovalorisation to obtain bioactive substances and food products. Studies on okara fermentation by fungi, bacteria and yeasts are highlighted, with their main drawbacks and challenges critically discussed and the research gaps identified. Key findings and conclusions Studies to date have demonstrated the feasibility of okara fermentation to produce a variety of functional ingredients and foodstuffs. The health benefits and nutritional quality of okara are often enhanced by fermentation, and the fermented okara is also an inexpensive substrate for extraction of bioactive substances. Present research remains largely at bench-scale, and the main challenges are related to scaling-up, efficiency and/or yield. There is much scope for further exploration into various aspects of okara biovalorisation, including applying bioprocessing treatments as a pre-fermentation step, using combinatorial microbes or enzymes, and evaluating organoleptic property, dietary effects and potential allergenicity of the fermented products.