Complex Food Systems Research Articles

The effect of polyvinylpyrrolidone addition on microstructure, surface aspects, the glass transition temperature and structural strength of honey and coconut sugar powders

Deep knowledge of the microstructure and physicochemical properties of polymeric food systems, such as honey powders (HP) and coconut sugars (CS), has practical importance for industry and end users. This study investigated the effect of polyvinylpyrrolidone (PVP) addition on microstructure, roughness, glass transition, α-relaxation temperatures and structural strength (S) of anhydrous complex carbohydrates mixtures. The addition of PVP slightly increased the glass transition and α-relaxation temperature for HP and CS systems as high molecular weight components. Systems with PVP addition showed “stronger” behaviour according to the S approach. Polarized light, scanning electron and atomic force microscopies showed slight differences in transparency and shapes between controls and systems with PVP addition. Surface morphological changes and roughness were investigated in this study to provide insight into HP and CS particles’ structural changes. Moreover, S-involved structural diagrams were built to determine S parameters for controlling the structural transformation of HP and CS systems with and without PVP addition. The results obtained in this work provide new information on polymer-carbohydrate interactions in complex food systems and structural transformations during their production and storage.

New Perspectives on the Delivery of Nutrients and Bioactive Compounds through Gastric Restructuring of Foods.

All foods come from living organisms in which macromolecules such as proteins and polysaccharides are assembled into complex hierarchical structures. Many of the nutrients and bioactive compounds are contained within these structures, from which they must be liberated and converted into an absorbable form during digestion. It has been realized that the modification of these structures during digestion plays a key role in determining the bioaccessibility and rates of absorption of bioactive compounds. The concept of "food structure design" has been applied to developing food structures to control the perception of fat, salt, and sugar in food products, but the role of food structure as a variable in nutrient and bioactive delivery is relatively unknown. Understanding the architecture and structures of foods and how they interact within the physiological environment of the GIT could lead to new foods that provide optimal bio-accessibility and absorption of bioactive compounds. Recent work at our institute has demonstrated the importance of understanding the state and structures of food materials in the environment of the GIT, particularly in the stomach, and the critical role of 'modified' structures on the kinetics of the release of nutrients and bioactive compounds from the food matrix (e.g., the rate, extent and type of released nutrients), gastric emptying and subsequent digestion of foods in the small intestine. The use of dynamic in vitro digestion in combination with in-vivo studies has provided new insights into the structural dynamics of complex food systems and subsequent interactions of food components during the gastrointestinal transit.

Lipid Recovery from Concentrated Emulsions by Freezing–Thawing as an Alternative to Solvent‐Based Extraction: A Case Study on Mayonnaise

AbstractMost analyses concerning the characterization of lipids present in complex food systems require separation and recovery of lipids prior to analysis. This may be achieved, for example, by solvent‐based extractions. In the case of concentrated emulsions, targeted physical destabilization and phase separation induced by a freeze–thaw treatment are also considered. This strategy would imply a simple, solvent‐free method with a high yield. In the present work, conventional mayonnaise and a vegan alternative are evaluated. The effect of the freezing–thawing conditions on lipid recovery, as compared to a classical solvent (hexane:n‐2‐propanol, 3:2 v/v)‐based extraction is investigated. In particular, two freezing temperatures (−20 and −80 °C) and the presence or not of additional water to aid phase separation are evaluated. The freezing temperature (which directly influences the rate and extent of water and lipid crystallization) largely impacts lipid recovery, in a matrix‐dependent manner: −20 °C is clearly the most suitable temperature for the conventional mayonnaise, whereas −80 °C seems somewhat better for the vegan alternative. Importantly, this alternative freezing–thawing approach does not alter the fatty acid composition nor the lipid class profile compared to a classical solvent extraction, which confirms its relevancy from a subsequent analytical perspective.Practical Applications: The induction of emulsion destabilization by freezing–thawing is a simple, high‐yield and solvent‐free methodology (i.e., compatible with green chemistry) for lipid recovery regarding analytical purposes. Lipid recovery can be greatly improved by settling the involved conditions. Herein authors propose some guidelines for selecting and reasoning over procedure parameters in concentrated emulsions. The performance of lipid recovery is tuned by the conditions of freezing and guided by the type of emulsion.

A ratiometric fluorescent aptasensor based on EXPAR to detect shellfish tropomyosin in food system

Shellfish allergy represents a crucial public health problem, resulting in an urgent requirement for an accurate, simple, and reliable method to quantify shellfish allergens in the complex food system. Tropomyosin (TM) is known as the major allergen in shellfish. Herein, a novel switch-conversional ratiometric fluorescent biosensor, using TM-specific aptamer as the recognition probe, was developed to detect TM in the complex food system. The proposed aptasensor exhibited good accuracy, stability, and selectivity for the quantification of TM in foodstuffs. Furthermore, the applicability of this proposed aptasensor in complex food samples was verified using seven different shellfish samples. Therefore, this ratiometric fluorescent aptasensor enables accurately detecting the presence of TM traces in foods, providing technical support for allergen label supervision.

Collective Consumption and Food System Complexity:

Focusing on consumption as key to managing complex food system dynamics has drawn controversy from scholars and activists who argue that a focus on consumption obfuscates the social and ecological consequences of the larger transnational food system. We argue that these concerns, while holding merit, are grounded in assumptions about food systems that fail to grasp the importance of agency as much as structure. Starting from an appreciation for the transdisciplinary fusion of knowledge and concepts across governance, political economy, and urban complexity, we utilize the concept of “collective consumption” as a way to rethink how a consumption politics can help transform the larger system through collaborative governance at the local or regional scale. We take Food Policy Councils (FPCs) in the United States as our subject to explore how experimental governance arrangements can reshape the way political organization around food consumption can drive longer term transformation. Our paper proceeds in four parts. First, we dive into Castells’ use of collective consumption as it relates to urban politics, which includes a close assessment of how both “consumption” and “collectivity” are relevant to urban food systems governance. Second, we offer a view of how collective consumption can be utilized to promote a justice-based perspective in urban food governance, which promotes socio-natural transformation of the current agro-industrial food system. Third, we develop a framework for imagining the possibilities of FPCs as part of new collaborative state-society relationships, offering a distinct reterritorialization of urban food politics tied to a socio-natural politics of urban metabolism. Finally, we conclude by offering comments on future challenges and opportunities in realizing the radical governance potential of FPCs.

Genetic, physiological, and cellular heterogeneities of bacterial pathogens in food matrices: Consequences for food safety.

In complex food systems, bacteria live in heterogeneous microstructures, and the population displays phenotypic heterogeneities at the single-cell level. This review provides an overview of spatiotemporal drivers of phenotypic heterogeneity of bacterial pathogens in food matrices at three levels. The first level is the genotypic heterogeneity due to the possibility for various strains of a given species to contaminate food, each of them having specific genetic features. Then, physiological heterogeneities are induced within the same strain, due to specific microenvironments and heterogeneous adaptative responses to the food microstructure. The third level of phenotypic heterogeneity is related to cellular heterogeneity of the same strain in a specific microenvironment. Finally, we consider how these phenotypic heterogeneities at the single-cell level could be implemented in mathematical models to predict bacterial behavior and help ensure microbiological food safety.

An updated review on the stability of anthocyanins regarding the interaction with food proteins and polysaccharides.

The health benefits of anthocyanins are compromised by their chemical instability and susceptibility to external stress. Researchers found that the interaction between anthocyanins and macromolecular components such as proteins and polysaccharides substantially determines the stability of anthocyanins during food processing and storage. The topic thus has attracted much attention in recent years. This review underlines the new insights gained in our current study of physical and chemical properties and functional properties in complex food systems. It examines the interaction between anthocyanins and food proteins or polysaccharides by focusing on the "structure-stability" relationship. Furthermore, multispectral and molecular computing simulations are used as the chief instruments to explore the interaction's mechanism. During processing and storage, the stability of anthocyanins is generally influenced by the adverse characteristics of food and beverage, including temperature, light, oxygen, enzymes, pH. While the action modes and types between protein/polysaccharide and anthocyanins mainly depend on their structures, the noncovalent interaction between them is the key intermolecular force that increases the stability of anthocyanins. Our goal is to provide the latest understanding of the stability of anthocyanins under food processing conditions and further improve their utilization in food industries. Practical Application: This review provides support for the steady-state protection of active substances.

The appeal of alternative diets – stories of carbohydrate-conscious eaters regarding motives, credibility of dietary advice and the authority of experiences

ABSTRACT Low-carbohydrate diets promote the idea that reducing carbohydrate intake is a key to a healthier life and more natural way to eat. The proponents of these diets form food communities, which share common ideas about food, put forward their own ‘alternative’ expertise and challenge mainstream dietary advice. This study focuses on the perspectives of self-identified followers of low-carbohydrate diets. We explore their rationales for choosing the diet and how they navigate between different sources of dietary information. The data consists of open-ended responses (n=996) to a food survey published in a leading national Finnish newspaper. The responses have been analyzed using thematic narrative analysis. Our results highlight how uncertainties and disappointments can increase the appeal of ‘alternative’ diets and expertise. Low-carbohydrate diets are used as a form of self-care, illness prevention, risk management and weight loss by people with chronic conditions and lingering symptoms. They offer a sense of control, an alternative to medications and bring together communities of like minded people. The stories intertwine with health populist discourses, casting doubt on traditional experts. In a world of complex food systems and conflicting information the diets offer clear explanations. Additionally, the results emphasise the credibility and authority of lived experiences.

Promoting Sustainability within the Nordic-Arctic Region’s Food System: Challenges and Trends

The food system has direct impacts on our health both at individual and planetary levels; however, there is a need to make it more sustainable. Many communities in the Nordic-Arctic region are faced with challenges that arise from the need to protect natural resources due to increased activities that are fostered by tourism in the region. In this paper, we explore the interrelated factors that can sustainably support the food system in the region. A better understanding of these associated challenges in a complex food system from production to consumption is required. In order to ensure sustainability in the future, it will be necessary to explore the impacts of food tourism while responding to megatrends in the society. It is important that the natural resources in the communities of this region are better preserved for the next generation. Traditional knowledge and digital solutions can be harnessed to support food security and sovereignty that can empower local communities of the Nordic-Arctic region without compromising their heritage and sustainability.

VaclavSmilHow the World Really Works: A Scientist's Guide to Our Past, Present and FuturePenguin, 2022, 325 p., $28.00.

VaclavSmilHow the World Really Works: A Scientist's Guide to Our Past, Present and FuturePenguin, 2022, 325 p., $28.00.

Novel strategy for color-controllable Pickering emulsion: Location control of pigments at different phase

To develop a novel strategy for preparing color-controllable emulsion by controlling pigments spatial location, the stable Pickering emulsion (O/W) was firstly established by using zein-chitosan nanoparticles (ZCNPs) as outer layer and medium chain triglyceride as inner phase. Three fat-soluble pigments (FSPs), curcumin, oil red and oil blue, were introduced into this emulsion system by controlling their location (in outer layer or inner phase). The physical properties, qualitative and quantitative color analysis of the emulsion were investigated by encapsulation efficiency, confocal laser scanning microscope and values of L*a*b*. The loading efficiency of ZCNPs to FSPs maintained at 87.6%–89.3%, and had 95% of oil encapsulation efficiency. Different from the blending coloring strategy, the emulsions formed in this paper showed better chroma (based on L*a*b* values) with even fewer additive pigments amount. Under the same amount of pigment, the saturation of the emulsion (FSPs in outer layer) could increase by 81.5%. This study might provide a new color control strategy for complex food systems. • The structure of Pickering emulsion was defined as outer layer or inner phase. • ZCNPs had a higher loading efficiency for the three FSPs. • Pickering emulsion stabilized by ZCNPs was stable. • Color could be adjusted by changing the location of pigments in the emulsion. • The emulsion color was more susceptible to outer layer.

Monitoring and Characterization of Milk Fouling on Stainless Steel Using a High-Pressure High-Temperature Quartz Crystal Microbalance with Dissipation.

Fouling at interfaces deteriorates the efficiency and hygiene of processes within numerous industrial sectors, including the oil and gas, biomedical device, and food industries. In the food industry, the fouling of a complex food matrix to a heated stainless steel surface reduces production efficiency by increasing heating resistance, pumping requirements, and the frequency of cleaning operations. In this work, quartz crystal microbalance with dissipation (QCM-D) was used to study the interface formed by the fouling of milk on a stainless steel surface at different flow rates and protein concentrations at high temperatures (135 °C). Subsequently, the QCM-D response was recorded during the cleaning of the foulant. Two phases of fouling were identified. During phase-1, the fouling rate was dependent on the flow rate, while the fouling rate during phase-2 was dependent on the flow rate and protein concentration. During cleaning, foulants deposited at the higher flow rate swelled more than those deposited at the lower flow rate. The composition of the fouling deposits consisted of both protein and mineral species. Two crystalline phases of calcium phosphate, β-tricalcium phosphate and hydroxyapatite, were identified at both flow rates. Stratification in topography was observed across the surface of the QCM-D sensor with a brittle and cracked structure for deposits formed at 0.2 mL/min and a smooth and close-packed structure for deposits formed at 0.1 mL/min. These stratifications in the composition and topography were correlated to differences in the reaction time and flow dynamics at different flow rates. This high-temperature application of QCM-D to complex food systems illuminates the initial interaction between proteins and minerals and a stainless steel surface, which might otherwise be undetectable in low-temperature applications of QCM-D or at larger bench and industrial scales. The methods and results presented here have implications for optimizing processing scenarios that limit fouling formation while also enhancing removal during cleaning.

Recent advances on the stability of dietary polyphenols

Recent advances on the stability of dietary polyphenols

Dynamics of Arabic gum aqueous solutions as revealed by NMR relaxometry.

The purpose of this article is to study molecular dynamics through nuclear magnetic relaxation (NMR) dispersion of Arabic gum aqueous solutions analysed in terms of two-fraction exchange model. The experiments revealed that relaxation of water molecules was non-monoexponential, which was interpreted in terms of a model describing the magnetization transfer due to exchange of water and polysaccharide protons. The analysis showed that water dynamics decreased slightly with gum content. Polymer-chain dynamics was assigned to regime II of the tube/reptation model. Peculiar temperature dependence of exchange rate was observed in the whole concentration range of Arabic gum solutions. NMR relaxation probed in a broad frequency and temperature range allows probing of the molecular dynamics of complex food systems. © 2022 Society of Chemical Industry.

Nudging more sustainable grocery purchases: Behavioural innovations in a supermarket setting

Increasing fruit and vegetable consumption in a shift towards more plant-based foods is considered a key component of a healthy and sustainable diet. Recent experimental work suggests that behavioural insights-based interventions in the immediate choice context may create opportunities for sustainable food-behaviour change. Among the many actors and elements of a complex food system, supermarkets are in a unique position as main gatekeepers to curate the interface between supply and demand and steer both in more sustainable directions. Sustainability-oriented retailers can use innovative behavioural tools to promote healthier and climate-friendlier foods (such as vegetables) while meeting the “triple bottom line”. A real-life supermarket trial in Denmark tested if multi-layered nudges can increase the purchase of fruit and vegetables. The intervention led to small increases in sales. These findings showcase the possibility that supermarkets, in principle, have agency and ability to nudge consumers towards more sustainable diets. To meaningfully shift consumers’ consumption patterns, supermarkets need an open sharing of best practices and the use of a sound methodology to better understand and effectively change consumer behaviour. In partnership with stakeholders, supermarkets could play a more active role in fostering a sustainable food transition by employing “nudges for good”.

Role of aqueous phase composition and hydrophilic emulsifier type on the stability of W/O/W emulsions

Double W1/O/W2 emulsions can act as fat substitutes in food matrices, although synthetic emulsifiers are commonly used due to their inherent instability and susceptibility to coalescence. In order to guarantee the stability of the W/O interface, the synthetic emulsifier polyglycerol polyricinoleate (PGPR − 4.5% w/w) was used. However, the replacement of chemically synthesized ingredients by natural alternatives has been extensively pursued in food applications. In this sense, whey protein isolate (WPI) and sodium caseinate (SC) were used to stabilize the external aqueous phase (W2) of water-in-oil-in-water double emulsions (W1/O/W2), in addition to Tween 80 that was used as a control. The composition of the internal aqueous phase and its effects on the double emulsion were studied by the addition of sodium chloride (0.2% w/w NaCl), gallic acid (0.5% w/w GA) or a GA/NaCl mixture (0.5% / 0.2% w/w). The effect of these different hydrophilic components was evaluated from measurements of droplet size, viscosity, ζ potential, interfacial tension and kinetic stability. SC-stabilized W/O/W emulsions showed better kinetic stability than WPI- and T80-systems. These results can be attributed to the initial droplet size (SC < T80 < WPI) and viscosity of the emulsions (SC < T80 < WPI). SC is a more flexible and unfolded protein that can quickly adsorb and rearrange at the interface, favoring the formation of smaller droplets and limiting the migration of inner water droplets to the outer phase. In addition to smaller droplets, the addition of SC (8% w/w) to the external aqueous phase promoted an increase in the viscosity of bulk systems, which reduced the destabilization rates by creaming and coalescence. All W/O/W systems containing NaCl in the inner aqueous phase presented greater kinetic stability during 7 days of storage. Although the addition GA was less efficient to stabilize double emulsions compared to NaCl, this phenolic compound reduced the interfacial tension, favoring the formation of WPI- and T80-droplets with smaller diameters. However, the use of GA/NaCl blend improved the stability and functionally of W/O/W double emulsions. We concluded that the type of hydrophilic emulsifier, the properties of the inner water droplets and the viscosity of phases influenced the droplet size, viscosity and kinetic stability of double emulsions. This work provides a better understanding of how composition influences the properties of double emulsions and how it can be used to design W/O/W emulsions as fat substitutes in more complex food systems.

Interfacial behavior of a polylactic acid active packaging film dictates its performance in complex food matrices

The convergence of food wasted due to spoilage and disposal of single use, non-compostable plastic packaging presents a significant economic and environmental burden. The ongoing market trend of reducing additive use in foods generates an opportunity to extend shelf life through alternative means. Active packaging technologies which seek to extend ‘clean label’ product shelf life at the post-retail level using bioderived polymers thus represents a unique solution in reducing volumes of both food and plastic municipal solid waste. An understanding of the active packaging interfacial behavior is necessary to predict performance in complex food systems. Here we present a characterization of the carboxylate pKa for polylactic acid (PLA) films grafted with the antioxidant nitrilotriacetic acid (NTA), PLA-g-NTA. Attenuated total reflectance Fourier transform infrared spectroscopy was used to determine the pKa values of 3.97 and 8.99 for the carboxylic acid groups of NTA and a pH dependent ABTS radical scavenging assay was performed to determine the pKa value of 6.74 for the tertiary amine of NTA. These results indicate PLA-g-NTA would be useful as an antioxidant material at the food interface with pH values above 6.74, as an electron transfer from the deprotonated tertiary amine was shown to be the largest driver of radical scavenging capacity. Utilizing a biodegradable antioxidant packaging material such as PLA-g-NTA thus gives way to protect food from oxidation while meeting consumer demands for reduced additive use towards the goal of reducing food waste and the environmental impact of petroleum based single-use plastics.

Exploration of the fipronil in egg contamination incident in the Netherlands using the Functional Resonance Analysis Method

Following the 2017 fipronil egg contamination incident in the European Union, improvements in safety management continue to be necessary, particularly for regulatory, preventive, and control activities. Drawing from the Dutch and European legislation, and the use of the Functional Resonance Analysis Method (FRAM), the aim of the study was to explore the regulatory framing of the elimination of red mites on poultry farms, the compliance of actual events in 2017 with these hygiene standards and regulations in order to reconcile actual practices with policy directives. The study considers the difference between policy implementation for work-as-imagined and the tasks undertaken in practice i.e., ‘work-as-done’. This allows for assessment and analysis of the gap between pre-defined hygiene policy and actual practice and allows for a systemic approach rather than a causal approach to examine the public health incident. The study concludes that it is important for high level policy makers to comprehend the challenges and barriers faced by those implementing policy, and how this could potentially mean that policy in practice is not aligned with what was originally intended. The presented analysis outlines the potential of the FRAM in assessing complex food systems to support a public health investigation of incidents, and to design practical and realistic food safety policies leading to higher levels of stakeholder compliance and improved safety management. • 2017 Fipronil in egg contamination incident in the Netherlands was explored. • Red mites were eliminated through practices that did not comply with regulations. • Performance variability in public hygiene policies was a key failure in work as done. • The use of FRAM was of value in assessing complex food systems.

Beta-Lactoglobulin as a Model Food Protein: How to Promote, Prevent, and Exploit Its Unfolding Processes.

Bovine milk beta-lactoglobulin (BLG) is a small whey protein that is a common ingredient in many foods. Many of the properties of BLG relevant to the food industry are related to its unfolding processes induced by physical or chemical treatments. Unfolding occurs through a number of individual steps, generating transient intermediates through reversible and irreversible modifications. The rate of formation of these intermediates and of their further evolution into different structures often dictates the outcome of a given process. This report addresses the main structural features of the BLG unfolding intermediates under conditions that may facilitate or impair their formation in response to chemical or physical denaturing agents. In consideration of the short lifespan of the transient species generated upon unfolding, this review also discusses how various methodological approaches may be adapted in exploring the process-dependent structural modifications of BLG from a kinetic and/or a thermodynamic standpoint. Some of the conceptual and methodological approaches presented and discussed in this review can provide hints for improving the understanding of transient conformers formation by proteins present in other food systems, as well as when other physical or chemical denaturing agents are acting on proteins much different from BLG in complex food systems.

FODMAP modulation as a dietary therapy for IBS: Scientific and market perspective.

A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) is a promising therapeutic approach to reduce gastrointestinal symptoms associated with irritable bowel syndrome (IBS). However, a shift toward a more sustainable, healthy diet with higher inclusion of whole-grain cereals (i.e., wheat, rye, barley) and pulses, naturally rich in FODMAPs, poses a severe challenge for susceptible individuals. Dietary restriction of fermentable carbohydrates (commonly called the "low FODMAP diet") has received significant consideration. Hence, the development of functional low FODMAP products is emerging in food science and the food industry. In this review, we evaluate the most promising yet neglected (bio)-technological strategies adopted for modulating the FODMAP contents in complex food systems and the extent of their uptake in the global food market. We extensively investigated the global low FODMAP market, contrasted with the status quo in food science and discussed the key principles and concomitant challenges of targeted FODMAP reduction strategies. Powerful tools are available which are based either on the use of ingredients where FODMAPs have been physically removed (e.g., by membrane filtration) or biotechnologically reduced during the food processing, mediated by added enzymes, microbial enzymes during a fermentation process, and seed endogenous enzymes. However,<10% of the small market of functional products with a low FODMAP claim (total ∼800 products) used any of the targeted FODMAP reduction techniques. The global market is currently dominated by gluten-free products, which are naturally low in FODMAPs and characterized by inferior sensory attributes.