On the changing colour of food & drink

Four-Dimensional (4D) Printing of Dynamic Foods-Definitions, Considerations, and Current Scientific Status

Since its conception, the application of 3D printing in the structuring of food materials has been focused on the processing of novel material formulations and customized textures for innovative food applications, such as personalized nutrition and full sensory design. The continuous evolution of the used methods, approaches, and materials has created a solid foundation for technology to process dynamic food structures. Four-dimensional food printing is an extension of 3D printing where food structures are designed and printed to perform time-dependent changes activated by internal or external stimuli. In 4D food printing, structures are engineered through material tailoring and custom designs to achieve a transformation from one configuration to another. Different engineered 4D behaviors include stimulated color change, shape morphing, and biological growth. As 4D food printing is considered an emerging application, imperatively, this article proposes new considerations and definitions in 4D food printing. Moreover, this article presents an overview of 4D food printing within the current scientific progress, status, and approaches.

On the manipulation, and meaning(s), of color in food: A historical perspective

While there has long been public concern over the use of artificial/synthetic food colors, it should be remembered that food and drink products (e.g., red wine) have been purposefully colored for millennia. This narrative historical review highlights a number of reasons that food and drink have been colored, including to capture the shopper's visual attention through to signaling the likely taste/flavor. Over the course of the last century, there has, on occasion, also been interest in the playful, or sometimes even deliberately discombobulating, use of food coloring by modernist chefs and others. The coloring (or absence of color) of food and drink can, though, sometimes also take on more of a symbolic meaning, and, in a few cases, specific food colors may acquire a signature, or branded (i.e., semantic) association. That said, with food color being associated with so many different potential "meanings," it is an open question as to which meaning the consumer will associate with any given instance of color in food, and what role context may play in their decision. Laboratory-based sensory science research may not necessarily successfully capture the full range of meanings that may be associated with food color in the mind of the consumer. Nevertheless, it seems likely that food color will continue to play an important role in dictating consumer behavior in the years to come, even though the visual appearance of food is increasingly being mediated via technological means, including virtual and augmented reality.

Production of pigments by Monascus ruber CCT0302 in culture media containing maltose as substrate

The aim of this study was to show how maltose production residues can be used to obtain natural pigments by Monascus ruber CCT 3802 in solid and submerged cultures. The microbial growth and the colour and heat stability characteristics of the pigments produced in both solid and submerged media, with different maltose syrup concentrations, were determined. The results showed that the addition of maltose provided significant increases in the velocity of microbial growth and production of red pigments. The highest radial growth velocity of Monascus ruber (0.1053 mm h−1) was obtained when cultivated in a medium containing 5 g L−1 of maltose syrup, corresponding to a 71.7% increase in growth as compared to the growth velocity in the control medium. Using submerged fermentation, the culture medium containing 10 g L−1 of maltose syrup provided the greatest concentrations of red pigments (14.54 AU510nm g−1 dry biomass) with an intense dark red colour, showing that Monascus ruber CCT 3802 had the capacity to assimilate the substrate and produce pigments. The red pigments produced in the cultures showed good heat stability with activation energies of 13.735 Kcal mol−1.

Crossmodal correspondences between basic tastes and visual design features: A narrative historical review

People tend to associate abstract visual features with basic taste qualities. This narrative historical review critically evaluates the literature on these associations, often referred to as crossmodal correspondences, between basic tastes and visual design features such as color hue and shape curvilinearity. The patterns, discrepancies, and evolution in the development of the research are highlighted while the mappings that have been reported to date are summarized. The review also reflects on issues of cross-cultural validity and deviations in the matching patterns that are observed when correspondences are assessed with actual tastants versus with verbal stimuli. The various theories that have been proposed to account for different classes of crossmodal correspondence are discussed, among which the statistical and affective (or emotional-mediation) accounts currently appear most promising. Several critical research questions for the future are presented to address the gaps that have been identified in the literature and help validate the popular theories on the origin and operations of visual-taste correspondences.

Visualise the tastes from the label: A study on the taste-colour crossmodal association of crisp and dry

Colour is an important guideline for selection and consumption. It also draws attention to the designers, as some modern design styles require them to illustrate the taste of the product with a limited number of colours. In this case, a precise description of the taste-colour association is required. The present study explored the colour-taste crossmodal association of two tastes, crisp and dry, which are normally found in beers and are the preferred flavours of Chinese consumers. Experiments were carried out to determine the characteristics of the colours associated with the two tastes. And the strength of the tastes perceived from the colours with different hue angles was investigated. The results of this study reveal that the hue and chroma can both affect the perception of these tastes. Both tastes can be perceived from the same colour, but the strength of the taste can be varied from different hues.

Recent developments on graphene and its derivatives based electrochemical sensors for determinations of food contaminants

The sensing of food contaminants is essential to prevent their adverse health effects on the consumers. Electrochemical sensors are promising in the determination of electroactive analytes including food pollutants, biomolecules etc. Graphene nanomaterials offer many benefits as electrode material in a sensing device. To further improve the analytical performance, doped graphene or derivatives of graphene such as reduced graphene oxide and their nanocomposites were explored as electrode materials. Herein, the advancements in graphene and its derivatives-based electrochemical sensors for analysis of food pollutants were summarized. Determinations of both organic (food colourants, pesticides, drugs, etc.) and inorganic pollutants (metal cations and anions) were considered. The influencing factors including nature of electrode materials and food pollutants, pH, electroactive surface area etc., on the sensing performances of modified electrodes were highlighted. The results of pollutant detection in food samples by the graphene-based electrode have also been outlined. Lastly, conclusions and current challenges in effective real sample detection were presented.

Progress in 4D/5D/6D printing of foods: applications and R&D opportunities

4D printing is a result of 3D printing of smart materials which respond to diverse stimuli to produce novel products. 4D printing has been applied successfully to many fields, e.g., engineering, medical devices, computer components, food processing, etc. The last two years have seen a significant increase in studies on 4D as well as 5D and 6D food printing. This paper reviews and summarizes current applications, benefits, limitations, and challenges of 4D food printing. In addition, the principles, current, and potential applications of the latest additive manufacturing technologies (5D and 6D printing) are reviewed and discussed. Presently, 4D food printing applications have mainly focused on achieving desirable color, shape, flavor, and nutritional properties of 3D printed materials. Moreover, it is noted that 5D and 6D printing can in principle print very complex structures with improved strength and less material than do 3D and 4D printing. In future, these new technologies are expected to result in significant innovations in all fields, including the production of high quality food products which cannot be produced with current processing technologies. The objective of this review is to identify industrial potential of 4D printing and for further innovation utilizing 5D and 6D printing.

Metallic: A Bivalent Ambimodal Material Property?

Many metallic visual stimuli, especially the so-called precious metals, have long had a rich symbolic meaning for humans. Intriguingly, however, while metallic is used to describe sensations associated with pretty much every sensory modality, the descriptor is normally positively valenced in the case of vision while typically being negatively valenced in the case of those metallic sensations that are elicited by the stimulation of the chemical senses. In fact, outside the visual modality, metallic would often appear to be used to describe those sensations that are unfamiliar and unpleasant as much as to refer to any identifiable perceptual quality (or attribute). In this review, we assess those sensory stimuli that people choose to refer to as metallic, summarising the multiple, often symbolic, meanings of (especially precious) metals. The evidence of positively valenced sensation transference from metallic serviceware (e.g., plates, cups, and cutlery) to the food and drink with which it comes into contact is also reviewed.

What's the Story With Blue Steak? On the Unexpected Popularity of Blue Foods

Is blue food desirable or disgusting? The answer, it would seem, is both, but it really depends on the food in which the color happens to be present. It turns out that the oft-cited aversive response to blue meat may not even have been scientifically validated, despite the fact that blue food coloring is often added to discombobulate diners. In the case of drinks, however, there has been a recent growth of successful new blue product launches in everything from beer to tea, and from wine to gin, arguing that coloring food products blue is more than simply a contemporary fad. In fact, the current interest in blue food coloring builds on the color's earlier appearance in everything from blue curacao to blue-raspberry candyfloss (cotton candy), and thereafter a number of soft drinks. Over the years, the combination of blue coloring with raspberry flavoring has also appeared in everything from bubble-gum to patriotic pop rocks (popping candy in The United States). Ultimately, it is the rarity of naturally-blue foods that is likely what makes this color so special. As such, blue food coloring can both work effectively to attract the visual attention of the shopper while, at the same time, being linked to a range of different flavors (since this is one of the few color-flavor mappings that are essentially arbitrary) depending on the food format in which it happens to appear. Note also that the basic descriptor "blue" covers a wide range of hues having a range of different associations, hence eliciting different reactions (be they positive or negative). While blue was once associated with artificiality, a growing number of natural blue food colorings have come onto the market in recent years thus perhaps changing the dominant associations that many consumers may have with this most unusual of food colors.

Magic on the Menu: Where Are All the Magical Food and Beverage Experiences?

Magic and dining have long been popular forms of entertainment. What is more, both involve some kind of transformation, and yet while the more theatrical aspects of dining have grown in popularity in recent decades, there is a surprising paucity of magical food and beverage experiences out there. In this article, we trace the historical appearance of food and drink and culinary items in the performance of magic. We also review some of the more magical elements of food design that have appeared on menus in bars and restaurants in recent years. We introduce the edible lightbulb dish from the menu at Kitchen Theory Chef’s Table and link it to the stage magic of Derren Brown. We also discuss some of the reasons as to why magical food experiences might be rare in the context of dining. In so doing, our hope is to highlight an intriguing area for future research and innovation. Along the way, we identify some possible candidate approaches for the introduction of edible magic onto the menu in the context of modernist cuisine.

Photostability of organic red food dyes

The shift from artificial to natural ingredients is a rising trend in the food industry. However, natural coloring agents tend to be less stable than their synthetic counterparts when exposed to light, air, changes in pH, and heat. This study compares the photostability of three organic red dyes, Red 40 (allura red AC), betanin and carminic acid, in aqueous and soft drink solutions. The degradation, traced through absorbance spectroscopy, is well fit to first-order kinetics. Two distinct timescales are observed in aqueous solution but only a single, faster decay in the soft drink matrix. Betanin is the least stable dye in both solvent environments and Red 40 exhibits the greatest destabilization in the soft drink solution. Anoxia has different impacts dependent upon both the dye and solvent system. The analysis provides further insight into the degradation mechanisms for these different red dyes and the role of environment on their photostability.

The Importance Given to Food Naturalness Attributes by Millennial University Students

So-called natural food is one of the most significant current trends in the food business. Despite this trend, previous research on the measurement of naturalness has made no distinction between different groups of consumers. Therefore, the objective of this study is to explore the attributes important to millennial university students when evaluating food naturalness. The study is based on a questionnaire administered to a sample of 372 respondents. Using a partial least square (PLS) methodology, it performs a standard confirmatory factor analysis for measurement and validations. As a result, it identifies one attribute linked to how the food is grown and eight attributes associated to how it is produced and processed. These findings have several implications. Apart from testing previous scales in a millennial context, they confirm that market strategies must take different understandings of naturalness into account contingent upon the consumer group.