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This chapter explores in detail what happens after a paper is published, in terms of the ways in which papers have an impact, the importance of subsequent citations, and how the importance of a paper to its parent field can be eventually judged. This is illustrated by following the citation trends of several key historical scientific papers (e.g., Watson and Crick on DNA, the first report of the identification of Buckminsterfullerene) and exploring rates of citation, the peak citation times, the manner in which the papers were referred to at different times, and, in general, the way in which ripples of information transfer across the scientific community. Examples of papers to which reaction was negative (e.g., the report on cold fusion) or mixed (NASA’s report of possible fossil micro-organisms in Martian rock) are also discussed.

This chapter is focused on the way in which scientists write, and the key characteristics that must describe their writing (i.e., clarity and avoidance of unnecessary complexity). The “voice” used in the modern scientific paper is discussed, with exploration of how this may be achieved, and some illustrative examples. In particular, examples are used to see how scientists present highly significant findings, or cast doubt on the findings of others. Some basic and simple principles for practicing and learning naturalistic yet professional writing skills are presented. The reader is encouraged to develop an ear for the rhythms of writing, and is equipped with the basic tools needed to do so. Further points that are discussed include the fact that effective scientific writing does not need to be stylish or deliberately complex, but must above all achieve clarity and a complete lack of ambiguity, while the writing should be “invisible” and place no barriers between reader and intended message. The chapter also considers the requirements for successful writing, including time, concentration, and suitable conditions.

What is scientific research? It is the process by which we learn about the world. For this research to have an impact, and positively contribute to society, it needs to be communicated to those who need to understand its outcomes and significance for them. Any piece of research is not complete until it has been recorded and passed on to those who need to know about it. So, good communication skills are a key attribute for researchers, and scientists today need to be able to communicate through a wide range of media, from formal scientific papers to presentations and social media, and to a range of audiences, from expert peers to stakeholders to the general public. In this book, the goals and nature of scientific communication are explored, from the history of scientific publication; through the stages of how papers are written, evaluated, and published; to what happens after publication, using examples from landmark historical papers. In addition, ethical issues relating to publication, and the damage caused by cases of fabrication and falsification, are explored. Other forms of scientific communication such as conference presentations are also considered, with a particular focus on presenting and writing for nonspecialist audiences, the media, and other stakeholders. Overall, this book provides a broad overview of the whole range of scientific communication and should be of interest to researchers and also those more broadly interested in the process how what scientists do every day translates into outcomes that contribute to society.

Today, a major consideration in scientific publishing is obviously ethical issues or those relating to research integrity, and key concepts around falsification, fabrication, and plagiarism are explored in this chapter, in terms of defining key principles for good research practice underpinned by the highest standards of integrity, as is expected of all researchers today. There have been many high-profile cases of controversies involving scientific papers, and key case studies are described. In addition, issues such as failure to acknowledge conflicts of interest for the authors (e.g., the Lancet study by Wakefield et al. on the link between the MMR vaccine and autism) are discussed. Likely future trends including the nature of the refereeing process and the access to experimental data are explored, and a key focus is on the rights and responsibilities of authors and coauthors.

This chapter looks at how and when a group of researchers decide the time is right to write a paper, the reasons for writing a paper, and what the paper must say. Key characteristics of a scientific paper that inform its structure are used to introduce the sections of a modern paper and explain their functions. This approach allows a logical exploration of the sections of a scientific paper and their function. In addition, this chapter considers the effective presentation of scientific evidence, in terms of construction of effective figures and tables.

In the modern scientific world, it is recognized that all researchers need to be able to explain their research to audiences other than those who are expert in the field, and that different skills and approaches are needed to be able to explain complex research to a range of audiences of different levels and backgrounds. In this chapter, key approaches to doing this successfully, whether in written or oral form, are explored, with examples to illustrate points. In addition, the place and use of alternative forms of communication of scientific information (e.g., social media) are discussed, as well as ideas such as competitions whereby students “dance their PhD” or present a “three-minute thesis,” and the writing of popular science articles and books. A final important part of this chapter concerns the relationships between scientists and the media, and the occasional conflicts between reporting of science through professional means and that in the media.

This chapter explores the detailed stages of publication of a scientific paper, starting with selection of journal by authors and submission of papers. The system architecture and roles of editors, editorial boards, and referees are examined, and the nature of the review process is discussed, including potential pitfalls, ethical considerations, possible outcomes, and the interactions between authors and journals. The significance of rejection of papers (and famous cases of papers that were first rejected by journals) is explored, and the steps following acceptance of a paper, right through to proof correction and publication, explained. In addition, future developments being evaluated today, such as postpublication (or even preresearch) peer review, are discussed.

This short final chapter draws together key conclusions from the preceding chapters to finish the book with some short conclusions. We reflect on the personal characteristics typical of a scientist and the way in which they are trained to know that their work is not complete until it has been passed on and made an impact, and how those who follow a career in science know that this is a key way in which their careers will be judged. The benefits of a career in science are considered, but placed alongside the responsibilities and expectations in terms of integrity and trust. Finally, the central role of communication in science, the theme for the book as a whole, is emphasized once again.

As well as producing scientific papers, researchers communicate in many different ways, some written (e.g., reports, theses) and others nonwritten (e.g., presentations, posters). This chapter focuses specifically on making a successful scientific presentation to a professional audience, and the differences in approach from writing to verbal presentation. The chapter explores key themes, in particular focusing on the need for a presenter to put themselves in advance into the seat of an audience member, and prepare with a view to what they wish someone in that seat to get from the experience (my primary principle of all forms of communication is “first, and last, consider your audience”). Tips and advice for preparing a presentation, from layout to delivery, and presented, along with advice on the preparation of scientific posters.

The goals and needs of a researcher in terms of publication and communication change from their first efforts as a graduate student to future professional careers up to the level of distinguished professors, including the type of publication strategy to adopt, and the growing responsibility to “give something back” to the field in terms of mentoring, reviewing, and editing as a career develops. This chapter explores these aspects of a career in science, as well as other professional types of writing, such as edited books and textbooks.

Taking oral antibiotics during childhood has been linked with an increased risk of childhood obesity. This study assessed any potential association in number of courses of antibiotics taken between 2–3 and 4–5 years of age and body mass trajectory up to age 5. The study was a secondary analysis of 8186 children and their parents from the infant cohort of the Irish National Longitudinal Study of Children. Antibiotic use was measured by parental recall between ages 2–3 and 4–5. Longitudinal models described the relationship between antibiotic exposure and body mass index (BMI) standard deviation scores and binary outcomes, and examined interactions between covariates, which included socioeconomic status, diet assessed by food frequency questionnaires and maternal BMI. Any antibiotic usage between 2 and 3 years did not predict risk of overweight or obesity at age 5. Four or more courses of antibiotics between 2 and 3 years were independently associated with obesity at age 5 (odds ratio 1.6, 95% confidence interval 1.11–2.31). Effect size was modest (coefficient + 0.09 body mass SD units, standard error 0.04, P = 0.037). Maternal BMI modified the relationship: ≥ 4 courses of antibiotics between 2 and 3 years were associated with a + 0.12 body mass SD units increase in weight at age 5 among children of normal-weight mothers (P = 0.035), but not in children of overweight mothers. Number of antibiotic courses, rather than antibiotic use, may be an important factor in any link between early antibiotic exposure and subsequent childhood obesity. Research is needed to confirm differential effects on babies of normal versus overweight/obese mothers independent of socioeconomic factors.

Patients with severe coronavirus disease 2019 (COVID-19) develop a febrile pro-inflammatory cytokinemia with accelerated progression to acute respiratory distress syndrome (ARDS). Here we report the results of a phase 2, multicenter, randomized, double-blind, placebo-controlled trial of intravenous (IV) plasma-purified alpha-1 antitrypsin (AAT) for moderate to severe ARDS secondary to COVID-19 (EudraCT 2020-001391-15).Patients (n = 36) were randomized to receive weekly placebo, weekly AAT (Prolastin, Grifols, S.A.; 120 mg/kg), or AAT once followed by weekly placebo. The primary endpoint was the change in plasma interleukin (IL)-6 concentration at 1 week. In addition to assessing safety and tolerability, changes in plasma levels of IL-1β, IL-8, IL-10, and soluble tumor necrosis factor receptor 1 (sTNFR1) and clinical outcomes were assessed as secondary endpoints.Treatment with IV AAT resulted in decreased inflammation and was safe and well tolerated. The study met its primary endpoint, with decreased circulating IL-6 concentrations at 1 week in the treatment group. This was in contrast to the placebo group, where IL-6 was increased. Similarly, plasma sTNFR1 was substantially decreased in the treatment group while remaining unchanged in patients receiving placebo. IV AAT did not definitively reduce levels of IL-1β, IL-8, and IL-10. No difference in mortality or ventilator-free days was observed between groups, although a trend toward decreased time on ventilator was observed in AAT-treated patients.In patients with COVID-19 and moderate to severe ARDS, treatment with IV AAT was safe, feasible, and biochemically efficacious. The data support progression to a phase 3 trial and prompt further investigation of AAT as an anti-inflammatory therapeutic.ECSA-2020-009; Elaine Galwey Research Bursary.

Many studies have reported astonishing statistics about the rate of introduction of new food products globally, with new products appearing probably at least every hour somewhere around the world, if not more frequently. If you could go into a food store anywhere in the world and somehow take a snapshot of the range of products on the shelf, then revisit it five years later and do a comparison of what you find, there would be a huge surprise in terms of the turnover. Many products will have disappeared, and many new ones will have appeared. For those that remain across this time span, there is a very high likelihood that they have changed in less visible ways, in terms of modifications to their formulation, package, or the process by which they are made. Even fresh foods like fruit, vegetables, meat, and fish are likely to have benefited from scientific advances in their production, quality, or transportation in an optimal state of quality and safety. Why is there such a high rate of change? There are two main drivers, one external to those who produce the food and that relates to the highly fluid and some­times unpredictable expectations and demand of consumers, and one more specific to the food producer that relates to new opportunities in technology, formulation, or scientific understanding. For any new product to be successful on the market requires two successful changes in behavior of consumers. The first is that, instead or as well as what they normally purchase, they need to buy to try a new product, and drop it into their basket or cart as a result of a planned or spontaneous decision to do so. To achieve this is primarily the responsibility of experts in marketing, who can divine what consumers want, develop a strategy accordingly, and then deploy the appropriate tools to bring the product to the attention of those who are most likely to buy the product, such as through promotions, advertisements, and probably, in today’s world, social media campaigns.

Of all food constituents, perhaps that which receives the worst press is fat. The merest mention of fat in food tends to be regarded as a negative thing, and for years the advice of nutritionists has tended to uniformly focus on its avoidance or reduction in our diet. While recent years have perhaps seen a reevaluation of the relative importance of fat, and its reputation may be undergoing a gradual thawing, my focus in this chapter is not on the controversies of its merits or otherwise from a nutritional perspective. As should be clear by now to anyone reading this book, neither my expertise nor my focus is in such realms, and so, for now, without fear or favor, I consider the properties of fats from an impartial perch, in their own regard as key constituents or ingredients of many food products, whether we like it or not. The picture of fat I want to paint here is one of a material that, before it enters our bodies to exert whatever physiological effects it may, hugely affects the properties of many food products, and in some cases can have effects on food texture even more significant than those of proteins and polysaccharides described in earlier chapters, where the level of fat present is sufficient to allow it to dominate the properties of the food. Why is this? Imagine for a moment a hypothetical magic material that determined texture and consistency of food in a way that was dependent on temperature such that it changed its properties dramatically when exposed to different temperatures regularly encountered by food. Maybe such a material would be solid, or almost so, at refrigeration temperatures, but melt at almost exactly the temperature of our mouths when we consumed the food, to soften and make our food easier to chew, while, at higher temperatures yet, as it might encounter during processing or cooking, it became a liquid, which could flow and move and be molded and reshaped, or even divided up, as we saw fit.

The beginning of the story of food is what is termed food production. This might sound logically like the process of making food, such as a chef or food company might, but this term is rather generally used in food science to refer to the so-called primary production of food, from growth of crops to harvesting of fish and minding and milking of cows. Primary production is, for example, what farmers do, producing the food that is brought to the farm-gate, from where the processors take over. So the food chain runs, according to your preference for a snappy soundbite, from grass to glass (for milk), farm to fork, slurry to curry, or (taking the food chain to its logical conclusion, and including the role of the human gut charmingly but appropriately in the chain) from farm to flush. But where do these raw materials that are yielded by primary production actually come from? It is often said that all things found on earth can be divided into categories of animal, vegetable, and mineral. To these could perhaps be added two more categories, microbial and synthetic (man-made). Within these five groups can essentially be placed everything we know as food, so using this classification to consider where our food comes from seems like a good starting point for this book. Perhaps the simplest group to start with is minerals, which might intuitively seem an unlikely source of foodstuffs (do we eat metal or rock?), until we consider where salt comes from and how much of it we add to our food (in other words, probably too much). Our bodies, however, absolutely need for us to consume certain metals and other chemical elements to survive, beyond the sodium and chloride we get from salt, and so many extracted minerals find their way from deposits in the earth into food products. This is particularly important where their biological effects are a desirable outcome (such as in carefully formulated nutritional products). In addition, products such as milk contain minerals like calcium, magnesium, zinc, and more, because the infant or calf needs them to thrive.

The goal of Molecules, Microbes, and Meals is to provide an overview of the science of food, exploring all aspects of how food products we purchase and consume come to have the characteristics they do. The key focus is on the science underpinning the appearance, flavor, texture and qualities of food, and the transformations that occur when we cook food products. Every food product is a highly complex scientific entity, and a key objective of the book is to show that an understanding of the science of food can enhance our appreciation and wonder at it. Another key theme will be the convergence of science and art in food, and the history of food, whereby we have known how to undertake what are exceptionally scientifically complex activities such as fermentation, pasteurization and cooking long before the scientific basis for what was happening was understood.

To this point, my focus has been largely on the transformations and processes that convert raw materials and ingredients into packaged final food products, while considering the relationships between such a scale and what happens in the kitchen. I believe that food science is food science whether it happens on a 10-tonne scale in a factory or in a kitchen at home or in a restaurant. It is just a matter of scale. But is this really a defensible proposition? As pointed out several times already, all food products consist of a set of raw materials and ingredients, which we submit to a process or series of processes and then place in a package in which it should remain safe and suitable for consumption for a defined period of time. What about a meal? Ingredients and raw materials, check, just taken from a larder, fridge, or freezer. Processes? Check, just maybe a different set and scale, as will be discussed. Package and storage? No, but one could say the plate, room, atmosphere, and a million other elements of presentation of a dish at home or in a restaurant are the package. Likewise, being able to maintain a shelf life may not be a priority, but it is usually regarded as a good thing when safety for the eater is guaranteed, while we often hope that those leftovers we put in the fridge or bring home in our doggy bags will retain some form of safe edibility for at least a while. Food science is science above all else, whatever scale it happens on. In the kitchen, our raw materials, animal or vegetable in particular, are products of biology, while the reactions that take place on plate or during cooking (or other processing steps) are driven by chemistry, and physics determines what happens when we heat, cool, mix, or all the other things we do. Like I said in the Introduction to this book, even the humblest kitchen is a highly scientific environment, and every meal is an experiment.

First, I have a confession to make. I am a food scientist. I have spent a large part of my life in a white coat, or working with students in white coats, studying, analyzing, and creating food products, subjecting them to a variety of processes and tests to see what happens, and occasionally, very occasionally, even tasting them. This is my passion, and to me is one of the most exciting types of scientific research in which I could be engaged, where the challenges are complex and really interesting, but in every case relate in some way to something central to everyday life. Food science is probably the only field in which a scientific experiment can lead to a change that can have a measurable impact you can point to on a shelf or plate within a matter of days. Also, it is great to work in a field of science where sometimes, if your experiment doesn’t work, you can at least eat it! However, I accept that, for many people, this is not food. Food comes on a plate. Food is an art. Food is an experience. Food is pleasure. Food is life. Food is not something to handle with a white coat on, not something to deconstruct in test tubes, and certainly not anything to do with chemicals. Definitely not anything to do with chemicals. Food is not science; food is art. People today know what they want from the food they buy. They want a wide variety of safe, natural, convenient, nutritious, great-tasting food. They likewise know what they do not want. They don’t want processed food, they don’t want chemicals in their food, they don’t want preservatives. This presents those who provide that food with great challenges as, to deliver the things consumers want, they often have to avoid the very tools they have traditionally used to achieve these goals. In this book, I want to explore the contradictions at the heart of our understanding of food, which arise in part from the fact that food is both science and art.

As mentioned already several times, the world of living things can be divided quite simply into that which we can see (animals, plants, us!) and that which we cannot see. We share this planet with microscopic life that actually far outnumber the life-forms we can see and whose importance to our lives across a huge range of areas is completely out of proportion to their size. We need the assistance of microscopes or other tools to reveal the incredible diversity, richness, and sheer vastness of this hidden world. In terms of the sphere of human life with which we are concerned in this book, food, we worry about two things to do with microorganisms in food, which are safety and spoilage, but these are not the same thing. For example, milk containing a bacterium called Pseudomonas could look green, be stinky, and have lumps floating in it, but could be quite safe, while milk containing listeria could look fresh as could be but would make you very ill, perhaps even fatally, were you to drink it. In addition, yogurt containing bacteria called Bifidobacteria might not only be neither unpleasant nor dangerous but might actually be good for you, as these are probiotic bacteria, which are believed to colonize the human gut and help keep us healthy. So (cue Ennio Morricone music, and distinctive whistling), bacteria in food can be good (like the probiotics), bad (like the pathogens), or ugly (like the types that cause spoilage). Of course, the population of living things we cannot see in food is much broader than bacteria too and encompasses viruses (generally these don’t come in good or ugly variants, and are usually simply bad news, as when they cause food poisoning because of their contamination of products like oysters) and fungi such as yeasts and molds.

It seems appropriate to finish this book with the equivalent of a dessert or aperitif, to send the reader off with a sense of satisfaction, satiation, and hopefully pleasure. I thought about polishing my crystal ball and trying to project into what food might look like in the future but, as the Nobel Prize-winning Danish physicist Niels Bohr once said, prediction is very difficult, especially when it is about the future. Futuristic predictions are of course notoriously unreliable, as can be seen by the fact that we should all surely have our personalized jet-packs by now. Interestingly, one theme that may have come through in this book is that the future of food, at least for the next few decades, is, to adapt a quote by the writer William Gibson, probably here already, but just not equally distributed. The progress of food science has happened sporadically and unevenly, as when Bert Hite showed that high pressures could preserve food a century before anyone figured out how to make that work in a practical sense, and when NASA was introducing innovations in food safety and packaging for space travel that years later have become common practice in our restaurant kitchens and on our supermarket shelves. The story of food science in the last century has been about taking all that we knew about the art, provenance, and processing of food in the prescientific era and underpinning anecdote with fact and understanding. I think that this great era of scientific study of food has answered the main questions, such that we understand broadly why most of the things we have observed since mankind emerged and started to eat things happen, and moreover how to control these to our greatest advantage. Many scientific phenomena relating to food are well described, in textbooks, websites, and a huge body of scientific papers, while of course leaving plenty of interesting questions and challenges for future generations of food scientists to explore.

History and fiction provide many examples of barriers being constructed to keep undesirable enemies away, containing a few points at which crossing from one side to the other is carefully controlled, whether it be Hadrian’s Wall, the Berlin Wall, or a 300-mile-long, 700-foot-tall ice wall. This is also the basic principle of food packaging: keep the food and its quality in, and keep all things that can impair that quality, or threaten consumer safety, out. Food packaging has many functions: Contain the product in a physical sense in a single mass and place. Protect the product from physical damage. Protect the product from chemical damage by controlling the access of gases, moisture, or light to the product inside, and also perhaps protect the product from sudden changes in temperature. Present the product to consumers in defined portion sizes. Provide convenience (for example, in how consumers can carry, open. or use and perhaps reuse the package). Provide surfaces on which information (marketing and practical) can be provided to consumers. Be compatible with whatever processes a consumer will subject it to, such as freezing or microwaving, if that is part of the function of the package and intended handling of the product. “Be the least evil” in terms of impact on the environment and our planet. The most common materials used for food today are cardboard, plastic, metal, and glass, while other materials occasionally used in food packaging include wood and ceramics. To achieve the properties just mentioned, though, most food packages today are complex composites of several materials, frequently bonded together in a way that is invisible to the naked eye. Such arrangements are necessitated by the fact that no one material usually has exactly the right properties needed, so such composites (called laminates where layers are glued together, as of paper, foil, and plastic, for example) are used to give a combination of strengths that overcomes any individual component’s disadvantages, like physical weakness, sensitivity to water or fat, or transparency.

We think perhaps instinctively of our tongues as supersensitive tasting machines, laden with taste buds that detect and analyze core flavors such as sweet, sour, and salty, from which we build up a picture of what the food tastes like. However, before the food gets there, it has to pass two arguably even more sensitive sensors, the impact of which on what we think the food tastes like is immense. The first is the eyes, and the second is the nose. Controlling the whole system, but perhaps more infallibly than it might think it does, is the brain. Let’s think about the eyes first. We all make automatic judgments about food based on observation, and these first impressions can be incredibly difficult to bypass. Appearance can make complete fools of us, if we let it. I have seen experienced food specialists taste bright orange sweets that comprised apple-flavored jellies with a strong orange dye added and, when asked to describe the flavor, voted verbally for orange, except a few lone and somewhat confused voices claiming for apple. Famously, even one of the best-known color/character differences in the food world can be hacked by playing with appearances and expectations. Red and white wine can be confused for each other when the taster cannot see the color, and obvious cues such as the temperature at which the wine is tasted are manipulated. This has been demonstrated repeatedly in experiments involving so-called experts in France and the United States, where completely different flavor profiles have been reported on tasting one glass of white wine and one of the exact same wine to which a flavorless red dye had been added. In addition, the flavor profile of wine has been shown to differ depending on factors such as the label placed on the bottle (and apparent perceived “fanciness” as a result), and there has frequently been shown to be no correlation whatsoever between price on the bottle and the results of sensory evaluation of flavor or desirability.

Compared with some of the processes we have discussed so far, like heating or cooling, drying is one we might think less of in a kitchen context and consider to be more a large-scale industrial process. However, when we look around a kitchen we find a lot of products of such activity, in terms of containers of powders like salt, sugar, spices, milk powder, soups, flavorings, flour, and much more, as illustrated in Figure 12.1. These have enormous advantages of long life, not needing to be kept in the fridge, taking up relatively little space, and providing a neat and concentrated source of whatever flavor or other character we wish to add to a dish. The key consideration is that whichever powder we use will behave in a convenient way when we come to use it, dissolving in water or other meal bases easily and reliably. We also routinely remove water from food in the kitchen, perhaps not by having a mini—spray dryer on the counter (at least not in most kitchens), but by removing a lid from a pot to allow some water to be driven off in the form of steam. We also essentially remove water from food more subtly, for example, by adding sugar to a jam recipe, which does not remove the water as such, but rather renders it less available for undesirable things like supporting microbial growth, thereby achieving many of the stabilizing and preservative benefits of actual drying without the drying. Removing water from food greatly improves the stability of food products and, by inhibiting the actions of microorganisms, increases its safety. As a result, drying of food, wholly or partially, has been practiced for centuries as a way to make food more stable. Not only does removing water from food add major hurdles in terms of stability and safety, but it adds an enormous bonus feature of convenience. To illustrate this clearly, I always think of what life would be like if we had to buy all our coffee in liquid form, and no dried (or highly concentrated pod) versions existed.

As I have discussed throughout this book, mankind has relied on heating to preserve and make safe our food for a very long time, even long before the science of how and why this works was understood. However, clearly using heat to process However, clearly using heat to process food is a rather blunt tool, sometimes as subtle in its effects as hitting it with a club or bat. Just as it kills bacteria, molds, and other microorganisms, it inflicts collateral damage on the sensory and nutritional quality of the food. The greater the level of kill, and hence stability and safety conferred, the greater damage to the “fresh-like” characteristics of the food has usually been caused. A question could then be posed as to whether, instead of applying such a crude and damaging (although undoubtedly effective) treatment, we could treat food with more of a surgical-scalpel or laser-focused treatment, which zoomed in on and very specifically destroyed the target microorganisms while leaving the surrounding food as little changed as possible. This is the target of so-called minimal (sometimes called invisible) processing, and today there are a range of technologies that have promise for achieving this goal. Indeed, because of the desirability of such an outcome, this has been thus one of the most active areas of research on food processing in recent years. We have encountered the importance of pressure several times already in this book, usually in how its manipulation can affect properties of water such as boiling. Pressure has another important application in food processing, though, in that it can replace heat as the physical force we apply to achieve desirable change in food. In food processing circles, high-pressure (HP) processing is often referred to as a novel processing technology, but in fact it has been around for quite a long time. Remarkably, around the same time that Pasteur was explaining how heat works in terms of preserving food, on the other side of the Atlantic an American scientist called Bert Hite at the West Virginia Agriculture Station was doing experiments on his own homemade pressure-generating apparatus.

Proteins are, in my view, the most impressive molecules in food. They influence the texture, crunch, chew, flow, color, flavor, and nutritional quality of food. Not only that, but they can radically change their properties and how they behave depending on the environment and, critically for food, in response to processes like heating. Even when broken down into smaller components they are important, for example giving cheese many of its critical flavor notes. Indeed, I would argue that perhaps the most fundamental phenomenon we encounter in cooking or processing food is the denaturation of proteins, as will be explained shortly. Beyond food, the value of proteins and their properties is widespread across biology. Many of the most significant molecules in our body and that of any living organism (including plants and animals) are proteins. These include those that make hair and skin what they are, as well as the hemoglobin that transports oxygen around the body in our blood. Proteins are built from amino acids, a family of 20 closely related small molecules, which all have in chemical terms the same two ends (chemically speaking, an amino end and an acidic end, hence the name) but differ in the middle. This bit in the middle varies from amino acid to amino acid, from simple (a hydrogen atom in the case of glycine, the simplest amino acid) to much more complex structures. Amino acids can link up very neatly, as the amino end of one can form a bond (called a peptide bond) with the acid end of another, and so forth, so that chains of amino acids are formed that, when big enough (more than a few dozen amino acids), we call proteins. Our bodies produce thousands of proteins for different functions, and the instructions for which amino acids combine to make which proteins are essentially what the genetic code encrypted in our DNA specifies. We hear a lot about our genes encoding the secrets of life, but what that code spells is basically P-R-O-T-E-I-N. Yes, these are very important molecules!

When we refer to food as containing “sugar,” we tend to picture white crystals we buy in bags or pour from sachets into our coffee, but to a food scientist sugar is not a single thing, but a type of thing. While, most commonly, when we say sugar we refer to sucrose, in reality there are many sugars that can be found in (or added to) food. They all have in common the chemical characteristic that they are carbohydrates, which means, as the name suggests, that they are based on carbon and water (giving hydrated carbon), and indeed the three core elements found in all sugars are carbon, hydrogen, and oxygen. One of the simplest sugars, molecularly speaking, is glucose, in which there are 6 carbon atoms, 6 oxygen atoms and 12 hydrogen atoms (so it is like 6 carbons plus 6 water molecules, as each water molecule has two hydrogens to one oxygen). These are arranged, not in a long chain, as in the proteins we discussed in the previous chapter, but rather in a ring structure (not technically round, but more like a hexagon might appear if you gave it a good twist). Glucose is the main sugar found in biology, being found in our bodies and also produced by plants by photosynthesis. Another simple sugar is fructose, found widely in fruit and honey, which has an even simpler structure, a pentagon structure, but again has 6 carbon atoms bound together with 6 oxygens and 12 hydrogens, while a rarer one (at least in its unbound state) is galactose, again with the same number of the core atoms but arranged in yet another slightly different state. Here is a wonderful example of the significance of chemistry for food, where the exact same number of atoms of the same three elements can naturally be found in (at least) three different arrangements, which reflect subtly different molecular shapes but yet give compounds that differ greatly in their sweetness, solubility, reaction with other components in food, and many other properties.

One term that has acquired a particular air of consumer suspicion in recent years is “processed food. ” Processing is seen as being something that is used to make food less fresh, less natural, and so more suspicious. However, even though we say we don’t want processed food, every food product, before it gets to your mouth, has been subjected to some form of processing and treatment that has a scientific basis. Even washing an apple, chilling sushi, or peeling a banana are forms of food processing, while the bag of salad we buy in a shop or market isn’t full of air as we might expect. All of these phenomena I will discuss in coming chapters. Before dealing with the science of food processing, it is worth discussing what exactly that highly loaded term means. To a food scientist (well, me anyway), food processing means subjecting foods or raw materials to external forces designed to cause a desirable change in the food, typically in terms of its safety and stability, and also in many cases its flavor, texture, and color. In many cases, the primary target of food processing is the resident population of contaminating microorganisms that, if not dealt with, might otherwise cause the food to spoil, or else spoil the day of consumers who finds themselves with a range of symptoms of food poisoning, up to the most lethal. The force most commonly applied in processing is temperature, whether low (refrigeration), very low (freezing), high (for example, pasteurization or cooking), or very high (canning or sterilization). Temperature is indeed probably the key physical variable of significance to food, as almost everything that happens in and to food is influenced by temperature, and most changes take place optimally in a relatively narrow band around body temperature (37 °C). If temperature is pictured as a line scale, the zone of greatest danger and likelihood is centered around that point, but food processors look far below and above that zone and have come to understand how we can work around the optimum temperatures for various reactions and biological changes in order to make our food safer and more stable.

In the last chapter, yeast was mentioned a few times as one of the generally less-problematic microbial denizens of food systems, and in fact the roles of yeast in the production of two of our most common and popular food categories, alcoholic beverages and bakery products such as bread, are so critical that it is worth dedicating a whole chapter just to the consideration of the science of these products. The ability of yeast to grow in a wide range of raw materials and convert sugars to alcohol, carbon dioxide, and other interesting products is the basis for production of products such as wine and beer, as well as higher-alcohol-level spirits, and is a process that has been exploited for the purposes of human pleasure for thousands of years. The origins of alcoholic fermentations, like those of many food products, are somewhat murky, but it is thought that honey or fruit may have been the original basis for the fermentation of such products, and that wine arose because of accidental adventitious spoilage of grapes and their juice that turned out to have, well, interesting consequences. The Greeks and Romans had wine-making down to an art, and it features frequently in their art; it also makes many appearances in the Bible (including a nonscientifically verifiable production protocol based apparently solely on water). The main reason alcoholic fermentation became of interest was as a way to prevent bacteria or other undesirable microorganisms from growing in juice by allowing a different kind of microorganism to get there first, use up the goodies, and produce products that made conditions highly unsuitable for colonization by later invaders. We routinely associate the word “intoxicated” with a formal description of the result of overconsumption of the outputs of such fermentation, but the heart of that word is “toxic,” which reminds us that alcohol is a poison. It just happens to be one that humans can tolerate only up to certain levels, beyond which poisoning and death can readily occur, but at lower levels has a range of effects that need not be described here.

Before we move forward from our previous chapters’ exploration of the importance of the microbiology of food from its many different angles to start to focus on how we process food to, among other effects, control that microbiology, we need to consider one more basic constituent of food. This is because, even after several earlier chapters in which the key functions of proteins, sugars, lipids, and other rather high-profile food constituents were discussed, we have yet to discuss explicitly the one that is perhaps the most significant of all. It was mentioned many times of course, lurking in the background like a supporting character actor in a movie who doesn’t dominate the foreground activity but is a key part of the scene. This magically powerful ingredient is water, yes water, that represents the majority of most food products, and without which most of their properties and characteristics would not exist. We have seen already how water can appear in food in many guises, depending on whether it deigns to interact with the other constituents present, leading to apparent logical surprises like the fact that a melon (a solid?) has actually more water per gram of its weight than milk (a liquid?), just because in one case the water is absorbed and robbed of its innate fluidity, while in the other no such restrictions apply. Besides influencing texture in a completely fundamental way, though, water influences behavior of just about every other molecule in food, from the structure of a protein (and hence the texture we perceive) to the suspension of oil droplets in the many food products that are emulsions. As well as this, almost all the dynamic changes we encounter in food, for better or for worse, depend on water. Microbes require water to live, as we can see when we preserve food by removing it (in drying), or else denying it more subtly by adding substances such as sugar or salt, which can suck the very water out of bacterial cells like molecular vampires.

As we have seen, heating of food is one of the oldest and most powerful ways of making food safe and stable, whether cooking a burger on a barbecue or pasteurizing juice, but is also a potentially highly damaging thing to do to many food products. So, it makes sense that a key principle of processing food is to understand how to control the flow of heat as precisely as possible. In Chapter 8, I introduced how we can maximize the efficient transfer of heat into and out of food in a kitchen in simple systems, like pots on stoves. In practice, in large-scale processes, to transfer heat efficiently from hot to cold, and in this way keep the lords of thermodynamics happy while minimizing damage to the food being heated, we need to use clever pieces of equipment, called heat exchangers (reflecting the fact that, just as the cold part of the system gets hotter, so the hot part gets colder in the deal; fair exchange is no robbery). To visualize a heat exchanger, imagine a simple metal tube, through which a cold liquid is flowing from one end to the other. Now surround that tube with a larger one, through which a hot liquid flows (as shown in Figure 11.1). The wall of the inner tube is exposed to cold on the inside and hot on the outside, and this temperature gradient is the pump that transfers heat across that wall, in nature’s obsessive quest for equality in all things temperature-y. So, now we have two tubes laid horizontally in concentric neatness, say with a hot and a cold liquid flowing in from the left-hand side; as they exit at the right-hand side, the outer hot liquid will be colder, and the inner liquid will have gained the lost heat and thus become hotter. If the tubes were sufficiently long, then both would come out at exactly the same temperature.

Proteins are not just interesting and significant in food in their intact or even aggregated or complexed states, but often lend their greatest value to food by their disappearance. For example, in cheese, as we discussed in the last chapter, proteins are critical for the coagulation of milk and conversion into curd, and cheesemakers choose the enzymes they use to cause that coagulation specifically for their lack of other impact on the milk protein casein. However, once the cheese is made, the intactness of the casein abruptly becomes a liability, in a sort of cosmic ingratitude, and indeed the cheese will not be considered fit to eat until it is at least partially gone. The reason for this is immediately apparent if the freshly made cheese (of just about any variety) is tasted. Does it taste like cheese? Only if you like your cheese bland and flavored almost entirely of salt. Does it have the texture of cheese? Only if you think cheese should take quite a while to chew while savoring its boring saltiness. This is the taste and flavor of (salted) intact casein curd. So, no one eats cheese in this state, and almost every variety of cheese, from Accasciato to Zamorano, is held for at least some time after manufacture to undergo what is called ripening, during which it develops the flavor and texture we will expect it to have. In the case of the Parmesan shown in Figure 3.1, the crumbliness we associate so closely with this cheese is achieved by a combination of breakdown of the protein network over very long ripening times (often 12 months to 2 years), and a parallel drying out to low-moisture contents (which also concentrates the wide range of compounds produced during such long ripening to give a very strong and piquant flavor). Interestingly, almost all freshly made cheeses enter the ripening stage with similar flavor, but they leave with a ridiculously wide variety of characteristics.

Background and objectives An environmental trigger has been proposed as an inciting factor in the development of anti-GBM disease. This multicenter, observational study sought to define the national incidence of anti-GBM disease during an 11-year period (2003–2014) in Ireland, investigate clustering of cases in time and space, and assess the effect of spatial variability in incidence on outcome. Design, setting, participants, & measurements We ascertained cases by screening immunology laboratories for instances of positivity for anti-GBM antibody and the national renal histopathology registry for biopsy-proven cases. The population at risk was defined from national census data. We used a variable-window scan statistic to detect temporal clustering. A Bayesian spatial model was used to calculate standardized incidence ratios (SIRs) for each of the 26 counties. Results Seventy-nine cases were included. National incidence was 1.64 (95% confidence interval [95% CI], 0.82 to 3.35) per million population per year. A temporal cluster ( n =10) was identified during a 3-month period; six cases were resident in four rural counties in the southeast. Spatial analysis revealed wide regional variation in SIRs and a cluster ( n =7) in the northwest (SIR, 1.71; 95% CI, 1.02 to 3.06). There were 29 deaths and 57 cases of ESRD during a mean follow-up of 2.9 years. Greater distance from diagnosis site to treating center, stratified by median distance traveled, did not significantly affect patient (hazard ratio, 1.80; 95% CI, 0.87 to 3.77) or renal (hazard ratio, 0.76; 95% CI, 0.40 to 1.13) survival. Conclusions To our knowledge, this is the first study to report national incidence rates of anti-GBM disease and formally investigate patterns of incidence. Clustering of cases in time and space supports the hypothesis of an environmental trigger for disease onset. The substantial variability in regional incidence highlights the need for comprehensive country-wide studies to improve our understanding of the etiology of anti-GBM disease.

Generalised linear regression models were used to identify factors associated with fatal/serious road traffic collision injuries for single- and multi-vehicle collisions. Single-vehicle collisions and multi-vehicle collisions occurring during the hours of darkness or on a wet road surface had reduced likelihood of a fatal/serious injury. Single-vehicle 'driver with passengers' collisions occurring at junctions or on a hill/gradient were less likely to result in a fatal/serious injury. Multi-vehicle rear-end/angle collisions had reduced likelihood of a fatal/serious injury. Single-vehicle 'driver only' collisions and multi-vehicle collisions occurring on a public/bank holiday or on a hill/gradient were more likely to result in a fatal/serious injury. Single-vehicle collisions involving male drivers had increased likelihood of a fatal/serious injury and single-vehicle 'driver with passengers' collisions involving drivers under the age of 25 years also had increased likelihood of a fatal/serious injury. Findings can enlighten decision-makers to circumstances leading to fatal/serious injuries.

A mesh improvement methodology is pre- sented which aims to improve the quality of the worst elements in 3D meshes with non-planar surfaces which cannot be improved using traditional methods. A nu- merical optimisation algorithm, which specifically tar- gets the worst elements in the mesh, but is a smooth function of nodal positions is introduced. A method of moving nodes on curved surfaces whilst maintaining the domain geometry and preserving mesh volume is proposed. This is shown to be very effective at improv- ing meshes for which traditional mesh improvers do not perform well.

General practice makes a critical contribution to healthcare in Ireland. However, there is a weak understanding of the general practice workforce in Ireland. The aim of this study is to estimate the number of general practitioners (GPs) and practice nurses in Ireland. A variety of data sources was used to corroborate counts of general practitioners and practice nurses. Capture–recapture methods were used to estimate the hidden population of GPs not identified by the databases included. There are 2,954 general practitioners in Ireland, equivalent to 64.4 per 100,000 population. There are 1,700 practice nurses nationally, equivalent to 37.1 per 100,000 persons. There is substantial regional variation in the number of general practitioners and practice nurses per 100,000. To some extent, deficits in one discipline may be counterbalanced by a surplus in the other. In the absence of a centralised register, it is not possible to track the number of GPs or practice nurses working in Ireland at present. This is despite the fact that there are twice as many general practice visits per annum compared to hospital visits.