Molecules, Microbes and Meals: The Surprising Science of Food

I am pleased to introduce another wonderful book about food science, Molecules, Microbes and Meals by Alan Kelly. Like Future Foods by Julian McClements, Kelly’s book presents a more positive outlook on the topic than my book, In Defense of Processed Food. I can’t help but feel overjoyed at the emergence of these two books and wish that I had been as bold and less defensive. So, I am happy to react to his own words in bold:

“This book is neither an attack on nor a deliberate defense of the practices, politics or ethics of the food industry, with the focus being on the tools used and their principles and effects, not the users and what they choose to use them for.” (p. 6) The author makes this disclaimer up front in an attempt to sidestep the walking-conflict-of-interest label that Marion Nestle has affixed to everyone who has a degree in Food Science. Are we shills for the food industry? I think not. Can we express a different professional opinion about food from the one advanced by Nestle, Michael Pollan and other critics of processed foods without being shamed in public? I certainly hope so.

Has society become so callous that we no longer need to attack ideas but rather just make character smears? Apparently. I concur with many of Nestle’s ideas, but I do reject her smear of an entire academic discipline and profession. Kelly makes the case for food processing and the beliefs of food scientists apart from the goals and behavior of the food industry. He also proclaims that, “Not only am I a food scientist, I am not a foodie.”

“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).” (p. 8) Kelly steers us away from the animal-based, plant-based dichotomy that seems to be dominating food conversations on the net these days. He introduces microbial—from the standpoint of fermentation. Fermented products, whether produced at home or in a factory seem to largely get a pass from being processed in the electronic media even though food scientists consider fermentation to be “a process.” Michael Pollan salutes fermented foods in Cooked. Kelly doesn’t shy away from synthetic ingredients and defends their use in ultra-processed foods to provide a safer and more pleasurable eating experience.

“Water, we salute you and your quiet power, and your control of the apparently much more complicated molecules with which you share food, deploying impressive and complex structures, but still in many cases dependent on the munificence of your actions for their properties.” (p. 132) The author’s ode to water is perhaps the most impressive chapter in the book. This quote also illustrates the complexity of the language used in the book and long sentences. I was instructed to use shorter sentences when attempting to communicate with a nontechnical audience. Here he pays tribute to the molecule that is the greatest quantity in most foods and describes the functional importance of this compound in so many of our foods.

It is interesting that he uses the term ‘molecule’ more frequently than the word ‘chemical.’ I prefer using ‘chemical’ as it has a negative connotation and ‘molecule’ a positive one. People know that H2O is a chemical but don’t think of water as a chemical. Maybe I just need to “get over it.”

“bacteria in a food can be good (like probiotics), bad (like the pathogens), or ugly (like the types that cause spoilage)” (p. 90)] In the media we generally hear about microbes as a source of food poisoning. We are now hearing more about prebiotics and our microbiome, but the connection of microbes with fermented foods is generally limited. Much of this chapter is on fermentation as the author’s expertise is in the area of cheese.  Elsewhere, he emphasizes the importance of food processing as its role in maintaining food safety and slowing spoilage. Spoilage microbes and pathogenic ones are not the same, despite the linkage of the two in the public mind. He helps differentiate between the good, the bad, and the ugly organisms that in our foods. In my lectures on the topic I also added in the free riders, the majority of microbes inhabiting our food that have no significance in their interaction with humans.

“even though we say we don’t want processed food, every food product, before it gets to your mouth, has been subject to some form of processing and treatment that has a scientific basis.” (p.133) The author describes the progression of food as it progresses through stages from raw to cooked to rotten. It hearkens back to a white paper that appeared in Food Technology several years ago to which I made a minor contribution. Once again, this quote shows a more in-your-face approach and not defensive positioning that much of my writing reflects. In a shorter piece Kelly pleads that we not demonize food additives and ultra-processed food.

“The main disadvantage of spray-drying for coffee is the fact that the hot air, when escaping from the dry product, strips off any molecules that are easily encouraged to enter a gas phase rather than staying behind in the dry solid powder.” (p. 179) One of the food processes described in the book is spray drying. The description brought back some not-so-pleasant memories from my grad-school days. I had extracted some natural colors from red cabbage and blueberries and wanted to turn them into powders. Spray drying seemed to be the right way to do it. Unfortunately, these pigments, known as anthocyanins, were very hygroscopic (water loving) and readily absorbed water vapor from the air to become a sticky mess. Instead of collecting a nice fluffy powder, I coated the inside of the spray dryer with a bright red layer of an extracted natural color. To produce a powder, I needed a base for the pigment. It was a chore scrubbing out the inside of the dryer with a scrub brush.

Other experiences of mine with food processes were not as difficult. The point in Molecules, Microbes, and Meals is that most processes in the industry are merely scaled up versions of processes used at home. The industry merely uses much bigger equipment to produce much more food. Chances are that readers of this blog do not have a miniature spray dryer in their home, but anyone using powders in a recipe to prepare a meal has probably taken advantage of this process. Kelly does a nice job of attempt to demystify food processing and what it can do for us.

“Every kitchen is a laboratory, and every meal is an experiment; it just depends on how you look at it.” (p.5) I hate to call out the author of a very fine book for an untruth, but he sure seems to write like a foodie if he is not one! Kelly relates back to kitchen processes throughout the book. He points out that many of us have elaborate types of processing equipment in our modern kitchens such as dual convection ovens, microwave ovens, huge refrigerator/freezers with multiple compartments and ice-makers, mixers, blenders, fryers, bread-makers, coffee-makers with French presses, sets of pots and pans to perform different functions, etc. And what about the elaborate sets of knives, each suitable for a specific task?

plate of cooked beef slices, asparagus spears and diced sweet-potato
A home-prepared meal from a meal kit

Maybe we don’t have a piece of equipment called a food processor anymore, but most of us who prepare food in a kitchen are not mere cooks but food processors who take raw materials and mix it with purchased ingredients (aka food additives) to prepare meals. At least we don’t use “industrial ingredients,” or do we? More on that topic later in the month. And then when we go out to eat at a fancy restaurant, are the chefs practicing molecular gastronomy, the marriage of the culinary arts and the chemistry of food?

I confess to being a processor of food at home with a nice but not elaborate kitchen. My experience is a far cry from the family described in Pressure Cooker who live in a motel with only a small refrigerator, microwave oven, hot plate and bathroom sink to store food, prepare it, serve up a meal and clean up after it. I am not a foodie, and, when my wife and I go out, we have spent more than $50 on a single meal less than five times in our lives.

Bottom line

Alan Kelly has written an impressive book that I would love to share with food skeptics out there. I had a few quibbles with some of what he wrote, but too few to mention. I thought Future Foods by Julian McClements would not be suitable as a text for an introductory Food Science class as it drifts too far afield to providing a necessary background. Molecules, Microbes, and Meals, however, would be an ideal book to excite Food Science majors in the wonderful things they could do with a scientific understanding of food and the ingredients, whether added in a processing plant, restaurant or at home.

Understanding much of what he wrote requires some background in science. He jumps into many topics without much fundamental prefacing, assuming his readers know it, but the instructor of such an introductory class could link back to basic principles in the lectures. Kelly and McClements have provided us with a refreshing change in perspective in these two wonderful books. I hope to use their positive attitude to keep my resolution alive in the future direction of the blog—“to be less combative as I continue to defend processed food.”

Next week: A model food molecule: Sorbitol


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