Gifts of the Spices and Seasonings

Sadly, this is not a post about bacon, or bacon-flavored ice cream, for that matter. However bacon is a good segue into the science I AM going to toss your way and that is antimicrobials. Why do you think such a salty, blood-pressure destroying thing was invented (without knowing how delicious it would be)? Salt-cured meats are HIGHLY resistant to spoilage via microbes and fungi. The salty environment sucks moisture from microbial and fungal cells, making them so hypertonic (thirsty and shriveled) they die.

Yet salt is not the only antimicrobial seasoning out there. In hot, tropical climates, a lot of salty food is a very bad idea unless you enjoy severe dehydration. Instead, hot, tropical cooks employ various spices containing compounds that naturally reduce spoilage by inhibiting the growth of bacteria, yeasts and mold. Now for some anthropology/microbiology crossover action: a study examining the use of 43 different spices in meat-based dishes from 36 different studies found that the higher the average annual temperature, the more spices were used in individual recipes. In addition, recipes of total studied used more spices and the more of the most potently antimicrobial spices (Billing and Sherman, 1998). But wait! There’s more…Not only can spices keep your food germ-free, but they keep you healthy too. Cinnamon alone helps with cholesterol and bloodsugar management, while garlic and onion (a vegetable, but often used as a seasoning) are excellent for lowering blood pressure and warding off vampires.

More microbe mauling spices include allspice, clove, oregano and various peppers. As well as sage, rosemary and thyme. Haven’t found anything scientific supporting parsley though.

Tomorrow I plan on exploring the compounds that help these spices work these wonders. But right now it’s sunny in Seattle and I need to enjoy this while it lasts.

 

Sources

Billing, J and PW Sherman. 1998. Antimicrobial functions of spices: why some like it hot. Quarterly Review of Biology 73(1):3-49.

Snyder, P. 1997. Antimicrobial Effects of Spices and herbs. Retrieved March 25, 2013, from Hospitality Institute of Technology and Management, St.Paul, Minnesota Website: http://www.hi-tm.com/Documents/Spices.html.

 

Bonus points if you got the song I attempted to reference.

Foraging for Pizza

Last night I had crabs. Rather, I had crab legs. A lot of them. They were buttery and delicious and I promptly fell asleep after. But as my mom, dad and I struggled with extracting every last crabby morsel, I had to wonder how many calories I was losing just to get the ones hiding in the end of my crab leg (Yes, I actually wondered that, I can’t make up how nerdy I am). This is actually an important question in the wild; how to maximize one’s caloric intake with a food item while minimizing the calories and time lost obtaining and handling said item. Biologists call this optimum foraging.

Optimum foraging is based on the hypothesis that natural selection has driven animals to evolve foraging habits that maximize caloric gain per unit time. The factors driving these habits include environment, prey type (right now I will include plants as “prey”, considering those require handling and obtaining as well), availability of prey and anti-predator defenses of prey (armor, toxins, etc). These influence hunting/gathering time, as well as handling time (the time it takes to eat the thing). If it takes time, it will take effort, as a result, a prey item that takes a long time to obtain/handle or takes a lot of effort, better have a high caloric content. That is, it had better be worth it. There is an actual equation (for you math-heads out there) for calculating energy gain per unit time from a given prey item as equal to number of prey encountered (per unit time), multiplied by caloric gain and minus energy, with all that divided by one plus number of prey encountered times handling time.

How about a translation? Let’s say I only eat pizza. Because optimal foraging applies more for specialists (will explain more on that shortly), let’s say I don’t just order pizza, I have to catch the delivery boy and somehow wrest the pizza from his grasp. So we have these wandering delivery boys, and there are a lot of them carrying only one pizza, but a few are carrying 3 or 4 pizzas. Because I’m a crazed, pizza-eating fiend, I do not have a calculator to work out the math of which delivery boy would be more advantageous to chase. I rely on experience, and experience tells me that the delivery boys with one pizza are very fast, but they aren’t any faster than those with four pizzas and I have to catch a lot more of them before I’m full. My pizza-crazy mind can then conclude that it is much more worthwhile to pursue the fewer, but more pizza-laden, delivery boys.

Now, let’s say those multi-pizza delivery boys start carrying their pizza in wooden boxes (it’s weird, I know, work with me here!). They are now a little slower, but I have significantly more trouble in handling my pizza. As in real life, if you have a difficult prey item that is not absolutely impossible to deal with, natural selection starts favoring animals even a little more adapted to dealing with that prey. Those animals survive and reproduce better as a result and, many (manymanymany) generations later, you have a species adapted to catching and eating that prey item. That species is a specialist; they specialize with one particular prey item. Generalists are much less picky. They evolve foraging habits that maximize caloric intake with a broader category of prey item (like carnivores with live prey, scavengers with dead prey, frugivores with fruit prey, etc). So in the case of pizza-fiend me, I may not do so well with my armored pizza, but if I have any kids with bigger teeth or sharper nails, they will be better adapted and will eventually lead to a species particularly adapted to getting pizza out of wooden boxes. And they will be optimal foragers and I will be such a proud (greatgreatgreatgreat) grandparent.

 

 

On an unrelated note, I was going to ignore the fact I missed a post yesterday, but this is as good a time as any to bring up the fact that I will be reducing my blog updates to five times a week. Unforgiveable, I know, but this will allow for unexpected busy-ness and crab boils.

 

Source

Bohn, K.M. 2011. “Optimal Foraging”. Ecology. Whitman College. Walla Walla, WA.