The science of smell and food preference

Have you ever wondered why you like certain foods, and dislike others? Or why you think some recipes are inedible while others seem to enjoy the taste? Baring the cultural aspect,  a lot of it comes down to how you perceive the smell of the foods.

All of us, at some point, have disagreed on what a particular food tastes or smells like (think coriander, durian, wine). And while you might think that the other person might be mistaken or have a poorly developed sense of smell, sensory scientists at The New Zealand Institute for Plant & Food Research have dissected some of the genetics behind flavour preferences and shown that we all live in our own unique world when it comes to odour perception.

A pair of studies published by Sara Jaeger, Jeremy McRae, Richard Newcomb and colleagues published in an August edition of journal Current Biology identified the genetic variations that underpin the differences in smell sensitivity and perception between individuals, which explain some of the reasons why people appear to have ‘blind spots’ in their tasting abilities. Continue reading

Eat like it’s 2,000,000 BC? Maybe not…

Lately I’ve been reading snippets of a new way of eating which seems to be the next big thing. The Paleo Diet states that we should eat the types of foods our hunter-gatherer ancestors survived on for millions of years. It also suggests that many modern illnesses (e.g. diabetes, cancers, cardiovascular disease, but even acne, depression and myopia!) are symptomatic of our bodies’ inability to cope with the modern diet of dairy, high carbs, alcohol and processed foods.

The Paleo Diet allows meats (including game and seafood), low carb vegetables, oils, nuts and fruit. It cuts out dairy, grains, fruit juices, starchy vegetables, legumes (includes soy products), alcohol and all processed foods (goodbye tomato sauce, chips and candy).

On the surface, the hype seems to make sense. The main argument hinges on the fact that agriculture is a reasonably late arrival to the evolutionary timeline; humans have only cultivated the land for the last 10,000 years. A blip in the human evolutionary timeline when you consider that the earliest hominids, Australopithecus roamed the earth nearly 4 million years ago.

I wanted to get some hard science to cut through all these hype. Paleofantasy by Marlene Zuk, a Professor of Ecology, Evolution and Behavior at the University of Minnesota, uses science to debunk the myth that our ideal modern lifestyle should mimic Pleistocene human adaptation. Prof Zuk also looks at the misunderstandings around social interactions, medical and daily activity, but I was predominantly interested in how our diet has evolved. Continue reading

Storing tomatoes – the flavour issue

Many of us purchase tomatoes from the supermarket or greengrocer, take them home and promptly shove them in the refrigerator without a second thought. Recently, a postharvest scientist told me that you should listen to your grandmother when she said to store your tomatoes at room temperature (mine didn’t cook with tomatoes or had a refrigerator for a very long time, so that point is moot). It may surprise you that all horticultural services state that you should never store tomatoes in the fridge. It certainly surprised me.

Tomatoes are sensitive to chilling, and low temperatures will destroy both the flavour and texture of ripe tomatoes.

Horticulture NZ advises that tomatoes should be stored at around 10-12°C, never in the fridge and away from sunlight. BUT, this is somewhat different from the scientific literature, which says to never store tomatoes below 13°C, or even 15°C. Continue reading