I’ve now finished reading Taste by Barb Stuckey, and still have ‘issues’ with parts of it.
I realize this is off-topic for the Michelin thread, but will respond here, which is where this was raised, but if we continue to discuss, this probably deserves a separate thread.
I DID like the parts where the influence of other senses and experiences were discussed. I mostly agree that history, culture and previous experiences can influence ‘taste’.
But there are several themes that occur throughout the book that I question. I did try and follow up some of the references (she includes hundreds, but only by chapter, not ‘specific detail’ within the chapter).
I have no issue with the ‘science of taste’ – it is fairly (and accurately) presented. But looking back over the past couple of years I will draw a parallel:
The ‘science’ of COVID was available to all - everybody was looking at the same ‘science’. However different jurisdictions came to different ‘conclusions’ – some said a second vaccination dose should be a month later; some 6 months later. Some advised double doses of the same vaccine; some allowed mixing. Different age restrictions were applied by different jurisdictions. My point is that ‘even if the science is identical, the conclusions drawn can be very different’. And my contention is that the conclusions in the book are suspect.
I’ll raise my most serious questions.
First and foremost, the stated assumption that 10% of the sense is taste and 90% is smell (in the Introduction) is really problematic, although I can’t find any specific reference in the listed References. This assumption is carried throughout the book.
Rather than list multiple issues I’ll just reference the following (admittedly published after the book)
The abstract
“It is frequently asserted that somewhere between 75 and 95 % of what we commonly think of as taste actually comes from the sense of smell. However, empirical evidence in support of such a precise-sounding quantitative claim is rarely, if ever, cited. Indeed, a closer look at the study that appears to have given rise to statements of this general type simply does not support the claim as made. “
In further support of my criticism, I refer to the table on Page 59 which summarizes which nerves are involved in Taste and Smell. There is a single olfactory nerve in the bridge of the nose (which transmits smell - at least a thousand …odors). And there are THREE nerves in the mouth (Trigeminal, Chorda Tympani, Glossopharyngeal) which, between them, only send five tastes to the brain. If we believe in Evolutionary Theory, it makes no sense that 1 nerve in modern humans can transmit a thousand different things, yet three nerves together can only transmit five. (I speculate that there are multiple taste sensations we have not yet ‘separately identified’ – except we really have identified them as I hope to show in my second point).
My second point is an amplification of my original questioning of ‘supertaster’ and ‘bitter’ – using the information in the book. Oversimplifying, a ‘Supertaster’ (the name is irrelevant, the author prefers Hypertaster – but the concept is used throughout the book) is particularly sensitive to bitter taste as represented by a chemical known as PROP (6 – n-propylthiouracil). Being able to taste this is (or not) is totally related to genetics and there are many studies on this. My interest in this topic was stimulated over 30 years ago when I discovered I was unable to taste a similar compound (PTC) but PROP is currently used in most experiments. Accordingly, I have been following this erratically but not keeping references as most studies are specifically genetic.
But, returning to taste, I note that the author describes work on developing products that ‘do not taste bitter’ (my paraphrase). On page 273 she discusses being able to ‘block’ bitter receptors and uses products produced by a company called IFF. They produce “different masking flavors to block different sources of bitterness” (exact quote). Logic (?) tells me that if there are multiple masking flavors to block different sources of bitterness – then there must be more than one kind of bitterness – yet the book insists that ‘bitter’ is a single taste. That despite the discussion of bitter (Chapter 9) which states “Humans have only one or two taste receptors for sweet but dozens of taste receptors for bitter” (ASIDE: The actual number is at least 25 – these are known as T2R receptors and are well documented in genetic science. To be fair, the author describes these as ‘different compounds’ and asserts that they all taste ‘bitter’]
Summarizing, my assertion is that there are 25 ‘different bitter tastes’, only one of which can be identified using PROP. Thus, I totally reject the ‘5-taste types’ theory – although I have no idea how many more have yet to be identified as separate ‘tastes’.
