Mg In En Pm

MG in Copenhagen (Thorvald Pedersen) Now let me come to my own credentials as far as Molecular Gastronomy is concerned. They fall in two parts primarily distinguished by their target groups and the corresponding appropriate wordings: Monthly articles (some 130 since 1988) in the periodical Dansk Kemi (Danish Chemistry), together with numerous underlying experiments in the kitchen and/or the lab. - I have two protocols from the time in the mid-nineties when I experimented with bread-baking. [86 of the articles covering 1988-1999 were published as a book in 2000]. The target group consists of chemists. They are fellow chemists interested in food on an amateur basis, chemistry teachers in high school and in other schools. My most recent book "Kemien bag gastronomien" (The Chemistry of Gastronomy, published in 2002, henceforth abbreviated to CoG) came about because another publisher asked me if I would be willing and able to write a textbook meant for a broader audience. I was willing enough but was I able? I was close to giving up on the project in 2001, but the publisher got me over a hurdle. The target group covered by the term "broader audience" covers people seriously if not necessarily professionally interested in cooking. I do not see the food industry in the target group. Their problems are of a different nature than the topics dealt with in the book and is properly dealt with in "Food Chemistry" which is already strongly represented at this university. I think the book qualifies as a Molecular Gastronomy textbook. It is in many ways similar to Peter Barhams book "The Science of Cooking", which came a year before mine - and there has been no cheating. Peter being a physicist has the point of view of a physicist while I have the point of view of a chemist. The level of the two books is comparable, except that my book has a technical lexicon at the end for the benefit of readers with some chemical background Please have another look at the definition of MG that I came up with in the programme after having found the definition of "Gastronomy" in "The Oxford Learned Dictionary": Art and science of choosing, preparing and eating good food. I did not choose a definition in English just because we were going to speak English today. I chose it because I was unable to find a similarly succinct definition in Danish Encyclopediae nor in the Danish Lexicon of Gastronomy ("Gastrolex") published by the Danish Academy of Gastronomy. In the Danish sources the word "science" (its Danish equivalent being "videnskab") simply does not occur. I must say about the "Gastrolex" though that it does a good job in explaining that gastronomy has become

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more democratic, it is no longer concerned with "the food and eating of the rich and powerful" but more with "quality eating" in general. I shall now consider the three components of the definition separately in the light of my own writings i A&S of choosing, ii A&S of preparing iii A&S of eating good food In CoG - my book - I devote 9 chapters to the raw materials we use in the kitchen. The first is about Bread-baking. i A&S of choosing, What we have to choose is primarily the flour and the leavening agent. So what are the scientific aspects of choosing flour, and are there relevant molecular aspects to address in this connection? Of science in general there is the biological/anatomical aspects of the various grains. To molecular science belongs the properties of the protein part of wheat in particular. Wheat has the potential for the formation leavened breads because it contains the so-called gluten forming proteins gliadin and glutenin, so for the subsequent leavening to be successful we should go for so-called "strong" flours. In Denmark the choice is limited. The COOP chain sells a Safir EXTRA wheat flour for bread baking. It has a higher gluten protein content than ordinary flour. The stated content is 12% protein due to the mixing of foreign wheat into Danish (where normal all-purpose flour has 8%?? the percentage in Danish wheat). It would be desirable if we could be informed about the nature of the protein. Why not have a booklet available with more MG-information? Should the flour be organic? "Organic" or not has no influence on the baking properties except that if is Danish organic then the gluten proteins are present in smaller proportion. If you can get it straight out of the mill the flour is fresher but its taste degrades faster because it usually contains unsaturated fat from the germ which is removed in commercial Danish flours. The mentioned flour contains E300 “flour improving agent”. E300 is ascorbic acid (Vitamin C) and it improves the raising capability of the flour (I discuss the mechanism later on). If it was not there I would add half a tablet of vitamin C to the dough for a 1,6 kg loaf (1 kg flour). Choosing leavening agent is most often the choice between yeast - which is pure Saccharomyses cerevisia or sour dough. Sour dough is prepared by letting a batter go sour. It is by nature not pure because a number of sour-tolerant yeasts and bacteria – mostly Lactobacillus species – present on the flour particles act at the same time. The sour therefore will be different from time to time, which you can either consider a

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charm or a nuisance. To make systematic experiments (as I did) my choice would be yeast (and a big sack of flour to ensure that the flour would also be the same). Biga is much used in Italian bread-making. A biga is a fore-dough obtained by taking away up to 1/2 of a dough and adding flour and water to it next day. It is by nature sour if not quite as sour as a sour dough . The sour dough's give breads with a sour taste owing to lactic and acetic acid. Obviously the choosing involves craftsmanship (i.e. Arts) as well as science. When it comes to sour dough’s I will say that craftsmanship prevails. ii A&S of preparing I shall not bore you with all the well-known details about the baking of a loaf, but come directly to the most relevant MG-aspects. The raising of the dough proceeds by the consumption – by the yeast – of the fermentable sugars in the dough (mono- and disaccharides). The CO2 developed during this fermentation is trapped in the gluten network which can be seen as a network of glutenine strands where gliadin is “blocking the wholes in the network” This gluten complex is developed during the kneading and is strengthened in proportion to the energy put into the kneading (measurements of volume of the loaf as a function of the energy put into the kneading process measured as the time of kneading times the wattage of the kneading machine). The strength of the network depends on the properties of the proteins. All the common amino acids are present in the protein – notably glutamine which got its name from gluten – and cystein. 2 cystein molecules can couple among themselves (coupling strands together) to form cystine complexes. This leads to a stronger glutenin network. An enzyme called “glutathione” acts to split the cystin complexes as soon as the dough has been laid up. It acts like virus attac. Ascorbic acid – the additive I mwn tioned above – acts by preventing this process through inactivating the glutathione. The bubbles form primarily by CO2 seeping into air-bubbles already present due to air becoming incorporated during the kneading – much air entailing smaller bubbles in the loaf. After the first raising the loaf is deflated. This leads to a certain redistribution of the nutrients (sugars) and a fresh start for the yeast. Aroma formation depends on the total raising time (over-night, socalled long-time raising under cold storage is beneficial in this regard). A steaming of the loaf in the beginning of the baking improves the final crust by pasting the starch grains in the surface. The colour of the final crust is formed by a mix of caramelization and Maillard reactions. This colour formation takes place at 150 C and above.

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I shall consider the eating/tasting aspects (iii A&S of eating) in more general terms below, so let me proceed to one more example, which is taken from another of the 9 chapters, namely the chapters (12) “Fruit, vegetables and spices” and (20) about the same topic but containing recipes relating to (12) The choice of item is usually dictated by the recipe and is on the whole an Arts-exercise like how do you feel whether the avocado is ready or not, or the pineapple. Potatoes are a little bit tricky since you might either want them “waxy” or “mealy” – we do not even have Danish words for these concepts which tells you whether or not the potato is good for mashing or baking or should just be cooked. On the whole the information level is low on potatoes in Denmark! So let me come to a number of examples of ii A&S of preparing, concentrating again on the MG-aspects. I shall start from the recipe and spell out the comments given for each in recipe. Green asparagus after Shirley Corriher Boumiano after Jane Grigson Chou rouge à la Limousine after Julia Child Olie med krydderurter (Spiced oils) Sorbetta di Mela Verde after Marcella Hazan

Finally let me now return to iii A&S of eating good food from a general point of view. I devote (Ch. 6, 25 pages) of CoG – the book – to the sensory aspects of foods. Let me begin with a quotation from Coultates “Food – The Chemistry of its components” “However much nutritionists and ‘health food’ enthusiasts may wish otherwise, it is the flavour and appearance of food rather than its vitamin contents that win the compliments at the dinner table” From this quotation I pick the word “flavour”, which I want to dwell upon for while. In modern sensory science flavour is taken to encompass 1) taste, 2) smell 3) trigeminal impressions.

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Only the third category needs a little explanation. Most relevantly in the tongue we find the nerve endings of the trigeminal nerve. (But also in the eye-region and around the lips). It transmits pain-like impressions like those stemming from hot things – including hot chilies, cold things – including peppermint, fractured things – like crystals in an ice or the crisp crust of the newly baked bread etc. and transmits them to the brain directly (i.e. outside the nerves transmitting taste and smell information). It is becoming more and more acknowledged that flavour is the key concept in connection with tasting. When I recently visited The Fat Duck (Blumenthals 3-star restaurant in Bray near London) I heard for the first time about his “Flavour-pairing principle” which he used as his guide when composing new combinations of ingredients. To take one example. I was served the odd combination of a “Pommery mustard grain ice cream with a read cabbage gazpacho”. Apart from the very appetizing appearance of a yellowish ice-cream with small spots of mustard there was this very intensely violet gazpacho one could not avoid asking: “What is going on here, why this unusual combination”. I was told by Blumenthal that it was based on his Flavour profile-pairing principle. The ingredients that tend to dominate the taste impression are called “mustard oils” because they were first located in mustard. They are abundant in all crucifera-species, cabbage being one example. (Anders Kjær – a Danish chemist, who is still alive at 85 – found many of these mustard oils. They share a sharp (Trigeminal!) flavour. Similar reasoning led him to pair Iranian caviar with white chocolate – which were also on my menu. Sensory scientists are becoming increasingly interested in the processes taking place in the brain upon eating and use NMR-scanning (fMRI) and other neurophysiological methods to investigate them. It turns out that a surprisingly large number of areas in the human brain are activated when we eat. Smell, taste and trigeminal stimulation all have separate areas devoted to represent what we perceive. At higher levels in the brain (f.ex. the socalled orbitofrontal cortex), information from the different sensory systems come together and activity in these areas represent affective properties of what we eat, i.e. whether we like a food or not. Hedonic properties of foods seem to be extracted separately from the more basic sensations eating gives rise to. A better understanding of the basic processes in the brain responsible for the different sensations and hedonic experiences have great applicability in gastronomical composition. The representations of preferences for foods are highly influenced by whether we are hungry and drive motivation to eat more of the same or another kind of food or whether the meal is terminated. The use of these modern, objective, methods will lead to a better understanding of food choice in terms of basic neurobiological processes and will also contribute to establish relationships between sensory properties of foods and nutritional processes in the brain and the gastrointestinal system.

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Work in this area has demonstrated how appetitive and other nutritional processes are closely intertwined with sensory and hedonic properties of foods. A separation of eating behaviour into purely ‘nutritive’ aspects and purely hedonic rewards is misguided and will not bring much understanding of normal eating behaviour. This is not to claim that modern sensory physiological techniques (fMRI and other) cannot be used to investigate in a rational way, gastronomical systems and guidelines like Blumenthal’s “Flavour profile-pairing principle”. A close collaboration between gastronomers and sensory physiologists will probably produce much new knowledge which will benefit both the hedonic aspects of eating as well as the more healthrelated ones. ------------------------------------------------------------------------------------

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