A fishy story

Writing this sent me down memory lane of my childhood neighborhood. In addition, I checked some of the distances on Goggle maps because I remember everything being much further away as I was a particularly small child. Some background might be helpful.

I grew up in Birmingham (England for my oh-so-amusing American friends who have said “you don’t sound like you are from Alabama”) in a suburb called Selly Park, which in my mind is part of Selly Oak . Selly Park was “posh”, Selly Oak was more lower class and industrial. I have no idea what either are like now.

A couple of days ago, I was reading this article from the Guardian, which bought back some great food memories. My mum was a health nut before there were health nuts or more likely before I knew there were health nuts. She refused to eat parsnips and black pepper for years because she heard they caused cancer. She ate whole wheat bread at the time that white sliced bread was the best thing ever and whole wheat bread was chewy and tough and essentially indigestible. She didn’t like chocolate.

One time I was being a brat about eating fish, I demanded fish fingers instead of the fresh fillets that she usually cooked. I didn’t want the fresh fish that mum had almost definitely got from the Birmingham fish market which was in the city center or Town as we called it. My parents didn’t drive so getting fish required her walking to the bus stop about 7 mins from our house and a 20 min bus ride into town, followed by a 10 min walk to the market. I’m sure she bought other stuff when there; if I was with her there were prawns in a little bag to keep me quiet. After buying fish she probably stopped at the Bullring market for fruit and veg, probably with me whining as I hated the market then, it was busy and noisy and I was terrified of losing mum [I was a very small child, remember]. Then she/we returned home. If she was carrying a lot she might get a taxi. Lacking a car meant we used lots of taxis.

If she didn’t go into Town she might walk up to the shops in Selly Oak that were 10 min away and she would stop at the greengrocer, the butcher, and the baker to get our different food supplies. Oh, and the shops were closed Wednesday afternoon and Sunday and probably all closed by 5:30 every day and earlier on Saturdays and she worked full-time after I was about 9 years old. I don’t remember when the first supermarket came to Birmingham. The first I remember was a Sainsbury’s in Northfield that must have opened around 1975ish. Northfield was south of us away from Town so we didn’t go there very often, as Town was more exciting. I remember Sainsbury’s have so much choice and they pumped out bakery smells into the shopping center. (In a fit of honesty, I should point out, because my brother will if I don’t, as we got older and independent it is was more likely that my brother and, once he left home myself, buying the food in Town. Actually dad might have bought the food before we did. So while mum had it tough, she gladly gave up her responsibilities for food shopping as soon as she could.)

So I refused those delicious cod or plaice fillets she had made such an effort to buy and demanded fish fingers. Her solution was to hand-make fish fingers, because she didn’t have enough to do all ready. I was really disappointed. Truly all I was hoping for the bright orange coated Bird’s Eye fish fingers that I got at friend’s house. That was real food!

 

Food Ways: Sea biscuits

OLDEST SHIP BISCUIT. This specimen appears at the Maritime Museum in Kronborg Castle, Elsinore, Denmark. The biscuit dates from 1852. Image: Paul A. Cziko (https://en.wikipedia.org/wiki/Hardtack#/media/File:Oldest_ship_biscuit_Kronborg_DK_cropped.jpg)

It has been an interesting journey doing the research on sea biscuits and I am sure there is more information I haven’t found doing a quick internet search. Sea biscuits are the Navy’s equivalent of hardtack, which is a relatively new comer as it was named by the 19th Century American army. Given the simple recipe (mix flour and salt with water to make a dough, roll out into patties, bake in a medium oven for 30 min at least twice) these biscuits were probably around in prehistoric times and still surviving in some hidden cave somewhere. These biscuits last longer than flour as they have a lower moisture content and water activity. One disadvantage is that sea biscuits will absorb moisture if the humidity increases. This was a problem when Royal Navy ships first traveled in the tropics.

When I travel, even on short journeys, I am in the habit of carrying some food and water with me. Travel delays on trains and planes have been part of my travel experience and I prefer to know I have food rather than hope I can buy something if necessary.  Travelers need food that has a long shelf-life, is robust, safe to eat, and calorie/nutrient dense. Many travelers’ food is dried as removing the moisture  extends the shelf life by essentially making the food inedible to bacteria. While removing water has the advantage of stopping bacterial growth, it doesn’t always give us a food that is robust and could stand up to the rigors of travel. There have been a number of times I have reached into my rucksack for a cookie/biscuit and found crumbs. Not the snack I was hoping for!

The sea biscuit has more in common with Terry Pratchett’s Dwarf’s rock cakes than any modern cookie or cracker. So robust that, typically sea biscuits need to soaked overnight or smashed with a hammer or rock to able to eat it. Sea biscuits are the original cracker that was crumbled into New England chowder, probably because that was the only way the biscuits could be eaten. The British navy used to bake/dry their biscuits 4 times. So if you think biscotti are hard to eat without dunking, double the force needed to bite into a sea biscuit and book that trip to a dentist to replace your teeth. They were so hard that apparently an American civil war soldier wrote a letter on the side of a hardtack and mailed it with the address on the other side and it survived in the mail without any protection. No wonder British soldiers were envious of American food rations in World War 2.

In the process of making sea biscuits you knead the flour and water together. This allows for gluten formation and most of the recipes have a 2:1 ratio of flour to water which is perfect for gluten formation. Gluten is the protein that gives bread its springy texture and the network of gluten stays in place once heating is complete which means that bread keeps its structure after baking. While soft bread goes stale very quickly due to the retrogradation of starch, the starch in hardtack is probably all retrograded before leaving the oven. An interesting question would be to find out how much starch granules hydrate and swell in making of sea biscuits. Is enough for the starch molecules to gelatinize? Perhaps the water is removed too quickly for gelation and retrogradation occurs very quickly with little rearrangement of the starch molecules. (Confused – see my post on starch here!)

If you want to make your own sea biscuits there are lots of recipes online due to reenactors and survivalists wanting a food that is traditional and/or last a long time. They are also popular in Hawai’i and Alaska. Personally I would prefer water biscuits or Scottish oatcakes carefully wrapped than a food that is hard to eat. Trail mix would be more desirable still. However, if a zombie apocalypse is ever threatened, I know what I could bake to help my long term survival.

References

All references visited on 29 January 2018

1. https://en.wikipedia.org/wiki/Hardtack background
2. https://www.wikihow.com/Make-Hardtack recipes
3. http://www.survivalnewsonline.com/index.php/2012/02/hardtack-a-great-survival-food-stock/ recipe
4. http://cookit.e2bn.org/historycookbook/904-hardtack-ships-biscuits.html recipe
5. http://www.gone-ta-pott.com/hard_tack_sea_biscuits.html recipe and history
6. https://youtu.be/FyjcJUGuFVg video, history and recipe
7. https://reclaimingtheloaf.wordpress.com/2012/03/01/biscuits/ history
8. http://www.foodtimeline.org/foodcookies.html#shipsbiscuit and http://www.foodtimeline.org/foodcookies.html#hardtack history
9. http://www.menshealth-questions.net/royalnavalmuseum.org/info_sheet_ship_biscuit.htm history
10. http://militaryhistorynow.com/2014/07/11/hard-to-swallow-a-brief-history-of-hardtack-and-ships-biscuit-2/ history
11. https://www.rmg.co.uk/discover/explore/ships-biscuit history
12. http://www.janeausten.co.uk/ships-biscuit/ history

 

Tasty Tuesday: With Less Salt

Eat less salt

NEJM article on salt reduction

Tasty Tuesday: Food Rules

Michael Pollan has a new book which gives the rules (guidelines) towards health eating.  My copy is on its way from Amazon and I’ll let you know what I think when I’ve read it.  In the meantime here is an interview from the Daily Show,  links to an article in the YT, to an interview at SlashFood and to an excerpt of the book at ABCnews.

(Hat-tip: Thanks to colleagues RG and RR for the original link.)

BTW, Tropicana Trop50 is disgusting, unfortunately proving Michael Pollan’s point about food manufacturing.  Once my current carton is gone, I’m sticking to straight orange juice.  If I want less sugar, I’ll dilute it.

Tasty Tuesday: Sugar Chemistry

I really should just sent you to Exploratorium which has an excellent section on sugar chemistry, but sugar chemistry is so cool, that I have share it with you myself.  In fact sugar chemistry is so interesting that it supports a whole sector of the food industry.  I am, of course, talking about candy.  Food Scientists typically divide the candy industry into chocolate and non-chocolate candy and most of the non-chocolate candy is made from different forms of sucrose.

If you remember sugar is the common name for sucrose, which has the very confusing chemical name of β-D-fructofuranosyl-α-D-glucopyranoside which is a fancy way of saying that it is made up of glucose and fructose.  In this post, I will interchange the words sugar and sucrose, but in chemistry sugar refers to saccharides which  are considered to be small carbohydrates.

The most important property of sucrose is its high solubility over a wide temperature range.  The different sugar candies are made by heating a sugar-water solution, as the heating time increases water evaporates.  This increases the sugar concentration and the temperature of the solution increases.  The temperature of the solution is dependent on sugar concentration:

Effect of Sucrose Concentration on Temperature

Candy technologists not only control the sugar concentration by heating the sugar-water mixture to a predetermined temperature, they also control the final physical arrangement of the sugar molecules by the other ingredients added and by the way they treat the sugar-water mixture while it is cooling. This determines whether the solution sets in a crystalline form or not.  The non-crystalline form is also known as amorphous.  Thus sugar candies are divided into crystalline and amorphous.

Crystalline candies include fudges, fondant and rock candies. Amorphous candies include cotton candy, hard candy and brittles, where the sucrose has been set into a glass, and caramel and taffy, which are chewy rather than hard.

References

For Figure:

Wikipedia Candy#Sugar Stages

Harold McGee On Food and Cooking 2nd Edition p681

Non-Enzymatic Browning Introduction 2

Food tastes best when browned.

Food in always complex unless you are studying something quite simple such as a beverage with few ingredients (vitamin water, anyone?).  Even sucrose has a complex chemistry, more of which I will share in a future post.  So individual NEB reactions cannot be isolated in food.  Quite often intermediates and products from one reaction become intermediates in another reaction, especially in the Maillard reaction. Thus, most food chemistry textbooks use Non-Enzymatic Browning (NEB) as synonymous with the Maillard reaction. However, the other NEB reaction cause browning in food without the use of enzymes.

Both caramelization and lipid oxidation cause browning in certain foods, i.e. sugar-based and fried foods, respectively. Ascorbic acid degradation is significant in food with a low pH (high acidity) especially in citrus juices.  The reaction of flavanoids is important in highly colored foods as the colorful anthocyanins degrade and lose their color.  The reaction of flavanoids may also be important in soy protein, but less because of a color change and more due to a lose of isoflavones.

NEB Intro Part 1

Tasty Tuesday: Raspberries

Raspberries

These look  delicious but they are still as hard as a rock. When they are ripe, I hope I get them before the birds do.  This is my first year for raspberries and I don’t know how greedy the birds will be.  Yeah, these are not meant to fruit their first year, but I couldn’t resist getting a few raspberries.

Raspberries must be my favorite berry, if not my favorite fruit.

Non Enzymatic Browning

My major interest in food chemistry is how food changes during processing and storage.  I am especially interested in how color changes take place.  The reactions I am interested in are called Non Enzymatic Browning reactions to differentiate them from the browning that occurs when you cut an apple or banana, which involves an enzyme.

Non enzymatic browning (NEB, non enzymic browning) reactions are the most important reactions in food, and, no, I am not biased.   Just image the aroma of melting chocolate, freshly baked bread or  a roasting leg of lamb, the golden color of a croissant, the dark amber color of a well brewed beer; caramels, toast.  These are all caused NEB reactions.

There are five different NEB reactions and I intend over the next few months to write about each of them:

1. Caramelization – browning of sugar, especially sucrose
2. Lipid Oxidation – the oxidation of fats and oils; including rancidity
3. Break down of flavonoids – highly c0lored compounds can also lose their color
4. Degradation of ascorbic acid (Vitamin C) – AsA is unstable even without oxygen
5. The Maillard Reaction –  reaction between carbonyl compounds and amino acids

Numbers (3) and (4) are not typically on a list of NEB reactions, but I did my thesis on ascorbic acid browning and it definitely goes brown without oxygen and without enzymes.  The degradation of flavonoids is one I have added and came to me in flash of inspiration when at a conference.  I am sharing it with you now, so this is new even though I had the idea three or four years ago.

More later…

Simple Sugars: Fructose, glucose and sucrose

Glucose, fructose, sucrose

Simple sugars are carbohydrates. Glucose and fructose are monosaccharides and sucrose is a disaccharide of the two combined with a bond.  Glucose and fructose have the same molecular formula (C₆H₁₂O₆) but glucose has a six member ring and fructose has a five member ring structure.

Fructose is known as the fruit sugar as its make source in the diet is fruits and vegetables. Honey is also a good source.

Glucose is known as grape sugar, blood sugar or corn sugar as these are its riches sources. Listed in food ingredients as dextrose.

Sucrose is the sugar we know as sugar or table sugar. Typically extracted as cane or beet sugar. If sucrose is treated with acid or heat, it hydrolyzes to form glucose and fructose.  This mixture of sucrose, glucose and fructose is also called invert sugar.

Nutritionally, these sugars are the same as they all provide 4 Cal/g. This is true for starch and other digestible carbohydrates too. Of the three sugars, fructose is the sweetest and glucose the least sweet, so typically less fructose can be used than table sugar (sucrose) – if sucrose has a sweetness of one, fructose is 1.7 and glucose 0.74

Fructose is more soluble than other sugars and hard to crystallize because it is more hygroscopic and holds onto water stronger than the others. This means that fructose can be used to extend the shelf life of baked products more than other sugars.

Wikipedia has lots information on sugars, including information on the three I am interested in fructose, glucose and sucrose.

Tasty Tuesday: Food Preservation Introduction – Reducing Moisture availability

The biggest problem with food is that it is unstable. Even relatively stable food products change over time. There are two ways in which these changes occur.

1. Internal changes to the chemical make up of food. A good example would be loss of vitamins
2. Spoilage caused by microorganisms. Moldy bread is a good example.

Preserving food has been going on for centuries. Without it humans would have been unlikely to stop being nomadic. By preserving food it allowed them to have a food supply throughout the seasons and not move to where there was fresh food growing. Later on, preserving food allowed for travel long distances where there was no certainty that fresh food existed, including off the planet.

Preserving food is essential a way to extend the shelf life of that food. Shelf-life to food scientists has a particular meaning representing when the food quality has deteriorated either from a sensory perspective or from a chemical perspective. Obviously, sometimes these are the same thing.

There are two ways in which to consider food preservation, how does food go bad and how can we stop it. How food deteriorates depends a lot on the particular food item. For example high moisture foods are more likely to have bacterial damage than low moisture foods. Living foods under changes after harvest; this includes the fact that fruit and vegetables continue to respire even after being picked and the fact that muscle protein changes after the slaughter process. I could write about all of these changes but that would be several posts long, if not unending.

More interesting is what do we do to preserve food and what changes does that cause to the food item. The commonest way to preserve food is to reduce the available moisture content, which is also known as the water activity.  Drying can be done by drying, salting, and making jams or jellies.  In the latter process, the food is preserved with large amounts of sugar. This reduces the water availability because sugar is hygroscopic and holds on to that water for itself. The fruit, and it typically is fruit that is preserved in this way, is also cooked which destroys enzyme activity, unfortunately degrade thermal unstable vitamins and softens the cell walls. For fruits high in pectin, softening the cell walls releases the gum which, when the jam is cool, sets. This gives jams and jellies their firm structure. Pectin can be added to fruit low in pectin so that the preserve sets. Even though this is a way of preserving, fruit that would normally last a week or two can now be kept up for a year, changes to the fruit preserves will take place during storage. Light colored jams will darken. Unsurprisingly, reduced sugar preserves are not a long lasting as regular preserves.

Dried fruits are common and drying is also used a lot for meat preservation. Drying or dehydration is the removal of moisture, the dryer the better as far as shelf life is concerned. There are many ways to dry foods, from sun drying to freeze-drying and spray drying. The latter two being more likely commercial methods, whereas heat drying and sun drying could be carried out at home. The method of drying alters the food in different ways. For example, freeze drying results in the formation of food products that are very little changed from the original – just without any moisture. As the new Strawberry pieces in cereals show – adding moisture back results in almost original fruit piece. Well, sort of. Spray drying, which is commonly used for liquids such as milk or juices, results in a fine powder.

Salting, smoking, and curing are mostly used for meat and fish. The addition of salt or smoke causes dehydration of cells through osmosis – the water moves out of cells into the salty surroundings. This causes the cells to die or become temporarily inactivated. This includes bacterial cells as well as food cells. Thus, bacteria cannot grow. However, the food itself is very different from fresh. We have got used to this as bacon, lox, kippers and ham are all treated in this way.

As you can see removal of available water does not have to occur by dehydration, other techniques such as adding salt or sugar have the same effect.

References:

1. Shephard, Sue Pickles, Potted and Canned
2. Bennion, Marion and Scheule, Barabar, Introductory Foods