On Saturday 02 July 2005 21:30, Pat Naughtin wrote: > Dear Pierre, > > I have renamed this thread and interspersed some remarks. > > on 2005-07-03 06.26, Pierre Abbat at [EMAIL PROTECTED] wrote: > > While metricating someone's food calculations, > > When you say 'metricating' do you mean changing old pre-metric measures > into metric units? > > When you do this which metric units are you aiming for? As I understand > history there were 5 or 6 different metric systems (with names such as cgs, > mks, mksA, etc.) before all of these were incorporated into the > International System of Units (SI) in 1960. There is now only one metric > system.
The original calculations start with yield in bushels per acre, pounds per acre, and even non-units such as cartons per acre, and end up with how many square feet she plants in each crop. I converted them to kilograms per hectare with the result in square meters. Most of them she and I then took the square root of. For some the end result is a number of plants. I'm not going to post it to the list now, as I'm not finished and she hasn't checked it. > I have not heard the term 'burnworth' before. I have used 'energy content' > and 'energy value'; of these I prefer 'energy content'. When I have changed > the units to SI units I do not then seek to change them into one or other > of the old metric systems as you have done here I just leave them in SI. > In this case I would not change 37 kilojoules per gram or 16 kJ/g any > further (although some purists might insist that I use 37 MJ/kg and 16 > MJ/kg because kilogram is the base unit in SI) It's a calque of German "Brennwert". I converted it to kcal/g because that's what I've heard, but now that I know it's 37 kJ/g I'll use that. > Here is a reasonable set of approximations, but be aware that not all fatty > acids and not all carbohydrates provide the same amount of energy The > dietary fibre can be a bit tricky too as it depends on whether the fibres > are broken down by bacteria in your large intestine. > > Fat - 37 kJ/g > Alcohol - 29 kJ/g > Carbohydrates - 16 kJ/g > Protein - 17 kJ/g > Dietary fibre - 13 kJ/g > Water - 0 kJ/g > > > As to the blueberries, do any of you know how many grams of blueberries > > (or any other cowberry - it shouldn't be much different) it takes to make > > a kilogram, or a liter, of jam? > > Looking over a range of jam recipes, it seems to me that jams are usually > about half fruit and half sugar with sometimes a little water added to dry > fruits and a little citrus added for pectin to help with setting (and to > add a little flavor). So if you have 500 grams of blueberries you should > add 500 grams of sugar and after boiling away some of the water this will > yield a little under a kilogram of jam. The yield will also be just under > one litre so you will probably 'fill' 5 x 200 mL jars to just below the > brim. > > Here's a good recipe to get you started. > > http://www.inmamaskitchen.com/RECIPES/RECIPES/Basics/jms_preserves/jam_berry.html I found http://www.waitrose.com/food_drink/recipes/recipesearch/Recipe/0207072-r02.asp , and it sounded reasonable when I substituted the figures in her calculations. The jam is the minor part of her blueberry usage, and I ended up with five bushes as she did. phma -- My monthly periods happen once per year. -Les Perles de la médecine
