Recipe Calculations

Susanne Westenbrink, RIVM, Netherlands

Mark Roe, Quadram Institute Bioscience

GCRF Workshop on Production, Management and Use of Food Composition Data to

support AFROFOODS

Pretoria, South Africa, 5-9 February 2018

Why do we need recipes in the databases?

• Impossible to analyse each food due to high costs

• Easy way to add foods e.g. needed for diet counselling and food consumption surveys

• Several variations possible e.g. • -porridge made with milk or water• -different cooking fats. • -recipes with and without salt

Recipe:

- Ingredients

- Amounts

- Description

Recipe Calculation Principle

European guidelines for recipe calculation published 2016

– Adopted for use by national authorities in Czech Republic, Norway

Calculation based on:

• the amount of ingredients used to prepare a food• nutrient composition of those ingredients• factors that consider changes in nutrient content during

preparation• Weight change during preparation (Yield factors)• Losses of nutrients during preparation (Retention factors)

How can we use the results?

1. Recipes to calculate composition of • Missing complex foods, such as cakes, soups, stews • Missing values e.g. vitamins and minerals in packaged foods

2. Recipes to calculate composition of cooked foods from raw (recipes with one or two ingredient(s) e.g. raw vegetable or pasta and water)

3. Averaged foods, e.g. citrus fruit not specified

Steps in recipe calculation

1. Collect recipes

2. Determine ingredient weights (take into account waste)

3. Calculate the recipe (use calculation programme)

a) Calculate the nutrient values b) Apply correction for effect of cooking (if applicable)c) Calculate back to 100 g of edible food

4. Document details of the recipe (including reference)

Collect recipes

• Selecting of recipes always depends on the goal!

• Should the collected recipes represent • the dishes eaten by whole population?

• How variable is an ‘everyday’ recipe?• dishes eaten by specific sub-groups e.g. children, ethnic

groups?

How to define commonly consumed dishes?

• Use sales statistics• market leading restaurants, fast food, take-aways or catering companies collection of menus

• market leading manufacturers or distributors of ready-to-eat dishes collection of labels and recipe leaflets

• most sold ready-to-eat dishes (brands)

• Use data from food consumption surveys• dishes most frequently consumed• visit homes and see cooking process

• Use popular cookbooks, magazines, recipe archives on internet• find out the most frequently published recipes

Details of the recipe to document:

• Ingredients (common names, scientific names, photos, food id)

• Preparation before cooking (e.g. peeling, cutting)

• Household measures and edible weights per ingredients (use scale!)

• Cooking method plus cooking time and temperature

• Weight of the final dish (use scale!)

• Source of the recipe (e.g. name of book, URL etc)

• Retention and yield factors

• Edible portions

• Recipe calculation method

• Recipe calculation software

• Nutrient values

Recipe archive

• Keep copies of the recipe • paper or pdf • FCDB

• Also keep older versions

Now you have a representative recipe...

• Omelette

• 4 eggs

• 1 tomato

• Half a cup of tap water

• 1 spoon of butter

• 0.5 tsp table salt

What do you do next?

Select food items from food comp table

• Find the best matching food item in your food composition table

• For example

• Flour: white or whole meal?

• Spinach: raw or frozen?

• Oil: which type of oil?

• Tuna: fresh, canned in oil, canned in water?

• Expert view needed based on food consumption data, national traditions, cooking experience

Ingredient 2uncooked

Ingredient 1uncooked

Edible portion

Yield factorWeight of

cooked composite food

Retention factor

Nutrient content of uncooked

ingredients

Nutrient content of

cooked composite

food

Edible portion

Example. What is the weight of one egg without eggshell?

• Usually expressed as % of the whole food

• Where to find information about edible portions?• Field work: weigh the edible and inedible portions of ingredient• From reports• Cook books• Food composition tables

• It is recommended to use national coefficients for edible portions!

Edible portion = edible material remaining after the inedible waste (bones, stones, peel etc.) has been trimmed away.

What is edible or inedible?

• Depends on cultural norms, individual preferences and animal species

• Are the skin and head of fish edible or inedible?

• Similar situation for meat cuts, insects, some plants

Determine edible portion

• Convert household units to gram weights

• 1 egg without shell 55 g

• 1 cup of flour 80 g

• If ingredient has inedible waste:

• Banana weighed with skin = 200 g

• Edible portion = 66%

200 g * 0.66 = 132 g banana without skin

Ingredient 2uncooked

Ingredient 1uncooked

Edible portion

Yield factorWeight of

cooked composite food

Retention factor

Nutrient content of uncooked

ingredients

Nutrient content of

cooked composite

food

Yield factor

Yield factor:

• Term is used for what is retained in weight after food preparation, processing or other treatment. Weight change is a result of moisture (e.g. water) and solid (e.g. fat) losses or gains

• Yield factor of e.g. 80% means that 20% of raw weight is lost and 80% retained

Examples of weight changes

• Loss (water/moisture) e.g. during baking• Gain e.g. cooking of pasta (water) or frying vegetables or meat

(fat)• Both gain (fat) and loss (water/moisture) in some processes

• Example: 100 grams of raw pasta needed for 300 g of cooked pasta

Weight gain is easiest calculated with water or fat (oil, butter) as

ingredient; take care that only the part of water that

is absorbed is taken into account as ingredient amount

Sources of yield factors

• Yield factors can be determined in experiments: weigh the ingredients before the cooking and weigh the final weight of dish

• Some factors in reports

• No harmonised yield factors available, because yield factors depend on cultural norms, cooking method, equipment, time and temperature.

• It is recommended to use national coefficients for yield factors!

Ingredient 2uncooked

Ingredient 1uncooked

Edible portion

Yield factorWeight of

cooked composite food

Retention factor

Nutrient content of uncooked

ingredients

Nutrient content of

cooked composite

food

Retention Factors

• Are used for nutrients retained after food preparation, processing or other treatment. This is usually applied to changes in water (moisture), fat, vitamin and mineral content

• Retention factors depend on: • Cooking method, cooking time and cooking temperature• Food quality (part of plant or animal, physical state,…)• Oxygen, light,…

• Factors available from reports,e.g. by Vásquez-Caicedo A. et al. (EuroFIR) or publications, e.g. Bognar. Based on food groups

• Retention factors can be determined in experiments. Complex protocols needed

Vitamin C loss when steaming red cabbage

Bognár (1988)

Recipe calculation systems

• To calculate from raw to cooked based on one ingredient

Multi ingredient recipes

• Summing nutrient content of (raw) ingredients

• Ingredient method

• Total recipe method

• Mixed method

Choice of method depends on

• Goal of food comp data

• Availability of yield and retention factors

• Available recipe calculation tool (DBMS; INFOODS tool (Excel); tailor made software)

Single ingredient recipes

Calculation methods in summary

Method Approach

Simple summation Ingredient 1: NVIngredient n: NV------------------------------------Sum of above

Ingredient method Ingredient 1: NV * 1/YF * RFIngredient n: NV * 1/YF * RF------------------------------------Recipe: Sum of above

Recipe method Ingredient 1: NVIngredient n: NV------------------------------------Recipe: Sum of above * 1/YF * RF

Mixed method Ingredient 1: NV * RFIngredient n: NV * RF------------------------------------Recipe: Sum of above * 1/YF

Based on FAO: UR Charrondiere

1. Simple summation

• Apply edible factors at ingredient level

• Calculate the nutrient values based on the weight of each ingredient

• Sum these nutrient values

• Back-calculate to 100 g of (raw) dish

• Use for

• Uncooked foods with raw ingredients; no need for yield or retention factors

• Average foods

• For cooked foods use cooked ingredients

Example 1

Omelette

4 eggs

1 tomato

half a cup of tap water

1 spoon of butter

0.5 tsp table salt

Methods applied

1. Simple summation of the raw ingredients

Sum the weights of ingredients:

Omelette with tomato:

eggs 220 g

tomato 50 g

table salt 1 g

tap water 60 g

butter 10 g

Total 341 g

Composition per 100 g from FCT

Food description is important:Chicken or duck egg, raw or cooked? Butter/margarine; which brand? Tomato raw/cooked; with/without skin?

Omelette with tomato

protein g thiamin mg water g

egg raw 12.5 0.1 75

tomato 0.7 0.02 95.4

table salt 0 0 0

tap water 0 0 100

butter 0.5 0 17

Summing of raw ingredients

Nutrient value/100 g * weight of ingredient (in g)

Food Protein Amount

Egg 12.5 g/100 g * 220 g = 27.5 g

Tomato 0.7 g/100 g * 50 g = 0.35 g

Table salt 0 g/100g * 1 g = 0 g

Tap water 0 g/100g * 60 g = 0 g

Butter 0.5 g/100 g * 10 g = 0.05 g

Protein total in recipe (341 g) = 27.9 g

Protein per 100 g of recipe:

100/341 * 27.9= 8.2 g per 100 g

Recipe calculation, FoodComp 2017

Summing of raw ingredients

weight g protein g thiamin mg water g

eggs 220 27.5 0.22 165

tomato 50 0.35 0.01 47.7

table salt 1 0 0 0

tap water 60 0 0 60

butter 10 0.05 0 1.7

Total 341 27.9 0.23 274.4

Per 100 g:

100/341 * 100 8.2 0.067 80.47

Per 100 g calculated by 100/341 * total nutrient value

2. Ingredient method

• Apply edible, yield and retention factors at ingredient level

• Sum weights of each ingredient as in cooked recipe

• Calculate nutrient values based on the weight of each ingredient

• Sum these nutrient values

• Back-calculate to 100 g of cooked dish

• Take care that yield factors are also applied to fluids

3. Total recipe method

• Apply edible factors at ingredient level

• Sum weights of each raw ingredient as in the recipe

• Calculate nutrient values based on the weight of each ingredient

• Sum these nutrient values

• Apply yield and retention factors at recipe level

• Back-calculate to 100 g of cooked dish

4. Mixed method

• Sum the weight of each raw ingredient in the recipe

• Apply yield factor at recipe level

• Adjust total weight of the cooked recipe

• Calculate nutrient values based on the weight of each ingredient

• Apply retention factors at ingredient level

• Sum these nutrient values

• Back-calculate to 100 g of cooked food

This method preferred method according to EuroFIR standards.And this is the most often used approach.

Example 2

Omelette

4 eggs

1 tomato

half a cup of tap water

1 spoon of butter

0.5 tsp table salt

Methods applied

4. Mixed method

Calculation by mixed method

• Same recipe

• Yield factor: 95%

• Retention factor for thiamin in egg: 0.70

• Retention factor for thiamin in tomato: 0.78

Apply yield factor to adjust for weight changes

● Raw weight g * yield factor = Cooked weight g

● If e.g. yield factor is 95% 95% of weight is retained during

cooking

● Total cooked weight of omelette will be:

341 g * 0.95 = 323.95 g

17.05 g weight loss, this is assumed to be moisture in this

recipe

Weight of the cooked dish

weight g

protein g

thiamine mg

water g

eggs 220 27.5 0.22 165

tomato 50 0.35 0.01 47.7

table salt 1 0 0 0

tap water 60 0 0 60

butter 10 0.05 0 1.7

subtotal 341 27.9 0.23 274.4

Adjusted

subtotal

341 *0.95

= 323.95 27.9

Per 100 g: 100

RF 0.70

RF 0.78

Apply retention factor to each ingredient to adjust for nutrient changes

Thiamin value * retention factor (RF)

Food Value in recipe RF

Eggs 0.22 mg * 0.70 = 0.154 mg

Tomato 0.01 mg * 0.78 = 0.008 mg

Butter/salt/water NA

Different retention factors can be applied to other nutrients

Thiamin content of cooked dish

weight g protein g thiamin mg water g

eggs 220 27.5 0.22*0.70 165

tomato 50 0.35 0.01*0.78 47.7

table salt 1 0 0 0

tap water 60 0 0 60

butter 10 0.05 0 1.7

subtotal 341 27.9 0.23 274.4

Adjusted

subtotal

341 *0.95

= 323.95 27.9

0.154+0.008

= 0.162

Per 100 g: 100

Calculate the water content of the cooked dish

raw weight – cooked weight = weight loss of total recipe

341 g – 323.95 g = 17.05 g

Water (moisture) content in raw recipe = 274.4 gWater (moisture) content of cooked recipe 274.4-17.05 = 257.35 g in 323.95 g of recipe

We assume all weight loss is water (moisture) loss in this recipe, otherwise RF for e.g. fat should be included

Note this is the component water = moisture, not the ingredient tap water

Water content of the cooked dish

weight g protein g thiamine mg water g

eggs 220 27.5 0.22*0.70 165

tomato 50 0.35 0.01*0.78 47.7

table salt 1 0 0 0

tap water 60 0 0 60

butter 10 0.05 0 1.7

subtotal 341 27.9 0.23 274.4

Adjusted

subtotal

341 *0.95

= 323.95 27.9

0.154+0.008

= 0.162

274.4 -

17.05

= 257.35

Per 100 g: 100

Calculate nutrient content per 100 g of cooked dish

nutrient valueweight cooked dish * 100 g

0.162 mg323.95 g * 100 g=0.05

mg/100 g

100 nutrient weight cooked dish * value

100323.95 * 0.162 = 0.05

mg/100 g

Similar approach for water, protein and other components

thiamin in recipe = 0.162 mgweight of cooked dish = 323.95 g

thiamin content per 100 g of cooked dish:

Composition of 100 g of cooked dish

weight g protein g thiamin mg water g

eggs 220 27.5 0.22 165

tomato 50 0.35 0.01 47.7

table salt 1 0 0 0

tap water 60 0 0 60

butter 10 0.05 0 1.7

subtotal 341 27.9 0.23 274.4

Adjusted

subtotal

341 *0.95

= 323.95 27.9

0.154+0.008

= 0.162

274.4 -17.05

= 257.35

Per 100 g:

100/323.95 * 100

100

323.95* 0.162

= 0.05

100

323.95∗257.35

= 79.44

100

323.95* 27.9

= 8.61

Finally values need to be rounded off

Calculate water (moisture) content by difference

• In this example: 100 g food minus

• 8.61 g protein

• 9.67 fat

• 1.51 g carbohydrate incl fibre (CHOT)

• 0.765 g ash

• Results in 79.44 g water/100 g of food

• Results are similar for both approaches if macronutrients add up to 100 g exactly

2. Calculate water loss during cooking process

Weight loss (%) = Weight of uncooked ingredients - Weight of cooked ingredientsx100

Weight of uncooked ingredients

= 167100g - 155000g x100

167100g

= 7.2%

Remarks

• Calculation fits perfectly when sum of nutrients per ingredient = 100 g

• also for water calculated by difference

• Reality is different due to different data sources or missing values

• Results need to be rounded to significant figures

• Recipe calculations need to be considered as estimations.

• Data quality not similar to analytical values

Compare recipe with and without factors

Largest difference is between applying or not applying factorsDocument which method is appliedUse same method for all your recipes; mixed method is preferred

weight

g

protein

g

thiamin

mg

water g Water by

diff. g

Simple

summation

100 8.2 0.067 80.47 80.47

Mixed method 100 8.6 0.05 79.44 79.44

Higher due to higher density because of weight loss

Lower due to loss during cooking

Single ingredient recipe

From raw to cooked using yield and retention:

• Apply YF to 100 g raw food (if RF is not applicable)• Nutrient value * 1/yield factor

• Apply YF and RF when both are applicable• Nutrient value * 1/yield factor * nutrient retention factor

• For water (moisture) of cooked food p 100 g: (water/100 g – (initial weight- cooked weight)/cooked weight)*100

Energy and other derived components

• Calculated from other components• Calculated using a formula• Needs to be done using the results of the recipe calculation

Quality of data inputs: Ingredient information

• Using data sources

– Needs to be accurate!

• Major ingredients (by %) important

• Minor ingredients can also be important

– e.g. salt, salt containing dry ingredients

• Units must be correct

• Specific gravity/Density may need to be considered for some ingredients

• Weight changes during preparation very important

– Usually water loss

• Could be water uptake

• Could be fat displacing water

– Should be measured not estimated

• Some ingredients in a recipe may need to be calculated separately (‘nested’ recipes), e.g.

• Cake toppings

• Pie fillings

• Sandwich fillings

Other types of calculations

Recipe calculated based on label information

Goal: fill in missing data for industrial foods; mainly vitamins and minerals

• Recipe based on ingredients on label• Ingredients listed in descending order; amounts to be estimated• Trial and error calculations

➢ When calculated macronutrients match with label information, it is assumed that vitamins and minerals are okay as well

➢ Be aware that results must be regarded as estimations

Quality of results: Calculated vs analysed values

Comparison of calculated nutrient content with analysed content, IFR (2015)Calculated by IFR/NIS Analysed values from product specifications or analysis by Eurofins Food Testing, Wolverhampton• 36 Food products• ice cream• sponge cake• sausage rolls• pasta products• cooked meat products• cereal based snack bars• granola• muesli• crispbread• savoury crackers

Quality of results: Calculated vs analysed values

An average of 84% of values within tolerance– Ranged from 64% (salt) to 95% (polyunsaturates)

Nutrient Number of samples

No. within tolerance % within tolerance

Fat 36 34 94

Saturates 36 32 89

Monounsaturatesa 21 17 81

Polyunsaturatesa 21 20 95

Carbohydrate 36 33 92

Sugars 36 27 75

Starch 36 31 86

Fibrea 33 30 91

Protein 36 27 75

Salt 36 23 64

aAnalytical values not available for all samples

Read more

EuroFIR website http://www.eurofir.org/

INFOODS website http://www.fao.org/infoods/infoods/en/

Machackova, M., Giertlova, A., Porubska, J., Roe, M., Ramos, C. and Finglas, P. (2018) EuroFIR Guideline on calculation of nutrient content of foods for food business operators. Food Chemistry (238), 35-41