COOKING LOSSES OF JUICE, HEME IRON, B3 AND B6 VITAMINS IN BEEF AS RELATED TO COOKING PRACTICES – CONSEQUENCES ON NUTRITIONAL VALUE OF MEAT G. Gandemer1,3, V. Scislowski2, C. Duchène3 and A. Kondjoyan4 1 National
Institute of Agronomic Research, Center of Lille, 2 chaussée Brunehaut, Estrées- Mons, 80207 Péronne, France, 2 ADIV, 10 rue Jacqueline Auriol, ZAC des Gravanches, 63039 Clermont Ferrand, cedex 2 France, 3 Centre d’Information des Viandes, Tour Mattei, 207 rue de Bercy, 75587 Paris cedex 12, France, 4 National Institute of Agronomic Research, UR370 QuaPA, 63122 St Genes Champanelle, France.
INTRODUCTION o Meat is mainly consumed after cooking. o Cooking causes both juice and soluble nutrient expulsion as a consequence of protein denaturation and shrinkage due to the increase of temperature in meat. o Some nutrients such as B6 vitamin or heme iron are subjected to additional cooking losses related to thermal degradation. o Evaluating cooking losses is essential to provide proper nutritional advice.
This poster provides data on the contents of total and heme iron and on B3 and B6 vitamins of cooked beef meat (Shoulder clod) according to the main cooking modes and degrees of doneness used by French consumers . These four nutrients are those mainly affected by cooking.
MATERIALS AND METHODS o Juice and nutrient cooking yields were estimated according to the kinetic models of juice, total and heme iron, B3 and B6 vitamins previously established by Kondjoyan and co-workers (1, 2, 3). o For juice and each nutrient, the cooking yields were calculated for the main cooking modes (pan fried, roast, boiled and braised) and various degrees of doneness (very rare, rare, well-done). Cooking yields were given with a range of several per cents to take into account uncontrolled parameters by consumers (temperature and water contents of raw meat, type of cooking equipment, etc.) o Contents of cooked meat were calculated for shoulder clod, a piece of meat which can be cooked according to various modes. The composition of raw shoulder clod from 16 cows has already been published (4). o Results are expressed in mg per portion of cooked meat after cooking 100 g of raw meat.
Yields of juice and the four nutrients according to cooking modes and degree of doneness
Cooking
Cooking yield (%)
Doneness
Weight
Total & heme iron
B3
B6
Very rare
90-95
90-95
90-95
90-95
rare
80-85
80-85
80-85
80-85
well-done
70-75
70-75
70-75
70-75
Roast
rare to well-done
65-80
70-85
65-80
60-80
Braised
well-done
55-70
30-55
55-70
30-55
Boiled
well-done
50-65
25-50
50-65
25-50
Mode Grilled or pan fried
RESULTS Nutrient contents of cooked shoulder clod according to cooking mode and degree of doneness (in mg/portion*) (VR = very rare, R = rare, WD = Well-done)
B6
0 Braised-WD-maxi Braised-WD-min Boiled-WD-maxi Boiled- WD-min Roast-WD Roast-R Grilled or pan fried-WD Grilled or pan fried-R Grilled or pan fried -VR Raw
0,1
0,2
0,3
Total iron
0
1
2
3
0,4
0,5
Heme iron
4
0
0,5
1
1,5
2
*Cooked meat portion: final weight after cooking 100g of raw meat
CONCLUSIONS o Cooking losses increased with time. The losses are significant only for long cooking time (roast, braised and boiled). o B6 vitamin and heme iron showed thermal denaturation in addition to the amounts expulsed in juice. o Cooking losses must be taken into account for roast, braised and boiled meat to provide consumers with proper nutritional advice.
REFERENCES (1) Ollic et al., 2011, (2) Portagen et al., 2012, (3) Scislowski et al., 2011, (4) Bauchard et al., 2011