Poster Beef ICoMST 2014Conference 60th International Congress of Meat Science and Technology, 17-22nd August 2014, Punta Del Este,

Uruguay

title MINIMISING PROTEIN OXIDATION IN RETAIL-PACKED MINCED BEEF USING THREE-GAS MA-PACKAGING

Authors Dimitrios Spanos2, Laura Baussá2, Caroline P. Baron2, Mari Ann Tørngren1*

1 Department of Meat Quality, Danish Meat Research Institute, Taastrup, Denmark2 National Food Institute, Division for Industrial Food Research, DTU, Kgs. Lyngby, Denmark

Introduction/Aim

Traditionally, rRed meat is commonly packed in MAP containing 70-80% oxygen (O2) to obtain an attractive bloom colour, and in 20-30% carbon dioxide (CO2) to extend shelf life. Unfortunately, high oxygen MAP results in less tender and less juicy meat with a more rancid flavour and premature browning (PMB) of the meat.negatively impacts meat sensory attributes including tenderness, juiciness, flavour, and causes premature browning (PMB) during cooking.

The objective of this study was to investigate the effect of lower oxygen three-mixture gas of gas mixture (O2, CO2, N2)for MAP on the shelf life, protein oxidation markers, and eating quality of minced beef.

Photo

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Materials & Methods

Experiment 1: Bovine muscles was were pre-ground at a Danish deboning plant, using nitrogen for cooling. The meat was then transported to a Danish packing plant, where it was weighed out into 500 g per trays and sealed with different gas mixturesgas mixtures 1-5, as presented detailed in Table 1 and Table 2. The samples were stored for 0, 6, 8, 11 and 13 days after packaging.

Table 1. Experimental design for experiment Experiment 1 - Raw meat evaluation: shelf life, lipid and protein oxidation.

1 x cut Shoulder clod (7% fat) - Minced 2 days after slaughter5 x gas 1 2 3 4 5

40% O2

20% CO2

40% N2

40% O2

40% CO2

20% N2

50% O2

20% CO2

30% N2

50% O2

40% CO2

10% N2

80% O2

20% CO2

-

1 x storag

eStorage

conditions

1200 lux, 5̊ C, for up to 13 days

Table 2. Experimental design for experiment 2 -Cooked meat evaluation: sensory profiling.1 x cut Fore quarter muscles (12% fat), Minced 6 days after slaughter3 x gas 1 2 3

40% O2

20% CO2

40% N2

50% O2

40% CO2

10% N2

80% O2

20% CO2

-1 x storage

1200 lux, 5̊ C, 6 days

Experiment 2: For the sensory profiling of cooked meat, forequarter muscles (12% fat) were minced 6 days after slaughter ,sealed in the gas mixtures 1,3 and 5, and stored for 6 days.

Results Shelf life: Packing Mminced beef packed in 50% O2 + 40% CO2 + 10% N2 will result in the same shelf life as high oxygen MAP (80% O2 + 20%) CO2). In contrast, using a three-gas mixture with 40% O2 + 20-40% CO2 the shelf life will be reduced by 2-4 days at 5°C (table 32)

Lipid oxidation: Beef packed with 40% oxygen (40/20/40 or 40/40/20) is more stable than samples packed in 50% or 80% O2. The CO2 content did not affect the development of lipid oxidation.

Protein oxidation: A time-dependent decrease in free thiol groups, irrespective of the gas composition, was observed during storage (Figure 2).

Low oxygen MAP did not significantly affect the sensory quality of cooked beef patties (table 2) in regards to the visual attribute of “cooked colour”, the flavour-related attributes of “cooked beef” and “warmed-over flavour”, and the textural “juiciness” and “rubbery texture”.

Experiment 1

Table 32. Cross section of MA-packed minced beef just after opening of the packaged, and the acceptability limit (approx. storage time for threashold score = 2.5) of raw minced beef stored in MAP with different gas mixtures at 5̊

C (n=25).Da

gGas composition/Da

y

40 % O2 + 20 % CO2 + 40 % N2

40 % O2 + 40 % CO2 + 20 % N2

50 % O2 + 20 % CO2 + 30 % N2

50 % O2 + 40 % CO2 + 10 % N2

80 % O2 + 20 % CO2 + 0 % N2

6

8

11

13

Accept 8 days 7 days 10 days 11 days 12 days

0

2

4

6

8

10

12

14

16

18

0 2 4 6 8 10 12 14

mg

MD

A/K

g sa

mpl

e

Storage days

40% O2 / 20% CO2 40% O2 / 40% CO250% O2 / 20% CO2 50% O2 / 40% CO280% O2 / 20% CO2

Figure 1. TBARS in raw meat samples from minced beef stored in different MAP gas mixtures for 6, 8 and 13 days.

Figure 2 Percentage of free thiol groups in raw meat samples from minced beef stored in different MAP gas mixtures for 6, 8 and 11 days.

Experiment 2

Table 4. Sensory attributes of cooked beef patties from minced meat stored for 5 days in MAP with different gas mixtures (O2/CO2/N2) at 5°C (n=48).

MAP40/20/40

MAP50/40/10

MAP80/20

Cooked colour 10.0 10.7 10.4

Cooked beef 4.8 5.1 5.0WOF 3.8 4.3 3.5Juiciness 6.2 6.3 6.5Rubbery 4.5 4.9 4.7

Conclusion It is possible to maintain the shelf life of MA-packed minced beef while reducing the oxygen content in from 80% to 50% O2 .Further reduction of O2 content to only 40% will also reduce lipid oxidation during storage. However, deviating from the established two-gas high-oxygen packaging practice does not result in any sensory benefits.

If reducing the oxygen content in MA-packed minced beef from 80% O2 to 50% O2, the shelf life can be maintained and by lowering the oxygen content to only 40% O2 the lipid oxidation is reduced. Unfortunately, there was no sensory benefits then using three gas MAP on minced beef.