How to check the quality of the red meat you are buying

The surest way to produce meals of excellent, consistent quality is to start with the best quality ingredients available. Red meat is one of the key ingredients on which dining customers base their assessment of the quality of the food served, and one of the most versatile products at the chef’s disposal. The fine quality and established provenance of red meat from Scotland makes it a delight to cook and serve, and ensures that it will always be a premium addition to your menu. In this section, we will look at key factors to be aware of – meat colour, drip loss, lipid oxidation, storing and handling – that affect the meat your customers will be served.

Developing a strong working relationship with your catering butcher will ensure that your expectations are met. But, as with all food ingredients purchased, as a chef it is your responsibility to check the quality and specification of the red meat coming into your kitchen.

In the Butcher section, labelling is discussed in close detail. You should also always ensure that all the specification criteria communicated to your butcher have been met, for example is it in the right form of packaging?; has it been trimmed correctly?; is the portion weight within your parameters?

Factors affecting weight loss in meat by drip and evaporation (and how to minimise them):

Factor	Effect	What you can do
Chilling rate	Considerate chilling reduces evaporative losses: cold shortening	Understand from your supplier(s) their chilling procedures – insist on considerate chilling
Pre-slaughter stress	Can lead to poor water retention/high drip loss can ensue	Visit your abattoir; Scotch Beef and Scotch Lamb should undergo heavily monitored pre-slaughter checks to reduce stress levels
Meat pH	High pH meat (>pH 6.0) has low drip loss	Many factors involved (see Abattoir section)
Electrical stimulation	In conjunction with considerate chilling, Electrical Stimulation (ES) can reduce evaporation	Understand from your supplier(s) their procedures (see Abattoir section)
Size of meat pieces	Drip loss in joints and roasts are 10 times lower than in steaks and chops (due to surface area)	Understand the benefits to you and write specifications accordingly
Packaging	Pressure exerted on meat by tight fitting films can increase drip loss	Understand the implications to you and write specifications accordingly; speak to your butcher and see what other packaging methods could be used
Freezing and thawing	Drip loss can double as a result of freezing	Manage your deliveries to reduce the volume of meat that needs to be frozen; minimise non-blast (rapid) freezing, or freezing completely

Source: Meat and Livestock Commission

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Why does my meat colour vary?

Depending on certain atmospheric conditions, red meat can change colour quite significantly and appear anywhere between bright red and dark brown. This is due to concentrations in the air of various gases and the reaction the meat pigment myoglobin has to it. The following diagrams and images explain this:

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The implications of drip loss

Drip loss is officially defined as:

1. The discharge of exudates (mainly water) from the carcase
2. The loss of fluid from retail cuts whilst on display
3. The loss of fluid from meat on thawing following freezing

Essentially, ‘drip’ is a red, watery fluid which seeps from the cut ends of meat over time. Commercially, any weight lost as water by drip or evaporation has a repercussion on the bottom line – weight equals cost.

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Muscle fibre

Meat is muscle tissue which is made up of bundles of long thin fibres. There are two main types of muscle fibres which can be described as being red or white. The proportions of the different fibre types vary between muscles. Red muscles tend to have higher proportions of red fibres. The muscle fibres are bound together in bundles by thin sheets of connective tissue.

Connective tissue is made up from proteins – collagen, elastin and reticulin. Each protein has specific characteristics and reacts differently during cooking. Most importantly, collagen is weakened by heat and forms gelatin, which is soluble. This change helps the meat to become tender.

For more information, log onto www.nutrition.org.uk

Lipid Oxidation (rancidity and off – flavours)

Fat is the other accomplice to myoglobin in affecting the odour, flavour and shelf life of fresh, frozen and cooked meat and meat products.

The effect of various factors on the onset of oxidative rancidity in fat:

Factor	Effect
Initiators	Oxidation is catalysed (i.e. accelerated) by heat (see below), light and iron (haem pigments)
Oxygen	Packaging that excludes oxygen, delays oxidation
Fatty acid composition	Beef and lamb are less likely to suffer from fatty acid oxidation because the fats they contain are more saturated and therefore more stable
Temperature	Higher temperatures increase oxidation
Antioxidant	Vitamin E is an antioxidant in meat. Occurs naturally in grass and can be added to animal feed to reduce oxidation
Comminution (‘mixing’)	Increases oxidation reducing shelf life
Cooked meat	Cooking speeds up oxidation. Free iron from heat denatured myoglobin acts as a catalyst

Source: Meat and Livestock Commission, British Nutrition Foundation 2004

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