Quality of foods of animal origin based on production and processing conditions

What role can livestock farming and animal-based foods play in our societies? This INRAE-led scientific assessment shed light on such questions and expanded on a previous assessment of the environmental, economic and social impact of European livestock production (2016) by focussing on animal product quality, which had not been considered during the earlier review. Over the past 50 years, Europeans, Americans (in both North and South America), and Australians have doubled their consumption of animal-based foods. Then, over the past 15 years, a large number of questions have been raised about the consumption levels of animal products, particularly meat. This expert assessment was commissioned as the États généraux de l’Alimentation (French parliamentary food summit - EGA) came to an end. The EGA was then followed by the development of animal sector plans at the Ministry of Agriculture and Food's request in order to better respond to challenges to both society and the environment, in particular by enhancing product quality.  Since that time, the Egalim Act (2019) has addressed such issues and the new 2019 French national nutrition and health plan (PNNS4) issued revised recommendations about foods of animal origin. This report provides an updated review of scientific knowledge about animal-based-food quality based on an analysis of some 3500 international reference documents.

Quality composed of seven properties under the control of many different stakeholders

The priority given to market-related properties, especially for so-called standard products, puts a strain on the others

A food's quality is determined by all the properties that allow it to meet a user's expressed or implicit needs (AFNOR). To take into account the various aspects of quality and the relationships between them, the expert group developed a chart with seven properties.  Of those properties, the market-related ones are given priority, particularly for so-called standard products, since they are the basis for payments to livestock farmers. For that reason, prices primarily rely on criteria such as weight, yield and appearance. Those criteria are not, however, a guarantee of other properties that are just as important either for consumers, e.g. organoleptic (taste and smell), nutritional and use properties, or for processors, e.g. technological properties. One way to ensure that more consideration is given to the various aspects of animal-based-food quality would be to include them in payments to livestock farmers. For example, an Australian system makes it possible to calculate, at the slaughterhouse, an estimated quality score for beef as viewed by consumers that is then integrated into the price paid to livestock farmers and included in consumer information. Another example: the commitments made in Label Rouge production specifications for adult cattle help ensure their meat will have enhanced organoleptic properties.

Sanitary properties are absolutely essential since with 70% of food-borne disease outbreaks linked to the animal products eaten, controlling microbiological risks is extremely important. The risks of chemical contamination in livestock farming can come from animal feed (persistent organic pollutants, mycotoxins, pesticide residue) and the indoor (equipment) or outdoor (soil, air, plants) environments. Chemical hazards during processing include additives and neo-formed compounds that arise during grilling or smoking and have adverse effects on health. Eating too much red and cured meat is associated with chronic diseases, including colorectal cancer, which has led to recommendations in the new PNNS on limiting their consumption.  Marinades or added antioxidants are solutions that are currently being studied to reduce harmful oxidation of fats during cooking and digestion.  Dairy products provide protection against colorectal cancer.  In regards to osteoporosis and degenerative diseases, proteins and calcium seem to provide protection, even though few cohort studies are available.

At the same time, foods of animal origin do have some worthwhile nutritional properties since they are the main source of high-quality proteins with their profiles in essential amino acids and long-chain n-3 polyunsaturated fatty acids (Omega 3) and the only source of vitamin B12, which specifically comes from ruminant products. They are rich in vitamins and minerals such as iron, zinc and calcium, but are low in fibre. However vegetarian diets should not be counted out since while they supply fewer minerals, they do make it possible to stay within the guidelines for good health. But vegan diets can raise the risk of an increased prevalence of low levels of certain nutrients, particularly vitamin B12.

Organoleptic properties drive both purchases and consumption but are still difficult to predict since they depend on diners' preferences as well as their eating and cultural habits.

Technological properties describe the raw material's suitability for processing (e.g. performance after salting, refining, cooking) and storage (sensitivity to oxidation, micro-organism development) and are mainly of interest to food manufacturers. Use properties refer to a product's convenience.

Finally, image properties, which cover the ethical, cultural and environmental aspects associated with production and processing conditions and the food's origin, are now determining factors for consumers and take in account changes in scientific knowledge.

How can quality be assessed?

No tools currently exist that can measure all the properties that quality is based on and then issue an overall assessment. Labelling is the main way to inform consumers about a food item's ingredients and how to prepare it, but this can be complicated given the various quality aspects to be considered - aspects which themselves are often made up of a variety of components. This does then raise the question of whether it is really possible to integrate all the aspects into an overall score. Since too much information can be confusing, labels need to be easy to read rapidly, which is what Nutriscore aims to do. While product formulation is now taken into account for certain nutritional scores (Nova classification), other items such as process intensity, environmental impact, and animal welfare are not. In addition, digital applications could help but they are not convenient to use and often lack transparency.

Improving quality? Synergies and conflicts  

What ensures quality? The factors that determine quality intervene at various stages of food production and processing from the animals' traits, rearing conditions, transport, slaughter, processing, storage, marketing through to preparation at home and consumption. This large number of factors leads to situations that reveal certain conflicts. That is why poultry, pork and fish, which come from animals whose production is often optimised for meat yield, increasingly consist of poorly structured muscle tissue. This has become a major problem for chicken filets and has led to questions about genetic selection as it promotes muscular development and growth rates to the detriment of other properties such as the muscle tissue holding up well during processing. Those muscles sometimes develop under conditions of reduced blood flow, with impaired functioning equivalent to a myopathy. For pork and fish, however, the origin of this problem is still unknown.

Consumer involvement has gradually led to greater consideration for ethical issues, e.g. eggs in Europe are now labelled 0 (organic farming), 1 (free range), 2 (on ground in enclosed building) or 3 (in cages). Cage rearing will be banned in 2025 but currently involves more than 50% of hens in France. Grinding up male chicks will be banned in 2021 with two options for farms to adapt, i.e. "in ovo” sexing or developing combined layer-broiler sectors. In the dairy sectors, the fate of males is also often an issue and has rekindled interest in a return to combined milk and meat production so as to make better use of those animals.

Dry cured ham production, on the other hand, displays a number of synergies between organoleptic and technological properties and between the rearing and processing stages. More broadly, an animal's diet is one way to improve nutritional properties, particularly via grass feeding or by providing feed rich in n-3 polyunsaturated fatty acids (pasture, linseed). This improves the lipid profile of meat, milk and eggs but fish, particularly fatty types, are still by far the best sources of n-3 polyunsaturated fatty acids.

Processes that are critical for quality

High-temperature cooking (grilling, frying) generates toxic "neoformed" substances that are harmful for health, while cooking at proper temperatures (~70°C) ensures an excellent level of digestibility of the meat's proteins and improved digestion speed, which are vital for controlling sarcopenia (muscle loss) in the elderly.

Industrialisation of food production and splitting raw materials into biochemical compounds (e.g. proteins, fats, minerals) have promoted both the standardisation of animal husbandry practices and reduced livestock biodiversity. The compounds that result from splitting are then reassembled to create a wide range of food products. This final step is formulation, which can lead to "ultra-formulated" or "ultra-processed" foods that contain additives, flavourings, etc. This expert assessment studied several key examples of this problem such as nuggets and baby formula. 

Improvement must involve all the stakeholders

The report laid out several priorities at the various stages of the work to improve quality. For livestock farming, selection is the starting point, while for processing, it involves redesigning processes and formulation. At the level of consumers, who also store and process foods, there is a need to raise awareness and strengthen learning.

In terms of public action, quality/origin labels and information have helped bring about a better understanding of the different properties. To overcome conflicts and promote synergies, regulatory frameworks will have to be changed and work done to identify alternative solutions based on innovation and redesigning production and processing systems.