The use of by-products is essential in a circular economy and contributes to the sustainability of food systems. Olive bioactive compounds can be incorporated into animal feed, promoting gut health. These compounds, obtained from olive by-products, may also influence some meat quality attributes important to consumer, although they have been scarcely studied.
Professor at Animal Production and Food Science Department
University of Zaragoza — Spain
The EU Farm to Fork Strategy aims to create fair and healthy food supply systems, ensuring a high level of health protection while promoting sustainability and innovation. It also included legally binding targets for food waste reduction targets to be achieved by 2030. This strategy is a key component in improving the sustainability of meat production. On one hand, sustainable practices help prevent health issues at the farm level, which would otherwise increase the waste of natural resources and reduce economic returns for primary producers. On the other hand, food waste at the retail level has financial, environmental and social consequences, eroding consumer trust. It has been estimated that one-fifth of food available to consumers is wasted at the retail, food service and household levels (UNEP, 2024). Therefore, extending the shelf life of meat is a promising strategy to mitigate these losses.
The olive oil industry is of major importance in Spain, the world’s leader producer. Several by-products generated during olive oil production (e.g. leaves, pomace) contain bioactive compounds, such as polyphenols (hydroxytyrosol) and triterpenes (maslinic and oleanolic acid). These compounds, when used as feed additives, represent a clear example of circular economy practices aligned with the EU Farm to Fork Strategy. These bioactive compounds help maintain the intestinal environment free of inflammatory processes avoiding oxidative stress in order to maintain an optimal digestive integrity and function (Pastor, 2025), contributing to a reduction in the use of antibiotics. In fact, together with other strategies, this approach contributes to the reduction in the use of antibiotics, that has achieved in Spain a decrease of 53% in the last 4 years (Rubio, 2025).
The strategy is widely applied in poultry production, particularly in intensive broiler systems, where animals reach the slaughter weight target at a younger age every year due to genetic selection, improved environmental conditions and optimal feed formulation. When the intestinal function is preserved, certain dietary antioxidants can be absorbed and deposited in muscle tissues, both in the lipid and aqueous fractions, modulating oxidative processes in the living animal as well as post-mortem.
Appearance is one of the most critical quality attributes that drives consumer purchasing decisions and is often the only feature assessable when meat is displayed in sealed packaging at retail. Appearance includes both physical characteristics and color, which are key indicators of perceived freshness (Kennedy et al., 2004). This perception is primarily associated with the characteristic pink color of chicken meat. The inclusion of different olive bioactive compounds has shown minimal to no impact in the development of meat color during display in film packaging (Figure 1). The most notable effect observed is a slight reduction in lightness, although values remain high throughout the display period up to 8 days of display, consistent with the typical appearance of light-colored meat. Longer display times are not considered safe due to microbial spoilage. Importantly, redness and yellowness are hardly affected by the inclusion of these compounds, indicating that consumer purchasing decisions are unlikely to be negatively influenced by color changes.
(L*, lightness; a*: redness; b*: yellowness; OE: Olive bioactives)
An important quality attribute in chicken meat is Water Holding Capacity (WHC), which is directly influenced by pH. A key indicator of freshness is the minimal presence of exudated water during retail display. After the animal’s death, the pH of the meat drops from an initial value just above 7 due to post-mortem anaerobic glycolysis, during which muscle glycogen is converted into lactic acid. Normal pH values for chicken meat typically range from 5.7 till 6.1.
Various factors, such as pre-slaughter handling, stress or storage temperature, can affect this post-mortem process. A rapid decline in pH to values below 5.7 while the carcass is still warm can result in the development of pale, soft and exudate (PSE) meat, which is characterized by very low WHC. Modern strains of broilers with highly developed breast muscles are more prone to producing PSE meat. PSE meat exhibits reduced WHC because the proteins responsible for binding intracellular water are closer to their isoelectric point, which limits their ability to retain water. As a result, more water is released, becoming visibly accumulated in the packaging during supermarket display. This visible drip loss often leads consumers to reject such products, thereby increasing retail-level food waste. The inclusion of olive bioactives in animal diets has shown promising results in reducing drip loss in breast meat with normal pH values (Figure 2).
CONCLUSION
The use of bioactive compounds derived from olive by-products, in addition to their properties in the live animal, may serve as a strategy to extend the shelf life of chicken meat by reducing water loss during retail display, without significantly altering meat color. This could help reduce food waste at retail level by improving consumer purchase decisions, thereby contributing positively to the overall sustainability of the meat production system.
References
1. Kennedy, O.B., Stewart-Knox, B.J., Mitchell, P.C., Thurnham, D.I. 2004. Consumer perceptions of poultry meat: A qualitative analysis. Nutrition & Food Science, 34, 122-129
2. Pastor, J.J. 2025. Olive bioactives as a strategy to improve animal intestinal integrity. Feed & Additive magazine, July
3. Rubio, J. 2025. Future challenges for poultry: Our vision at LUCTA. Feed & Additive magazine, May
4. United Nations Environment Programme (2024). Food Waste Index Report 2024. Think Eat Save: Tracking Progress to Halve Global Food Waste. https://wedocs.unep.org/20.500.11822/45230
About Dr. María del Mar Campo
Holding a Degree in Veterinary Medicine and a PhD in Veterinary Science, Dr. María del Mar Campo has focused her research career on the effects that husbandry or technological factors along the production chain have on the quality of meat across different species. She is currently a Professor at the Animal Production and Food Science Department at the University of Zaragoza, Spain.
