Antioxidants For Meat And Poultry: Clean Label Perspectives

Friday, May 25th, 2018

Shelf-life extension can provide a critical solution in the effort to improve profitability and reduce waste, say Alessandra Pham-Mondala, Lee Zhi Ying, and Poulson Joseph from Kalsec (Kalamazoo, United States, and Asia Pacific).

Meat and meat products offer a nutritionally dense source of protein, often added by consumers as an ingredient during food preparation, in addition to the ‘centre of the plate’ concept. Consumers consider convenience when purchasing decisions are made, which enables processed meat products to be an important food category. Among the key factors, oxidative (flavour) and colour-stability are critical in ensuring the quality as well as consumer acceptability of meat products. These quality attributes are critical in protecting the product and brand image. As a result, antioxidants have been utilised in the meat and food industry as a preventive strategy.

Recently, the food industry has been witnessing a surge in clean label demands that include meat products as well. Growing consumer health concerns and the need for cleaner ingredient labelling have provided the impetus for the restricted use of synthetic food additives and their replacement with naturally occurring ingredients that have similar functions. Recent surveys, including research from Innova Market Insights, suggest that consumers feel strongly about clean labels with 29 percent of US consumers claiming that a clean label is a factor that influences their food purchasing decision. Most consumers consider no artificial ingredients or additives and preservatives as being natural or clean label. In a Kalsec-conducted survey, US and UK consumers chose meat and poultry as the top food category that they prefer to not contain artificial ingredients.

As consumers increasingly demand transparency in ingredient disclosure, the need for naturally sourced solutions that make food and beverages look better, taste better, and last longer, is expected to increase. These include extractives of rosemary with standardised antioxidant activity and flavour, plus the addition of quenchers and/or chelators that have a synergistic/additive effect on managing oxidation in the system, extending shelf-life, and reducing food waste. While rosemary extract is still the dominant natural extract in Europe and the US, additive combinations with other compatible plant extracts are also on the rise for meat applications. The selection and application of such natural antioxidants is matrix-based and will be explored in this article as case studies.

Offering Fresh Meat Colour Stability With Natural Antioxidant Formulations

Consumers often associate the freshness of meat with its colour, preferring red colour (oxymyoglobin) as compared to brown discoloration (metmyoglobin). Any discoloration will result in discounted prices or disposal, leading to loss of revenue and food waste. Shelf-life extension, therefore, can provide a critical solution in the effort to improve profitability and reduce waste.

A major emphasis has been given by the meat industry in preserving the red meat colour—with the advent of case-ready packaging—by utilising modified atmosphere packaging (MAP). Natural antioxidants help to extend the colour shelf-life in case-ready packaging conditions while offering additional benefits of limiting lipid oxidation. The results from the trial with fresh ground beef under various retail packaging conditions suggest that incorporating Herbalox Rosemary Extract offers an improvement in colour shelf-life and flavour stability. For additional colour stability in the fresh ground meats category (ground beef, poultry, fresh sausages, etc.) Kalsec has developed Duralox Oxidation Management Systems (which can include combinations of rosemary and acerola extracts). In figure 1, fresh ground beef under overwrap conditions has shown an improvement in colour shelf-life with the incorporation of a Duralox Oxidation Management System.

(Figure 1 Colour Stability of Overwrapped Fresh Ground Beef)

Similarly, with respect to flavour stability, it has helped to reduce hexanal evolution (Figure 2), a secondary product of lipid oxidation, during refrigerated storage. Herbalox Rosemary Extract or Duralox Oxidation Management Systems can be added to beef after the first grind, during mixing, before chilling or before the final grind. In whole muscle, it can be injected into sub-primal cuts and before portioning to retail.

(Figure 2 Flavour Stability of Overwrapped Fresh Ground Beef)

Offering Flavour Stability In Cooked Meats And Ready-To-Eat Products

Lipid oxidation in cooked meat and poultry results in an undesirable off-flavour and off-aroma described as ‘warmed-over-flavour’ (WOF). This has also been referenced as ‘Modified Flavour Deterioration (MFD)’ in cooked meats. WOF can be caused by rupturing of the muscle cells, resulting in the oxidation of phospholipids along with fat, and accelerated in the presence of iron from heme-pigments.

Unappealing flavours directly affect consumer purchasing behaviour. Flavour protection, therefore, is an ongoing concern in partially cooked (frozen) and pre-cooked meat and poultry products that are either ready-to-cook (RTC) or ready-to-eat (RTE). Natural antioxidants offer a clean label solution to improve the flavour and shelf-life of pre-cooked and prepared meat products. Specifically, rosemary extract (Herbalox) alone and combinations of rosemary and green tea extracts (Duralox) can provide the advantage of flavour stability by minimising the intensity of WOF, both in cooked red meats and poultry meat products. Both were effective at managing oxidation as evidenced by hexanal (Gas Chromatography) analysis (Figure 3). Sensory panellists could easily identify WOF in cooked chicken products at around 8 ppm of hexanal, based on these trials (Figure 4), after two days of refrigerated storage in permeable packaging.

Furthermore, the performance of Duralox blends was comparable or better than synthetic antioxidants (BHA/BHT) in extended cooked/uncured chicken sausage throughout 33 days of shelf-life in our own trials. This becomes particularly important when product developers are trying to replace BHA, BHT, propyl gallate, and TBHQ on the ingredient list to meet clean label requirements without compromising existing shelf-life.

(Figure 3 Instrumental Evaluation of Lipid Oxidation in Cooked Chicken Patties)

(Figure 4 Sensory Evaluation of Lipid Oxidation in Cooked Chicken Patties)

Processed Meats: Special Considerations

The interest in the application of naturally cured ingredients is largely due to increasing consumer demand for processed meats with clean label solutions. Maintaining colour and flavour stability is critical in dry-fermented type sausages, which are highly susceptible to oxidative changes when sliced and stored. Interaction of oxygen, lipids, and carotenoid pigments result in colour fading. We evaluated the effect of adding Duralox (rosemary/green tea extract combinations) on the storage quality and shelf-life of pepperoni formulations using natural cure (pre-converted vegetable juice powder) or conventional cure. Our findings demonstrated the antioxidative efficacy of Duralox Oxidation Management Systems in dry-fermented (“naturally cured’)-type sausages by helping to maintain their colour life and inhibiting lipid-derived rancidity during storage, which was equivalent to BHA/BHT efficacy in conventionally cured versions.

Value Addition For Meat By-Products Through Shelf-Life Extension

Stabilisation of meat by-products—especially chicken fat and chicken powder—with natural antioxidants, provides additional value for clean label requirements. Herbalox Rosemary extract has clearly shown efficacy in animal fats, typically measured using rapid methods such as OSI (Oxidative Stability Index). Furthermore, the incorporation of Herbalox Rosemary Extract during the cooking process has shown positive benefits in further processed products such as chicken powder (Figure 5), as indicated by Peroxide Value (PV) results. PV is an assessment of primary oxidation products, while TBARS or hexanal denotes the extent of secondary oxidation products that are responsible for off-aromas and off-flavour. Both these case studies highlight the point that apply in ‘Good Oxidation Management Practices’ in meat, poultry and animal protein/fat matrices: ‘Add early in the process’.

Herbalox Rosemary Extract, in combination with good oxidation management practices, can maintain colour- and flavour-life in meat products, while providing a consumer-friendly label. For additional flavour and colour stability, additive or synergistic antioxidant combinations such as Duralox Oxidation Management Systems (rosemary/green tea extracts and rosemary/acerola extracts) can be used. It is, therefore, important to validate the technical and functional effects of natural antioxidants in fresh meats and processed meats prior to commercialisation as all plant extracts will not provide the same results.

Furthermore, the end application needs are also important in selecting the suitable natural antioxidant. It is also important to maximise its efficiency; thus, application consultation would be beneficial to meat/food processors. Proven suppliers as well as product and processing experience can bring value to meat processors through consistent performance and quality assurance, ultimately providing a competitive edge in the market place.