Processed Meat and Polyphenols: Opportunities, Advantages, and Difficulties.

Currently, processed meats appear increasingly as a nonhealthy food because of their content of fat, salt, nitrite, and particularly in red meat, for the heme-iron concerning oxidant effect and radicals formation in human gut. Polygonum cuspidatum and rosemary extract has been tested to counteract these effects and experiments were carried out to add polyphenols into whole meat cuts with the aims to improve their healthiness. The addition of these extracts can reduce the oxidation-reduction potential of products, increasing the antioxidant power. Nevertheless, a low percentage of polyphenols were found in the products because of the process effects and an interaction with the ascorbate residue was observed. In addition, some drawbacks were a decrease in of yield and a worsening of some sensorial properties when large amount of extract was added. The balance between the improvement of the wholesomeness content and the acceptability of products is the challenge the current research have to overcome.

Feasibility of addition of polyphenol-rich vegetable extracts in whole cooked products: Benefits and drawbacks.

Pork loins were cooked with 5 different polyphenol-rich vegetable extracts: Polygonum cuspidatum, oregano extract, rosemary extract, white grape extract and green tea extract. These extracts were added to brine, taking into account their solubility, for subsequent injection and cooking. Loins with added vegetable extracts exhibited higher antioxidant effect compared to controls, as shown by the oxidized/reduced ascorbate ratio, the potential of reduction and the fat oxidation rate. However, some effects were observed in terms of taste, colour changes and, in some cases (green tea and oregano), presence of blots on meat slices. Poor diffusion of the brine through the muscle fibres and insolubility of the extracts in localized spots are weaknesses of these products. A significant amount of polyphenols was lost or destroyed during the cooking phase of the process. Sensory tests show that only Polygonum cuspidatum and rosemary extract result in an acceptable product. In this case the contribution of active molecules in the final product is rather limited.

Microbial, chemical, textural and sensory properties of coated rainbow trout by chitosan combined with pomegranate peel extract during frozen storage.

The current study was aimed to investigate the combined effects of chitosan (Ch) and pomegranate peel extract (PPE) on the overall quality of rainbow trout (Oncorhynchus mykiss) during the frozen storage. Fresh gutted fishes were dipped for 60s either in sterile distilled water (Control) or in chitosan combined with 0 (Ch), 1% (Ch+PPE1), 2% (Ch+PPE2), or 4% (Ch+PPE4) (w/v) PPE. Microbial, chemical, textural and sensory properties of the samples were intermittently checked during six months. At the end of storage, the highest and lowest values of psychrophilic, lactic acid bacteria and mold counts in the control and Ch+PPE4 groups were respectively, 5.14±0.19, 2.91±0.00; 3.11±0.03, 0.33±0.57 and 2.86±0.19, 2.24±0.13. Our results showed the best performance to prevent the oxidation of fats and protein was in the chitosan combined with 4% PPE, however, due to its undesirable color, the chitosan combined with 2% PPE was preferred. A considerable improvement in the chemical, microbial, sensory and textural properties was shown in the Ch+PPE2 groups. Therefore, this active coverage was suggested as safe to store rainbow trout up to 6 months frozen storage.