Effect of High-Pressure Processing on the Microbial Quality throughout the Shelf Life of Vacuum-Packed Sliced Ham and Frankfurters

Macroalgae-Fortified Sausages: Nutritional and Quality Aspects Influenced by Non-Thermal High-Pressure Processing

The present work evaluated the nutritional impact of macroalgae flours used as new ingredients in fermented sausages and the feasibility of using high-pressure processing (HPP) as a non-thermal pasteurization methodology to keep the quality attributes of the new food products. A commercial macroalgae mix was used in the formulation of new macroalgae-fortified meat frankfurter sausages (F-MFS), macroalgae-fortified vegetable frankfurter sausages (F-VFS) and in macroalgae-fortified traditional Portuguese sausage "chouriço" (F-TPS), overall incrementing the contents of Mg, K, Ca, Mn and Fe and decreasing the Na/K ratio. The application of HPP allowed extending the shelf-life of frankfurters by about 3-fold and improved the safety of "chouriço" along 180 days of storage, keeping its microbial load below the detection limit. The prevention of microbial growth in F-MFS and F-VFS was accompanied by pH stability of the products. In addition, no significant detriment on surface color and fatty acids was observed between pressurized and non-pressurized sausages, allowing consolidating the suitability of HPP in seaweed-fortified fermented sausages.

Valorization of Carob Fruit Residues for the Preparation of Novel Bi-Functional Polyphenolic Coating for Food Packaging Applications

The food industry has become interested in the development of innovative biomaterials with antioxidant and antimicrobial properties. Although several biopolymers have been evaluated for food packaging, the use of polyphenolic coatings has been unexplored. The purpose of this work was to develop an antioxidant and antimicrobial coating for food packaging through the polymerization of carob phenolics. At first, the polyphenolic coatings were deposited in glass surfaces polymerizing different concentrations of carob extracts (2 and 4 mg mL⁻¹) at three pH values (7, 8 and 9). Results demonstrated that the coating produced at pH 8 and at a concentration of 4 mg mL⁻¹ had the most potent antioxidant and antimicrobial potential. Then, the coating was applied directly on the salmon fillet (coating) and on the plastic container (active packaging). Peroxide and thiobarbituric acid-reactive substances (TBARS) methods were used to measure the potency to inhibit lipid oxidation in salmon fillets. Furthermore, the anti-Listeria activity of coatings was also assessed. Results showed a significant decrease of lipid oxidation during cold storage of salmon fillets for both treatments; the superiority of applied coating directly on the salmon fillets was also highlighted. Regarding the antimicrobial potency, the polyphenolic coating depleted the growth of Listeria monocytogenes after 10 days storage; while the active packaging had no effect on Listeria monocytogenes. Overall, we describe the use of low-cost carob polyphenols as precursors for the formation of bifunctional coatings with promising applications in food packaging.