Red Seaweed Powder Cuts Fat and Slows Spoilage in Romanian Parizer Sausage

A laboratory-scale study published in Food Production, Processing and Nutrition reports that adding 5% powdered Gracilaria gracilis, a red macroalga, to Parizer, a Romanian Bologna-type emulsified sausage, lowered the product’s fat content from 32.65% to 29.86% and raised dietary fiber from 0.82% to 2.17%, while protein levels stayed essentially unchanged at around 13%. The fortified sausage also showed slower lipid oxidation, slower protein breakdown, and a more cohesive microstructure during eight days of refrigerated storage compared with an unfortified control.

The researchers prepared four Parizer formulations containing 0%, 1%, 3%, and 5% G. gracilis powder, using minced pork meat and fat, spices, and algal biomass with a particle size below 2 mm supplied by a Spanish aquaculture company. Higher inclusion levels of 7 to 10% were excluded because they produced excessive firmness, a pasty texture, uneven color, and processing difficulties. After pasteurization at 75 °C for one hour, the sausages underwent sensory evaluation as a screening step, and the 5% formulation received the highest overall acceptability score. Only the control and the 5% version, named Gracilaria-Parizer, were then selected for detailed compositional, biological, and storage analyses, with three independent batches per formulation.

The proximate analysis showed that the fat reduction reflects partial replacement of high-fat pork fat with low-fat seaweed biomass, lowering the contribution to the adult recommended daily intake of fat from 46.6% to 42.7% per 100 g of product. Ash content rose significantly from 3.02% to 4.32% and carbohydrates from 1.18% to 3.97%, while the overall energy value changed little, at roughly 342 versus 353 kcal per 100 g. Moisture did not change significantly, which the authors attribute to the low inclusion level despite the water-binding capacity of seaweed polysaccharides.

Because processed meats have been associated with impaired intestinal barrier function and low-grade inflammation, the team also tested water-soluble extracts of both sausages on human cell cultures. In THP-1-derived macrophages and in both undifferentiated and differentiated Caco-2 intestinal epithelial cells, viability remained high after 24 and 72 hours of exposure at concentrations of 50, 100, and 200 µg/mL, staying above 98% across the tested models with no concentration- or time-dependent cytotoxicity. In some Caco-2 conditions, viability even rose significantly at the higher doses, which the authors note may reflect increased metabolic activity or cell number, since the MTT assay measures mitochondrial enzymatic activity rather than cell count directly.

The inflammatory potential of the extracts was assessed by measuring gene expression of IL-1β, IL-6, IL-8, MCP-1, and TNF-α in macrophages after 24 hours. Both formulations kept IL-1β, IL-8, MCP-1, and TNF-α close to baseline, indicating no significant inflammatory activation. A notable difference emerged for IL-6: the control extract induced a moderate increase of about 2.2-fold over untreated cells, whereas the Gracilaria-Parizer extract reduced expression to roughly 0.8-fold, near baseline. The authors link this attenuation to sulfated polysaccharides from macroalgae, which have been reported to suppress IL-6 production through NF-κB–dependent signaling, while stressing that these in vitro results warrant investigation in more complex models.

During refrigerated storage at 4 °C and 55% relative humidity, samples were analyzed at days 0, 3, 5, and 8. The peroxide value, a marker of primary lipid oxidation, started at 2.75 meq O₂/kg fat in both sausages but climbed to 12.25 meq O₂/kg in the control by day 8, approaching and exceeding the CODEX limit of 10 meq O₂/kg, versus 11.25 meq O₂/kg in the fortified product. The p-anisidine value, which quantifies secondary oxidation products such as aldehydes responsible for rancid off-flavors, rose 3.14-fold in the control but only 2.62-fold in the Gracilaria-Parizer. The iodine value, an indicator of unsaturated double bonds, declined 1.11-fold in the control and 1.07-fold in the fortified sausage, indicating slower oxidation of unsaturated fatty acids.

Protein degradation followed a similar pattern. Easily hydrolysable nitrogen, a marker of proteolysis, rose from 21.53 to 29.10 mg/100 g in the control, close to the regulatory limit of 30 mg/100 g, but only to 24.80 mg/100 g in the fortified sausage. Assuming linear kinetics, the authors calculate that the control would reach the limit in about 8.2 days versus roughly 23 days for the Gracilaria-Parizer. Fourier-transform infrared spectroscopy of the amide I band showed that the control’s protein secondary structure destabilized after just three days, with β-sheets collapsing into disordered random coils, whereas the seaweed formulation delayed this transition until day five and better preserved α-helical structures.

Microscopic and image-analysis findings supported these biochemical results. The control sausage showed progressive surface heterogeneity, fragmented protein networks, pore formation, and fat coalescence by day five, while the Gracilaria-Parizer largely maintained structural integrity, with a more cohesive protein network and better-dispersed fat. Reflectance spectroscopy further indicated more uniform pigment behavior and reduced oxidative heterogeneity in the fortified product, whose darker color stems from endogenous algal pigments such as phycobiliproteins and chlorophyll a. A principal component analysis of sixteen variables, covering color, protein structure, lipid oxidation, and protein degradation, separated the two formulations cleanly along the first principal component, which together with the second explained 84.51% of the total variance, with the fortified product remaining on the side associated with preserved iodine values, β-sheet structure, and moisture.

The authors propose that the observed stabilization arises from a combination of mechanisms rather than antioxidant activity alone: agar-type polysaccharides, reported at 36.8% to 46.6% of the dry weight of G. gracilis, form a hydrated gel network that restricts protein unfolding and immobilizes water, while interfacial protein–polysaccharide layers around fat droplets may limit oxygen and pro-oxidant access, and algal polyphenols may scavenge radicals, chelate metals, and inhibit proteolytic enzymes. They caution, however, that the underlying molecular mechanisms were not directly investigated and that the 5% inclusion level may limit the full protective effect of the seaweed’s antioxidants.

The study’s limitations are explicitly acknowledged: it tested a single inclusion level over a short eight-day window chosen to capture early-stage storage rather than commercial shelf life, no microbiological analyses were performed, and all biological effects were assessed only in vitro, so they cannot be extrapolated directly to in vivo conditions. Future work, the authors write, should include in vivo validation, detailed bioactive profiling, life-cycle assessment, and monitoring of elemental composition, particularly sodium, iodine, and heavy metals, under real market conditions. Within those boundaries, the findings position G. gracilis as a promising multifunctional ingredient for reformulating emulsified meat products with less fat, more fiber, and slower chemical deterioration.

Subject of Research: Laboratory-scale fortification of Parizer sausage with the red seaweed Gracilaria gracilis to improve nutritional quality and refrigerated storage stability

Article Title: Gracilaria gracilis fortification as a sustainable strategy for improving nutritional quality and storage stability of Parizer: a laboratory-scale study

Article References: Dumuta, A., Mihaly Cozmuta, A., Scarfi, S., Moussa, M., Mirata, S., Baldassari, S., Drava, G., Malta, E.-J., Macias Andrade, M., Pop, F., Peter, A., Nicula, C., Szakács, Z., & Mihaly Cozmuta, L. (2026). Gracilaria gracilis fortification as a sustainable strategy for improving nutritional quality and storage stability of Parizer: a laboratory-scale study. Food Production, Processing and Nutrition, 8(1), Article 66. https://doi.org/10.1186/s43014-026-00414-8

Image Credits: AI Generated

DOI: 10.1186/s43014-026-00414-8

Keywords: Gracilaria gracilis, red seaweed, Parizer, Bologna-type sausage, meat reformulation, dietary fiber, lipid oxidation, protein denaturation, Caco-2 cells, THP-1 macrophages, refrigerated storage, functional ingredient