Effect of fermented blueberry on the oxidative stability and volatile molecule profiles of emulsion-type sausage during refrigerated storage

Whey Protein Hydrogels and Emulsion Gels with Anthocyanins and/or Goji Oil: Formation, Characterization and In Vitro Digestion Behavior

Whey protein isolate (WPI) has functional properties such as gelation and emulsification. Emulsion gels combine the benefits of both emulsions and hydrogels. In this study, WPI hydrogels and emulsion gels were developed with goji oil (GO) as the oil phase by the inclusion of blueberry extract (BE) in the protein matrix. Heat-denatured WPI (hWPI) particles and emulsions were characterized in terms of size distribution, ζ-potential, interfacial protein, and anthocyanin partition. The inclusion of anthocyanins-rich blueberry extract led to the aggregation of hWPI particles, but it also increased the interfacial protein of 10% goji oil emulsions to 20% and decreased their size distribution to 120 and 325 nm. WPI hydrogels and emulsion gels were analyzed in terms of their water-holding capacity, which decreased from 98% to 82% with the addition of blueberry extract and goji oil. Syneresis, rheological, and morphological characteristics were also analyzed. The gelation time of hWPI particles and emulsions was shortened from 24 h to 12 h when incorporating blueberry extract to form a dense network. The network was the most homogeneous and densest in the presence of 3% blueberry extract and 5% goji oil. The co-inclusion of blueberry extract and goji oil increased the syneresis during the freeze-thaw cycles, with the values rising from 13% to 36% for 5% BE hydrogel and BE-containing emulsion gels after the first cycle. All WPI hydrogels and emulsion gels exhibit predominantly elastic behavior. Moreover, anthocyanin release, antioxidant activity, and the fatty acid composition profile were also analyzed during in vitro digestion. Soluble and free anthocyanins in the digested medium were reduced with the goji oil content but increased with the blueberry extract content. The stability of polyunsaturated fatty acids in the digested medium was improved by the addition of blueberry extract. The antioxidant activity of the digested medium increased with the content of blueberry extract but decreased with the content of goji oil. The ABTS∙+ scavenging capacities decreased from 63% to 49% by increasing the content of GO from 0% to 10% and they increased from 48% to 57% for 5% BE and 10% GO emulsion gels as the BE content increased from 0% to 5% after 6 h of digestion. The data gathered should provide valuable insights for future efforts to co-encapsulate hydrophilic and hydrophobic agents, thereby enhancing their stability, bioavailability, and functional properties for potential applications in food industries.

Physicochemical, Antioxidant, Organoleptic, and Anti-Diabetic Properties of Innovative Beef Burgers Enriched with Juices of Açaí (Euterpe oleracea Mart.) and Sea Buckthorn (Hippophae rhamnoides L.) Berries

BACKGROUND

The aim of this study was to evaluate the selected quality parameters of innovative beef burgers produced with the addition of açaí and/or sea buckthorn berry juices.

METHODS

Five variants of innovative burgers were obtained, differing in the proportion of juices in the recipe. The pH of meat stuffing, thermal losses, production yield, color (CIE L*a*b*), content of polyphenolic compounds, degree of oxidation of the lipid fraction (TBARS), and antioxidant activity against ABTS radicals were determined. Anti-diabetic activity was measured as the ability to inhibit α-glucosidase and dipeptidyl peptidase-4 activity. A sensory evaluation was also performed.

RESULTS

Beef burgers formulated with açaí and sea buckthorn juices had up to five times higher total polyphenol content than burgers without added juices. The addition of the juices increased antioxidant activity against ABTS radicals (from 42 to 440 µmol/L/100 g) and effectively inhibited oxidation of the lipid fraction of the beef burgers. Recipe modifications resulted in changes in the color parameters of the beef burgers and had a positive effect on the sensory quality attributes evaluated. Beef burgers containing 0.5 g of açaí juice and 1.0 g of sea buckthorn juice were rated the best in terms of acceptability of appearance, aroma, color, juiciness, and tenderness. The addition of açaí and sea buckthorn juice did not increase the inhibitory activity against α-glucosidase and dipeptidyl peptidase-IV of the innovative beef burgers.

CONCLUSIONS

The proposed recipe modification may be an effective way to fortify beef burgers with phytochemicals with antioxidant properties while maintaining their sensory properties.

Fermentation of Vaccinium floribundum Berries with Lactiplantibacillus plantarum Reduces Oxidative Stress in Endothelial Cells and Modulates Macrophages Function

Accumulating evidence suggests that high consumption of natural antioxidants promotes health by reducing oxidative stress and, thus, the risk of developing cardiovascular diseases. Similarly, fermentation of natural compounds with lactic acid bacteria (LAB), such as Lactiplantibacillus plantarum, enhances their beneficial properties as regulators of the immune, digestive, and cardiovascular system. We investigated the effects of fermentation with Lactiplantibacillus plantarum on the antioxidant and immunomodulatory effects of Pushgay berries (Vaccinium floribundum, Ericaceae family) in human umbilical vein endothelial cells (HUVECs) and macrophage cell line RAW264.7. Polyphenol content was assayed by Folin–Ciocalteu and HPLC-MS/MS analysis. The effects of berries solutions on cell viability or proliferation were assessed by WST8 (2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt and Lactate dehydrogenase (LDH) release, Trypan blue exclusion test, and Alamar blue assay. Antioxidant activity was evaluated by a cell-based chemiluminescent probe for the detection of intracellular H₂O₂ production in HUVECs. Heme oxygenase-1 (HO-1) expression levels were investigated by RT-qPCR. Glutathione reductase (GR), glutathione peroxidase (Gpx), superoxide dismutase (SOD), and catalase (CAT) activities, as markers of intracellular antioxidant defense, were evaluated by spectrophotometric analysis. The immunomodulatory activity was examined in RAW 264.7 by quantification of inducible nitric oxide synthase (iNOS) and Tumor Necrosis Factor—alpha (TNFα) by RT-qPCR. Data showed that fermentation of Pushgay berries (i) enhances the content of quercetin aglycone, and (ii) increases their intracellular antioxidant activity, as indicated by the reduction in H₂O₂-induced cell death and the decrease in H₂O₂-induced HO-1 gene expression in HUVECs treated for 24 h with fermented berries solution (10 µg/mL). Moreover, treatment with Pushgay berries for 72 h (10 µg/mL) promotes cells growth in RAW 264.7, and only fermented Pushgay berries increase the expression of iNOS in the same cell line. Taken together, our results show that LAB fermentation of Pushgay berries enhances their antioxidant and immunomodulatory properties.

Effects of ergothioneine-enriched mushroom extract on oxidative stability, volatile compounds and sensory quality of emulsified sausage

OBJECTIVE

The aim of this work was to assess the effect of ergothioneine (ESH)-enriched mushroom extract on oxidative stability, volatile compounds, and sensory quality of emulsified sausage.

METHODS

The ESH content was determined by high performance liquid chromatography. The antioxidant activity of Flammulina velutipes (F. velutipes) extract was determined through radical-scavenging activity of 1,1 diphenyl-2-picryl-hydrazyl, 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) and hydroxyl radicals. Four different groups of emulsified sausage were manufactured: control, no antioxidants; BHA, 0.01% butylated hydroxyanisole; EEME, 0.8% ESH-enriched mushroom (F. velutipes) extract; AE, 0.012% authentic ESH, after storage for 14 days (at 4°C), the quality of sausage including oxidative stability (2-thiobarbituric acid reactive substances and protein carbonyls content), volatile compounds and sensory quality were studied.

RESULTS

It was demonstrated that adding ESH-enriched F. velutipes extract to sausage could effectively prevent lipid and protein oxidation, and its efficacy was equivalent with 0.01% BHA. During meat processing, the ESH mainly contributed to the antioxidative activity of F. velutipes extract. The flavor and sensory attributes of emulsified sausage were improved through adding ESH-enriched F. velutipes extract.

CONCLUSION

Accordingly, the extract of F. velutipes contained high-level of ESH and could be a good antioxidant candidate for processed meat production.

Overview of Studies on the Use of Natural Antioxidative Materials in Meat Products

Studies conducted in the past decade related to the use of natural antioxidants in meat products revealed the prevalent use of plant-based antioxidative materials added as powders, extracts, or dried or raw materials to meat products. The amount of antioxidative materials varied from 7.8 ppm to 19.8%. Extracts and powders were used in small amounts (ppm to grams) and large amounts (grams to >1%), respectively. Antioxidative materials used in meat products are mainly composed of phenolic compounds and flavonoids, which are able to inhibit lipid peroxidation of meat products, thereby preserving meat quality. However, the main ingredients used in processed meat products are the traditional additives, such as sodium erythorbate, sodium hydrosulfite, and synthetic antioxidants, rather than natural antioxidants. This difference could be attributed to changes in the sensory quality or characteristics of meat products using natural antioxidants. Therefore, novel research paradigms to develop meat products are needed, focusing on the multifunctional aspects of natural antioxidants.