Whey protein isolate (WPI), soy protein isolate (SPI), and sodium caseinate (CAS) can inhibit lipid oxidation when they produce a positive charge at the interface of emulsion droplets. However, when proteins are used to stabilize oil-in-water emulsions, only a fraction of them actually absorb to the emulsion droplets, with the rest remaining in the continuous phase. The impact of these continuous phase proteins on the oxidative stability of protein-stabilized emulsions is not well understood. WPI-stabilized menhaden oil-in-water emulsions were prepared by high-pressure homogenization. In some experiments WPI was removed from the continuous phase of the emulsions through repeated centrifugation and resuspension of the emulsion droplets (washed emulsion). Unwashed emulsions were more oxidatively stable than washed emulsions at pH 7.0, suggesting that continuous phase proteins were antioxidative. The oxidative stability of emulsions containing different kinds of protein in the continuous phase decreased in the order SPI > CAS > WPI, as determined by both hydroperoxide and headspace propanal formation. Iron-binding studies showed that the chelating ability of the proteins decreased in the order CAS > SPI > WPI. The free sulfhydryls of both WPI and SPI were involved in their antioxidant activity. This research shows that continuous phase proteins could be an effective means of protecting omega-3 fatty acids from oxidative deterioration.

The antioxidant activity of carnosine, a β‐alanine‐histidine dipeptide found in skeletal muscle, was investigated. Carnosine (25 mM) inhibited the catalysis of lipid oxidation by iron, hemoglobin, lipoxidase and singlet oxygen from 35–96% suggesting that the antioxidant mechanism of carnosine is not solely due to metal chelation. Heating the carnosine at 100°C for 15 min had no effect on its ability to inhibit these lipid oxidation catalysts, and the activity of carnosine was not affected over the pH range of 5.1–7.1. Studies using tocopherol‐containing liposomes suggest that carnosine and tocopherol do not act synergistically to inhibit lipid oxidation. These data indicate that carnosine has excellent potential for use as a natural antioxidant in processed foods.

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A yogurt mix (2 g fat and 17g solids/100 g) was supplemented with an algae oil emulsion to provide 500 mg omega-3 fatty acids per 272 g serving of yogurt white mass. The emulsion was added to the yogurt mix either before or after the homogenization step and prior to pasteurization. It was then flavoured with a strawberry fruit base and fermented and stored for up to three weeks. The oxidative deterioration of the products was determined by hydroperoxide measurements and by trained and consumer sensory evaluations. The hydroperoxide content of the supplemented yogurts increased over the storage treatment and was unaffected by the stage of addition. The trained panel could distinguish a stronger fishy flavour in both of the supplemented yogurts after 22 days storage, but the consumer panel rated both control and supplemented samples similarly, as 'moderately liked'.

Staphylokinase (SAK) as the third generation thrombolytic molecule is a promising agent for the treatment of thrombosis. SAK variant of SAKфC was expressed in Pichia pastoris strains KM71H and GS115. The codon adaptation index of SAK was improved from 0.75 to 0.89. The expression of recombinant SAK (rSAK) reached to its maximum (310 mg/L of the culture medium) after 48-hr stimulation with 3% methanol and remained steady until day 5. The maximum activity of the enzyme was at pH 8.6 and 37°C. It was highly active at temperatures 20-37°C and pH ranges of 6.8-9 (relative residual activity more than 80%). It was determined that rSAK was 73.8% of the total proteins secreted by P. pastoris KM71H into the culture media. The specific activities of rSAK were measured as 9,002 and 21,042 U/mg for the nonpurified and purified proteins, respectively. The quantity of the purified protein (>99% purity) was 720 µg/mL with a purification factor of 2.34. Western blot analysis showed two bands of nearly 22 and 18.6 kDa. It was concluded that P. pastoris is a proper host for expression of biologically active and endotoxin-free rSAK due to its high expression and low protein impurity in culture supernatant.

Colorectal cancer (CRC) is the third most common cause of cancer globally and the fourth attributable cause of mortality and morbidity due to cancer. An emerging factor contributing to CRC is the gut microbiota and the cellular changes associated with it. Further insights on this may help in the prevention, diagnosis and new therapeutic approaches to colorectal cancer. In most cases of CRC, genetic factors appear to contribute less to its aetiology than environmental and epigenetic factors; therefore, it may be important to investigate these environmental factors, their effects, and the mechanisms that may contribute to this cancer. The gut microbiota has recently been highlighted as a potential risk factor that may affect the structural components of the tumor microenvironment, as well as free radical and enzymatic metabolites directly, or indirectly. Many studies have reported changes in the gut microbiota of patients with colorectal cancer. What is controversial is whether the cancer is the cause or consequence of the change in the microbiota. There is strong evidence supporting both possibilities. The presence of Fusobacterium nucleatum in human colorectal specimens has been demonstrated by RNA-sequencing. F. nucleatum has been shown to express high levels of virulence factors such as FadA, Fap2 and MORN2 proteins. Our review of the published data suggest that F. nucleatum may be a prognostic biomarker of CRC risk, and hence raises the potential of antibiotic treatment of F. nucleatum for the prevention of CRC.

: This study was carried out to determine the effect of processing and cooking on n‐3 polyunsaturated fatty acid (PUFA) stability and to determine the efficacy of antioxidants (ANTI) to minimize lipid oxidation in cooked n‐3 PUFA‐fortified meat products. An emulsion of n‐3 PUFAs (25% algal oil) was incorporated into ground turkey, pork sausages, or restructured hams (500 mg n‐3 PUFA/110 g meat) with or without an “antioxidant cocktail” containing citrate (0.5% w/w), erythorbate (1 g/kg product), and rosemary (0.2% w/w). Ground turkey and pork sausages were frozen 2 d, then cooked to 71°C, and stored at 4°C for 2 d. Cooked, restructured hams were sliced, vacuum packaged, and stored at 4°C, or frozen and thawed with subsequent storage at 4°C. Treatments were CON (control), n‐3 (n‐3 PUFAs), CON + ANTI and n‐3 + ANTI. Products were analyzed for color, lipid oxidation (TBARS and peroxide values), and n‐3 PUFA profile. TBARS of n‐3 PUFA‐fortified treatments in ground turkey and pork sausages increased with storage (P < 0.05); there were no changes in TBARS for CON + ANTI and n‐3 + ANTI groups (P > 0.05). For restructured hams nitrite curing appeared to delay lipid oxidation such that antioxidant treatment effects were unobservable (P > 0.05). Overall recovery of n‐3 PUFAs after heat processing was 69% to 85%, and there was no effect of storage on n‐3 PUFA concentration in raw or cooked products (P > 0.05). Sensory scores for n‐3 treated restructured hams were lower than controls (P < 0.05). Results suggested that cooking resulted in some losses of n‐3 PUFAs in fortified meat products and that an “antioxidant cocktail” protected against lipid oxidation during subsequent storage in non‐cured meat products.

Polyols have been incorporated into fish oil emulsions as a means for the inhibition of lipid oxidation and suppression of fishy flavor. However, the role of sugars and polyhydric alcohols as antioxidants has not been clearly established. Selected polyols were evaluated for their performance as antioxidants and modifiers of oxidation pathways in a model system. Oil/water (O/W) emulsions were prepared with freshly steam-deodorized menhaden oil. A layer of emulsion in aluminum pans held at 5 degrees C was exposed to 2550 lx fluorescent lights for 24 h before peroxide values and volatile flavor compounds were analyzed by GC headspace entrainment procedure. Antioxidant activity was confirmed for fructose, sucrose, raffinose, sorbitol, or mannitol when incorporated at 16% of the aqueous phase into model fish oil-in-water emulsions. Peroxide values were suppressed 10-18% in treated samples compared to control samples. Viscosity data did not exclude possible contributions from a restricted oxygen diffusion mechanism in the antioxidant activity, but revealed that emulsion viscosity did not govern fish oil oxidation rates. Combining polyols with phenolic antioxidants (alpha-tocopherol, BHT, or TBHQ) frequently diminished the antioxidant activity compared to that for individual phenolic antioxidants, which was interpreted as indicating that the H-donating activity of phenolic antioxidants was hindered by the H-bonding activity of polyols. A viscosity-based inhibition of the retroaldol conversion of (E,Z)-2,6-nonadienal to (Z)-4-heptenal with a high fructose concentration (67%) was attributed to a restriction of molecular mobility of reactants, but the conversion was only slightly inhibited by the concentration of fructose (16%) used in experimental emulsions. The data supported a hypothesis that either or both free radical scavenging and transition state metal chelation activities were provided by polyols in fish oil emulsions. Also, polyols retarded the water-requiring retroaldol decomposition of (E,Z)-2,6-nonadienal to (Z)-4-heptenal in the model systems and the reaction may be involved in some suppression of fishy flavors in emulsions.