Assessment and comparison of the antioxidant activities and nitrite scavenging activity of commonly consumed beverages in Korea

Assessment of Potential Nitrite Safety Risk of Leafy Vegetables after Domestic Cooking

Improper cultivation can easily cause excessive nitrate accumulation in leafy vegetables, and the cooking processes used to prepare them can upset their nitrate/antioxidant balance, affecting their potential nitrite safety risk (PNSR). We investigated the impacts stir-frying, steaming, microwaving, and boiling on the nitrate, nitrite, and antioxidant capacity in water spinach and cabbage, and observed the impacts of storage duration on the PNSR. The antioxidant/in vivo nitrite ratio (A/N) was used to evaluate the nitrite risks in the cooked vegetables. Boiling achieved the highest A/N ratio (1.57) for water spinach, reducing the nitrate content by 25% without significantly affecting the antioxidant capacity. Stir-frying achieved the highest A/N ratio (6.55) for cabbage, increasing the antioxidant capacity by 140% without significantly affecting the nitrate content. Furthermore, it was found that the storage periods for boiled water spinach and stir-fried cabbage should not exceed 12 h and 24 h, respectively. Appropriate cooking methods and limited storage times are thus required for leafy vegetable to prevent adverse health effects.

A review of pears (Pyrus spp.), ancient functional food for modern times

BACKGROUND

Pears have been world-widely used as a sweet and nutritious food and a folk medicine for more than two millennia.

METHODS

We conducted a review from ancient literatures to current reports to extract evidence-based functions of pears.

RESULTS

We found that pears have many active compounds, e.g., flavonoids, triterpenoids, and phenolic acids including arbutin, chlorogenic acid, malaxinic acid, etc. Most of researchers agree that the beneficial compounds are concentrated in the peels. From various in vitro, in vivo, and human studies, the medicinal functions of pears can be summarized as anti-diabetic,-obese, -hyperlipidemic, -inflammatory, -mutagenic, and -carcinogenic effects, detoxification of xenobiotics, respiratory and cardio-protective effects, and skin whitening effects. Therefore, pears seem to be even effective for prevention from Covid-19 or PM2.5 among high susceptible people with multiple underlying diseases.

CONCLUSION

For the current or post Covid-19 era, pears have potential for functional food or medicine for both of communicable and non-communicable disease.

Anti-Thrombotic, Anti-Oxidant and Haemolysis Activities of Six Edible Insect Species

In Korea, various insect species such as crickets and grasshoppers, as well as honey bee and silkworm pupae, have been consumed as food and used in oriental medicine. In this study to evaluate useful the bioactivities and potentially adverse effects of edible insects, ethanol extracts of Allomyrina dichotoma (AD), Tenebrio molitor (TM), Protaetia brevitarsis (PB), Gryllus bimaculatus (GB), Teleogryllusemma (TE), and Apis mellifera (AM) were prepared and evaluated with regard to their anti-thrombosis, anti-oxidant and haemolysis activities against human red blood cells. AD and TE extracts showed strong anti-oxidant activities, which were not related to polyphenol content. All ethanol extracts, except AM extract, showed strong platelet aggregation activities. The platelet aggregation ratios of the extracts were 194%–246% of those of the solvent controls. The effects of the AD, TM, PB, GM, and AM extracts on thrombin, prothrombin and various coagulation factors were negligible. Only the extract of TM showed concentration-dependent anti-coagulation activities, with a 1.75-fold aPTT (activated Partial Thromboplastin Time) extension at 5 mg/mL. Of the six insect extracts, TM and AM extracts exhibited potent haemolytic activity. Our results on the insect extracts’ functional properties suggest that edible insects have considerable potential not just as a food source but as a novel bio-resource as well.

Valorization of byproducts from tropical fruits: Extraction methodologies, applications, environmental, and economic assessment: A review (Part 1: General overview of the byproducts, traditional biorefinery practices, and possible applications)

Tropical fruits represent one of the most important crops in the world. The continuously growing global market for the main tropical fruits is currently estimated at 84 million tons, of which approximately half is lost or wasted throughout the whole processing chain. Developing novel processes for the conversion of these byproducts into value-added products could provide a viable way to manage this waste problem, aiming at the same time to create a sustainable economic growth within a bio-economy perspective. Given the ever-increasing concern about sustainability, complete valorization through a bio-refinery approach, that is, zero waste concept, as well as the use of green techniques is therefore of utmost importance. This paper aims to report the status on the valorization of tropical fruit byproducts within a bio-refinery frame, via the application of traditional methodologies, and with specific attention to the extraction of phenolics and carotenoids as bioactive compounds. The different types of byproducts, and their content of bioactives is reviewed, with a special emphasis on the lesser-known tropical fruits. Moreover, the bioactivity of the different types of extracts and their possible application as a resource for different sectors (food, pharmaceutical, and environmental sciences) is discussed. Consequently, this review presents the concepts of tropical fruit biorefineries, and the potential applications of the isolated fractions.

Nitrite scavenging impact of fermented soy sauce in vitro and in a pork sausage model

The objective of this study was to determine nitrite scavenging activity of fermented soy sauce in vitro and in a pork sausage model. In vitro nitrite scavenging activity (pH 6.0) of fermented soy sauce (10 mg/mL) was 13.2%. Within selected concentrations (10-100 mg/mL), in vitro nitrite scavenging activity and total phenol content of fermented soy sauce were highly dose-dependent (P < 0.001). In pork sausage model containing 120 mg/kg of NaNO₂, fermented soy sauce resulted in significantly lower residual nitrite content (35.28 mg/kg) compared to only NaNO₂ addition (40.12 mg/kg) at initial storage. During 4 weeks of cold storage, however, fermented soy sauce showed little effect on the residual nitrite content. This study indicates that fermented soy sauce could initially contribute to reduce residual nitrite content, and the nitrite scavenging impact of fermented soy sauce was less effective in the pork sausage model than in vitro evaluation.

ANTIBACTERIAL AND ANTIOXIDANT POTENTIAL OF STEM BARK EXTRACT OF BOMBAX CEIBA COLLECTED LOCALLY FROM SOUTH PUNJAB AREA OF PAKISTAN

Background:

Ethnic medication systems have been used extensively by humans since their origin. Now a day, in the developing countries these systems are being used due to their effectiveness and affordability. Especially inhabitants of rural areas still rely on these systems as first line of treatment against diseased conditions. Till now, majority of medicines is derived from the natural origin particularly plants owing to their little side effects and cost effectiveness.

Materials and Methods:

In the present work, we evaluated antibacterial and antioxidant activity of methanolic extract of Bombax ceiba stem bark. Total phenolic and flavonoid contents were also assessed in the extract. The antioxidant capacity was determined by DPPH, Nitric Oxide scavenging and reducing power activity. For antibacterial activity, Gram-negative (Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi) and Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus) were used.

Results:

Phenolic content was 133.21±1.56 μg GAE/mg of extract while Flavonoid content was 997.93±2.14 μg QE/mg. Plant extract demonstrated strong antiradical activity with EC₅₀ 18.78 ± 0.69 and 23.62 ± 1.99fg/ml for Nitric Oxide and DPPH assay respectively while EC₅₀ in case of reducing power activity was 139.4 ± 0.98μg/ml. Plant extract displayed inhibitory effect against microbial growth with S. typhi as the most resistant strain and Staphylococcus aureus the most sensitive one.

Conclusion:

This study revealed that Bombax ceiba of local origin has broad spectrum antibacterial activity and it can also provide defense against oxidative stress.

Design and development of caffeic acid conjugated with Bombyx mori derived peptide biomaterials for anti-aging skin care applications

This study examined the significant features of caffeic acid conjugated with peptide (APPPKK) to determine if it meets the requirements for a cosmetic anti-aging biomolecule.

Extraction, Structural Characterization, and Potential Antioxidant Activity of the Polysaccharides from Four Seaweeds

Four seaweed polysaccharides were extracted from Sarcodia ceylonensis, Ulva lactuca L., Gracilaria lemaneiformis, and Durvillaea antarctica, respectively, by microwave-assisted extraction. The effect of three significant variables (extraction time, extraction temperature, and the ratio of water to raw material) on the process for extracting polysaccharides was investigated, along with the optimization of the extraction using the response surface method (RSM) with a Box–Behnken design. The polysaccharide structure, monosaccharide composition, degree of sulfation, and molecular weight (M_W) distribution were analyzed by infrared (IR) spectrometry, gas chromatography (GC), and high-performance gel permeation chromatography (HPGPC). IR spectrometry showed that Sarcodia ceylonensis polysaccharide (SCP), Ulva lactuca L. polysaccharide (ULLP), and Durvillaea antarctica polysaccharide (DAP) were all sulfated polysaccharides and, except Gracilaria lemaneiformis polysaccharide (GLP), all belong to β-pyranosidic polysaccharides. The average molecular weight (M_W) of SCP, ULLP, GLP, and DAP was 466, 404, 591, and 482 kDa, respectively. The quantitative and comparative results with external standards indicated that the main monosaccharide in SCP and ULLP was mannose; and GLP and DAP were mainly composed of galactose and glucose, respectively. Then the in vitro antioxidant activity of all of the polysaccharides was evaluated using different assays—2,2–azino –bis (3-ethylbenzthiazoline-6- sulfonate) (ABTS), hydroxyl radical, nitrite scavenging capacity, and reducing power—and the relationship between their antioxidant activity and chemical characteristics were also examined. ULLP presented the highest ABTS radical scavenging activity; ULLP, SCP and DAP also showed a strong effect on the ABTS radical scavenging activity. SCP and ULLP exhibited excellent hydroxyl radical scavenging activities, about 83.33% ± 2.31% and 80.07% ± 2.17%, respectively, at 4 mg/mL. The reducing power of DAP was relatively more pronounced than that of the three other polysaccharides. However, the nitrite scavenging activities of the four seaweed polysaccharides were weaker than other antioxidant activity (ABTS), hydroxyl radical scavenging capacity, and reducing power. In addition, GLP exhibited lower activities than the other three samples in all of the tests for the antioxidant activity.

The effect of clove bud powder at a spice level on antioxidant and quality properties of emulsified pork sausage during cold storage

BACKGROUND

Clove bud is a widely used spice in meat and meat products, and it contains high level of phenolic compounds. The effectiveness of the clove as a spice has not been fully studied at a general level of addition in the meat products. Therefore, in the present study, the antioxidant, antimicrobial, and nitrite scavenging abilities of clove bud powder (CBP) was assessed at spice level (0.1% and 0.2%) in emulsified pork sausage, during 6 weeks of cold storage.

RESULTS

CBP had DPPH radical scavenging ability, but CBP addition at 0.1% and 0.2% did not decrease the TBARS value. An antimicrobial effect of CBP was also not observed during the cold storage. However, residual nitrite at storage weeks 4 and 6 was shown to be lower (P < 0.05). Addition of CBP decreased CIE L* and a* values, but it produced unacceptable sensory properties. Texture profile analysis was not affected by the addition of CBP in emulsified pork sausage (P > 0.05).

CONCLUSIONS

The positive effect on nitrite scavenging could be expected by the addition of 0.2% CBP as a spice. However, antioxidant and antimicrobial abilities were not observed, as well as improvement in the quality of characteristics, in emulsified pork sausage. © 2016 Society of Chemical Industry.

Lab-on-a-disc for simultaneous determination of total phenolic content and antioxidant activity of beverage samples

In this paper, we present a fully integrated and automated lab-on-a-disc for the rapid determination of the total phenolic content (TPC) and antioxidant activity (AA) of beverage samples. The simultaneous determinations of TPC and AA on a spinning disc were achieved by integrating three independent analytical techniques: the Folin-Ciocalteu method that is used to measure TPC, the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) method and the ferric reducing antioxidant power method that are used to measure AA. The TPC and AA of 8 different beverage samples, including various fruit juices, tea, wine and beer, were analyzed. Unlike conventional labor-intensive processes for measuring TPC and AA, our fully automated platform offers one-step operation and rapid analysis.