Evaluation of Free Radical Scavenging Activity and Antioxidant Potential of a Few Popular Green Leafy Vegetables of Malaysia

Blackcurrant (Fruits, Pomace, and Leaves) Phenolic Characterization before and after In Vitro Digestion, Free Radical Scavenger Capacity, and Antioxidant Effects on Iron-Mediated Lipid Peroxidation

Blackcurrant (Ribes nigrum L.) is a berry bush widely cultivated in Europe for producing juices, jams, jellies, and syrups. In addition to berries, blackcurrant leaves and pomace, as byproducts, have also been shown to have health-promoting effects. Static digestion, simulating oral, gastric, and small intestinal digestion, was applied, and blackcurrant leaves, fruits, and pomace and the polyphenol bioaccessibility were evaluated in terms of recovery index. The results were related to sample type, and the recovery index presented higher values in the case of fruits, indicating this morphological part of blackcurrant as the most bioaccessible. The antioxidant potential of blackcurrant was evaluated using four different methods, with the leaves proving to be a significant and powerful antioxidant compared to fruits and pomace. The counteracting potential of inhibiting the oxidation process was evaluated using in vitro-induced lipid peroxidation and the inhibition potential of superoxide and hydroxyl anions. The antioxidant evaluation and the inhibition of biological and non-biological radicals indicate the leaf extract is the most powerful antioxidant studied. Also, the results proved that not only fruits but also the blackcurrant byproducts (pomace and leaves) are promising sources of bioaccessible antioxidants with potential benefits in animal nutrition.

Synergistic Antioxidant and Antibacterial Advantages of Essential Oils for Food Packaging Applications

The development of food-borne and infectious diseases has increased globally at an anomalous rate and is combined with emerging social and economic problems. This highlights the need for new and improved antibacterial agents with novel and different mechanisms of action at regular intervals. Some chemical or artificial food additives are considered harmful if they are used beyond their permissible levels. Today, consumers are demanding alternative, green, safer, and natural food additives to increase the shelf life of food. Essential oils (EOs) are concentrated liquid mixtures of volatile compounds with antioxidant and antibacterial properties that can be used as natural, eco-friendly, renewable, and cost-effective additives. The use of combinations of different EOs and their components is a promising strategy to increase the synergistic and additive effects of EOs in foods. In this article, we review the recent literature on EOs concerning the chemical constituents, extraction methods, antioxidant and antibacterial activities, and their mechanisms of action. Additionally, we discuss the synergistic interaction of different EOs and their components, challenges, and future directions of EOs as natural food preservatives, with special emphasis on shelf life extension and applications in the packaging of food products.

The effect of chelating agents including potassium tartrate and citrate on the maximum reduction of lead and cadmium during soaking and cooking from some different varieties of rice available in Iran

This study aimed to determine the percentage of reduction of lead and cadmium by chelating agents (potassium tartrate and potassium citrate) in the steps of soaking, cooking, and simultaneous soaking and cooking in some varieties of rice for the first time. Each chemical experiment was performed in ten replications. Inductively coupled plasma mass spectrometry (Agilent-7700X ICP-MS) was used to assess the complete Cd and Pb content in rice samples acid-digested (500 mg dry-sample, 9 ml HNO3: 3 ml HCl). The cooking-only treatment was more successful in terms of lead reduction than the soaking-only treatment in chelating agent-containing solutions (either potassium tartrate or potassium citrate), though it had the same effect on cadmium reduction. Simultaneous soaking and cooking in chelating agents such as potassium tartrate and potassium citrate significantly reduced lead (reduction rate compared to control 99.43% with potassium tartrate and 98.96% with potassium citrate) and cadmium (reduction rate compared to control 95.13% with potassium tartrate and 92.77% with potassium citrate). Potassium tartrate outperforms potassium citrate in terms of lead reduction, but potassium tartrate is equivalent to potassium citrate in terms of cadmium reduction. Up to 200 ppm applicable chelating agents, sensory analysis showed no statistically significant difference between the treatments. In general, rice cookers are advised to use levels up to 200 ppm of citrate or potassium tartrate in combination in the 3-hr rinsing period and then in the 15-min cooking period to reduce the percentage of dangerous heavy metals, especially lead 99%-99.4% and cadmium 92.8%-95.1%.

High sodium food consumption pattern among Malaysian population

BACKGROUND

Sodium is an essential mineral needed by the human body that must be obtained from food. An excess intake, however, can lead to many diseases. As food is the main source of sodium, this study aims to provide information on high sodium food consumption patterns in the Malaysian adult population.

METHODS

The Malaysian Community Salt Study (MyCoSS) was a nationwide cross-sectional study, conducted between October 2017 and March 2018. A multistage complex sample was applied to select a nationally representative sample of respondents aged 18 years and above. Face to face interview by a validated Food Frequency Questionnaire (FFQ) comprising 104 food items was used to gain information on high sodium food consumption patterns.

RESULTS

A total of 1047 respondents were involved in this study, with 1032 (98.6%) answering the FFQ. From the number, 54.1% exceed the recommendation of sodium intake <2000mg/day by FFQ assessment. The results also demonstrated that fried vegetables (86.4%) were the most common high sodium food consumed, followed by bread (85.9%) and omelet (80.3%). In urban areas, bread was the most common while fried vegetables took the lead in rural areas. By sex, bread was most commonly eaten by males and fried vegetables by females. The results also found that kolok mee/kampua mee contributed the highest sodium, 256.5mg/day in 9.0% adult population, followed by soy sauce 248.1mg/day in 33.2% adult population, and curry noodles 164.2mg/day in 18.5% adult population.

CONCLUSION

Fried vegetables, bread, and soy sauce were the main source of sodium consumption among adult. Reducing the amount of sodium added to these foods should be the top priority to reduce population sodium intake and thereby prevent sodium-related diseases in Malaysia.

Optimized preparation, characterization, and antioxidant activity of chitooligosaccharide-glycine Maillard reaction products

In this study, chitooligosaccharide (COS) and glycine (Gly) were selected to prepare Maillard reaction products, which were designated COS-Gly-MRPs. Changes in the FTIR and fluorescence spectra confirmed the formation of the COS-Gly-MRPs. Using ferric reducing antioxidant power (FRAP) as a response, the optimal reaction conditions, i.e., a time of 107 min, temperature of 121 °C, pH of 6.0, and n_COS:n_Gly = 2.5:1, were obtained by one-variable-at-a-time method and by response surface methodology. The resulting COS-Gly-MRPs exhibited much stronger antioxidant activity than their substrates. The FRAP of COS-Gly-MRPs was 32.14 mmol Fe²⁺/L, and the radical scavenging activity of COS-Gly-MRPs reached 78.6, 89.0, 92.3, and 86.0% for ABTS, superoxide, DPPH, and hydroxyl radicals, respectively. After 7 days of storage, COS-Gly-MRPs-treated fruit juices showed higher antioxidant capacity than those treated with a mixture of COS and Gly.

Valorizing Dairy Waste: Thermophilic Biosynthesis of a Novel Ascorbic Acid Derivative

l-Ascorbic acid (l-AA) is an essential nutrient that is extremely unstable and cannot be synthesized by the human body. Therefore, attempts have been performed to develop biologically active l-AA derivatives with improved stability. This work presents a facile, scalable, and efficient enzymatic transgalactosylation of lactose to l-AA using β-glucosidase (TN0602) from Thermotoga naphthophila RKU-10. β-Glucosidase TN0602 displays high transgalactosylation activity at pH 5.0, 75 °C, and l-AA/lactose ratio of 2:1 to form a novel l-AA derivative [2-O-β-d-galactopyranosyl-l-ascorbic acid (l-AA-Gal)] with a maximal productivity of 138.88 mmol L^-1 in 12 h, which is higher than most reports of enzymatic synthesis of l-AA-α-glucoside. Synthetic l-AA-Gal retains most l-AA antioxidant capability and presents dramatically higher stability than l-AA in an oxidative environment (Cu²⁺). In conclusion, this work reports a new way to valorize dairy waste lactose into a novel molecule l-AA-Gal, which could be a promising l-AA derivative to be used in a wide range of applications.

Phytochemical compositions of extract from peel of hawthorn fruit, and its antioxidant capacity, cell growth inhibition, and acetylcholinesterase inhibitory activity

BACKGROUND

Hawthorn fruit (HF) is a well-known traditional medicine in China with the effects of improving digestion and regulating qi-flowing for removing blood stasis. Modern pharmacological experiments showed that HF extract has various pharmaceutical properties and flavonoids are considered as the main bioactive compounds. In this paper, Diaion HP-20 adsorption chromatography was used to enrich flavonoids in PHF, and the phytochemical composition of EPHF was analyzed by high performance liquid chromatography (HPLC) and liquid chromatography tandem mass spectrometry (LC-MS). In addition, EPHF's antioxidant capacity, acetylcholinesterase (AChE) inhibitory activity and cytotoxic activity were evaluated.

METHODS

EPHF was obtained by Diaion HP-20 adsorption chromatography. Phytochemical composition of EPHF was analyzed qualitatively and quantitatively using HPLC and LC-MS. Radical scavenging capacity of EPHF was estimated using 2,2-diphenyl-1-picryhydrazyl (DPPH) assay and oxygen radical absorbance capacity (ORAC) assay. The AChE inhibitory activity of EPHF was evaluated by Ellman method. Cytotoxic activity of EPHF was assessed by means of MTT assay.

RESULTS

Eight kinds of components were identified, in which ideain with the value of 179.4 mg/g was identified to be present in the highest level in EPHF, followed by (-)-epicatechin, chlorogenic acid, cyanidin 3-arabinoside, hyperoside and isoquercitrin at the concentrations of 40.9, 10.0, 1.4, 0.4 and 0.2 mg/g, respectively. The contents of these compounds in EPHF were much higher than those in PHF and HF. In addition, EPHF exhibited strong antioxidant and AChE inhibitory activity (ORAC value: 11.65 ± 2.37 μM Trolox equivalents (TE)/mg, DPPH IC50 value: 6.72 μg/mL, anti-AChE activity IC50 value: 11.72 μg/mL) compared with PHF and HF. Moreover, EPHF exhibited high levels of cytotoxicity on MCF-7 and SKOV-3 human tumour cell lines in a dose-dependent manner with the IC50 of 2.76 and 80.11 μg/mL, respectively.

CONCLUSIONS

Macroporous resin is useful for the extraction and separation of the total flavonoids from PHF. The contents of flavonoids especially anthocyanin in EPHF were increased significantly compared with the PHF, and EPHF exhibited strong antioxidant, AChE inhibitory activity and cytotoxicity on human tumour cells.

Polyphenol composition and antioxidant capacity from different extracts of Aster scaber

Phenolic contents and antioxidant capacities from different solvent extracts (petroleum ether, ethyl acetate, methanol, butanol and water) of Aster scaber leaf were investigated. Antioxidant activity was evaluated by three different methods, namely DPPH radical scavenging activity, reducing power assay and phosphomolybdenum activity. A total of twenty-three polyphenolic compounds were identified and quantified from A. scaber leaf extracts, including hydroxybenzoic acids, hydroxycinnamic acids, flavonols and other groups of phenolic compounds. Ultra high performance liquid chromatography (UHPLC) analysis of the leaf extract revealed that myricetin (4850.45 μg/g) was the most dominant flavonols, compared to quercetin and kaempferol. Caffeic acid was the dominant phenolic compound in A. scaber leaf extracts, it constituted about 104.20 μg/g, followed by gentisic acid (84.50 μg/g), gallic acid (61.05 μg/g) and homogentisic acid (55.65 μg/g). The total phenolic and flavonoid content was the highest in ethyl acetate extract (322.43 and 6.51 mg/g). The decreasing order of antioxidant activity among the A. scaber leaf extracts assayed through all the three methods was found to be ethyl acetate > butanol > methanol > petroleum ether > water extract.