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The purpose of this paper is to prepare calcium oxide (CaO) nanoparticles by green synthesis technique and study its structural, morphological and optical properties. The prepared samples were calcined at, 200°C, 300°C and 500°C, and the variation in the properties at different temperatures were investigated.

Green approach has been used in the present work to synthesise the CaO nanoparticles using Murraya Koenigii leaf (curry leaves) extract as a capping agent. This technique involves the use of nontoxic reagents and natural products derived from various parts of plants.

Studies reveal that CaO nanoparticles with good optical properties can be synthesized successfully by green approach. The optical absorbance spectra show a broad absorption peak around 400–500 nm. FTIR studies confirm the presence of different functional groups that help in the stabilization of CaO nanoparticles. PL emission spectra show a high intensity emission peak at around 231 nm in addition to peaks at 375 nm and 400 nm. XRD studies show planes of CaO cubic phase. SEM images show a nonuniform distribution of spherical particles along with some clusters. EDX spectra confirm the presence of calcium and oxygen.

CaO nanoparticles have wide applications in optical devices as well as in phototherapy. It is thus interesting to devise new and eco-friendly techniques to synthesise these nanoparticles to suit these applications.

This work would provide a new insight into the preparation of different metal oxide nanoparticles by a very simple and cost-effective green technique without the use of toxic reagents.

The study aims to describe the main classes of antioxidants existing in fruit, beverages, vegetables and herbs and the different extraction and application of antioxidants in food. Oxidative degradation of lipids, especially induced by reactive oxygen species, leads to quality deterioration of foods and cosmetics and could have harmful effects on health. A major challenge is to develop tools to assess the antioxidant capacity and real efficacy of these molecules. Recently, many review papers regarding antioxidants from different sources and different extraction and quantification procedures have been published. However, none of them has all the information regarding antioxidants (sources, extraction and application in food).

This paper tries to take a different perspective on antioxidants for the new researcher involved in this field.

Antioxidants from fruit, vegetables and beverages play an important role in human health, for example, preventing cancer and cardiovascular diseases and lowering the incidence of different diseases. A number of plant products act as scavengers of free radical species and so have been classified as antioxidants. Antioxidants are an important group of food additives that have the ability to protect against detrimental change of oxidizable nutrients and consequently they extend shelf-life of foods.

Most of the antioxidants present in foods are phenolic and polyphenolic compounds, but their efficacy in food for the prevention of oxidation or in the body for dealing with oxidative stress and its consequences depends on different factors.

This study collected the last finding in the field of sources and applications of natural antioxidants.

In the Indian system of medicine – Ayurveda, Musa paradisiaca has been mentioned as a remedy for various diseases and ailments. Based on the folkloric use, the purpose of this paper is to verify and compare the hypoglycemic potential of unripe, ripe and overripe fruit extract of Musa paradisiaca.

Hypoglycemic activity of fruit extracts has been evaluated using various in vitro methods, namely, determination of glucose adsorption capacity, glucose uptake in yeast cells, amylolysis kinetics and glucose diffusion.

The extracts of unripe, ripe and overripe fruits of Musa paradisiaca adsorbed glucose, and the adsorption of glucose increased remarkably with an increase in glucose concentration. In the amylolysis kinetic experimental model, the rate of glucose diffusion was found to increase with time, and all the extracts of unripe, ripe and overripe fruits of Musa paradisiaca demonstrated significant inhibitory effects on the movement of glucose into external solution across the dialysis membrane as compared to the control. The extracts under study also promoted glucose uptake by the yeast cells in all the five glucose concentrations used in the study.

Here, the authors have verified and compared the hypoglycemic potential of Musa paradisiaca, its unripe fruit extract was found to show a better activity than ripe and overripe fruit extracts.

Banana, being an all season readily available fruit, is widely consumed due to its ready availability and low cost. It acts as a complete food for even low socio-economic classes of society, owing to its rich nutritional values. Even in a processed and unprocessed manner, it is an important constituent of diet. The research suggests that instead of consuming ripe and overripe fruit, the unripe fruit will help in management of diabetes.

The purpose of this investigation was to study the inhibitive action and adsorption potential of chitosan extracted from Archachatina marginata snail shells on the corrosion of plain carbon (mild) steel in acid media.

Weight loss and thermometric methods were used during this investigation. Characterization of the obtained chitosan was accomplished with Fourier transform infrared spectroscopy analysis. The effects of parameters influencing the inhibition process (concentration and temperature) were evaluated, and the sorption isotherms and thermodynamic parameters were derived.

The results obtained showed that chitosan has good inhibition potential with an efficiency of 93.2 per cent. The inhibition efficiency decreased with an increase in temperature but increased with increasing concentration of chitosan. Test results best fitted the Langmuir Isotherm with a correlation coefficient (R2) of 0.999. The thermodynamic parameters studied reveal that the adsorption of chitosan on the surface of mild steel is spontaneous.

The paper fulfills an identified need in finding solutions to the problems of metal corrosion using agricultural wastes.

The purpose of this study is to evaluate the pattern of carotenoids distribution in three underutilized Malaysian ‘ulam’ or traditional vegetables in Malaysia (Averrhoa carambola, Manihot esculenta and Ipomoea batatas) and their valuable pro-vitamin A activities. These assessments will yield valuable knowledge and insight into the importance of these underutilized traditional vegetables and highlight their potential for applications in medicinal and functional colorant industries.

In this study, the authors have evaluated the distribution of carotenoid compounds in aerial organs of three underutilized traditional vegetables (Averrhoa carambola, Manihot esculenta and Ipomoea batatas). The content of the individual carotenoids were quantified using high-performance liquid chromatography (HPLC) and the organ with the highest accumulation of these compounds were identified. Their valuable pro-vitamin A activities were also reported to indicate their medicinal potential which can further be exploited as pharmacologically active natural colorants and in other applications.

In total, three major chromatographic peaks corresponding to lutein, violaxanthin and β-carotene were observed through HPLC. Among the compounds detected, lutein and β-carotene were the most abundant carotenoids found in both shoots and petioles of all three species. Violaxanthin was only detected in I. batatas shoots. Overall, carotenoid content was observed to be higher in the shoots than in the petioles, where I. batatas contained the highest amount of total carotenoid, followed by M. esculenta and A. carambola. The opposite trend was observed in the petioles, where A. carambola petioles had the highest carotenoid content, while I. batatas contained the least.

The distribution and abundance of these individual carotenoids suggested that the petioles contained the highest amount of carotenoid, contributing to its high pro-vitamin A activity, and could be potentially useful for medicinal application, as it can act as storage site that is not as prone to natural drying or degradation during harvest and sample storage. Future research work should include improvements in the extraction and purification procedures as well as robust identification methods which may lead to better detection and identification of other compounds that could attribute to its bioactivity, to complement the findings of the current study.

This analysis provides valuable information on the importance of underutilized traditional vegetables as important biofactories for sustainable production of valuable pigments (such as carotenoids) with medicinal benefits and can further be exploited in various industries, such as in formulation of functional natural colorants. This study also highlights the importance of petiole as a storage site of pharmacologically active compounds that is not as prone to natural drying or degradation during harvest and sample storage.

To date, there is no previous report found on comparative analysis of carotenoid content and quantification of individual carotenoid concentration in the edible aerial parts of Averrhoa carambola, Manihot esculenta and Ipomoea batatas, although they have been traditionally consumed as “ulam” in Malaysia. Therefore, the results reported in this study provide new insights on carotenoid accumulation in the selected ‘ulam’ species.

Ulam is a traditional salad that contains high levels of antioxidants and is commonly consumed in raw form. However, the average ulam consumption among the low-income Malaysian population was only ½ serving daily. Thus, this study aimed to explore the motivators and barriers to ulam consumption among residents of low-cost housing areas (household income RM4849 or $1015.50) in Kuala Lumpur, Malaysia.

Six focus group discussions were conducted with 27 Malay residents aged 18–59 years in Kuala Lumpur, Malaysia. The researchers asked the participants a series of semi-structured questions. All the interviews were audio-recorded and transcribed verbatim. Two researchers coded the transcripts independently, and several themes were identified. The data were analysed using Nvivo version 12 software.

Three main factors for ulam consumption were identified in this study: personal, environmental and behavioural. The motivators and barriers were identified based on nine main themes and 16 sub-themes.

The results of this study identified potential areas for an effective intervention to increase ulam intake among residents in low-cost housing areas.

This work has the potential to identify the factors that have an impact on consumers' ulam preferences to help fulfil daily vegetable recommendations.

This paper aims to evaluate the inhibitive action of different concentrations of Sesbania grandiflora leaf extract on the mild steel corrosion in an aggressive HCl medium under different experimental conditions.

Weight loss investigation, open-circuit voltage analysis, Tafel polarisation, AC impedance analysis, etc. were used for the evaluation of inhibition efficiency. The influence of immersion period on inhibition efficiency was evaluated. The mechanism of action of the inhibitor is also discussed. Infrared (IR) spectroscopy and energy-dispersive X-ray spectroscopy analysis were used to characterise the passive film.

The results suggested that 10,000 ppm solution has maximum inhibition efficiency of 98.01 per cent at room temperature, while 1,000 ppm solution also exhibited a better efficiency of about 96.16 per cent. Efficiency of inhibitor solution was found to increase with an increase in its concentration. Polarisation study proposed the solution as an anodic inhibitor. Impedance study confirmed the formation of a protective layer over the surface of the specimen, and the constituents of the film were identified using IR spectroscopy. Stability of the film adsorbed on the steel was cleared from the steady open-circuit potential value. Study on action of the inhibitor under accelerated conditions revealed the fact that the efficiency of extract in preventing corrosion is good under stimulated conditions also.

The action of inhibitor sustains for a sufficient time period and could sustain under stimulated conditions. Hence, its application is practically possible in industries. The proposed inhibitor is widely available and is environmentally safe.

HCl is an industrially important chemical used for acid cleaning, acid pickling, etc. HCl was used as an aggressive corrosion environment. As the chances for mild steel to be in contact with HCl were very high, it was important to develop an efficient, economical and eco-friendly inhibitor for corrosion.

Black cumin (Nigella sativa L.) is well known for its strong, hot, peppery taste and has many nutritional, pharmaceutical and traditional therapeutic uses. The aim of this study was to investigate the antioxidant effect of different solvent extracts of black cumin seed to retard lipid and protein oxidation in raw ground pork meat during refrigerated storage (4 ± 1°C) for nine days.

Black cumin extracts (BCEs) were prepared using different solvents, namely, ethanol, water, ethanol:water (60:40) and methanol:hot water (60:40). Extracts were analysed for total phenolic content (TPC), 1,1 diphenyl-2-picrylhydrazil (DPPH) radical scavenging activity and reducing power. Based on the results, water extract (WE) and ethanol–water extract (EHWE) of black cumin were selected and incorporated at 1.5 per cent into freshly minced pork meat and compared with a synthetic antioxidant, butylated hydroxytoluene (BHT; 100 ppm), in retarding lipid and protein oxidation. Treated and control samples were aerobically packed in low-density polyethylene bags for analysis of various parameters (pH, colour and odour score, peroxide, lipid and protein oxidation) during nine-day refrigerated storage study.

Results showed that BCEs had a good amount of TPC (4.4-7.4 mg gallic acid equivalents/g) and also DPPH scavenging activities (33.96-44.23 per cent), with WE and EHWE extracts showing highest reducing power and promising antioxidant capacity. Hence, BCEs (WE and EHWE) incorporated at 1.5 per cent into freshly minced pork meat was tested, compared to BHT (100 ppm) and control samples, in retarding lipid and protein oxidation during storage. In BCE-treated samples, thiobarbituric acid reacting substances, free fatty acids, peroxide, formation of protein carbonyls and off-odour or rancid odour development were lower than control and values were comparable with BHT. Incorporation of BCE did not negatively affect the colour of ground pork.

BCEs (WE and EHWE) at 1.5 per cent inhibited protein and lipid oxidation and it could be exploited commercially as an effective alternative in retarding oxidative deterioration of meat products.

The purpose of this paper is to test bagasse extract as an effective corrosion inhibitor.

The bagasse was extracted without any toxic substance and was found to be effective for corrosion of J55 steel.

The inhibition efficiency of bagasse was more than 90 per cent in 3.5 per cent NaCl solution saturated with CO₂ for corrosion inhibition of J55 steel.

The inhibition effect of Saccharum sinense bagasse extract on the corrosion of J55 steel in 3.5 weight per cent NaCl saturated with CO₂ solution was investigated by means of Fourier transform infrared spectroscopy, electrochemical impedance spectroscopy, polarization curve and scanning electron microscope.

It can be used as low-cost corrosion inhibitor.

It is an environment-friendly corrosion inhibitor.

This work is original and carried out in Southwest Petroleum University, China. This is not communicated anywhere else.

The purpose of this paper is to investigate the inhibitive performance of Coreopsis tinctoria (C. tinctoria) plant extract for the corrosion of mild steel in 0.5 M H₂SO₄.

The inhibition efficiency was studied by weight loss, electrochemical measurements and the surface analysis was done by Raman, scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDS) and atomic absorption spectroscopy (AAS) analysis.

Maximum inhibition efficiency of C. tinctoria in 0.5 M H₂SO₄ on mild steel is 80.62 per cent (500 ppm) at 303 ± 1K. The adsorption of the C. tinctoria on the mild steel surface in 0.5 M H₂SO₄ was found to obey Langmuir adsorption isotherm. Temperature studies were carried out and the significant parameters, such as change in enthalpy (ΔH^°), change in entropy (ΔS^°) and change in free energy (ΔG°_ads) and heat of adsorption (Qads), were calculated. The productive layer formed on the mild steel surface in 0.5 M H₂SO₄ were confirmed by the Raman spectral analysis.

This paper provides information on the inhibitive properties of C. tinctoria plant extract which is found to be a good corrosion inhibitor for mild steel in 0.5 M H₂SO₄.