Pharmacological potential of (L.) P. Royen (Sapodilla): a narrative review.

Herbal medicine is safe and effective in treating various diseases. Traditional herbal medicine plays a tremendous role in treatment of various diseases and accompanying complications, hence herbal medicine requires remarkable attention in further research for the development of numerous active formulations for treatment of health troubles. The plant needs special consideration for development and research of unidentified compound and characterization of novel active molecules that overcome multiple pathological abnormalities. The genus Manilkara contains 135 plants around the world. This overview discusses all the virtues of most important and commonly used plant Manilkara zapota (L.) P. Royen (M. zapota), also known as Sapodilla. M. zapota has various traditional beneficial effects in treatment of various diseases and disorders dating back to prehistoric times and used in ancient traditional system of herbal medicine.

Fabrication of jamun seed starch/tamarind kernel xyloglucan bio-nanocomposite films incorporated with chitosan nanoparticles and their application on sapota (Manilkara zapota) fruits.

The present work develops bio-nanocomposite packaging films by valorizing agricultural byproducts jamun seed starch (JaSS) and tamarind kernel xyloglucan (XG), and adding varying concentrations of chitosan nanoparticles (ChNPs). The blending of JaSS and XG promotes a dense polymer network in the composite films with enhanced packaging attributes. However, ChNPs incorporation significantly reduced the viscosity and dynamic moduli of the JaSS/XG film-forming solutions. The FTIR and XRD results reveal improved intermolecular interactions and crystallinity. The DSC and TGA thermograms showed improved thermal stability in the ChNP-loaded JaSS/XG films. The addition of 3 % w/w ChNPs significantly enhanced the tensile strength (20.42 MPa), elastic modulus (0.8 GPa), and contact angle (89°), along with reduced water vapor transmission rate (13.26 g/h.m2) of the JaSS/XG films. The films exhibited strong antimicrobial activity against Bacillus cereus and Escherichia coli. More interestingly, the JaSS/XG/ChNPs coating on the sapota fruits retarded the weight loss and color change up to 12 days of storage. Overall, the JaSS/XG/ChNP bio-nanocomposites are promising packaging materials.

Immunostimulant effects of diet supplementation with yellow (Pouteria campechiana), white (Casimiroa edulis), and black (Diospyros digyna) sapote nanocapsules on laying hens: in vitro and in vivo study.

Poultry is commonly infected by different bacteria and parasites in the environment, resulting in increased morbidity and mortality, but immunostimulants have been enhancing non-specific defense mechanisms conferring laying hens' protection. For this purpose, the pulp of yellow (Pouteria campechiana), white (Casimiroa edulis), and black (Diospyros digyna) sapotes were nanoencapsulated (YWB-SN) and evaluated in laying hens' peripheral blood leukocytes to test their addition to the experimental diets at a concentration of 0.5% (5g/kg of dry food) for 1 month (with two samples at days 15 and 30). The YWB-SN were safe when exposed to peripheral blood leukocytes (PBLs). The in vitro experiment showed that these nanocapsules enhanced reactive oxygen species production, and B-SN stimulated phagocytosis activity. Concerning the proinflammatory cytokine (TNF-α) transcription, this gene was upregulated after W-SN stimulation, while B-SN upregulated the IgG gene expression significantly. IgM was upregulated with any YBW-SN in PBLs after 24 h of stimulation. The in vivo study showed a notable B-SN immunostimulation in serum and an upregulation of TNF-α, IgM, and IgG mRNA transcription. Therefore, this study provides a new result of the yellow, white, and black sapote nanocapsules as a functional food for the poultry industry, highlighting the black sapote Diospyros digyna immunostimulant effect.

Regulation mechanism of magnetic field on pectinase and its preliminary application in postharvest sapodilla (Manilkara zapota).

In this study, regulation mechanism of magnetic field on pectinase was investigated and it was preliminarily applied in postharvest sapodilla. Results indicated pectinase activity decreased by 44 % when treated by magnetic field (3 mT, 0.5 h) with kinetic parameters Vmax/Km decreasing from 0.799 to 0.366 min. The optimal temperature (48 °C) and pH (4.8) of pectinase was not altered by magnetic field but Ca2+ at 0.05 mol/L strengthened its regulation effect. Ultraviolet and fluorescence spectra suggested tyrosine and tryptophan residues in treated pectinase became more hydrophobic while opposite in phenylalanine. CO, CNH, COO- groups in pectinase were also influenced, resulting in decreased ß-sheet (from 53 % to 49 %), increased random coil (from 20 % to 22 %) and ß-turn content (from 27 % to 29 %). More importantly, the firmness of treated sapodilla remained 45 % of maximum at 12 days' storage. Our findings provided new insights to illustrate the role of magnetic field in fruit preservation.

Effect of microfluidization on quality characteristics of sapodilla (Manilkara achras L.) juice.

Various oxidative enzymes account for the quality degradation of sapodilla (Manilkara achras L.) juice and need to be inactivated through emerging and continuous green pressure processing technology. In this study, pressurization of sapodilla juice was attempted via microfluidization (MF) at pressure range of 10,000-30,000 pound per square inch (psi) with 1-3 passes or cycles. The impact of microfluidization on the activity of polyphenol oxidase (PPO), peroxidase (POD), color, total soluble solid (TSS), viscosity, serum cloudiness along with particle size, and microbial load of sapodilla juice was assessed. Results showed that microfluidization (MF) decreased the residual PPO activity from 100 to 80.78 % and POD activity from 100 to 40.57%. However, TSS (18.81-19.01 %), viscosity (2.64-2.06 cP), serum cloudiness (2.19-1.22 %) and total color change (3.19-18.54) was also significantly affected. Most of these changes were observed due to particle size (PS) reduction that varied from 65.19 to 8.13 µm. Microfluidized juice revealed color improvement at particular MF pressure and pass due to enzyme inactivation. Moreover, lowest microbial load (2.89 Log CFU/ mL) was found at 30,000 psi/3 pass of MF as compared to control sample (unprocessed juice) (7.57 Log CFU/ mL). Consequently, MF can be potential candidate in processing of juices against spoilage.

Gene Flow and Genetic Structure Reveal Reduced Diversity between Generations of a Tropical Tree, Manilkara multifida Penn., in Atlantic Forest Fragments.

The Atlantic Forest remnants in southern Bahia, Brazil, contain large tree species that have suffered disturbances in recent decades. Anthropogenic activities have led to a decrease in the population of many tree species and a loss of alleles that can maintain the evolutionary fitness of their populations. This study assessed patterns of genetic diversity, spatial genetic structure, and genetic structure among Manilkara multifida Penn. populations, comparing the genetic parameters of adult and juvenile trees. In particular, we collected leaves from adults and juveniles of M. multifida in two protected areas, the Veracel Station (EVC) and the Una Biological Reserve (UBR), located in threatened Atlantic Forest fragments. We observed a substantial decay in genetic variability between generations in both areas i.e., adults' HO values were higher (EVC = 0.720, UBR = 0.736) than juveniles' (EVC = 0.463 and UBR = 0.560). Both juveniles and adults showed genetic structure between the two areas (θ = 0.017 for adults and θ = 0.109 for juveniles). Additionally, forest fragments indicated an unexpectedly short gene flow. Our results, therefore, highlight the pervasive effects of historical deforestation and other human disturbances on the genetic diversity of M. multifida populations within a key conservation region of the Atlantic Forest biodiversity hotspot.

UPLC-QTOF-MS/MS analysis and antibacterial activity of the Manilkara zapota (L.) P. Royen against Escherichia coli and other MDR bacteria.

With the spread of bacterial resistance against clinically used antibiotics, natural plant-derived products are being studied as new sources of antibacterial molecules. Manilkara zapota is a common plant species in the American continent that is used as a food source. Studies show the M. zapota extract is rich in phenolic substances that can serve as basic molecules for the pharmaceutical industry. An extract from fresh M. zapota leaves was produced and tested to identify the compounds present, as well as its direct antibacterial and clinical antibiotic modulatory activities. To analyze the results, a new statistical methodology based on the Shannon-Wiener index was tested, capable of correcting distortions in heterogeneous environments. The Hydroethanolic Extract of Manilkara zapota leaves (HEMzL) presented a wide variety of phenolic products, as well as tannins, in the UPLC analysis. The extract showed direct antibacterial activity against the standard Staphylococcus aureus strain, however, it either acted antagonistically when associated with the tested antibiotics, or it did not present statistical significance when compared to the control. This demonstrates a need to be cautious when associating natural products with antibiotics for clinical use, as a hindrance to infectious treatments may occur. As for the statistical analysis mechanism tested, this proved to be effective, reducing false negatives at low antibiotic concentrations and false positives at high concentrations in the microdilution plate.

Fatty acid ethyl ester from Manilkara zapota seed oil: a completely renewable biofuel for sustainable development.

This article reports the deliverables of the experimental study on the production of a completely renewable biofuel from Manilkara zapota fruit and seed oil. It was attempted to synthesis ethyl ester from Manilkara zapota seed oil using bioethanol synthesized from decayed Manilkara zapota fruit. Bioethanol was produced through fermentation of decayed Manilkara zapota fruit, waste skin, and pulp with Saccharomyces cerevisiae and then distilled at 72°C. The bioethanol yield was noted as 10.45% (v/w). The 95.09% pure bioethanol and 4.9% water molecules were present in the distilled sample. Mechanically extracted raw Manilkara zapota seed oil was used for ethyl ester conversion. The molar ratio of bioethanol to oil, the quantity of KOH, and process temperature were investigated for the maximum yield of Manilkara zapota ethyl ester. A 9:1 molar ratio of bioethanol to oil, 1.5% (w/w) KOH, and 70°C process temperature were identified as enhanced ethanolysis process parameters. The maximum yield of ethyl ester was identified as 93.1%. Physicochemical characteristics of Manilkara zapota oil, bioethanol, and ethyl ester were measured as per the corresponding ASTM standards. It was found that both Manilkara Zapota ethyl ester and bioethanol synthesized from decayed Manilkara zapota fruit could be promising substitutes for fossil diesel and gasoline.

Morphological and molecular characterization of Neopestalotiopsis vitis associated with leaf blight disease of Manilkara zapota-a new record from India.

Sapota is an important horticultural crop grown in India, and Karnataka is a major producer of sapota. A characteristic leaf blight disease was observed in Southern Karnataka during field surveys conducted in 2019 with an incidence of 13-22% in approximately 45 ha of sapota field. The leaf blight-associated pathogen was isolated on the potato dextrose agar medium. A total of 12 isolates obtained from each location were identified culturally and morphologically. Based on the morphological and cultural features, the pathogen was identified as Pestalotiopsis or Neopestalotiopsis, which was further confirmed by molecular identification using a representative isolate (MZ03). The ITS rDNA and ß-tubulin genes were amplified and sequenced using ITS1/ITS4 and T1/T22 primer pairs respectively. nBLAST search analysis and concatenated (ITS-rDNA and TUB2 loci) phylogenetic analysis confirmed the pathogen identity as Neopestalotiopsis vitis. Pathogenicity tests conducted on detached leaves by inoculation with a conidial suspension of N. vitis produced typical blight symptoms after 4-5 days and progressed to cover the entire leaf lamina after 10-12 days. The pathogen's identity was confirmed after re-isolation by cultural and morphological features. Although Pestalotiopsis clavispora and Pestalotiopsis versicolor causing diseases on sapota seedlings and trees have been reported, no reports are available for the occurrence of N. vitis to sapota from India. This is the first report of N. vitis associated with leaf blight disease of sapota from India.

Antimicrobial and anthelmintic activities of the ethanolic extract, fractions and isolated compounds from Manilkara zapota L. P. Royen (Sapotaceae).

OBJECTIVES: To evaluate the antibacterial, antifungal and anthelmintic activities of the ethanolic extract (EEMz), fractions (LPFMz and HPFMz) and compounds isolated from the leaves of Manilkara zapota L. P. Royen. METHODS: Extract and fractions were produced by turbolization. LPFMz fraction was analysed by gas chromatography-mass spectrometry. The isolated compounds from HPFMz were purified by flash and preparative chromatographic methods, and chemically characterised by UPLC-ESITOFMS, optical rotation, and one- and two-dimensional 1H and 13C NMR techniques. Anthelmintic against Strongyloides venezuelensis and antimicrobial activities against Candida albicans, Trichophyton rubrum and Staphylococcus aureus were evaluated. KEY FINDINGS: EEMz showed mainly phenolic compounds and pentacyclic triterpenes from Δ12-oleane/Δ12-ursane series. Chlorogenic acid, myricetin-3-O-ß-D-glucopyranoside, mearnsitrin, germanicol and germanicol acetate were reported to M. zapota leaves for the first time in this work. EEMz, HPFMz, LPFMz showed significative activity against C. albicans (16 µg/mL), while isolated flavonoids were active against S. aureus (<32 µg/mL). EEMz, phenolic-rich compounds (F2), and chlorogenic acid were potentially active against S. venezuelensis at 24 h. CONCLUSIONS: M. zapota and its bioactive compound can be eligible such as a potential phytomedicine for the treatment of microbial and strongyloidiasis drug-resistant infections.

Bioactive constituents from Manilkara obovata (Sabine & G.Don) J.H.Hemsl.

The phytochemical investigation of the methanolic extracts of roots, stem bark, leaves and twigs of Manilkara obovata has led to the isolation of one new friedelane triterpene, lacefriedelic acid or 3ß,23-dihydroxy D:A-friedooleanan-28-oic acid (1) and one new prenylated xanthone, lacexanthone or 4,7-dihydroxy-2,3,3,9,9-pentamethyl-2,2-dihydrofurano[2,3-a]pyrano[2,3-i]xanthen-13(9H)-one (2) alongside twenty-four known compounds. Compounds 1-11 are reported here for the first time from the genus Manilkara. The structures of all compounds were determined by spectroscopic analyses and X-ray crystallography. The methanolic extracts of twigs and leaves showed anti-oxidant activity of 93.2 and 91.1%, respectively, at 100 µg/mL when measured by DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate), while the twig extract displayed 86.3% at 100 µg/mL against the urease inhibition assay. Some isolated compounds (1-4, 15 and 20) showed significant to moderate anti-oxidant activity and urease inhibition assay. It is estimated that significantly active anti-oxidants and urease inhibitors metabolized by the plant may find future application in food industry.

In vitro antioxidant and antityrosinase activities of Manilkara kauki.

Manilkara kauki L. Dubard is a tropical plant in the genus Manilkara of family Sapotaceae. This study investigated the total phenolic and flavonoid contents, and antioxidant and antityrosinase activities in different parts of M. kauki (fruits, leaves, seeds, stem barks and woods) and in fractions of stem barks. The total phenolic and flavonoid contents of the methanol and aqueous crude extracts of different parts of M. kauki ranged from 10.87 to 176.56 mg GAE (gallic acid equivalents) per gram of crude extract and 14.33 to 821.67 mg QE (quercetin equivalents) per gram of crude extract, resp. Leaves and stem barks exhibited higher total phenolic and flavonoid contents and antioxidant and anti-tyrosinase activities than fruits, seeds and woods. Stem barks were sequentially extracted with n-hexane, ethyl acetate, methanol and water and then the fractionated extracts were subjected to antioxidant and antityrosinase activities testing. The ethyl acetate and methanol extracts of stem barks exhibited higher total phenolic and flavonoid contents and antioxidant and antityrosinase activities than the n-hexane and aqueous extracts. Moreover, ethyl acetate extract of M. kauki stem exhibited the highest antityrosinase activity. It may be a potential source of tyrosinase inhibitors for pharmaceutical and cosmetic applications.

Manilkara hexandra (Roxb.) Dubard Ameliorates Acetic Acid-induced Rat Gastric Ulcer.

Manilkara hexandra (Roxb; Family:sapotaceae) is reported to exert preventive effect in several experimental ulcer models. However, there is no report of M. hexandra on gastric ulcer healing property. Thus, the present study was designed to evaluate the gastric ulcer healing activity of methanolic stem bark extract of M. hexandra (MH) and to derive a plausible molecular level of mechanism of action. MH was subjected to several phytochemical screening tests and standardized to quercetin by HPTLC. In the first pharmacological experiment, the standardized MH (50, 100 and 200 mg/kg) was carried out for ulcer healing activity against acetic acid (AA)-induced gastric ulcer in male rats. MH (100 and 200 mg/kg) ameliorated AA-induced rat gastric lesions. Further, MH (100 and 200 mg/kg) attenuated AA-induced changes in the levels of lipid peroxidation (LPO), reduced glutathione (GSH), oxidized glutathione (GSSG) and ratio of GSH/GSSG and activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) enzymes, and level of hame oxygenase-1 (HO-1) in stomach tissue. In the subsequent set of experiment, trigonelline (30 mg/kg; p.o.), a potent Nrf2 antagonist, significantly abrogated the gastric ulcer healing activity of MH (100 mg/kg) in AA challenged animals. Further, trigonelline attenuated the effects of MH (100 mg/kg) on the levels of LPO, GSH, GSSG and ratio of GSH/GSSG and activity of SOD, CAT, GPx and GR enzymes, and level of HO-1 in AA challenged rodents. These observations implicate the fact that MH could be a better therapeutic alternative in the management of gastric ulcer.

Manilkzapotane, a novel dimeric alkylresorcinol derivative from the stem bark of Manilkara zapota.

A novel dimeric alkylresorcinol derivative, manilkzapotane (1), along with seven known compounds, lupeol acetate (2), lupeol (3), arjunolic acid (4), ergosterol peroxide (5), taraxerol (6), hederagonic acid (7), and glochidiol (8) were isolated from the stem bark of Manilkara zapota. Their structures were determined on the basis of spectroscopic data. DFT-NMR chemical shift calculations and a modified probability (DP4+) method were applied to define the relative configuration of 1. To the best of our knowledge, this represents the first isolation of a dimeric alkylresorcinol derivative from the Sapotaceae family.

Metabolite Profiling of Manilkara zapota L. Leaves by High-Resolution Mass Spectrometry Coupled with ESI and APCI and In Vitro Antioxidant Activity, α-Glucosidase, and Elastase Inhibition Assays.

High-resolution mass spectrometry equipped with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) sources was used to enhance the characterization of phytochemicals of ethanol extracts of Manilkara zapota L. leaves (ZLE). Sugar compounds, dicarboxylic acids, compounds of phenolic acids and flavonoids groups, and other phytochemicals were detected from the leaves. Antioxidant activity and inhibition potentiality of ZLE against α-glucosidase enzyme, and elastase enzyme activities were evaluated in in vitro analysis. ZLE significantly inhibited activities of α-glucosidase enzyme at a lower concentration (IC50 2.51 ± 0.15 µg/mL). Glucose uptake in C2C12 cells was significantly enhanced by 42.13 ± 0.15% following the treatment with ZLE at 30 µg/mL. It also exhibited potential antioxidant activities and elastase enzyme inhibition activity (IC50 27.51 ± 1.70 µg/mL). Atmospheric pressure chemical ionization mass spectrometry (APCI-MS) detected more m/z peaks than electrospray ionization mass spectrometry (ESI-MS), and both ionization techniques illustrated the biological activities of the detected compounds more thoroughly compared to single-mode analysis. Our findings suggest that APCI along with ESI is a potential ionization technique for metabolite profiling, and ZLE has the potential in managing diabetes by inhibiting α-glucosidase activity and enhancing glucose uptake.

Photocatalytic, antiproliferative and antimicrobial properties of copper nanoparticles synthesized using Manilkara zapota leaf extract: A photodynamic approach.

Copper nanoparticles were synthesized using Manilkara zapota leaf extract. The synthesis of the nanoparticle was primarily visualized when the colour of the reaction mixture turned into reddish-brown. Biosynthesized nanoparticles were characterized by UV-vis, FT-IR, XRD, SEM and EDX. The UV spectra showed maximum absorption at 584 nm. FT-IR studies showed stretching frequency at 592.76 cm-1, which is the fingerprint region for Cu-O bond. The crystallinity of the synthesized copper nanoparticles (Mz-Cu NPs) was revealed through XRD analysis. The synthesized Mz-Cu NPs were spherical with an average size of 18.9-42.5 nm and it was shown by SEM analysis. EDX analysis displayed that the nano sample contains 58 % of copper. The antimicrobial property of the synthesized nanoparticles was evaluated against fungal plant pathogens Rhizoctonia solani (MTCC 12232), Sclerotium oryzae (MTCC 12230) and bacterial species, namely Bacillus subtilis (ATCC 23857), Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923), Vibrio harveyi (ATCC 35084), Vibrio parahaemolyticus (ATCC 33845). In in-vitro haemolytic assay, the particle showed 5.73, 3.34, 0.5 % hemolysis at 100, 50, 25 µg/mL concentration respectively. In the antiproliferative assay, the IC50 values of MCF7 and Vero cells were found to be 53.89 and 883.69 µg/µl. The particle degraded Methyl violet, Malachite green and Coomassie brilliant blue by 92.2, 94.9 and 78.8 %, within 50, 40 and 60 min, respectively, through its photocatalytic activity.

Modulation of octopaminergic and cholinergic pathways induced by Caatinga tree Manilkara rufula chemical compounds in Nauphoeta cinerea cockroaches.

The entomotoxic potential of Manilkara rufula crude extract (CEMR) and its aqueous (AFMR) and methanolic (MFMR) fractions were evaluated against Nauphoeta cinerea cockroaches. The results point out to a direct modulation of octopaminergic and cholinergic pathways in insect nervous system. CEMR induced an anti-acetylcholinesterase (AChE) effect in cockroach brain homogenates. CEMR significantly decreased the cockroach heart rate in semi-isolated heart preparations. CEMR also caused a broad disturbance in the insect behavior by reducing the exploratory activity. The decreased antennae and leg grooming activities, by different doses of CEMR, mimicked those of phentolamine activity, a selective octopaminergic receptor antagonist. The lethargy induced by CEMR was accompanied by neuromuscular failure and by a decrease of sensilla spontaneous neural compound action potentials (SNCAP) firing in in vivo and ex vivo cockroach muscle-nerve preparations, respectively. AFMR was more effective in promoting neuromuscular paralysis than its methanolic counterpart, in the same dose. These data validate the entomotoxic activity of M. rufula. The phentolamine-like modulation induced in cockroaches is the result of a potential direct inhibition of octopaminergic receptors, combined to an anti-AChE activity. In addition, the modulation of CEMR on octopaminergic and cholinergic pathways is probably the result of a synergism between AFMR and MFMR chemical compounds. Further phytochemical investigation followed by a bio-guiding protocol will improve the molecular aspects of M. rufula pharmacology and toxicology to insects.

Development of a reduced-calorie high pressure processed sapodilla (Manilkara zapota L.) jam based on rheological, textural, and sensory properties.

High pressure technology (400 MPa at 27 ± 1.5 °C for 10 min) was applied for the processing of jam, and target was the reduction (∼47%) of sugar requirement by using a fiber-rich fruit, that is, sapodilla. Different formulations of jam containing various combinations of pectin (0.5 to 5.0%), sugar (45 to 65%), and acid (0.5 to 1) were investigated for textural, rheological, and sensory properties of the pressure-processed jam. The textural parameters mainly hardness (varied 16 to 594 g force) of the jam samples were significantly (P < 0.01) affected by the formulation ingredients viz. sugar and pectin content. Also, an interaction effect (P < 0.01) of sugar and pectin was observed on the jam hardness. The rheological parameters (gel strength, K') also varied (1036 to 2852 Pa) with the change in total soluble solids (TSS) and pectin content. However, the samples having lower TSS content (e.g. 45%) and appropriate pectin content (4.0, 4.5, or 5.0%) were similar (P > 0.05) to the samples having higher TSS content (65%) and corresponding pectin level (0.5, 1.0, or 1.5%) based on the rheological properties. On the other hand, the samples with middle levels of pectin at the corresponding TSS level (45 to 65%) were highest (score of >6 on seven-point hedonic scale) and equally preferred (P > 0.05) by the sensory panelist based on overall acceptability calculated from the scores obtained for sensory attributes viz. color, aroma, sweetness, sourness, texture, and spreadability. Therefore, the jam formulation containing sapodilla pulp as a base material, TSS 45%, pectin 4.5%, and citric acid 0.5% was determined to be the preferred formulation for the production of reduced-calorie, pressure-processed jam based on its gel strength, overall acceptability, and storage stability. PRACTICAL APPLICATION: High-fiber fruit was used for the development of a reduced-calorie high pressure processed jam in this study. The inherited or externally added fiber can favor the reduction in sugar requirement of a food product particularly those processed by high pressure, leading to reduction in calories. The findings of this study can be used for the development of novel HPP products with functional properties.

Identification of calcium carbide-ripened sapota (Achras sapota) fruit by headspace SPME-GC-MS.

The effect of post-harvest ripening by ethylene and calcium carbide was studied by headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) method. Sapota (sapodilla) fruits were ripened with ethylene gas, technical grade calcium carbide and pure calcium carbide ripeners and the samples were homogenised after complete ripening. The samples were subjected to HS-SPME-GC-MS and the obtained results showed the presence of various alcohols, aldehydes, acids, ketones and esters which were commonly present in the samples. The fruit samples ripened with technical grade calcium carbide showed the presence of 3,5-dimethyl-1,2,4-trithiolane isomers, which can be used as markers to identify sapota fruits ripened with technical grade calcium carbide. The technical grade calcium carbide contains divinyl sulphide which might have been transformed into the trithiolane isomers. These isomers were not observed in the fruits ripened with pure calcium carbide and also with ethylene gas. Hence the formation of trithiolane residues may be attributed to the presence of divinyl sulphide impurity present in calcium carbide and its conversion due to the action of ethylene releasing enzymes present in the fruits.

Optimization of lead removal in exhausting Manilkara zapota based activated carbon: application of response surface methodology.

The present study demonstrates the removal of lead ion from aqueous solution by the adsorption process using Manilkara zapota tree wood-based activated carbon (MZTWAC) as an adsorbent. The MZTWAC was characterized using a scanning electron microscope and Fourier transform infrared spectroscopy. XRD analysis was carried on MZTWAC. Batch adsorption studies were designed and performed to evaluate the adsorption property of MZTWAC for the removal of lead from an aqueous solution based on the central composite design with response surface methodology. The experiments were focused on the individual and combined effects of process parameters, namely, lead concentration, pH and adsorbent dose on the uptake of lead from aqueous solution. A quadratic polynomial equation was established between the adsorption capacity of the activated carbon and the parameters influencing the adsorption with a coefficient of determination R 2 = 0.9792. The analysis of variance gauged the significance of process parameters and the optimization of process variables was attained by desirability function. There was a noticeable indication of the strong connotation of lead adsorption with Langmuir (R 2 = 0.9911) and Freundlich (R 2 = 0.8368) isotherm models. The D-R isotherm model indicated that physisorption occurred in the adsorption of lead by MZTWAC. The pseudo-second-order adsorption kinetic model (R 2 = 0.9973) perfectly fitted into the present study.