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ThesisItem Open Access Nanocomposite of magnesium ferrite and manganese oxide as polyphenol oxidase mimic and photocatalyst(Punjab Agricultural University, Ludhiana, 2022) Harmilan Kaur; Manpreet KaurArtificial enzymes have received immense interest due to their exceptional properties such as high stability and low-cost. Polyphenol oxidase enzyme mimic is well known for its contribution in the field of food industry, biosensors, medicine and water remediation. In the present study, Mn3O4 and MgFe2O4 nanoparticles and nanocomposites were synthesized by sol-gel and ultra-sonication methods. Their polyphenol oxidase (PPO) mimic activity was comparatively analyzed. The synthesized nanoparticles and nanocomposites were characterized by FT- IR, XRD, SEM-EDS, BET, and VSM. The results revealed that MgFe2O4@Mn3O4 possess unique catalytical features. XRD analysis of synthesized materials depicted crystalline nature. The PPO-like activity of synthesized NPs and NCs were analyzed using catechol and resorcinol as substrates. MgFe2O4@Mn3O4(1:2) were observed to be the best PPO mimic. Kinetic analysis under optimized conditions indicated higher binding affinity of nanocomposite as compared to pristine manganese oxide. MgFe2O4@Mn3O4 (2:1) showed to be best photocatalytic potential for catechol and resorcinol degradation in aqueous solution. The efficiency of degradation was put to the test in relation to the variation of several experimental parameters including: pH; nanoparticles dose and contact time These aforementioned parameters were optimized and examined for the influence that they exerted on the efficiency of degradation which involved the usage of the Box-Behnken design methodology. According to the ANOVA results that yielded a confidence level of 95 %, a high regression along with fitting values were obtained between the results of the experimental degradation of catechol and resorcinol and the predicted quadratic model. Thus, the present study indicated that a catalyst of MgFe2O4@Mn3O4 nanocomposite in different ratios have promising performance as photocatalyst and PPO-mimic for degradation of polyphenols.ThesisItem Embargo Chemical composition and antifungal potential of kalonji (Nigella sativa L.) seeds and clove (Syzygium aromaticum) essential oils and their major constituents(Punjab Agricultural University, Ludhiana, 2022) Akansha; Kaushal, SoniaThe present study investigates the chemical composition and antifungal potential of kalonji (Nigella sativa L.) seeds and clove (Syzygium aromaticum) buds essential oils and their major constituents. The kalonji seeds and clove buds essential oils were extracted by hydrodistillation and characterized by Gas Chromatography-Mass Spectrometry. Thymoquinone (18.07%) and eugenol (68.64%) were major compounds in kalonji seeds and clove buds essential oils respectively and were isolated by column chromatography. Both the essential oils and their major compounds were tested for their antifungal activity against Colletorichum gloeosporoides and Penicillium digitatum using poison food technique. Among the essential oils, clove buds essential oil was more effective having MIC values of 18 and 35 ppm against P. digitatum and C. gloeosporoides respectively. Among the major compounds, thymoquinone was more effective having MIC values of 7.0 and 8.5 ppm against P. digitatum and C. gloeosporoides respectively. The synergistic interaction of kalonji seeds / clove buds essential oils and thymoquinone /eugenol against above said fungi was tested by checkerboard method. The combination of eugenol and thymoquinone showed a synergistic interaction against P. digitatum (FICI: 0.48). Molecular docking studies of major compounds present in kalonji seeds and clove buds essential oil suggested that thymoquinone bound effectively with targeted fungal protein i.e., α-β-tubulin with the maximum binding energy of -5.15 kcal mol-1 . Hence, thymoquinone and combination of thymoquinone and eugenol present as major compounds in kalonji seeds and clove buds essential oils can be used as natural and ecofriendly antifungal agents against C. gloeosporoides and P. digitatum respectively.ThesisItem Embargo Nanocomposite of magnesium ferrite and manganese oxide as polyphenol oxidase mimic and photocatalyst(Punjab Agricultural University, Ludhiana, 2022) Harmilan Kaur; Manpreet KaurArtificial enzymes have received immense interest due to their exceptional properties such as high stability and low-cost. Polyphenol oxidase enzyme mimic is well known for its contribution in the field of food industry, biosensors, medicine and water remediation. In the present study, Mn3O4 and MgFe2O4 nanoparticles and nanocomposites were synthesized by sol-gel and ultra-sonication methods. Their polyphenol oxidase (PPO) mimic activity was comparatively analyzed. The synthesized nanoparticles and nanocomposites were characterized by FT- IR, XRD, SEM-EDS, BET, and VSM. The results revealed that MgFe2O4@Mn3O4 possess unique catalytical features. XRD analysis of synthesized materials depicted crystalline nature. The PPO-like activity of synthesized NPs and NCs were analyzed using catechol and resorcinol as substrates. MgFe2O4@Mn3O4(1:2) were observed to be the best PPO mimic. Kinetic analysis under optimized conditions indicated higher binding affinity of nanocomposite as compared to pristine manganese oxide. MgFe2O4@Mn3O4 (2:1) showed to be best photocatalytic potential for catechol and resorcinol degradation in aqueous solution. The efficiency of degradation was put to the test in relation to the variation of several experimental parameters including: pH; nanoparticles dose and contact time These aforementioned parameters were optimized and examined for the influence that they exerted on the efficiency of degradation which involved the usage of the Box-Behnken design methodology. According to the ANOVA results that yielded a confidence level of 95 %, a high regression along with fitting values were obtained between the results of the experimental degradation of catechol and resorcinol and the predicted quadratic model. Thus, the present study indicated that a catalyst of MgFe2O4@Mn3O4 nanocomposite in different ratios have promising performance as photocatalyst and PPO-mimic for degradation of polyphenols.ThesisItem Embargo Chemical modifications of paddy straw xylan for the preparation of sustainable bio films(Punjab Agricultural University, Ludhiana, 2022) Kapil, Sristhi; Mankoo, Ramandeep KaurThe present study involved valorization of paddy straw by conversion of its constituent polymer xylan and chemically modified xylans into biofilms. Paddy straw was found to contain 44% cellulose, 22% hemicellulose, 8% lignin, 21% extractives, and 5% silica. Hemicellulosic xylan (19.94%) extracted with 10% NaOH (85°C, 2.6 h) was chemically modified to acetylated (AX) and carboxymethylated xylan (CMX) followed by their structural characterization by FT-IR and NMR spectra. Xylan was found to show maximum antioxidant potential (Ascorbic acid equivalents value 7.6 at 10 mg/ml) and CMX showed highest antibacterial potential (Inhibition zone diameter of 31.80 and 29.75 mm against Bacillus and Pseudomonas, respectively). Biofilms were prepared by reaction of xylan/modified xylan (1 and 2%) with polyvinyl alcohol using eco-friendly and cheap crosslinker citric acid and glycerol as plasticizer. FT-IR and SEM analysis were performed for biofilms characterizations. 2% xylan biofilms showed maximum inhibition (94.25%) of DPPH radical at 4 mg/ml. 2% CMX biofilms exhibited maximum antibacterial effectiveness with diameter of zone of inhibition 33.5 and 30.5 mm against Bacillus and Pseudomonas, respectively. This may be due to large number of undissociated COO- ions (citric acid) in CMX biofilms which was evident from lesser cross-linking observed in their SEM images. 2% CMX biofilms also showed highest biodegradation (86.5%) which may be attributed to formation of ether bonds along with ester bonds which leads to their fast degradation. Owing to good bioactive properties of prepared biofilms, it was concluded that these can be appropriate material for food packaging by replacing synthetic plastics.ThesisItem Embargo Evaluation of Micro and Nano Emulsions of Monarda citriodora Essential Oil Against Penicillium digitatum(Punjab Agricultural University, Ludhiana, 2022) Kiranjot Kaur; Tandon, RituPostharvest fungal pathogenic invasions are the major root cause of reduced shelf life of kinnow fruit, thereby contributing to the postharvest losses. Development of eco-friendly alternates are the need of the hour owing to health safety concerns for replacing the ongoing synthetic fungicide use. Essential oils with promising antimicrobial activities offer a promising solution but their hydrophobicity poses a big hindrance for exploiting the same. Present work was planned to explore their antimicrobial potential by developing their hydrophilic formulation with the use of nanotechnology. An in vitro study was conducted to assess the efficacy Monarda citriodora essential oil and its emulsions against major postharvest fungal pathogen of Kinnow; Penicillium digitatum. The total phenol and flavanoid content in Monarda citriodora essential oil is estimated to be about 28.3 µg ml-1 and 35.54µg ml-1 respectively. Both micro and nanoformulations were prepared for different ratios of Monarda citriodora essential oil (0.5 to 3%) with different surfactant combinations and oil-surfactant-ratios of 1:1 to 1:3. The influence of several process factors such as surfactant and oil phase concentrations, as well as sonication time intervals, on emulsion stability was investigated using droplet diameter, Polydispersity index (PDI) and zeta (δ) potential. An emulsion formulated with 1% oil and 1:1 OSR and treated with ultrasonic waves for 15 min was optimized with droplet diameter of 52.2 nm, 0.245 PDI, and -21 mV of δ potential with consistent stability till 1 month. Further, in vitro antifungal activity of the optimized Monarda citriodora essential oil nanoemulsion exhibited the best efficacy with 100% inhibition at 200 mg L-1. The treated Monarda citriodora essential oil emulsions showed morphological alteration with additional reduction in hyphal diameter on optical micrographs. Further studies need to be conducted to explore the potential of Monarda citriodora essential oil nanoemulsions for enhancing shelf life of Kinnow fruits.ThesisItem Embargo Preparation and Evaluation of Citronella and Lemon Grass Essential Oil Formulations Against Phomopsis Blight of Brinjal(Punjab Agricultural University, Ludhiana, 2022) Pooja; UrvashiThe present investigation deals with the extraction and chemical investigation of lemon and citronella grass essentiall oil and their emulsifiable concentrates (EC) formulation as fungicide against Phomopsis vexans. GC-MS analysis of the lemongrass EO revealed citral B (37.75%), citral A (21.93%) and farnesene (8.80%) as the major compounds whereas citronella grass EO showed citronellal (24.80%), geraniol (21.88%) and citronellol (14.58%) as major compound. EC formulations comprising of EO were prepared using castor oil as solvent and emulsifier blends (10%) with hydrophilic-lipophilic balance (HLB) value (12.86) suitable for the EO formulation. Among six EC formulations prepared from each EO, CF6 and LF6 type performed well in terms of emulsion stability, cold test, accelerated storage and foam test indicating feasibility for their commercial production. EC50 value of citronella, lemon grass EO and EC formulations CF6 and LF6 were 0.0087, 0.0098, 0.009 and 0.0126, respectively which were tested by Poisoned Food Technique and were compareable with Zineb 75 WP. CF6 and LF6 formulation at 0.1% inhibits the growth of P. vexans under field condition. Among all the tested components, CF6 formulation was better as compared to LF6 formulation. EC formulations are the better way for the effective application of EO under in vitro and in vivo condition as they are easy to prepare and can be used ecofriendly.ThesisItem Embargo Evaluation of trace elements and heavy metal analysis in commercial tea(Punjab Agricultural University, Ludhiana, 2022) Manbeer Singh; Tandon, RituTea is one of the world's most popular non-alcoholic beverage owing to its nutritional value and antioxidant potential due to catechins and flavonoids. Recently, the consumption rate of various teas has increased rapidly. Stringent guidelines laid by food regulations by FSSAI, EU, USFDA etc. for tea have made the analysis of inorganic metal contaminants as a mandatory requirement for its sa consumption as well as export. ICP-MS (inductively coupled plasma mass spectrometry) is among the most sensitive equipment for analysis of the same at trace and ultra-trace levels but with the use of validated method. The study was therefore planned to validate ICP-MS method for analysis of heavy metals and trace elements in three types of tea viz. green, black and herbal along with their nutritional status. High sensitivity was observed with low LOD and LOQ values for both heavy metals (Chromium, Arsenic, Cadmium, Nickel, Mercury, Lead) and trace metals (Copper, Zinc, Selenium, Cobalt) in various teas in the range of 0.003 to 0.620 µg/kg and 0.010 to 2.048 µg/kg respectively. The linearity for all metals was obtained with R≥ 0.995 and accuracy of the method was established by spiked experiments where recoveries were achieved in the range of 75 to 125%. Precision data indicated very small %RSD ranging 0.46% to 13.44% For nutritional analysis, total polyphenol content (TPC) and antioxidant capacity of three tea, was carried out in relation to steep time where 15 min steep time was optimized for maximum extraction of the both. The study indicated good correlation among the both parameters.ThesisItem Open Access Synthesis and antimicrobial potential of barbituric acid derivatives(Punjab Agricultural University, Ludhiana, 2022) Madhvi; Utreja, DivyaFunctionalized 5-aryl-pyrimido[4,5-b]quinoline-2,4(1H,3H,5H,10H)-diones were synthesized in high yields using one-pot three-component approach by reacting barbituric acid, aryl aldehydes, aryl amines and p-toluenesulfonic acid as catalyst. These synthesized compounds were characterized with the help of various spectral techniques viz. 1HNMR, 13CNMR, FT-IR spectroscopy and Mass spectrometry. All the synthesized compounds were screened to evaluate their in vitro antimicrobial potential against bacterial strain Dickeya sp. with respect to Gentamicin as standard and against fungal strain Fusarium oxysporum with respect to Carbendazim as standard. It was concluded that the barbituric acid derivatives 8-bromo-5-(4nitrophenyl)pyrimido[4,5-b]quinoline-2,4(1H,3H,5H,10H)-dione (5e) and 8-nitro-5-(4nitrophenyl)pyrimido[4,5-b]quinoline-2,4(1H,3H,5H,10H)-dione (5g) showed better antimicrobial potential at with MIC = 3000 μg/mL and MFC = 5000 μg/mL as compared to the other screened compounds.ThesisItem Embargo Synthesis of dihydropyrimidinone-isatin derivatives and their nematicidal activity(Punjab Agricultural University, Ludhiana, 2022) Jashandeep Kaur; Utreja, DivyaEight spiro(dihydropyrimidinone-isatin) derivatives were synthesized by nucleophilic addition of the urea on the C-3 position of isatin under acidic conditions. All the synthesized derivatives were characterized using 1HNMR, 13CNMR, FT-IR spectroscopy and mass spectrometery techniques. The synthesized derivatives were evaluated against root knot nematode Meloidogyne incognita. All the compounds showed significant nematicidal potential against in vitro egg hatching and mortality of the Meloidogyne incognita. Maximum egg hatching inhibition potential and maximum mortality potential was exhibited by compound ethyl-6'-methyl-2-oxo-2'-thioxo-2',3'-dihydro-1'Hspiro[indoline-3,4'-pyrimidine]-5'-carboxylate (6e).
