Aims: Oxidation of p-anisaldehyde by Quinolinium dichromate (QDC) in the aqueous acetic acid medium in the presence of sulphuric acid using surfactants. Background: The oxidation studies of anisaldehyde is very important as the oxidized products are used as a synthetic intermediate for the preparation of a variety of drugs. Quinolinium dichromate (QDC) has emerged as a very useful and versatile oxidant. Micellar medium enhances the reaction rate. Objective: 1. To study the kinetics of the reaction, which includes the determination of order, rate, and activation parameters. 2. Spectral characterization of QDC by NMR and the kinetic study of the reaction mechanism is done through UV – A visible spectrophotometer. 3. Solvent effect for the oxidation of anisaldehyde by QDC. 4. Determination of critical micelle concentration (CMC) of used surfactants (CTAB and SDS). Methods: The reactions were followed at constant temperature and were followed by monitoring the UV – Visible spectrophotometer (Double Beam – 2203) in a quartz cuvette of 1 cm path length by following the absorbance decay of Cr (VI) at 440 nm Result: KINETIC RESULTS: 1. The reaction follows first-order dependence on p-anisaldehyde and QDC. 2. The reaction is found to be acid-catalysed. A plot of log [k] versus log [H+] was found to be a straight line with a slope of 1.07. EFFECT OF SOLVENT: The rate of reaction increases with the increase in acetic acid proportion in the medium, which suggests that the reactions were of the ion–dipole type. MICELLAR EFFECT: 1. Experimental results demonstrated that anionic surfactant SDS catalysed and accelerated the study more effectively than CTAB, which is a cationic surfactant, and the rate of reaction increases with an increase in the concentration of the SDS while in the case of CTAB, the rate decreases with an increase in its concentration. 2. CMC values of CTAB and SDS were 3.9 mM and 8.2 mM, respectively. Conclusion: The value of negative ΔS (entropy of activation) and positive ΔH (enthalpy of activation) suggests the formation of more ordered activated complexes, and the transition state is highly solvated. SPECTROSCOPIC ANALYSIS 1.NMR characterisation of synthesised QDC shows a resemblance with pure QDC. 2. Effect of oxidant QDC, p-anisaldehyde and acid was studied by considering the spectra of the reaction mixture and varying their concentration.

Aim: The aim of the present study was to study the effect of chitosan treatment on extending the shelf life of tomatoes stored at room temperature (27ºC±2) for 21 days. Methodology: Chitosan working formulation were prepared by dissolving chitosan in 1 % glacial acetic acid to get final concentrations with adjusting pH above 5 with 1N NaOH until suspension appears as colloide. Selected tomatoes were dipped in different concentrations of chitosan (0.01, 0.04, 0.08, 0.12, 0.16 and 0.20 % and water (control) for 6 min and kept in well ventilated paper baskets for storage at room temperature (27°C±2) with 55±2 % relative humidity. Results: Chitosan treated tomatoes were evaluated for different parameters related to post harvest losses. Chitosan at 0.16 % effectively prevented microbial decay, physiological loss in weight, maintained the firmness and reduced the respiration rate. Chitosan treatment further decreased the loss of titratable acidity (TA), retained the total soluble solids (TSS), total sugar, ascorbic acid, reducing sugar during storage period. Chitosan effectively preserved lycopene content, inhibit polyphenol oxidase (PPO) activity, maintained L*, a*, b* value and organoleptic score during storage from day 1 to day 21 as compared to control tomatoes. Interpretation: The study delves that low concentration of chitosan (0.16%) effectively extend the shelf life of tomato.

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