Browsing by Author "G. Jeevarathinam"

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    Infrared-aided hot-air drying of coconut: Impact on drying kinetics and quality metrics
    (2024) R. Pandiselvam; Sneha Davison; M. R. Manikantan; G. Jeevarathinam; Anjitha Jacob; S. V. Ramesh; P. P. Shameena Beegum
    This study explored various drying techniques and temperatures to analyze their effects on the drying kinetics and quality of copra. The initial moisture content of coconut kernels was 50%–55% (w.b.), which decreased to 6%–8% (w.b.) as a result of the drying process. This study focuses on evaluating the individual and hybrid effects of infrared drying (IRD) and hot-air drying (HAD) techniques to enhance the quality of copra. Three drying methods were used: IRD, HAD, and infrared-assisted hot-air drying (IRAHAD). Coconut pieces were subjected to different drying temperatures (50, 60, and 70 C) with a constant air speed of 2 m/s. Optimal results were achieved by employing the IRAHAD method at 60 C, preserving a crucial fat content of 68.4% essential for increased extraction of oil from copra and comparatively high drying rates. In particular, the drying rates in IRAHAD were twice as high as those in IRD and HAD. At a drying temperature of 60 C, the logarithmic model and the diffusion approximation model were deemed the best fit for HAD and IRAHAD, respectively.
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    Optimization of continuous flow pulsed light system process parameters for microbial inactivation in tender coconut water, pineapple and orange juice
    (2021-09-11) P. Preetha; N. Varadharaju; G. Jeevarathinam; J. Deepa; A. P. Mohan Kumar; M. Balakrishnan; P. Rajkumar; Pandiselvam, R.
    Continuous flow pulsed light (PL) system was designed and fabricated with a residence time of 3.5 s at a flow rate of 100 ml/min to study the effect on microbial quality of the fruit juice. The circuit was designed to deliver pulse energy between 12.6 and 756 J/cm2 with a flash lasted 360 μs at a frequency of three pulses per second. Tender coconut water, pineapple and orange juice was treated with different input voltage (500–1000 V) to the lamp, distance of the lamp exposed to the sample (5–15 cm) and treatment time (15–45 s) to reduce the population of aerobic plate count (APC), yeast and mold. Box–Behnken design (BBD) was used to optimize the PL process parameters. The process condition was optimized based on the microbial reduction rate. The optimized condition was input voltage of 1492, 1499, and 1486 V, distance of 7.6, 10.2, and 5.3 cm, and treatment time of 43 s (12 passes), 44 s (13 passes), and 45 s (13 passes) for tender coconut water, pineapple and orange juice, respectively at the target of five log reduction for APC and four log reduction for Y&M. These results recommend that a continuous flow PL system could improve the microbial safety of the fruit juice. PL is a nonthermal method for inactivating food microbes, extending food's shelf life. For industrial purposes, the batch system is virtually impossible. As a result, continuous flow systems for liquid foods can provide a better way to handle large volumes. The optimized setup was found to achieve a microbial death rate of at least 5 log CFU/ml, consistent with FDA guidelines for fruit juice. The BBD of response surface methodology helps in optimizing the process parameters such as input voltage of the lamp, distance of the PL lamp to treatment tube and treatment time. The resulting mathematical model provides the PL process conditions for designing the equipmentfor different fruit beverages to obtain microbiologically safe products.