Optimization of continuous flow pulsed light system process parameters for microbial inactivation in tender coconut water, pineapple and orange juice

Abstract

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/cm 2 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 equipment for different fruit beverages to obtain microbiologically safe products.

Effect of different storage conditions on the quality attributes of sweet lime juice subjected to pulsed light and thermal pasteurization

“…Further, Kaya et al 25 reported that in verjuice beverage PL could inactivate 0.96 ± 0.27 log cfu mL −1 in S. cerevisiae even after delivering a dose of 34 J cm −2 and being placed 5 mm away from the lamp. Preetha et al 26 reported a maximum log reduction of 5.54 cfu mL −1 of APC populations observed in tender coconut water followed by pineapple and orange juice with 5.38 and 5.24 log reductions by treating them with higher energy of 729 J cm −2 . The inactivation of microbes depended on the properties of light absorption by the fruit juices.…”

Effects of pulsed electric field technology on the nutritional value and biological function of plant food

“…With advantages such as requiring low temperatures, rapid processing time, and being environmentally friendly, PEF is rapidly gaining attention as a promising food processing technology (Manzoor et al, 2019a,b;Rahaman et al, 2020;Lal et al, 2021). PEF causes negligible damage to food nutrients compared to traditional food processing techniques and can eliminate some hazardous microorganisms to extend the preservation time of food (Soliva-Fortuny et al, 2009;Napotnik et al, 2016;Peng et al, 2016;Liu C. Y. et al, 2021;Nabilah et al, 2022;Preetha et al, 2023). Most research in PEF has focused on active substance extraction, pasteurization, and the drying and thawing of food products, and there is relatively little research on the influence of PEF on biometabolic pathways that induce the synthesis of nutrients in food products (Boussetta et al, 2011(Boussetta et al, , 2012Rahaman et al, 2019;Ahmed et al, 2020;Preetha et al, 2021).…”