Pilot scale study on UV-C inactivation of bacterial endospores and virus particles in whole milk: evaluation of system efficiency and product quality

UV-C processing of whole milk (WM) using a designed pilot scale Dean flow system was conducted at flow rates (11.88, 23.77, and 47.55 gph), Reynolds number ranges from 2890-11562 and the Dean number (at curved region) calculated as (648-2595) to inactivate bacterial endospores and virus particles. Biodosimetry studies were conducted to quantify the reduction equivalent fluence at selected experimental conditions. Results revealed that the dose distribution improved as flow rate increases, attributed to increase in Dean effects and turbulence intensity. Microbial inactivation studies conducted at 47.55 gph showed 0.91 (stdev:0.15) and 2.14 (stdev:0.19) log reduction/ pass for B. cereus endospores and T1UV phage. Linear inactivation trend was observed against number of passes which clearly demonstrates equivalent dose delivery during each pass. Lipid peroxidation value and volatile profile did not change significantly at UV dose of 60 mJ/cm 2. Lower E EO value signifies the higher electrical efficiency of the system.

Impact of high pressure processing on microbiological, nutritional and sensory properties of food: a review

Purpose The increased demand for high-quality, nutritionally rich processed food has led to non-thermal food processing technologies like high pressure processing (HPP), a novel process for microbial inactivation with minimal loss of nutritional and sensory properties. The purpose of this paper is to highlight the impact of HPP on the microbiological, nutritional and sensory properties of food. Design/methodology/approach Recent research on the role of HPP in maintaining food quality and safety and the impact of process conditions with respect to various food properties have been explored in this paper. Also, the hurdle approach and the effectiveness of HPP on food quality have been documented. Findings HPP has been verified for industrial application, fulfilling the consumer demand for processed food with minimum nutrition loss at low temperatures. The positive impact of HPP with other treatments is known as the hurdle approach that enhances its impact against microorganism activity and minimizes the effects on nutrition and sensory attributes. Originality/value This paper highlights the impact of HPP on various food properties and a good alternative as non-thermal technology for maintaining shelf life, sensory properties and retention of nutrients.

RANCANG BANGUN ALAT PASTEURISASI NON THERMAL DENGAN PULSED ELECTRIC FIELD (PEF)

ABSTRACTPackaged beverages have become a product that is very much on the market both internationally and nationally. In the process of making packaged beverages, in order to last longer the microbes in the drink must first be inactivated in order for the drink to last longer, the microbial inactivation process in the drink is called pasteurization. Convernsional pasteurization is done by heating the drink to be in production. But the high temperature of the drink can change the taste, color, and even nutrition of the drink. This is underpinning the non-thermal pasteurization process by using high voltage impulses (Pulsed Electric Field,PEF). PEF is a technology that utilizes high voltage DC to produce a field between two electrodes. Pateurization occurs when between electrodes there is milk that is flowed with high voltage DC. High voltage generation is performed using flyback transformers with voltage output up to 30 kV. In the pasteurization process given 6 voltage variations namely 5, 10, 12,5, 15, 20, and 30 kV. Pasteurization results are then tested in fmipa microbiology laboratory to find out the success of the tools that have been made. In each voltage variation it is obtained that all treatments have reached pasteurized milk quality standards based on SNI where at 5kV voltage variation can inactivat microbes up to 83.33%, voltage variation of 10kV can inactivat microbes up to 94.5%, At a voltage variation of 12.5 kV can inactivae microbes up to 83.6%, 15kV voltage variation can inactivae microbes up to 88.8%, while voltage variation of 20 kV can inactivae microbes up to 84.2% and at voltage variation 30 kV can inactivae microbes up to 84.8%.Key Words: PEF, Flyback Transformer, ZVS Driver, Pasteurization.

Effect of turbidity on ultraviolet disinfection of domestic wastewater for agricultural reuse

Water treatment and reuse are fundamental because of the increasing demand for freshwater, especially in agriculture. Accordingly, this study evaluated the effects of turbidity of wastewater processed at the Effluent Treatment Station (ETE) of the UFSCar/Araras and of UV dose on microbial inactivation. The ETE treats up to 2000 L of wastewater daily from toilets and a university restaurant and has five components (grease box, septic tank, microalgae tank, upflow anaerobic filter, and wetlands). Pretreated effluents were used in the experiments, and sampling sites consisted of inspection boxes located after the wetlands. Sample collection, inspection, preservation, and analyses were performed according to standard methods. Sample turbidity was adjusted to 5, 50, 100, 200, and 300 nephelometric turbidity units (NTU), and UV doses of 7.2–28.8 mWs cm-2 were used. A 5 x 5 factorial design (five turbidity levels and five radiation doses) was used, totaling 25 treatments. Each treatment was performed in triplicate. The data were submitted to analysis of variance and Tukey’s test. The results showed that the increase in turbidity significantly decreased disinfection efficiency in samples with turbidity levels higher than 50 NTU. The microbial inactivation coefficients obtained here can be extrapolated to disinfection of wastewater with turbidity up to 300 NTU to eliminate thermotolerant coliforms. The UV sterilizer is feasible for wastewater treatment and its reuse in agriculture. Keywords: domestic effluent, sustainability, ultraviolet radiation, water reuse.