The effect of ultrasound (US), osmotic dehydration (OD), and osmosonication (OS) pretreatments on total phenolic content (TPC), total flavonoids content, (TFC), phytochemical constituents (gingerol derivatives and diarylheptanoids), polyphenol oxidase (PPO), peroxidase (POD), 2,2‐azino‐bis‐(3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS), cupric ion reducing capacity (CUPRAC), 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH), ferric reducing antioxidant power capacity (FRAP), and color of ginger slices dried under relative humidity convective dryer was investigated. OS pretreatment improved the preservation of TPC (13.80–34.79 mg GAE/g d.w), TFC (26.46–62.16 mg CE/g d.w), ABTS (30.37%–86.10%), CUPRAC (36.89–73.97 mg/g), DPPH (50.57%–92.60%), FRAP (26.44‐83 mg/g), and phytochemical constituents than US and OD. The OS‐treated sample was more effective in inactivating both PPO (12.09%–35.93%) and POD (16.21%–39.58%) enzymes compared to US and OD‐treated samples. However, US pretreatment retained the color quality of dried ginger slices than the OS and OD treatments. OS pretreatment (5.43) also increased the total color change (ΔE) of the dried ginger samples compared to US (2.81) and OD (4.60). Practical applications Ginger is commonly used in the food, beverage, and pharmaceutical industries owing to their distinctive flavor and various health potentials. However, its high moisture content makes its inappropriate for long‐term storage which results in its high perishability. Drying is one of the most common techniques to prolong its shelf life. Hence, any pretreatment for ginger that reduces the moistures content and lessens the drying time by preserving the quality of the crop is of vital importance. Ultrasound, osmotic dehydration, and osmosonication are novel pretreatment techniques that are widely used prior to drying of various agricultural products due to its numerous advantages over conventional methods. Its application in drying of foods could help shorten the drying time, reduce processing costs, improve energy consumption and efficiency, and preserve the physical and nutritional properties of the dried product. The current findings will also offer more information for selecting pretreatment techniques for ginger drying.

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Ginger slices were dried with Freeze drier (FD), relative humidity convective drier (RHCD), infrared drier (IR), and microwave drier (MD) at a temperature of 60 C. The influence of the drying techniques on total phenolic content (TPC), total flavonoid content (TFC), antioxidant activities, ABTS (2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid), DPPH (1,1-diphenyl-2-picrylhydrazyl), FRAP (Ferric reducing antioxidant power capacity), and CUPRAC (Cupric ion reducing capacity), rehydration ratio (RR), color, enzyme inactivation (polyphenol oxidase, PPO and peroxidase, POD), energy consumption rate (ECR), microstructure, volatile compounds (aroma profile), and drying kinetics were assessed. The results showed that FD-ginger slices retained the highest antioxidant properties, ABTS (51.88 mgTE/g db), CUPRAC (95.51 mgTE/g db), DPPH (132.95 mgTE/g db), and FRAP (95.32 mgTE/g db), TPC (118.70 mg GAE/g db) and TFC (98.94 mg CE/g db), preserved microstructure and higher volatile compounds compared RHCD, IR, and MD. The RHCD-ginger slices attained the highest RR (3.6), lowest ECR (7.88 kWh/kg), lowest PPO (17%), and POD (22%) residual activity with preserved color properties than FD, IR, and MD. RHCD also enhanced the drying kinetics and lessened the drying time compared to FD, IR, and MD. Page model best fitted the experimental results of drying kinetics (R 2 > 0.99). Practical applicationOne of the world's most consumed and used spices is ginger and due to its high moisture content, drying is normally used for its preservation. Therefore, to attain dried ginger of better quality, an effective, safe, efficient drier that can preserve product quality and reduce processing time, as well as energy consumption, is required for commercial purposes as a poor selection can have an adverse effect on the product quality. The outcome of the current investigation will offer a better understanding of various drying techniques and also provide more information on the selection of the best drying technique for drying ginger.

Food safety issues across the global food supply chain have become paramount in promoting public health safety and commercial success of global food industries. As food regulations and consumer expectations continue to advance around the world, notwithstanding the latest technology, detection tools, regulations and consumer education on food safety and quality, there is still an upsurge of foodborne disease outbreaks across the globe. The development of the Electronic nose as a noninvasive technique suitable for detecting volatile compounds have been applied for food safety and quality analysis. Application of E-nose for pathogen detection has been successful and superior to conventional methods. E-nose offers a method that is noninvasive, fast and requires little or no sample preparation, thus making it ideal for use as an online monitoring tool. This manuscript presents an indepth review of the application of electronic nose (E-nose) for food safety, with emphasis on classification and detection of foodborne pathogens. We summarise recent data and publications on foodborne pathogen detection (2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018) and by E-nose together with their methodologies and pattern recognition tools employed. E-nose instrumentation, sensing technologies and pattern recognition models are also summarised and future trends and challenges, as well as research perspectives, are discussed.

The objective of this present work was to investigate the effect of ultrasound (US), osmotic dehydration (OD), and osmosonication (OS) pretreatment on microstructure, weight loss, texture, mass transfer, chromatic properties and drying kinetics of ginger slices under relative humidity convective drying. The results revealed that OS pretreatment yielded higher weight loss (16.5%) and lower firmness (12.11 N) than US (9.8%, 20.33 N) and OD (6.5%, 15.30 N). Microstructure analysis showed that OS, US, and OD pretreatments altered cell structure and resulted in the observable formation of several microchannels and collapsed the cell structure. Mass transfer data showed that the OS pretreated sample led to higher solid gain (3.2%) and water loss (5.1%) than the US (2.36%, 4.2%) and OD (1.7%, 2.53%) pretreatments. The chromatic property analysis revealed that the chroma value and hue angle was higher for OS treated sample (29.74, 88.77 ) compared the US (26.95, 85.76 ) and OD (22.96, 82.24 ) treated sample. Among the three pretreatments, OS was found to enhance the drying kinetics comparative to the US and OD pretreated sample. Weibull model fitted well to the experimental results (R 2 > .99) than the first order. Practical applicationsUltrasound, osmotic dehydration, and osmosonication are unique pretreatment techniques that are widely used prior to drying of various agricultural products due to its numerous advantages over conventional methods. Its application in the drying of foods could help shorten the drying time, reduce processing costs, improve energy consumption and efficiency and preserve the physical and nutritional properties of the dried product. The outcomes of the present study will provide a better understanding of different nonthermal pretreatment methods and also make available more information for selecting pretreatment techniques for ginger drying.