Extraction of tomato by-products’ bioactive compounds using ohmic technology

Abstract

Tomato by-products Ohmic heating Extraction optimization By-products valorization New extraction method Polyphenols Carotenoids a b s t r a c tTomato peels and seeds are the main by-products of the tomato industry and represent an interesting source of bioactive compounds (BC) including carotenoids, which can be then used as colorant to commercial aquaculture. The aim of the present work was to optimize the extraction of BC from tomato by-products using Ohmic heating (OH) technology. OH extraction experiments were done in the presence of moderate electric fields (MEF) of different intensity (i.e. 4, 6 and 11 V cm −1 ) to identify the presence of non-thermal effects on the extraction process and its influence on bioactive properties of the extracted compounds. Polyphenol extraction using OH was successfully optimized with the best extraction conditions being 70 • C for 15 min using 70% ethanol as a solvent, which exhibited rutin recovers of 77% higher than control samples. It allowed to recover up to 4.93 g/gFW lycopene from tomato by-products without resorting to organic solvents. OH can be used as an environmental-friendly, fast and economic process to polyphenols recover from industrial tomato by-products. In addition, the use of different MEF during extraction shows to have a high potential to cause different levels of permeabilization and cell stress that can help to define a selective extraction process of valuable components from tomato by-products.

Using Ohmic Heating effect on grape skins as a pretreatment for anthocyanins extraction

“…USA), using a UV-vis photodiode array detector. The absorption spectra were recorded between 212 and 720 nanometers (Coelho et al, 2019). A Symmetry ® C18 column (250 × 4.6 mm, 5 m, Agilent, USA) was used as the stationary phase.…”

“…OH has been successfully used for thermal processing of foods (i.e. blanching, pasteurization, sterilization) (Jaeger et al, 2016;Pereira et al, 2016;Coelho et al, 2019). This energy efficiency can be achieved because OH is capable of a precise control of the temperature allowing volumetric HTST process avoiding contact with hot surfaces.…”

The use of emergent technologies to extract added value compounds from grape by-products

“…OH is an environmentally friendlier and more efficient thermal technology than traditional methods currently used in food processing; in OH, an electric current is passed directly through materials having electrical resistance, generating heat and increasing the instantaneous and homogeneous temperature inside the product (Coelho et al, 2019;Pereira et al, 2016). This technology has an energy efficiency of over 90% and, when compared to the conventional thermal method, which is less efficient, can achieve energy savings of up to 70% (Rocha et al, 2018).…”

“…Currently, the "green extraction" alternatives have been increasingly studied and implemented without the need for "clean-up" processes to recover the compounds that may be safely and immediately consumed or further used in the manufactured of foods (Bursać Kovačević et al, 2018;Deng et al, 2015). Numerous authors have suggested the alternative extraction methods, such as ultrasonic, microwaves, electrical technologies (pulsed electric fields, high electric discharges, and ohmic heating) and mechanical treatment (pressurized hot water extraction and subcritical fluid extraction) (Coelho, Pereira, Rodrigues, Teixeira, & Pintado, 2019;Deng et al, 2015;Galanakis, 2012Galanakis, , 2015aGalanakis, Tsatalas, Charalambous, & Galanakis, 2018;Kalli, Lappa, Bouchagier, Tarantilis, & Skotti, 2018). These are processes suitable for the improved recovery of valuable compounds since they use green solvents and reduce solvent consumption, and at the same time, they facilitate the plant cell disruption and compounds extraction, minimizing the impact on the BCs (Barba, Zhu, Koubaa, Sant'Ana, & Orlien, 2016).…”

Mass transfer in beef: effect of crossbreeding and ultrasound application

“…Different studies have used vacuum pulsing (Martins et al, 2019), ohmic heating (Coelho et al, 2019), electrodialysis (Xue et al, 2018), high pressure (Shinwari and Rao, 2018), microwave (Leonelli and Mason, 2010), and high-power ultrasound (Polachini et al, 2019;Goula et al, 2017), in order to accelerate mass transfer rates. Ultrasound is a promising emerging technology in the food processing industry, as it is innovative, achieving important results generally complementary to classical techniques, such as salting (Sharma and Dash, 2019).…”