416 The nutrition handbook for food processors cannot be discharged without proper treatment. Mizrahi" compared hot water blanching and ohmic heating blanching. Hot water blanching was carried out by placing sliced or diced beet into boiling water and taking water samples every 30 seconds; blanching by ohmic heating was done by immersing whole, sliced or diced beets in an aqueous salt solution and passing an AC voltage through the medium. Betanine and betalamic acid concentration in the samples were deter mined. Solute leaching with both methods followed a similar pattern, and was proportional to the surface to volume ratio and the square root of the process time By removing the need for dicing and shortening the process time, ohmic heating blanching considerably reduced by one order of magnitude the loss of solutes during blanching of vegetables 19.6 Electrolysis and contamination Another factor we must consider is electrolysis, particularly the dissolution of metallic(stainless steel) electrodes at 50-60Hz, which could contaminate the finished products, and/or contribute to undesirable chemical reactions. Several measures have been taken to circumvent this problem. For example, commercial facilities using frequencies above 100kHz showed no apparent indications of metal hydrolysis after 3 years(the industry safety standard). Low frequencies such as 50 or 60 Hz power can be used with inert carbon or coated electrodes without causing noticeable dissolution. Some new plastic materials with suitable electrical and mechanical properties can be used for housing the electrodes and for lining the stainless steel pipes through which food products flow. 19.7 Future trend We have demonstrated that ohmic heating is a very unique thermal process Ohmic heating is considered a 'minimal process besides the HTST process Potential uses of ohmic heating include. 547-50 1 Cooking 2 Sterilisation and pasteurisation 3 Blanching 4 Thawing 5 Baking. However, as mentioned earlier, there has been only limited research quantifying the potential benefits of ohmic heating processes in terms of nutrition preserva tion. More research is needed to realize the advantages of ohmic heating and to promote the commercialisation of the process There are other major challenges hindering the commercialisation of the ohmi heating process. They are:(1)lack of temperature monitoring techniques forcannot be discharged without proper treatment. Mizrahi46 compared hot water blanching and ohmic heating blanching. Hot water blanching was carried out by placing sliced or diced beet into boiling water and taking water samples every 30 seconds; blanching by ohmic heating was done by immersing whole, sliced or diced beets in an aqueous salt solution and passing an AC voltage through the medium. Betanine and betalamic acid concentration in the samples were deter￾mined. Solute leaching with both methods followed a similar pattern, and was proportional to the surface to volume ratio and the square root of the process time. By removing the need for dicing and shortening the process time, ohmic heating blanching considerably reduced by one order of magnitude the loss of solutes during blanching of vegetables. 19.6 Electrolysis and contamination Another factor we must consider is electrolysis, particularly the dissolution of metallic (stainless steel) electrodes at 50–60 Hz, which could contaminate the finished products, and/or contribute to undesirable chemical reactions. Several measures have been taken to circumvent this problem. For example, commercial facilities using frequencies above 100 kHz showed no apparent indications of metal hydrolysis after 3 years (the industry safety standard). Low frequencies such as 50 or 60 Hz power can be used with inert carbon or coated electrodes without causing noticeable dissolution. Some new plastic materials with suitable electrical and mechanical properties can be used for housing the electrodes and for lining the stainless steel pipes through which food products flow. 19.7 Future trends We have demonstrated that ohmic heating is a very unique thermal process. Ohmic heating is considered a ‘minimal process’ besides the ‘HTST’ process. Potential uses of ohmic heating include:15,47–50 1 Cooking. 2 Sterilisation and pasteurisation. 3 Blanching. 4 Thawing. 5 Baking. 6 Enhanced diffusion. However, as mentioned earlier, there has been only limited research quantifying the potential benefits of ohmic heating processes in terms of nutrition preserva￾tion. More research is needed to realize the advantages of ohmic heating and to promote the commercialisation of the process. There are other major challenges hindering the commercialisation of the ohmic heating process. They are: (1) lack of temperature monitoring techniques for 416 The nutrition handbook for food processors