Methods and apparatuses for thermal treatment of foods and other biomaterials, and products obtained thereby

Abstract

Methods and apparatuses for thermally treating flowable materials using electromagnetic radiation, and foods and materials obtained thereby. Also provided are methods of continuous flow thermal treatment of biomaterials, apparatuses for performing the same, and products prepared using the methods and/or apparatuses.

1 . A process for thermally treating a flowable material while passing the flowable material as a continuous stream through a thermal treatment apparatus, the process comprising: 
 (a) passing a flowable material continuously through a conduit, wherein at least a portion of the conduit is transparent to electromagnetic radiation;    (b) heating the flowable material by exposing the at least a portion of the conduit that is transparent to electromagnetic radiation; and    (c) mixing the flowable material to provide for thermal equalization in at least a portion of the flowable material.    
   
   
       2 . The process of  claim 1 , wherein the flowing occurs at a constant flow rate.  
   
   
       3 . The process of  claim 1 , wherein the flowing occurs at a constant heating power input or at a constant mass mean temperature at the heating exit for the flowing biomaterial.  
   
   
       4 . The process of  claim 1 , wherein the flowable material is selected based on at least one of rheological, dielectric, and thermophysical properties, or combinations thereof, of the flowable material.  
   
   
       5 . The process of  claim 1 , wherein the flowable material is a biomaterial.  
   
   
       6 . The process of  claim 5 , wherein the biomaterial is a food biomaterial.  
   
   
       7 . The process of  claim 6 , wherein the food biomaterial is selected based on at least one of rheological, dielectric, and thermophysical properties, or combinations thereof, of the food biomaterial.  
   
   
       8 . The process of  claim 1 , wherein the heating results in an average bulk temperature increase rate in the flowable material of at least about 1 degree Fahrenheit per second or 0.5 degrees Celsius per second.  
   
   
       9 . The process of  claim 8 , comprising one or more additional heating steps.  
   
   
       10 . The process of  claim 9 , wherein the one or more additional heating steps precedes, accompanies, or follows the heating that results in an average bulk temperature increase rate in the flowable material of at least 1 degree Fahrenheit per second or 0.5 degrees Celsius per second.  
   
   
       11 . The process of  claim 1 , wherein the heating is substantially free of heating by contacting the flowable material with a surface having a temperature that exceeds a maximum temperature level of the flowable material itself.  
   
   
       12 . The process of  claim 1 , wherein the electromagnetic radiation has a wavelength of about 1×10 −4  meters or greater.  
   
   
       13 . The process of  claim 1 , wherein the electromagnetic radiation has a frequency of about 3×10 12  waves per second or less.  
   
   
       14 . The process of  claim 1 , wherein the mixing occurs before, during, or after the heating, and combinations thereof.  
   
   
       15 . The process of  claim 1 , wherein the mixing is accomplished by altering a cross-sectional geometry of the flow.  
   
   
       16 . The process of  claim 1 , wherein the mixing occurs passively, actively, or both actively and passively.  
   
   
       17 . The process of  claim 1 , wherein the flowable biomaterial is not subjected to a heated surface.  
   
   
       18 . The process of  claim 16 , wherein the mixing is accomplished by using at least one passive, active, or both passive and active mixing devices, which serves to increase physical contact and heat exchange between regions of the flowable material having a higher temperature level and regions of the flowable material with a lower temperature level, which would not occur in the absence of the mixing devices.  
   
   
       19 . The process of  claim 18 , wherein the mixing provides at least a 10% reduction in temperature distribution variability across the flowable material when compared to temperature distribution variability across the flowable material in the absence of the mixing devices.  
   
   
       20 . The process of  claim 18 , comprising placing the mixing devices at a location selected from the group consisting of one or more points of entry, one or more points within, one or more exits, and combinations thereof, of the portion of the conduit that is exposed to the electromagnetic radiation.  
   
   
       21 . The process of  claim 1 , further comprising packaging the flowable material for refrigerated storage.  
   
   
       22 . The process of  claim 1 , wherein the heating and the mixing provide a sufficient temperature for a sufficient time to accomplish one of sterilization and pasteurization of the flowable material.  
   
   
       23 . The process of  claim 22 , further comprising aseptically packaging the flowable material.  
   
   
       24 . The process of  claim 1 , wherein the flowable biomaterial contact surface is sterilized prior to introduction of the flowable biomaterial.  
   
   
       25 . The process of  claim 23 , comprising holding the flowable material at a predetermined temperature for a predetermined length of time, and cooling, packaging and hermetically sealing the flowable material under aseptic conditions in a sterilized package.  
   
   
       26 . The process of  claim 22 , where the flowable material is filled at a predetermined temperature level into a non-sterile package under one of atmospheric and increased pressure conditions in order to achieve concurrent sterilization of package surfaces in contact with the flowable material and then hermetically sealing the package.  
   
   
       27 . A product produced by the process of  claim 1 .  
   
   
       28 . A commercially sterile biomaterial having one or more quality attributes that is preserved to a greater extent as compared to a reference biomaterial that has been sterilized using a thermal treatment method comprising contacting of the reference biomaterial with a surface whose temperature is consistently higher than a predetermined treatment temperature for the reference biomaterial.  
   
   
       29 . The commercially sterile food biomaterial of  claim 28 , wherein the one or more quality attributes are preserved for at least 12 weeks of storage at about 25° C.  
   
   
       30 . The food biomaterial of  claim 28 , wherein the one or more quality attributes is selected from the group consisting of nutrient content, color, texture, flavor and general appearance.  
   
   
       31 . The food biomaterial of  claim 28 , wherein the food biomaterial is one of hermetically packaged, shelf stable, and both hermetically packaged and shelf stable.  
   
   
       32 . The food biomaterial of one of claims  28  and  31 , wherein the food biomaterial is sweet potato.  
   
   
       33 . A commercially sterile food biomaterial having one or more quality attributes that is preserved to a greater extent as compared to a reference food biomaterial that has been sterilized using a thermal treatment method comprising contacting of the reference food biomaterial with a surface whose temperature is consistently higher than a predetermined treatment temperature for the reference food biomaterial, wherein: 
 (i) the food biomaterial is one of packaged for refrigeration, hermetically packaged, shelf stable, both packaged for refrigeration and shelf stable, and both hermetically packaged and shelf stable;    (ii) the food biomaterial is sweet potato or white (e.g., Irish) potato, optionally a puree;    wherein optionally no preservatives or acidulants, such as but not limited to an additive that makes the product more stable under thermal treatment, have been added to the food biomaterial but wherein optionally, water, salt, spices, flavors, peeling agents, and/or sodium acid pyrophosphate and other anti-browning additives can be added to or present in the food biomaterial.    
   
   
       34 . A thermally treated food biomaterial having a quality profile comprising one or quality attributes that substantially matches a quality profile of an untreated food biomaterial of the same type, wherein the thermally treated food biomaterial is commercially sterile and shelf stable.  
   
   
       35 . The food biomaterial of  claim 34 , wherein the quality attribute is selected from the group consisting of nutrient content, color, texture, flavor and general appearance.  
   
   
       36 . The food biomaterial of  claim 35 , wherein the food biomaterial is hermetically packaged.  
   
   
       37 . The food biomaterial of  claim 34 , wherein the food biomaterial is sweet potato.  
   
   
       38 . A thermally treated food biomaterial having a quality profile comprising one or quality attributes that substantially matches a quality profile of an untreated food biomaterial of the same type, wherein: 
 (i) the thermally treated food biomaterial is one of commercially sterile, packaged for refrigeration, hermetically packaged, shelf stable, and any combination thereof; and    (ii) the food biomaterial is sweet potato or white (e.g., Irish) potato, optionally a puree;    wherein optionally no preservatives or acidulants, such as but not limited to an additive that makes the product more stable under thermal treatment, have been added to the food biomaterial but wherein optionally, water, salt, spices, flavors, peeling agents, and/or sodium acid pyrophosphate and other anti-browning additives can be added to or present in the food biomaterial.    
   
   
       39 . An apparatus for thermally treating a flowable material, the apparatus comprising: 
 (a) a conduit for receiving a flowable material, wherein at least a portion of the conduit is transparent to electromagnetic radiation;    (b) a device for providing electromagnetic radiation to at least a portion of the conduit; and    (c) a mixing structure disposed within or along the conduit to provide for thermal equalization in at least a portion of the flowable material.    
   
   
       40 . The apparatus of  claim 39 , wherein the electromagnetic radiation can be provided at a wavelength of about 1×10 −4  meters or greater.  
   
   
       41 . The apparatus of  claim 39 , wherein the electromagnetic radiation can be provided at a frequency of about 3×10 12  waves per second or less.  
   
   
       42 . The apparatus of  claim 39 , wherein the mixing structure comprises an altered cross-sectional geometry of the conduit.  
   
   
       43 . The apparatus of  claim 39 , wherein the mixing structure comprises one or more passive mixing structures, one or more active mixing structures, or both.  
   
   
       44 . The apparatus of  claim 43 , comprising any combination of passive, active, or both passive and active mixing structures which serve to increase physical contact and heat exchange between regions of a flowable material having a higher temperature level and regions of the flowable material with a lower temperature level, which would not occur in the absence of the mixing structures.  
   
   
       45 . The apparatus of  claim 43 , wherein the mixing structures provide at least a 10% reduction in temperature distribution variability (standard deviation) across the flowable material when compared to temperature distribution variability (standard deviation) across the flowable material in the absence of the mixing structures.  
   
   
       46 . The apparatus of  claim 43 , comprising mixing structures at a location selected from the group consisting of one or more points of entry, one or more points within, one or more exits, and combinations thereof, of the portion of the conduit that is transparent to electromagnetic radiation.  
   
   
       47 . The apparatus of  claim 39 , comprising a control device for controlling a flow through the conduit at a constant flow rate.  
   
   
       48 . The apparatus of  claim 39 , comprising a control device for controlling a flow through the conduit at a volumetric flow rate of at least 0.25 gallons per minute.  
   
   
       49 . The apparatus of  claim 39 , comprising a control device for controlling a power level of the device for providing electromagnetic radiation such that heating of a flowable material in the conduit can occur at an average bulk temperature increase rate in the flowable material of at least 1 degree Fahrenheit per second or 0.5 degrees Celsius per second.  
   
   
       50 . The apparatus of  claim 39 , comprising a control device for controlling a power level of the device for providing electromagnetic radiation such that heating of a flowable material in the conduit occurs at a higher rate than heating of the conduit, such the heating of the flowable material is substantially free of heating by contacting the flowable material with a surface of the conduit having a temperature that exceeds a maximum temperature level of the flowable material itself.  
   
   
       51 . The apparatus of  claim 39 , comprising a control device for controlling a power level of the device for providing electromagnetic radiation such that the power level can be maintained constant.  
   
   
       52 . The apparatus of  claim 39 , comprising a control device for controlling a power level of the device for providing electromagnetic radiation such that the power level can be preset automatically or manually adjusted to a level predetermined to provide a predetermined thermal treatment of the flowable biomaterial at a predetermined mass flow rate.  
   
   
       53 . The apparatus of  claim 39 , comprising a packaging device for one of packaging the flowable material for refrigerated storage, aseptically packaging the flowable material, and both packaging the flowable material for refrigerated storage aseptically packaging the flowable material.  
   
   
       54 . The apparatus of  claim 39 , comprising a hold tube adapted for fluid communication with the conduit.  
   
   
       55 . The apparatus of  claim 39 , capable of having the flowable biomaterial product contact surface rendered commercially sterile prior to the introduction of the flowable biomaterial.  
   
   
       56 . The product of  claim 33  or  claim 38 , wherein the package can be of any standard size, including but not limited to individual size.  
   
   
       57 . The product of  claim 33  or  claim 38 , wherein the volume of food biomaterial in the package exceeds a volume of food biomaterial that can be accommodated in a Type 10 can.  
   
   
       58 . A commercially sterile shelf stable food biomaterial, wherein the food biomaterial comprises sweet potato or white potato and has a shelf life of 24 weeks or more, and further wherein no preservatives or acidulants that enhance stability of the food biomaterial to thermal treatment have been added to the food biomaterial, but wherein optionally the food biomaterial can comprise one or more of water, salt, spices, flavors, peeling agents, and sodium acid pyrophosphate and other anti-browning additives.  
   
   
       59 . The commercially sterile shelf stable food biomaterial of  claim 58 , wherein the food biomaterial is a puree.