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.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is based on and claims priority to U.S. Provisional Application Ser. No. 60 / 627,499, filed Nov. 12, 2004, and U.S. Provisional Application Ser. No. 60 / 664,762, filed Mar. 24, 2005, the disclosures of each of which are herein incorporated by reference in their entireties.TECHNICAL FIELD [0002] The presently disclosed subject matter relates to methods and apparatuses for thermally treating flowable materials using electromagnetic radiation, and foods and materials obtained thereby. More particularly, the presently disclosed subject matter relates to methods of continuous flow thermal treatment of biomaterials, apparatuses for performing the same, and products prepared using the methods and / or apparatuses. BACKGROUND [0003] In order to be sold to the public, food often needs to be treated to minimize microbial growth that can occur between the time that the foodstuffs are harvested and they are purchased by the consumer. T...

AI Technical Summary

Benefits of technology

[0014] In some embodiments of the presently disclosed subject matter, the mixing precedes, accompanies, or follows the heating. In some embodiments, the mixing is accomplished by altering a cross-sectional geometry of the flow. In some embodiments, the mixing occurs passively, actively, or both actively and passively. In some embodiments, the mixing is accomplished by using any combination of passive, active, or both passive and active mixing devices which serve 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. In some embodiments, the mixing provides 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 devices. In some embodiments, the process comprises 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.

[0025] In some embodiments of the presently disclosed subject matter, the mixing structure comprises an altered cross-sectional geometry of the conduit. In some embodiments, the mixing structure comprises one or more passive mixing structures, one or more active mixing structures, or both. In some embodiments, the apparatus comprises 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. In some embodiments, 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.

Problems solved by technology

However, many foodstuffs and other biomaterials are negatively impacted by the application of heat, either in terms of taste, aesthetic appearance, nutrient levels, or other characteristics so that the ways in which this material can be treated are limited.

Preservation of SPP by freezing is a well-established method, but the frozen puree requires considerable investment in frozen distribution and storage as well as a lengthy and poorly controlled defrosting treatment prior to use.

Canned puree typically requires excessive thermal treatment, especially when processed in institutional-size packages, provides poor utilization of storage space, and presents a difficulty in handling, opening, and dispensing of the product, as well as disposing of the emptied packages.

Particularly at the edges, the product is often severely over-processed, resulting in dark discoloration and burnt flavor.

Thus, the useful can size is frequently limited to can size number 10 (i.e., a volume of about 13 cups), and this size limitation is a major obstruction to the wider applications of canned sweetpotato puree in the food processing industry.

Other thermal processing technologies such as scraped surface heat exchangers or flash sterilization treatment also have limitations in that SPP is characterized by low thermal diffusivity (Smith et al., 1982).

The low thermal diffusivity of SPP leads to very long periods of heating when conventional thermal processing methods are used in order to achieve required sterilization levels, which in turn causes degradation of the nutrients in SPP and poor product quality.

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