Broadband Viscoelastic Spectroscopy: A New Technique for Characterizing Rheological Behavior of Solid Foods

Abstract

The broadband viscoelastic spectroscopy (BVS) is a new technique for characterizing rheological behavior of solid foods. Conventional methods to obtain rheological behavior of materials over a broad range of frequencies are time-temperature superposition (TTS) technique and direct method using specific instruments. TTS technique works only for materials that are thermorheologically simple and over a limited range of about three decades of time or frequency. Materials for which the measured curves do not overlap by making a horizontal shift on the frequency axis are thermorheologically complex. Food systems are inherently complex with multiple constituents rendering them thermorheologically complex. Thus, it is necessary to acquire data directly over a wide frequency range in a single test to truly characterize such complex materials. The problems associated with TTS can be circumvented by using the BVS, which is capable of directly measuring viscoelastic properties over an extended frequency range. Applications of the BVS are introduced for characterizing viscoelastic behavior of food materials. Some advantages of the BVS technique over the TTS and other available instruments are also discussed.