Can hydro-thermo-mechanical treatment by instant controlled pressure-drop (DIC) be used as short time roasting process? Effect of processing parameters on sensory, physical, functional, and color attributes of Egyptian carob powder

Sabah Mounir; Atef Ghandour; Rana Mustafa; Karim Allaf

doi:10.1007/s13197-020-04553-9

Can hydro-thermo-mechanical treatment by instant controlled pressure-drop (DIC) be used as short time roasting process? Effect of processing parameters on sensory, physical, functional, and color attributes of Egyptian carob powder

J Food Sci Technol. 2021 Feb;58(2):451-464. doi: 10.1007/s13197-020-04553-9. Epub 2020 May 31.

Authors

Sabah Mounir^{1

2}, Atef Ghandour³, Rana Mustafa⁴, Karim Allaf²

Affiliations

¹ Food Science Department, Faculty of Agriculture, Zagazig University, Zagazig, 44519 Egypt.
² Laboratory of Engineering Science for Environment LaSIEUMR7356, CNRS, La Rochelle University, 17000 La Rochelle, France.
³ Agricultural Engineering Research Institute, Agricultural Research Center, Dokki, Giza, Egypt.
⁴ College of Agriculture and Bioresources, Department Plant Sciences, University of Saskatchewan, 51 Campus Drive, Saskatoon, S7N 5A8 Canada.

Abstract

This study deals with the manufacture of a specific cocoa-like powder from Egyptian carob. The crucial unit operation consists of texturing/roasting unseeded carob kibbles, with the aim being to ensure perfect control of the chemical transformations that generate the desired flavor, drying to remove excess moisture, deodorizing to eliminate the undesirable flavor, and texturing to favor the physical/micro-mechanical changes that regulate the microstructure of the end product, in order to obtain an expanded-granule powder that can be used in many food formulations. The effect of saturated steam pressure of 0.30-0.60 MPa (133.5-158.8 °C) and processing time of 40-70 s, on the sensory attributes, physical and functional properties, and color characteristics were evaluated and optimized using response surface methodology (RSM). DIC-texturing/roasting could be used to improve the sensory and color characteristics, increase the expansion ratio and oil holding capacity, and decrease the bulk density of DIC-textured/roasted carob powder. The desired quality of textured/roasted carob powder was obtained at 0.60 MPa (158.8 °C) for 55 s (experimental conditions) with water holding capacity close to those of non-textured/unroasted sample. DIC can be used as a coupled process of texturing and roasting at 0.60 MPa for 68 s as predicted by RSM.

Keywords: Bulk density; Carob powder; Color; Expansion ratio; Instant controlled pressure-drop; Texturing/roasting; Water and oil holding capacity.