Process of compacting a microporous fat powder and compacted fat powder so obtained

Abstract

The present invention relates to a process of compacting a microporous fat powder, notably a microporous fat powder that can suitably be used as an oil structuring agent. One aspect of the invention relates to a process for compacting a microporous fat powder, said process comprising: feeding the fat powder into the feed zone of an extruder having a forwarding screw and a barrel within which said screw is centrally positioned; rotating said forwarding screw to advance said fat powder feed through a compacting zone of the extruder where the barrel comprises a plurality of venting openings having a shorter dimension that exceeds the volume weighted average diameter of the fat powder feed and that is less than 10 mm; and expelling the compacted fat powder from the extruder; wherein the temperature of the fat powder during passage through the extruder is maintained below 40° C. and wherein the compaction factor achieved exceeds 1.5 Another aspect of the invention relates to a compacted microporous fat powder having the following characteristics: a freely settled density in the range of 90-600 g/l; a particle size distribution with at least 90 vol. % of the particles having a diameter in the range of 20 to 600 μm; a maximum G′ i /G′ d ratio of more than 2.0, wherein G′ represents the elastic modulus at 10 C of a dispersion of 2 wt. % of the compacted fat powder in glycerol, and wherein the maximum ratio is determined by recording G′ i whilst increasing the frequency from 0.1 to 15 s −1 , by subsequently recording G′ d whilst decreasing said frequency from 15 to 0.1 s −1 , and by calculating the ratio G′ i /G′ d at the frequency at which said ratio is highest.

1 . A process for compacting a microporous fat powder in an extruder, said microporous fat powder having the following characteristics:
 a fat content of at least 50 wt. %;   a solid fat content at 20° C. (N 20 ) of least 10 wt. %;   a freely settled density in the range of 10 to 200 g/l, preferably in the range of 20 to 150 g/l;   a particle size distribution with at least 90 vol. % of the particles having a diameter in the range of 3 to 400 μm, preferably in the range of 5 to 300 μm;   
       said process comprising:
 feeding the fat powder into the feed zone of an extruder having a forwarding screw and a barrel within which said screw is centrally positioned; 
 rotating said forwarding screw to advance said fat powder feed through a compacting zone of the extruder where the barrel comprises a plurality of venting openings having a shorter dimension that exceeds the volume weighted average diameter of the fat powder feed and that is less than 10 mm; and 
 expelling the compacted fat powder from the extruder; 
 
       wherein the temperature of the fat powder during passage through the extruder is maintained below 40° C. and wherein the compaction factor achieved exceeds 1.5. 
     
     
         2 . Process according to  claim 1 , wherein the amount of solid fat that is molten during extrusion does not exceed 30%, preferably does not exceed 15% by weight of the fat powder. 
     
     
         3 . Process according to  claim 1 , wherein at 20° C. the fat powder has a solid fat content of at least 20 wt %. 
     
     
         4 . Process according to  claim 1 , wherein the fat powder has a melting point in excess of 40° C. 
     
     
         5 . Process according to  claim 1 , wherein the compaction factor achieved in the process lies in the range of 1.5 to 10, preferably in the range of 1.7 to 6, even more preferably in the range of 1.9 to 3.0. 
     
     
         6 . Process according to  claim 1 , wherein the shorter dimension of the venting openings exceeds 50 μm. 
     
     
         7 . Process according to  claim 1 , wherein the venting openings represent 3-60% of the surface area of the barrel in the compacting zone. 
     
     
         8 . Process according to  claim 1 , wherein the compacted fat powder has a freely settled density of at least 90 g/l, preferably of 120 to 600 g/l. 
     
     
         9 . A compacted microporous fat powder having the following characteristics:
 a fat content of at least 50 wt. %;   a solid fat content at 20° C. (N 20 ) of least 10 wt. %;   a freely settled density in the range of 90-600 g/l;   a particle size distribution with at least 90 vol. % of the particles having a diameter in the range of 20 to 600 μm;   a maximum G′ i /G′ d  ratio of more than 2.0, wherein G′ represents the elastic modulus at 10° C. of a dispersion of 2 wt. % of the compacted fat powder in glycerol, and wherein the maximum G′ i /G′ d  ratio is determined by recording G′ i  whilst increasing the frequency from 0.1 to 15 s −1 , by subsequently recording G′ d  whilst decreasing said frequency from 15 to 0.1 s −1 , and by calculating the ratio G′ i /G′ d  at the frequency at which said ratio is highest.   
     
     
         10 . Compacted microporous fat powder according to  claim 9 , wherein G′ i /G′ d  ratio is at least 2.5, more preferably at least 3.0. 
     
     
         11 . Compacted microporous fat powder according to  claim 10 , wherein the compacted fat powder has a full width at half maximum of the first order long spacing X-diffraction peak that is less than 0.00056×free flowing density+0.213. 
     
     
         12 . Compacted microporous fat powder according to  claim 9 , wherein the compacted fat powder is obtainable by a process according to  claim 1 . 
     
     
         13 . Use of the compacted microporous fat powder according to  claim 9  as an oil-structuring agent. 
     
     
         14 . A process of preparing a food product, said process comprising mixing the compacted microporous fat powder according to  claim 9  with liquid oil. 
     
     
         15 . Process according to  claim 14 , wherein the food product is selected from the group of spreads, kitchen margarines, bakery margarines, shortenings.