Characterization of the surface stickiness of fructose-maltodextrin solutions during drying
- Authors: Adhikari, Benu , Howes, Tony , Bhandari, Bhesh , Truong, V.
- Date: 2003
- Type: Text , Journal article
- Relation: Drying Technology Vol. 21, no. 1 (2003), p. 17-34
- Full Text: false
- Reviewed:
- Description: A probe tack test has been used for the in situ characterization of the surface stickiness of hemispherical drops with an initial radius of 3.5 mm while drying. Surface stickiness of drops of fructose and maltodextrin solutions dried at 63degreesC and 95degreesC was determined. The effect of addition of maltodextrin on fructose solution-was studied with fructose/maltodextrin solid mass ratios of 4: 1, 1: 1, and 1:4. Pure fructose solutions remained completely sticky and failed cohesively even when their moisture approached zero. Shortly after the start of drying, the surface of the maltodextrin drops formed a skin, which rapidly grew in thickness. Subsequently the drop surface became completely nonsticky probably due to transformation of outer layers into a glassy material. Addition of malto,dextrin significantly altered the surface stickiness of drops of fructose solutions, demonstrating its use as an effective drying aid.
Glass transition behaviour of fructose
- Authors: Truong, V. , Bhandari, Bhesh , Howes, Tony , Adhikari, Benu
- Date: 2004
- Type: Text , Journal article
- Relation: International Journal of Food Science and Technology Vol. 39, no. 5 (2004), p. 569-578
- Full Text: false
- Reviewed:
- Description: The glass transition temperature and the second transition (the endothermic change between the glass transition and melting temperatures) of fructose were studied. The thermal history strongly affected both transitions of fructose. Storage for 10 days at 22degreesC increased the dynamic glass transition temperature from 16 to 25degreesC and decreased the second transition of fructose from 110 to 98degreesC in the first differential scanning calorimetric (DSC) scan. The amplitude of the second transition increased slightly with storage time and reached 260% of the first transition for vacuum oven dried samples. The effect of thermal history on the glass transition temperature of fructose can be removed by scanning the sample in a DSC to 130degreesC. The effects of water content, glucose and sucrose on the two transitions were also investigated.
In situ characterization of stickiness of sugar-rich foods using a linear actuator driven stickiness testing device
- Authors: Adhikari, Benu , Howes, Tony , Bhandari, Bhesh , Truong, V.
- Date: 2003
- Type: Text , Journal article
- Relation: Journal of Food Engineering Vol. 58, no. 1 (2003), p. 11-22
- Full Text: false
- Reviewed:
- Description: A stickiness testing device based on the probe tack test has been designed and tested. It was used to perform in situ characterization of drying hemispherical drops with an initial radius 3.5 mm. Tests were carried out in two drying temperatures, 63 and 95 degreesC. Moisture and temperature histories of the drying drops of fructose, honey, sucrose, maltodextrin and sucrose-maltodextrin mixtures were determined. The rates of moisture evaporation of the fructose solution was the fastest while those of the maltodextrin solution was the lowest. A profile reversal was observed when the temperature profiles of these materials were compared. Different modes of failure were observed during the stickiness tests. Pure fructose and honey solutions remained completely sticky and failed cohesively until the end of drying. Pure sucrose solution remained sticky and failed cohesively until complete crystallization occurred. The surface of the maltodextrin drops formed a skin shortly after the start of drying. It exhibited adhesive failure and reached a state of non-adhesion. Addition of maltodextrin significantly altered the stickiness of sucrose solution. (C) 2002 Elsevier Science Ltd. All rights reserved.