The effect of addition of flaxseed gum on the emulsion properties of soybean protein isolate (SPI)
- Authors: Wang, Yong , Li, Dong , Wang, Li Ming , Adhikari, Benu
- Date: 2011
- Type: Text , Journal article
- Relation: Journal of Food Engineering Vol. 104, no. 1 (2011), p. 56-62
- Full Text: false
- Reviewed:
- Description: The effect of addition of flaxseed gum on the emulsion properties of soybean protein isolate (SPI) were investigated in this study. Flaxseed gum with 0.05-0.5% (w/v) concentration was used together with 1% (w/v) SPI to emulsify 10% (v/v) soybean oil. The emulsion was analyzed for emulsion activity (turbidity), stability, particle size, surface charge, and rheological properties. The turbidity and absolute zeta-potential values decreased initially by the addition of flaxseed gum and subsequently increased with further increase in the gum concentration to reach their peak around 0.35% (w/v) gum. The particle size of the emulsion decreased and reached a minimum value at 0.1% (w/v) gum concentration. Any increase in gum concentration beyond this value resulted into increase in the particle size. This study would help to widen the application of SPI and flaxseed gum mixture, and also contribute to the understanding of protein-gum interaction in emulsion. © 2010 Elsevier Ltd. All rights reserved.
Effects of emulsification of fat on the surface tension of protein solutions and surface properties of the resultant spray-dried particles
- Authors: Xu, Yun , Howes, Tony , Adhikari, Benu , Bhandari, Bhesh
- Date: 2013
- Type: Text , Journal article
- Relation: Drying Technology Vol. 31, no. 16 (December 2013), p. 1939-1950
- Full Text: false
- Reviewed:
- Description: To examine the effect of protein adsorption on the fat-water interface on the surface composition of spray-dried particles, whey, hydrolyzed whey, and soy protein isolate emulsions were prepared at three different protein to fat ratios of 1:1, 1:5, and 1:10 and spray dried. Non-hydrolyzed whey protein isolate (WPI) and the more hydrolyzed whey protein solutions at 20.2% degree of hydrolysis (DH) had significantly lower surface tension values with fat than without fat. The correlation between the reduction of surface tension value of an emulsion and the increase in protein surface composition of powder particles was observed for WPI and HWP406 but was not observed for the other protein isolate types. It was clear that the spray-dried emulsions had fat as the dominant component on the surface of the powder particles and that the amount of protein on the surface became severely depressed at higher fat addition levels. In terms of its powder morphology, the unique powder structures such as the indentations and folds usually found on the surface of protein containing powders were not evident because they were compromised by the presence of high surface fat. The powder with higher surface fat had more crumpled particle structures and dimpled surfaces.
- Description: C1
Interfacial and emulsifying properties of lentil protein isolate
- Authors: Joshi, Matina , Adhikari, Benu , Aldred, Peter , Panozzo, Joe , Kasapis, Stefan , Barrow, Colin
- Date: 2012
- Type: Text , Journal article
- Relation: Food Chemistry Vol.134 no.3 (2012), p.343-1353
- Full Text:
- Reviewed:
- Description: The dynamic interfacial tension (DIFT) at oil-water interface, diffusion coefficients, surface hydrophobicity, zeta potential and emulsifying properties, including emulsion activity index (EAI), emulsion stability index (ESI) and droplet size of lentil protein isolate (LPI), were measured at different pH and LPI concentration, in order to elucidate its emulsifying behaviour. Sodium caseinate (NaCas), whey protein isolate (WPI), bovine serum albumin (BSA) and lysozyme (Lys) were used as benchmark proteins and their emulsifying property was compared with that of LPI. The speed of diffusion-controlled migration of these proteins to the oil/water interface, was in the following order: NaCas > LPI > WPI > BSA > Lys, while their surface hydrophobicity was in the following order: BSA > LPI > NaCas > WPI > Lys. The EAI of emulsions stabilised by the above proteins ranged from 90.3 to 123.3 m 2/g and it was 93.3 ± 0.2 m 2/g in LPI-stabilised emulsion. However, the stability of LPI-stabilised emulsions was slightly lower compared to that of WPI and NaCas-stabilised emulsions at the same protein concentration at pH 7.0. The ESI of LPI emulsions improved substantially with decrease in droplet size when protein concentration was increased (20-30 mg/ml). Reduction of disulphide bonds enhanced both the EAI and ESI compared to untreated samples. Heat treatment of LPI dispersions resulted in poor emulsion stability due to molecular aggregation. The stability of LPI-stabilised emulsions was found to decrease in the presence of NaCl. This study showed that LPI can be as effective emulsifiers of oil-in-water emulsions as are WPI and NaCas at ≥20 mg/ml concentrations both at low and neutral pH. The emulsifying property of LPI can be improved by reducing the intra and inter-disulphide bond by using appropriate reducing agents. © 2012 Elsevier Ltd. All rights reserved.