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Water Sorption and Plasticization Behavior of Spray‐dried Lactose/Protein Mixtures
Author(s) -
Haque M.K.,
Roos Y.H.
Publication year - 2004
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.2004.tb09900.x
Subject(s) - lactose , crystallization , sorption , chemistry , chromatography , food science , organic chemistry , adsorption
Water sorption properties, effects of proteins on glass transition temperature, and time‐dependent lactose crystallization of spray‐dried lactose and lactose in lactose/WPI (3:1), lactose/Na‐caseinate (3:1), lactose/albumin (3:1), and lactose/gelatin (3:1) mixtures were investigated. Brunauer‐Emmett‐Teller (BET) and Guggenheim‐Anderson‐de Boer (GAB) models were used to model water sorption. Lactose/protein mixtures sorbed high amounts of water at low relative vapor pressure (RVP) up to 23.1%. Above 23.1% RVP levels, water sorbed by pure lactose was higher, up to 44.1% RVP, except in the case of the lactose/gelatin mixture. Lactose/ gelatin also sorbed a high amount of water at 33.2% RVP. Loss of sorbed water resulting from crystallization of amorphous lactose was observed. Crystallization of pure lactose and lactose crystallization in lactose/protein mixtures occurred at RVP ≥ 44.1% within 24 h. After crystallization at RVP ≥ 54.5%, water contents remained higher for lactose/protein mixtures than for pure lactose. The rate of lactose crystallization was less in all lactose/protein mixtures than was observed for pure lactose. WPI had the lowest effect on lactose crystallization. Crystallization occurred most slowly in lactose/gelatin mixtures. Both GAB and BET models fitted to water sorption data up to 0.441 a w . It seems that different proteins interact with lactose differently. Water sorption and time‐dependent lactose crystallization of lactose/protein mixtures have important consequences to processing and storage behavior of lactose‐protein based products.