STUDIES ON DRYING AND DENATURATION KINETICS OF WHEY PROTEIN ISOLATE (WPI) IN CONVECTIVE DRYING ENVIRONMENT USING SINGLE DROPLET DRYING
The drying and denaturation kinetics of WPI solutions in convective air drying environment were investigated using single droplet drying.A custom-built single droplet drying instrument was used for this purpose.Single droplets with 5±0.1 μL volume (initial droplet diameter 1.5±0.1 mm) containing 10% (w/v) WPI were dried at air temperatures of 45o,65o and 80oC.Both the moisture and temperature histories of these droplets were measured.The degree of denaturation as a function of drying temperature and time was measured by collecting the droplets at every 60 sec for 600 sec.The denaturation was measured by using reversed-phase HPLC.The denaturation kinetics obtained in convective drying (CD) process was compared to the denaturation kinetics obtained in isothermal heat treatment (IHT).The IHT experiments were carried out at 65o and 80o C using water as heating medium.The results showed that at the end of CD process of 600 sec at 65°C,the denaturation of WPI was 68.3% while it was only 10.8% during IHT at the same medium temperature.At heating/drying medium temperature of 80oC,the denaturation loss of WPI was 90.0% and 68.7% during IHT and convective drying,respectively; suggesting that the extent of denaturation of WPI in convective drying and IHT depends on whether drying/heating was carried out above or below its denaturation temperature.The dehydration and interface related stresses rather than the thermal stress were found to be responsible for denaturation of WPI below at both the drying temperatures of 45oC and 65oC.
WPI drying kinetics denaturation kinetics convective drying isothermal heat treatment
M.A.Haque P.Aldred J.Chen B.Adhikari
Food and Nutritional Sciences,University of BallaratVictoria-3350,Australia State Key Laboratory for Food Science and Technology,Jiangnan University Wuxi,China
国际会议
The 18th International Drying Symposium Conference(第十八届国际干燥学术大会(IDS2012))
厦门
英文
1-7
2012-01-11（万方平台首次上网日期，不代表论文的发表时间）