Phospholipids And Poly(glutamic Acid)/hydrolysed Gluten: Interaction And Kinetics

摘要

The effect of poly(glutamic acid) (PGA) and hydrolysed wheat gluten (HG) on the thermal and kinetics properties of lysophosphatidylcholine (LPC) was determined using DSC. A model system containing PGA or HG was added to 40% LPC aqueous suspension. The results from the study showed reduced AH values as a function of PGA molecular weight, which signified some kind of penetration of PGA or HG into the LPC bi-layer but not enough to minimise the order of LPC vesicle structure. The ability of LPC molecules to rearrange itself into a bi-layer again was evident in the emergence of crystallisation profiles in the course of the cooling cycle. The calculated activation energy (E_a) of pure LPC vesicle disruption (heating) and formation (cooling) was 696.6 and 520.4 kJ/mol, respectively. Overall, the trend of lower E_a as a function of PGA molecular weight was apparent during both heating and cooling cycles. Although, both PGA and HG reduced the E_a, HG was less effective in reducing E_a. The purported molecular interaction between phospholipids and gluten has been confirmed using FT-IR spectroscopy. The FT-IR results indicated that interactions occurred in LPC/HG blends and in model mixtures consisting of LPC/PGA with different molecular weight.