Effect of hydrophilic and hydrophobic emulsifiers on physio-chemical, structural and water distribution properties of meat-based cookies

Abstract

Meat-based products are highly susceptible to weak gel formation upon heating. In this study, the effect of different emulsifiers on the rheological, pasting and microstructural properties of meat-based sugar-snap cookies was investigated. Cookies were processed with the addition of freeze-dried fish meat (1% w/w) and emulsifiers (0.5% w/w of wheat flour). The addition of emulsifiers especially diacetyl tartaric acid ester of mono- and diglycerides (DATEM) increased storage modulus (G′), a viscous behavior, compared to control and other emulsifiers. Expansion and hardness were significantly (P < 0.05) improved in DATEM and sodium pyrophosphate (SPP) samples compared to the control indicating the compact structure of starch-protein and emulsifiers molecules. The gelatinization characteristics particularly peak and final viscosities were significantly (P < 0.05) increased in DATEM samples with high water holding capacity (WHC) suggesting the strong interaction among starch-protein and emulsifiers. Low-field magnetic resonance (LF-NMR) analysis exhibited that T21 relaxation time, an indication of tightly bound water, was also highest in DATEM sample while unbound water (T23) was highest in control and sodium dodecyl sulphate (SDS) samples. Scanning electron microscopy (SEM) analysis revealed that DATEM containing samples were dense and uniform whereas wide holes were found in control and SDS samples. It was concluded that DATEM could be an effective emulsifier with improved physio-chemical, structural and pasting properties of meat-based cookies. The study will open a new window for the best use of suitable emulsifiers for meat-based cookies, however, future studies are needed to check their storage stability.