Texture and structure of gelatin/pectin-based gummy confections

Abstract

The texture of gelatin:high-methoxyl pectin gummy gels was quantified by instrumental and sensory techniques and their microstrucuture examined by light and transmission electron microscopy. Gelatin:HM pectin confectionery gels (33.4% sucrose and 29.8% 42 DE corn syrup solids) with 3.0, 4.5, or 6.0% gelatin and 0.0, 0.5, 1.0, or 1.5% HM pectin were formed into oval-shaped samples and fractured in tension. Descriptive sensory evaluation was done on seven of these gels in duplicate by 10 experienced panelists using free choice profiling. The addition of pectin reduced the strain at fracture of gelatin gels. Stress at fracture could be described by upper and lower bound behavior. Microstructural analysis suggested that at high total polymer or pectin concentration, increased phase viscosity and rate of gelation influenced structure by preventing coalescence of the dispersed gelatin-rich phase. Micrographs suggested that gelatin in the pectin-rich phase was concentrated enough to gel and contributed to mixed gel properties. Gels were described variously as soft to firm and brittle to rubbery. Mixed gels were more fruity, sweet, and tart than pure gelatin gels. Gels with a high degree of coalescence of the dispersed phase were described as pulpy. Sensory texture first principal component values correlated with strain at fracture ( r=0.90), log [stress at fracture] ( r=0.87), and flavor first principal component values ( r=0.83).