Investigating the matrix effect of high/low methoxyl pectins on typical aroma of apple juice using HS-SPME-GC-MS and NMR analysis.

Aroma quality is a key focus for apple juice producers and consumers alike. This study explored how pectin affects aroma release in apple juices. Initially, study selected 14 typical aroma compounds to examine pectin's matrix effects in both model and actual juices. The molecular interactions between pectin and these aromas were analyzed by using Nuclear Magnetic Resonance. Physicochemical analyses revealed that the concentration of pectin retained aroma in cloudy juice was higher. Juices with high methoxyl pectin retained more aroma than those with low methoxyl pectin. The addition of pectin inhibits the release of most volatile substances, such as esters and aldehydes, while promoting the release of alcohols. This is because D-galacturonic acid chemically bonded with esters and aldehydes. Sensory tests showed that pectin addition masked off-flavors and boosted floral notes, also extending the finish of the apple juice. The findings suggest methods and provide theoretical support for improving apple juice aroma by managing pectin levels.