Comparative analysis of functional, techno-functional, rheological, and thermal properties of honey fillings formulated with rind from watermelon waste and xanthan gum: Pre- and post-baking assessment

This study presents a novel investigation into the impact of baking on the physiochemical, antioxidant, techno-functional, textural, thermal, and rheological properties of honey cookie fillings, which were prepared using the combination of xanthan gum (XG) and watermelon rind paste (WMRP). At a constant concentration of XG (1.0% w/w), increasing WMRP from 15% (w/w) to 30% (w/w) resulted in an increase in the moisture content by 39.23% and 39.93%, total phenolic content (TPC) by 27.04% and 73.05%, radical scavenging activity (RSA) by 6.21% and 12.38%, and degree of syneresis (DOS) by 290.49% and 162.60%, while decreasing the total soluble solids (TSS) by 9.58% and 10.13%, 5-hydroxymethylfurfural (HMF) content by 42.80% and 14.61%, and diastase activity by 33.82% and 39.41% in fresh and baked fillings, respectively. In comparison, at the higher concentration of XG at 2.0% (w/w), increasing WMRP from 15% (w/w) to 30% (w/w) led to more pronounced increases in moisture content by 41.83% and 39.05%, TPC by 14.11% and 20.48%, RSA by 2.63% and 4.48%, DOS by 450.98% and 181.63%, while a similar reduction was observed in TSS by 9.45% and 10.29%, HMF content by 41.88% and 7.96%, and diastase activity by 45.73% and 36.18% in fresh and baked honey fillings, respectively. Increasing WMRP concentration from 15% (w/w) to 30% (w/w) decreased the viscoelastic nature of fresh honey-filling samples; however, no significant change was observed in baked samples. Furthermore, increasing XG concentration from 1.0% (w/w) to 1.5% (w/w) significantly enhanced the strength of gel network and viscoelastic behaviour of both fresh and baked honey filling samples. On the thermal properties, an increase in WMRP (15% w/w and 30% w/w) showed a significant impact in comparison to the XG.

Graphical Abstract