Work

D-optimal mixture design optimization of a natural date syrup jelly with an orange albedo powder–lemon juice suspension: quality attributes and processing-induced citrus pectin modifications

Year: 2026

Type: article

Abstract: This study optimized a natural, additive-free jelly formulated from date syrup (DS), orange albedo powder (OAP), and lemon juice (LJ) using a constrained D-optimal mixture design. The study also investigated whether the mild acid–heat jelly-processing could induce partial and potentially favorable structural modification of citrus pectin. To balance nutritional quality and texture, the optimal formulation was 75% DS, 2% OAP, and 23% LJ (w/w), yielding a hardness of 10 N, pH 3.46, total sugar content of 79.01 g/100 g (mainly sucrose), 40 mg/100 g vitamin C and phenolics content of 220.95 mg /100 g. The optimized jelly was also rich in minerals (K, Mg, Ca). FTIR, ¹H NMR, and GC-MS monosaccharide profiling provided evidence of processing-induced remodeling of the recovered pectic material, including partial de-esterification, and changes in HG and RG-I related features, suggesting that gelation was driven mainly by HG-rich domains. Neutral sugar analysis indicated co-extraction from DS, while OAP-associated side-chain sugars (galactose, arabinose, mannose) confirmed a contribution of OAP-derived RG-I domains.Beside yielding a jelly with interesting nutritional and structural properties, the results show that jelly processing can generate, in situ, a food matrix containing partially modified pectic material, while highlighting orange albedo powder as a multifunctional ingredient.

Source: LWT

DOI: 10.1016/j.lwt.2026.119724