Phytochemical Profiling and Characterization of Honeydew, Cantaloupe, and Galia Melon Peel Extracts for Potential Prebiotic Activities

This study characterized the peel extracts of Cucumis melo L. varieties and evaluated their in vitro prebiotic-like activity supporting the growth of Lactobacillus delbrueckii subsp. bulgaricus and Bifidobacterium bifidum. Melon peel extracts were prepared and freeze-dried for analyzing sugar composition, enzymatic digestibility, and probiotic stimulation in various sample extracts. Among the tested varieties, cantaloupe peel exhibited the highest concentration of non-digestible polysaccharides (29.20 ± 1.0 mg/g) and significantly enhanced L. delbrueckii and B. bifidum growth to 9.81 ± 0.04 and 9.79 ± 0.01 log CFU/g. Total polyphenol content was greatest in cantaloupe (175 mg/100 g), followed by galia (173 mg/100 g) and honeydew (121 mg/100 g). FTIR and ¹H-NMR analyses showed the presence of polysaccharides, sugars, polyphenols, and other bioactive functional groups. Hydrolysis resistance to acid and α-amylase was 9.52% and 34.67% for cantaloupe, and 6.12% and 30.65% for honeydew, respectively. Overall, melon peel extracts demonstrated substantial prebiotic-like activity, attributed to their high levels of non-digestible polysaccharides, reducing sugars, phenolic compounds. These findings identify melon peel as a promising, sustainable source of bioactive ingredients for gut health promoting functional foods.