Medlar (Mespilus germanica L.) is a plant species that belongs to the Rosaceae family. Despite the nutritional and functional value of the medlar fruit, there is limited research, particularly regarding its potential as a source of dietary fibers, indigestible plant-based components, important for improving health. Fungal cellulase enzymes were used to treat medlar fruit in physiological (PRM) and consumable (CRM) maturity and obtain insoluble dietary fibers (IDF). The yield of obtained insoluble dietary fibers was 83% for both PRM and CRM. Fungal strains Aspergillus welwitschiae have proven to be significant producers of the cellulase enzyme complex and are also safe for use in food production. Swelling capacity exhibited the most pronounced response to the enzymatic treatment; 8.51–8.65% vs. 12.24–12.86% (untreated and treated fruits, respectively). Dietary fibers extracted from medlar fruits exhibited antioxidant activity that can be attributed to the presence of bound polyphenolic compounds within the fiber material. Microscopic analysis and FTIR spectra revealed structural changes in the medlar fibers due to enzyme activity, indicating partial hydrolysis of lignocellulosic components. This process enhances the functional properties of medlar-based IDF, making it a valuable ingredient for fiber-enriched food products.
Mićanović et al. (Fri,) studied this question.