Indigenous fungal strains isolation and molecular identification from coffee pulp for the production of pectic oligosaccharides.

Coffee pulp (CP) is a significant agro-industrial waste generated during coffee bean processing, which possess substantial environmental contamination and is rich in pectin. The primary objective of this study was to investigate the conversion of pectin extracted from coffee pulp into pectic oligosaccharides (POS) using native microbial strains. The study aimed to optimize the growing conditions, including temperature, time, and pectin concentration, to assess the productivity of pectinase. Two fungal strains that exhibited the highest growth on CP were isolated and subsequently identified as Aspergillus fumigatus P-1007 and A. fumigatus HA1, employing 5.8S rRNA gene sequencing. The optimization of temperature for the organism was carried out between 25 and 45 °C; compared to the other temperatures at 45 °C the productivity of pectinase was high; the exact temperature was used for the time experiment where we found that compared to the A. fumigatus P-1007, A. fumigates HA1 was showed high enzyme productivity on 6th day. Hence, the highest productivity of endo-pectinase was seen at a temperature of 45 °C on the 6th day using isolated A. fumigates HA1 in the CP with 1% of coffee pectin. Additionally, the produced POS were screened and confirmed through TLC and HPLC analysis. The antioxidant activity of the POS derived from the separated CP demonstrated an effective concentration (EC(50)) of 400 µg/ml. The study indicates that the efficient utilization of CP waste for producing potentially valuable functional food ingredients, such as POS, holds promise for commercial development. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-023-03811-9.