Evaluation of coffee pulp as substrate for polygalacturonase production in solid state fermentation

Abstract

The purpose of this research is to evaluate the coffee pulp, a by-product of coffee processing, as substrate for polygalacturonase production by solid state fermentation. In addition, it is a way to take advantage of the coffee pulp. Characterization of the coffee pulp revealed a high content of nutrients for fungi growth, such as reducing sugars (5.4% of dry pulp), proteins (9.4% of dry pulp), pectins (20.5% of dry pulp), which are inducers of pectic hydrolases production and source of carbon after degradation, and caffeine (1.4% of dry pulp), among others. The characterization of the cell-wall of coffee pulp revealed, after polysaccharides fractionation, the content in cell-wall pectins (25.5%), hemicelluloses (11.5%) and cellulosic residue (44%). A strain of Aspergillus niger, called van Thiegem, has been selected as a good producer of polygalacturonases (60 U/ml) using the coffee pulp as the growth substrate. During fermentation, reducing sugars, caffeine and phenolic compounds were consumed till almost exhaustion. A partial characterization of the polygalacturonase using high methoxyl pectin as substrate indicates an optimal pH of 4.0 and 45oC as optimal temperature, which are good values for the use of the enzyme in vegetable processing, including coffee processing.

An Extracellular Pectinase from ISH16 Bacteria Isolated Induced by Coffee Pulp Waste Substrate

“…Therefore, the next production of pectinase uses a coffee pulp medium (without AIS treatment) because it is considered more efficient, economical, and environmentally friendly. The research, as reported by Frómeta et al (2020), stated that the pectin content in the coffee pulp increased by 20.5% after being treated with AIS. Another critical factor to consider in the SSF process is the sufficient water content in the medium (Sella et al, 2009).…”

“…Every 5 tons of wet processing of coffee will produce about 3 tons of coffee pulp by-products (Chanakya and De Alwis, 2004;Fan et al, 2003), and at least 6.5-8% of it is pectin (Murthy and Madhava Naidu, 2012). The pectin content of dry coffee pulp can increase up to 20.5% after being treated with AIS (insoluble solid alcohol) by precipitation of polysaccharides on the coffee pulp with high concentrations of alcohol (Frómeta et al, 2020), which is expected to increase the amount of enzymes released during the production process.…”

Valorization of Coffee Pulp in the Production of Pleurotus pulmonarius in Rural Communities of Colombia

“…Many studies have proposed the use of coffee production waste for several purposes such as vermiculture, animal feed, obtaining odors and flavors for the food industry, ethanol production, enzymes, vinegar, proteins, probiotics, , and compost . A difficulty faced by all of these proposals is that of technology transfer, even more so when it comes to making this transfer to small-scale coffee farmers.…”

Pectinase Production of Aspergillus sp. VTM5 Through Solid State Fermentation Using Coffee Pulp Substrate and Its Purification

“…However, the content of coffee pulp as waste is categorized as still high, especially for the growth of microorganisms such as fungi. Based on Frometa et al [7], The content in coffee pulp includes reducing sugars (5.4% of dry pulp), proteins (9.4% of dry pulp), pectins (20.5% of dry pulp after Alcohol Insoluble Solid (AIS) fractionation), hemicellulose (9.2% of dry pulp after AIS fractionation), cellulose (35.6% of dry pulp after AIS fractionation) and caffeine (1.4% of dry pulp). This high content of pectin in coffee pulp is an inducer for the production of pectinase by fungi.…”