Coffee residues as substrates for aroma production by Ceratocystis fimbriata in solid state fermentation

Abstract

The ability of two different strains of Ceratocystis fimbriata for fruity aroma production by solid state fermentation (SSF) was tested on coffee pulp and coffee husk complemented with glucose as substrates. Experiments were carried out in 250 mL Erlenmeyer flasks and the experimental conditions were: 70% of initial moisture, 20% of glucose addition and pH 6.0. Aeration was made by passive diffusion through the gauze covering the flasks. Headspace analysis of the culture by gas chromatography (GC) showed that 12 compounds were produced with coffee husk. Maximum total volatiles (TV) concentration was reached after 72 h of culture with coffee husk as substrate (28 µmol.L -1 .g -1 ). Ethyl acetate, ethanol and acetaldehyde were the major compounds produced, representing 84.7%, 7.6% and 2.0% of TV, respectively. A pre-treatment with heat (100ºC/ 40 min) of substrates did not improve TV production. Respirometry analysis was used to determine the growth of the culture by measuring carbon dioxide produced. Results showed that the CO2 production follows the aroma production. This result shows the great potential for the use coffee pulp and coffee husk as substrates to microbial aroma production by solid state fermentation.

Improving fruity aroma production by fungi in SSF using citric pulp

“…1 and 4). Comparing these results with those presented by Medeiros et al (2003) and Soares et al (2000), the production of total volatile compounds and isoamyl acetate in citric pulp reached greater values in a shorter time of fermentation.…”

“…Ceratocystis fimbriata has the potential for synthesizing esters, it grows quickly and produces a variety of aromas (peach, pineapple, banana, citrus and rose), depending on the strain and culture conditions (Bluemke & Schrader, 2001;Medeiros, Pandey, Vandenberghe, Pastore, & Soccol, 2003;Medeiros, Soccol, Vandenberghe, & Woiciechowski, 2007;Pandey et al, 2000).…”

Solid-State Fermentation as a Novel Paradigm for Organic Waste Valorization: A Review

“…The production of fruity aroma compounds was increased (99.60 µmol·g −1 ) using waste from citric juice production industry (citric pulp) cultivated with C. fimbriata by SSF supplemented with 50% of soya bran as a nitrogen source and 25% of sugarcane molasses as a carbon source [200]. This yield is higher than other ones reported in previous studies using other solid substrates [197]. The influence of oxygen on the total volatile compounds was demonstrated in studies carried out using cassava bagasse as a substrate for K. marxianus in SSF using packed bed reactors.…”

“…Apart from that, in the SSF process with food industry waste mixtures as a substrate for cultivation of S. cerevisiae, K. marxianus and kefir respectively, the production of ε-pinene was only observed as a product of kefir fermentation yielding a high amount (4208 mg·kg −1 of SSF product) [196]. Several authors have demonstrated the production of fruity aroma compounds by C. fimbriata in SSF using coffee residues (coffee husk, coffee pulp) as substrates [197,198]. Steam treated coffee husk is appropriate for aroma production by C. fimbriata supplemented with 20% of glucose concentration, while the addition of leucine improves the aroma intensity by 58%, especially by increasing the ester production [199].…”

Kidney Function Indices in Mice after Long Intake of Agaricus brasiliensis Mycelia (=Agaricus blazei, Agaricus subrufescens) Produced by Solid State Cultivation

“…In addition, the SSC medium generally contains low water content, which not only reduces the risk of contamination but also offers a favorable condition for fungal growth, because it resembles the natural habitats for fungi [13,14] . Agro-industrial residues are used for several bioprocess, including production of organic acids [15] , enzymes and biological detoxification of coffee husks [16] , aroma compounds [17][18][19] , entomopathogenic fungi for biological control [20,21] , edible mushrooms [22,23] . Further, SSC can be used as a method for produce food, when the used substrates are nutritionally valuable and free of toxic components, such cereals.…”