Proximate and nutrient composition of three types of indigenous edible wild mushrooms grown in Tanzania and their utilization prospects

In Tanzania wild edible mushrooms collected during the rainy season have broad cultural acceptance and constitute a traditionally very important nutritious food.  However, their assessment as food, which is based on their chemical analysis, has not been adequately studied and documented. The objective of the study was to determine the proximate nutritive potential of three indigenous edible wild  mushrooms namely Coprinus cinereus, (Schaeff) S. Gray s.lat., Pleurotus  flabellatus, (Berk and Br.) Sacc. and Volvariella volvaceae (Bull.ex.Fr) Singer, grown on composted solid sisal decortication residues. Standard procedures were used to determine the proximate chemical composition of dried samples of domesticated indigenous edible wild mushrooms. Atomic absorption spectrophotometry was used to determine the mineral element composition. The results were compared using an analysis of variance test. There were significant differences in the proximate  nutritive values of the three edible mushrooms (p>0.05). Despite differences in the chemical composition of the three indigenous edible mushroom species, the overall nutritional potential of the three mushroom species was quite good. Furthermore, the overall results indicated that the fruit bodies of the three native mushrooms studied have nutrient qualities similar to other cultivated exotic edible mushrooms, and a higher protein content than many cereals and vegetables. The results on a dry weight basis demonstrated significant amounts of protein, vitamin C and minerals, ranging from 17-28 %, 33-55 mg/100g and 5.2-3232 mg/100g, respectively. Furthermore crude fibre ranged between 6.6-11 % and carbohydrate, at 50-62 %, both of which were found to be relatively high. All three species were low in fat content, with a range of 1 to 3.3 %, and energy value (calculated), 302-313  kcal/100g. These results indicated that the studied mushrooms have good nutritive value for human beings. The fact that the domesticated mushrooms were grown  using locally adapted biotechnology increases the likelihood of their incorporation in the diet as a food item contributing protein, vitamin C and mineral nutrients. The high crude fibre and low fat content are also important from a nutritional  perspective. The researchers believe that it would be appropriate to popularise theutilization of the three mushrooms as unconventional protein rich food sources to supplement the traditional cereal Tanzanian based diet, aimed at combating the problem of protein malnutrition in Tanzania in particular and in developing counties in general.Key words: Proximate composition, Wild edible mushroom

Two-Stage Fungal Pre-Treatment for Improved Biogas Production from Sisal Leaf Decortication Residues

Sisal leaf decortications residue (SLDR) is amongst the most abundant agro-industrial residues in Tanzania and is a good feedstock for biogas production. Pre-treatment of the residue prior to its anaerobic digestion (AD) was investigated using a two-stage pre-treatment approach with two fungal strains, CCHT-1 and Trichoderma reesei in succession in anaerobic batch bioreactors. AD of the pre-treated residue with CCTH-1 at 10% (wet weight inoculum/SLDR) inoculum concentration incubated for four days followed by incubation for eight days with 25% (wet weight inoculum/SLDR) of T. reesei gave a methane yield of 0.292 ± 0.04 m3 CH4/kg volatile solids (VS)added. On reversing the pre-treatment succession of the fungal inocula using the same parameters followed by AD, methane yield decreased by about 55%. Generally, an increment in the range of 30–101% in methane yield in comparison to the un-treated SLDR was obtained. The results confirmed the potential of CCHT-1 followed by Trichoderma reesei fungi pre-treatment prior to AD to achieve significant improvement in biogas production from SLDR

Performance of biofilm carriers in anaerobic digestion of sisal leaf waste leachate

Three methanogenic biofilm bioreactors were studied to evaluate the performance of three types of carriers. The carrier material were consisted of sisal fibre waste, pumice stone and porous glass beads, and the bioprocess evaluated was the methanogenesis anaerobic digestion of sisal leaf waste leachate. Process performance was investigated by increasing the organic loading rate (OLR) step-wise. The best results were obtained from the bioreactor packed with sisal fibre waste. It had the highest chemical oxygen demand (COD) removal efficiencies in the range of 80-93% at OLRs in the range of 2.4-25 g COD L-1d-1. The degradation pattern of volatile fatty acids (VFAs) showed that the degradation of propionate was limiting at higher OLRs. The stable pH and higher partial alkalinity (PA) of the outflow illustrated that packed-bed bioreactors have a good ability to withstand the variations in load and volatile fatty acid concentrations that can occur in a two-stage anaerobic process. In conclusion, sisal fibre waste was shown to be a novel promising biofilm carrier and would work very well in methanogenic biofilm bioreactors treating sisal leaf tissue waste leachate. Furthermore both sisal wastes are available in the neighbourhood of sisal industries, which makes anaerobic digestion scale up at sisal factory level feasible and cost-effective

Proximate And Nutrient Composition Of Three Types Of Indigenous Edible Wild Mushrooms Grown In Tanzania And Their Utilization Prospects

In Tanzania wild edible mushrooms collected during the rainy season have broad cultural acceptance and constitute a traditionally very important nutritious food. However, their assessment as food, which is based on their chemical analysis, has not been adequately studied and documented. The objective of the study was to determine the proximate nutritive potential of three indigenous edible wild mushrooms namely Coprinus cinereus , (Schaeff) S. Gray s.lat., Pleurotus flabellatus , (Berk and Br.) Sacc. and Volvariella volvaceae (Bull.ex.Fr) Singer, grown on composted solid sisal decortication residues. Standard procedures were used to determine the proximate chemical composition of dried samples of domesticated indigenous edible wild mushrooms. Atomic absorption spectrophotometry was used to determine the mineral element composition. The results were compared using an analysis of variance test. There were significant differences in the proximate nutritive values of the three edible mushrooms (p>0.05). Despite differences in the chemical composition of the three indigenous edible mushroom species, the overall nutritional potential of the three mushroom species was quite good. Furthermore, the overall results indicated that the fruit bodies of the three native mushrooms studied have nutrient qualities similar to other cultivated exotic edible mushrooms, and a higher protein content than many cereals and vegetables. The results on a dry weight basis demonstrated significant amounts of protein, vitamin C and minerals, ranging from 17-28 %, 33-55 mg/100g and 5.2-3232 mg/100g, respectively. Furthermore crude fibre ranged between 6.6-11 % and carbohydrate, at 50-62 %, both of which were found to be relatively high. All three species were low in fat content, with a range of 1 to 3.3 %, and energy value (calculated), 302-313 kcal/100g. These results indicated that the studied mushrooms have good nutritive value for human beings. The fact that the domesticated mushrooms were grown using locally adapted biotechnology increases the likelihood of their incorporation in the diet as a food item contributing protein, vitamin C and mineral nutrients. The high crude fibre and low fat content are also important from a nutritional perspective. The researchers believe that it would be appropriate to popularise the utilization of the three mushrooms as unconventional protein rich food sources to supplement the traditional cereal Tanzanian based diet, aimed at combating the problem of protein malnutrition in Tanzania in particular and in developing counties in general

Performance of biofilm carriers in anaerobic digestion of sisal leaf waste leachate

Three methanogenic biofilm bioreactors were studied to evaluate the performance of three types of carriers. The carrier material were consisted of sisal fibre waste, pumice stone and porous glass beads, and the bioprocess evaluated was the methanogenesis anaerobic digestion of sisal leaf waste leachate. Process performance was investigated by increasing the organic loading rate (OLR) step-wise. The best results were obtained from the bioreactor packed with sisal fibre waste. It had the highest chemical oxygen demand ( COD) removal efficiencies in the range of 80-93% at OLRs in the range of 2.4-25 g COD L(-1)d(-1). The degradation pattern of volatile fatty acids (VFAs) showed that the degradation of propionate was limiting at higher OLRs. The stable pH and higher partial alkalinity (PA) of the outflow illustrated that packed-bed bioreactors have a good ability to withstand the variations in load and volatile fatty acid concentrations that can occur in a two-stage anaerobic process. In conclusion, sisal fibre waste was shown to be a novel promising biofilm carrier and would work very well in methanogenic biofilm bioreactors treating sisal leaf tissue waste leachate. Furthermore both sisal wastes are available in the neighbourhood of sisal industries, which makes anaerobic digestion scale up at sisal factory level feasible and cost-effective

High bioethanol titre from Manihot glaziovii through fed-batch simultaneous saccharification and fermentation in Automatic Gas Potential Test System.

A process for the production of high bioethanol titre was established through fed-batch and simultaneous saccharification and fermentation (FB-SSF) of wild, non-edible cassava Manihot glaziovii. FB-SSF allowed fermentation of up to 390g/L of starch-derived glucose achieving high bioethanol concentration of up to 190g/L (24% v/v) with yields of around 94% of the theoretical value. The wild cassava M. glaziovii starch is hydrolysable with a low dosage of amylolytic enzymes (0.1-0.15% v/w, Termamyl® and AMG®). The Automatic Gas Potential Test System (AMPTS) was adapted to yeast ethanol fermentation and demonstrated to be an accurate, reliable and flexible device for studying the kinetics of yeast in SSF and FB-SSF. The bioethanol derived stoichiometrically from the CO2 registered in the AMPTS software correlated positively with samples analysed by HPLC (R(2)=0.99)

Characterisation and evaluation of a novel feedstock, Manihot glaziovii, Muell. Arg, for production of bioenergy carriers: Bioethanol and biogas.

The objective of this study was to characterise and evaluate a wild inedible cassava species, Manihot glaziovii as feedstock for bioenergy production. Tubers obtained from 3 different areas in Tanzania were characterised and evaluated for bioethanol and biogas production. These bioenergy carriers were produced both separately and sequentially and their energy values evaluated based on these two approaches. Composition analysis demonstrated that M. glaziovii is a suitable feedstock for both bioethanol and biogas production. Starch content ranged from 77% to 81%, structural carbohydrates 3-16%, total crude protein ranged from 2% to 8%. Yeast fermentation achieved ethanol concentration of up to 85g/L at a fermentation efficiency of 89%. The fuel energy of the bioethanol and methane from flour-peels mix ranged from 5 to 13 and 11 to 14MJ/kgVS, respectively. Co-production of bioethanol and biogas in which the peels were added to the fermentation residue prior to anaerobic digestion produced maximum fuel energy yield of (15-23MJ/kgVS)