Protein enrichment of cassava peel by submerged fermentation with Trichoderma viride (ATCC 36316)

Cassava (Manihot esculenta Crantz) peel is one of the solid wastes produced as a consequence of cassava processing. It is low in protein but contains a large amount of carbohydrate, causing an environmental problem with disposal. In order to add-value to this major cassava processing waste and also reduce its resultant environmental pollution, this study investigated the effect of submerged fermentation using Trichoderma viride ATCC 36316 on the protein content and amino acid profile of enzyme and non-enzyme pre-treated cassava peel. Compositional analysis of the product obtained with T. viride in the fermentor revealed that dry biomass increased in crude protein, true protein, crude fat, crude fibre, ash and total dietary fibre. The crude protein increased from 4.21 to 37.63 and 36.52% for enzyme and non-enzyme pre-treated fermented samples respectively with 31.6% as true protein for the former and 29.03% as true protein for the latter while the starch contents reduced considerably in both samples. Starch reduction was from 51.93 to 24.34 and 26.07% for enzyme and non-enzyme pre-treated fermented samples, respectively. The fermented products contained all the essential amino acids; however the chemical score of essential amino acids indicated methionine as the limiting amino acid

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Construction and performance evaluation of an on-farm scale solid state fermenter

The protein enrichment of cassava peel using solid state fermentation (SSF) was studied on both laboratory and on-farm scales using Trichoderma viride as a starter culture. The fermentation of cassava peel was carried out using cassava peel with particle size 4.00>p>3.35 mm, initial moisture content of 60% at pH 6.0, 30oC incubation temperature with ammonium sulphate (10g N / kg substrate) as additional nitrogen source for 8 days at the laboratory scale and 28-30oC at the on-farm scale. A high relative humidity of 90-95% was maintained throughout the fermentation period. The fermented peel was oven-dried at 60oC, ground and analysed. for crude protein, true protein, crude fat, crude fibre, ash, carbohydrate, starch and cyanide using standard methods. Comparable values were obtained for laboratory and on-farm scale fermentation. However, the on-farm technique yielded higher protein enrichment compared with laboratory experiments. Cassava peel fermented on-farm yielded 10.93% protein while laboratory scale yielded 10.43%Key words: cassava peel, laboratory scale, on-farm scale, protein enrichment, solid-state fermentation

Effects of Chemical Peeling and Cultivars on the Antinutritional and Mineral Contents of Some Cassava Products

The effects of chemical peeling and cassava cultivar on some antinutritional and mineral contents of chemically peeled cassava flours and starches were studied. Batches of (TMS01/1371yr, TMS91/02324, TMS92/0326, TMS97/4763, TMS97/2205, TMS30572) roots were peeled using three different methods: manual peeling, chemical peeling with either 10% NaOH followed by treatment with 3% citric acid, or 10% NaOH solution followed by treatment with 15% NaCl. Peeled roots were either chipped or processed into starch and oven dried at 65oC. Dried chips were processed into flour. Flours and starches were analysed to determine some of their mineral and antinutritional characteristics. Results showed that phytate levels decreased from 6.28 mg/g for fresh cassava roots to 0.10, 0.13 and 0.10mg/g in cassava flours obtained from manual, NaOH/citric acid and NaOH/NaCl peeled TMS 30572 roots respectively. The HCN contents of the peeled cassava flour ranged between 9.06 to 16.56 mg HCN equivalent/Kg. Peeling treatments resulted in reduction in the phytic and hydrogen cyanide contents of the cassava starches and significant increase in the Na content of some of the flours produced. Peeling with NaOH/citric acid resulted in cassava starch with higher calcium content (14.85, 14.51, 25.9 and 58.31 mg/100g) for TMS 92/0326, TMS 97/2205, TMS 97/4763 and TMS 1/1371yr cassava cultivars respectively.Keywords: Cassava-roots, peeling-treatment, mineral, antinutritional, cassava-cultiva