Effect of Fermentation and Processing on Chemical and Microbiological Characteristics of Two Sorghum Cultivars

Abstract

This study was conducted to examine the effect of fermentation and cooking on chemical composition, in vitro protein digestibility, antinutritional factors, amino acids and microbiological characteristics of two varieties of feterita (Gadam El-Hamam and Arfa Gadmak ) . The results showed that the fermentation period of two varieties of feterita recorded significant differences (P<0.05). There was an increase in moisture content, protein content, in vitro protein digestibility, isolucine and leucine which recorded higher values 5.95%, 12 .86%, 14.07%, 4.00mg/100g and 13.05mg/g for Gadam El-Hamam at 12h, respectively and 6.07%, 14.13%, 16.25%, 4.835mg/g and 13.45mg/g for Arfa Gadamk at 12h, respectively. Fat content, fiber content, ash content, carbohydrate content, tannin content, phytate and lysine decreased and recorded lower value at 12h in Gadam El-Hamam 2.61%, 2.08%, 1.67%, 74.83%, 0.11%, 88.99mg/100g and 2.70mg/100g, respectively. Arfa Gadamk variety recorded 2.84%, 2.01%, 1.63%, 73.3o%, o.23%, 100mg/100g and 2.90mg/100g at 12h, respectively. The minerals content, tyrosine and thrionine were not affected by fermentation. The cooking after fermentation of two varieties of feterita recorded higher values in moisture content and lower values in protein content, in vitro protein digestibility, fat content, crude fiber , carbohydrate content, antinutritional factors, isolucine , leucine, tyrosine and thrionine and ash content of Arfa Gadamk. Minerals content and ash not affected by cooking. The fermentation period of the two varieties of feterita recorded higher numbers in total bacterial count (4.20x104 cfu/ml) and (5.30x104 cfu/ml) for Gadam El-Hamam and Arfa Gadamk at 12h, respectively. Lactic acid bacteria recorded higher numbers (3.50x108 cfu/ml) and (2.70x108cfu/ml) for Arfa Gadamk and Gadam El-Hamam at 12h, respectively. Moulds and yeasts recorded higher number (5.10x106 cfu/ml) in Arfa Gadamk variety at 12h and (2.90x107 cfu/ml) for Gadam El-Hamam variety at 6h. The number of Coliforms decreased to zero at 6 and 12h for two varities. Cooking decreased coliform, moulds and yeasts to zero in kissra and aceda of two varieties of feterita. The total bacterial count decreased after cooking to (7.10x102 cfu/ml) and (8.20x102 cfu/ml) for Gadam El-Hamam and Arfa Gadamk kissra, respectively, and to absent in Gadam El-Hamam and Arfa Gadamk aceda. Lactic acid bacteria decreased to zero in Gadam El-Hamam kissra and ceda, but in Arfa Gadamk variety decreased to (2.40x102cfu/ml) for kissra and absent in aceda.