Organic and inorganic constituents analysis of cane molasses and its affect on microbial fermentation industries Saoud A. Mohamed (1), Abdel-Aziz A. Said (2), Abdel- Naser A. Zohri (3), Hamed A. Tawfek (4) and Ahmed A. El-Samman (5) (1) Professor of Organic Chemistry, Faculty of Science, Assiut University. (2) Professor of Physical Chemistry, Dean Faculty of Science, Assiut University. (3) Professor of Microbiology, Botany Department, Faculty of Science, Supervisor of Industrial Fermentation, STRI, Assiut University. (4) Dr. Hamed A. Tawfek, Chairman of Egyptian Co.,For Starch and Yeast, Alexandria. (5) Ahmed A. El-Samman, ESIIC, Edfu Sugar Factory, Egypt. Introduction Leo 1 stated that the chemical composition of molasses shows wide variation. Its composition is influenced by factors such as soil type, ambient temperature, moisture, season of production, variety, production practices at a particular processing plant, and by storage variables. Praj 2 stated that Factors affecting composition of molasses are: variety of cane, composition of soil, climatic condition, harvesting practices, sugar manufacturing process and handling and storage. Kulkarni 3 stated that molasses with its sugars of 50-55% serves as an ideal raw material for fermentation and most of the molasses is thus converted into ethyl alcohol in India. In respect of storage of molasses, two important points need special consideration: One-any deterioration of the sugar in molasses has to be prevented, two-the danger of froth fermentation resulting in complete decomposition has to be checked. Abou Ela 4 studied effect of storage time on Egyptian Cane molasses quality, that the effect of storage time on molasses quality was investigated; 200 kg samples of molasses from Kom Ombo raw sugar factory were stored in an open pit for 24 months, and analysis carried out every 5 months for total solids, total sugars, sucrose, aldoses, total N, cationic, acidity, viscosity, un-fermentable reducing substances and alcohol. Paper chromatography was used for separate and identifies amino-acids and sugars present in both fresh and stored molasses. Tabulated and graphed results indicate the changes that take place with storage time, resulting in a loss of fermentation efficiency. Saha 5 et al reported that alcohol yields from fresh molasses were found by a south Indian distillery to lower than from molasses stored for 2-3 months, so fresh molasses samples were obtained and analyses carried out at intervals. During the period there were substantial falls in apparent purity, gravity purity TL4.2/ 1
and sucrose, but no corresponding rise in reducing sugars. There was a gradual but slight increase in fermentable sugars. Many of the anomalous results are not understood, but may result from sampling error as there was a quantity of sugar crystals in the molasses. Further tests are to be made, but the molasses will be filtered before storage and analysis. Molasses from cane which has deteriorated in the field due to borer or other pest infestation is reported 6 to contain higher nitrogen than that from normal cane and while procuring such cane, extra precautions are required in respect of a heating of molasses and it is advisable to either dispose of such molasses without delay or store it separately to protect the major stock of molasses of normal characteristics and thereby to save the remaining stock of molasses from rapid deterioration. Bronn 7 stated that the most important constituents of molasses that are yeast toxic are shown below Table (1). Bronn 7 stated that good quality process water should be of the same quality as drinking water as following parameters: Iron was 0.3 mg/l, nitrate 50 mg/l, ph value was (6.5-8.5), no E. coli bacteria in 100 ml and little microbiological germs as possible. Table (1): The most important constituents 7 of molasses those are yeast toxic Composition Concentration (%) in molasses Normal occurrence Safe Increase occur Toxic Origin Nitrite < 0.001 0.05 Microbial reduction of nitrate. Sulfite < 0.010 > 0.15 added in sugar factory. Formic acid < 0.10 > 0.25 Oxidation of formaldehyde that is added to the clarified juice as disinfectant in the sugar factory. Acetic acid < 0.50 > 0.60 Partially originating. Propionic acid Traces > 0.05 From beet and cane, partially formed. Butyric acid Traces > 0.02 Through microbial infection. Properly stored molasses 8 with its 15-20 % water is not susceptible to microbiological decomposition and can keep well for months together without any appreciable changes of composition. Changes in composition of Cuban molasses at ambient temperature over extended periods have shown the following: loss in polarization 18-46%, loss in sucrose 18-71%, increasing in reducing sugar 4.47%, loss in total sugar as invert sugar 15.2%, Loss in total solids 3%, great increase in color and finally increase in organic non-sugar 13%. TL4.2/ 2
3- Material and Methods Fermentation Fermentation experiments were done at the mobile fermentation unit of Egyptian Sugar and Integrated Industries Company (ESIIC), Research & Development Affairs at Hawamdia Distillery Factory and two strains of Saccharomyces cerveisiae were tested for ethanol production, one of them was factory s strain (S.cerveisiae USA 111) while the other one was from Assiut University, Faculty of Science, Botany Department (S.cerveisiae AU 71). 4- Results and Discussions Cane Molasses was obtained from the five Sugar Factories of ESIIC, which are sulftation system. Complete analysis were done for analyze quantitative and qualitative analysis and also analysis by using HPLC for determining sucrose, glucose and fructose of molasses contents. Table (2): Consumption of sulfur % cane added during crushing season 2007 Nag Factory Quantity Kous Armant Edfu KomOmbo Hamm Sulfur % cane 0.04 0.034 * 0.053 0.05 0.06 *Kous factory was producing brown sugar (not sulfitation) at this season. Table (3): Consumptions of Sulfur % crushed cane added during crushing season 2008 Nag - Kom- Factory Analyses Kous Armant Edfu Hammady Ombo Sulfur % cane 0.038 0.05 0.052 0.04 0.043 Table (4): Detection of R2O3, SO2, Na2O and K2O % in cane molasses at January of storage season 2007 Factory Molasses Nag - Hammady Armant Kous Edfu Kom- Ombo Brix 85.81 86.20 85.62 85.08 85.17 Purity 38.40 38.20 36.31 38.94 39.11 Ash % solid matters 12.70 11.39 12.70 12.05 12.05 R 2 O 3 % solid matters 0.17 0.41 0.29 0.21 0.24 SO 2 % solid matters 0.27 0.30 0.40 0.29 0.56 Na 2 O % solid matters 0.30 0.45 0.26 0.30 0.26 K 2 O % solid matters 3.69 3.82 3.94 3.60 3.14 TL4.2/ 3
Table (4) shows the analysis of sulfur content of cane molasses. It appears a increase in SO2 % solid matters from Nag-Hammady, Edfu, Armant, Kous then Kom Ombo, respectively. Analysis results of Kous cane molasses during storage season 2007 40 30 Purity Degree 20 10 0 1 2 3 4 5 6 7 8 9 10 11 12 Storage Months Fig. (1): Decreasing of purity at Kous s molasses during storage time (January to December, 2007) Purity Degree 40 35 30 25 20 15 10 5 0 1 2 3 4 5 6 7 8 9 10 11 12 Storage Months Fig. (2): Decreasing of purity at Kom Ombo s molasses during storage time (January to December, 2007) Analysis results of cane molasses before and after Maillard reaction during storage season 2007 Table (5) shows the temperatures of Kom Ombo s molasses stored during June, 2007. Temperature of the whether at this period was over than 45 C. Table (5): Temperatures of Kom Ombo s molasses stored during June, 2007 No. of Tank 1 2 3 4 5 6 Temp. C 50 85 51 54 51 65 TL4.2/ 4
Table (5) shows that temperature of storage tank no. (2) was increased sudden, and reached to 85 C and sudden violent decomposition left in a carbonized matter, the quantity of stored molasses at this tank was 5260 metric tons (mt), these quantity was converted to a solid state, this was refer to: 1. There was no cooling system, 2. Mixed between new molasses with old quantity, 3. Increasing amount of reducing sugars and amino acids accelerate decomposition reaction. 4. Cleaning and sanitation were not done before storing. Table (6): Analysis of cane molasses before and after Maillard reaction during storage season 2007 Results Brix Purity Total sugars ph Before 86.1 26.3 46.2 4.6 After 35.0 6.0 23.0 3.2 Differences -51.10-20.30-23.20-1.40 The results in Table (6) shows effect of decomposition reaction on quality of stored cane molasses where the medium became more acidic (ph=3.20), also great losses of total sugars where it is clear more decreasing from 46.20 to 23.00 during time of reaction just few hours. Table (7): Average analysis results of cane molasses before and after Maillard reaction Temp. of mol.ºc ph Brix Total sugars Purity Before 52 4.6 86.1 46.2 26.3 After 33 3.2 35.0 23.0 6.00 TL4.2/ 5
Table (8): Summarized analysis of molasses in the four factories in addition to the mixture of all molasses Analyses Molasses Nag Hammady Kous Armant Edfu Mixture Ph 5.5 5.3 5.3 5.4 5.2 Specific gravity 1.45 1.38 1.42 1.40 1.40 Brix 86.26 86.9 86.20 85.08 86.20 Total sugars % 52.00 46.0 49.2 51.0 50.2 Un- fermen. sugars 4.2 5.1 4.6 4.3 4.4 Calcium, CaO% 0.77 1.36 0.82 0.79 1.10 Ash % 10.64 12.39 11.80 11.04 11.88 Total nitrogen % 2.1 5.5 4.6 2.5 3.9 Crude protein 2.5 4.6 3.7 2.9 4.0 Potassium (K 2 O) % 3.69 3.82 3.60 3.79 3.70 Sodium (as Na 2 o) % 0.10 0.39 0.16 0.13 0.18 Magnesium (MgO) % 0.30 0.59 0.33 0.32 0.36 Sulfate (as SO 3 ) % 2.70 2.94 2.80 2.79 2.88 Sulfite (as SO 2 )% 0.27 0.56 0.35 0.30 0.32 Silicate (as SiO 2 ) % 0.66 0.75 0.70 0.70 0.67 Oxides (as R 2 O 3 ) % 0.17 0.29 0.20 0.19 0.20 Chlorides % gm 1.0 1.3 1.1 1.0 1.0 Total organic volatile acids (mg/l) 2000 3000 1800 1950 2230 Biotin (H) % 1.6 1.2 1.3 1.1 1.4 HMF, ppm 23 60 44 49 49 Acetic acid, ppm 1700 2500 2000 1800 1900 Formic acid, ppm 500 2000 800 900 900 Wax, Sterols % 0.1 0.23 0.14 0.12 0.18 TL4.2/ 6
Table (9): Summarization of the results of ethanol production by the two yeast isolates under study using the different kinds of cane molasses S. cerevisiae USA 111 S. cerevisiae AU 71 Parameters Molasses Starting Sugar Fermentation Period (h) Maximum Ethanol Level % Theoretical Ethanol value % Unconsumed Sugar % Kous 16.82 18 6.20 8.60 2.15 72.09 16.80 17 6.80 8.59 1.75 79.16 Armant 15.03 17 6.20 7.68 2.10 80.73 16.01 23 6.80 8.18 1.81 83.13 Nag Hammady 17.39 17 7.60 8.89 1.70 85.49 17.40 17 7.65 8.89 1.65 86.05 Edfu 17.40 18 7.70 8.89 1.60 86.61 17.40 19 7.75 8.89 1.55 87.18 Mixture 17.51 18 7.65 8.95 1.75 85.48 17.63 18 7.80 9.01 1.65 86.57 TL4.2/ 7 Efficiency of Fermentation % References 1. V. Leo Curtin, Types of molasses, Molasses-General consideration, National feed Ingredients Association, 1983, pp.3-11. 2. J. Godbole, Ethanol from Cane molasses, Praj industries ltd., India, Hawaii ethanol workshop, Nov., 2002. 3. V. M. Kulkarni, Deterioration of molasses during storage: Possible cause and means to prevent, Proc. Int. Soc. Sugar Technol., Vol. 26, 2007, pp. 1141-1143. 4. Abou El-Ela, Effect of storage time on Egyptian cane molasses quality, Sugar Journal, 1984, Vol. 86, No. 1027, pp.10a. 5. J. M. Saha, D. L. N. Rao and V. Singh Difference in yield of alcohol from fresh and stored molasses, Proc. 29th, Conc. Sugar Tech. Assoc., India, 1961, (1), pp. 103-110. 6. D. P. Kulkarni, Deterioration in Storage, Cane Sugar Manufacture in India, pp.393-396. 7. W. K. Bronn,, The technology of yeast production: Baker yeast,1985, pp.1-30 8. D. P. Kulkarini, Cane Sugar Manufacture in India, editor The Sugar Technologists Association of India, 2001, pp. 390-397. Starting Sugar Fermentation Period (h) Maximum Ethanol Level % Theoretical Ethanol value % Unconsumed Sugar % Efficiency of Fermentation %