Sweet sorghum

There are yield and weed control costs in other commodities besides corn and sorghum. Sweet corn and popcorn have similar weed pests, but fewer herbicide substitutes than field corn. Of course, these crops are more valuable crops per area than field corn, so losses per acre are large relative to field corn. Both yield and cost of production changes were computed for sweet com and popcorn using the same agronomic and analytical approach as for field com. Sweet com losses are estimated to be 80.5 million and 62.4 million if triazines or atrazines were not available, respectively. 

The annual world production of s. by - wet milling is 45 X 10 mt. Production is concentrated on just a few s. carriers, which are - maize, - cassava, - wheat, ->potato, sorghum, sweet potato, and - rice (- Starch, EU-Market). Production and application of s. from barley, oats, rye and triticale have been successfully tried as well as s. of legumes, such as pea, beans or lentils. Some other tropical s. sources are of local interest, mainly to third world countries . Special varieties with extraordinary high contents of - amylose or - amylopectin are of partial interest in special industrial and food applications. 

A biomass power generation industry is emerging that can provide substantial quantities of feedstock such as sugarcane residue (bagasse), sweet sorghum. 

Fermentation of Sweet Sorghum into Added Value Biopolymer of Polyhydroxyalkanoates (PHAs)... 

Fig. 2. Sweet sorghum (strain Khon Kean University 40 KKU 40) from agricultural plantation area of Khon Kaen University, Khon Kaen, Thailand...

Since the duration of sweet sorghum for maturation is approximately 3-5 months, 2-3 crops could be harvested annually in Thailand. Therefore, the production yields of sugar would be double or triple. We can see the possibility of reducing the world energy crisis if sweet sorghum can be converted to energy efficiently. Typically, after harvest, the leaves of the fresh crop are stripped and the stems are squeezed in a roller mill (Fig.3) to obtain sweet sorghum juice, ft should be noted that the stems are stored at 4° C while the juice is kept at -20° C prior to use. 

Fig. 3. Stems of sweet sorghum are squeezed by a roller mill for preparing sweet sorghum juice (SSJ)...

Table 1. Type and sugar contents in sweet sorghum collected from several areas...

Fig. 5. Growth curve and PHAs production during batch fermentation of sweet sorghum by Bacillus arybhattai in 3 L fermentor (Tanamool et al., 2011)...

Fig. 6 shows a fed batch fermentation of sweet sorghum juice (SSJ) by Bacillus aryabhattai in 3 L fermentor under cultivating condition with agitation rate at 200 rpm, air rate of 1.5 1/min, at 30° C and feeding time at 18 and 24 hr during log phase of the culture. It was found that the cell could continuously produce both biomass and PHAs. Maximum cells were obtained at about 14.20 g/1 at 54 hr when PHAs content reached 4.84 g/1 after 66 hr (Tanamool et al., 2011). In addition, in Table 2, fed batch fermentation by A, latus was used for the production of PHAs (Yamane et al, 1996 Wang Lee, 1997). It could yield high productivity with the use of cheap carbon sources. 

After fermentation, subsequent midstream to downstream processes such as cell disruption, centrifugation, extraction and drying will be carried on for product recovery. Fig. 9 shows a white sheet of PHB obtained from fermentation of sweet sorghum juice (SSJ) by Bacillus aryahhattai. 

A novel non-petroleum based biodegradable plastic produced from sugar based agricultural raw materials as sweet sorghum, sugarcane and molasses, having potential properties comparable with conventional or synthetic plastics, is under development and could lower the contribution of plastic wastes to municipal landfills at about 20% of the total waste by volume and 10% by weight and can achieve a satisfactory for the environmental imperative. 

Biofuel generation from sweet sorghum Fermentative hydrogen production and anaerobic digestion of the remaining biomass. Biores. Technol. 99 (1), 110-119. 

An alternative approach to the bioconversion of sweet sorghum carbohydrates to ethanol. Biomass and Bioenergy, 8, 99-103. 

---