Sweet Sorghum Syrup Research Articles

Enhancement of biohydrogen production from sweet sorghum syrup by anaerobic seed sludge in an anaerobic sequencing batch reactor by nutrient and vitamin supplementations

This study attempted to enhance biohydrogen production from sweet sorghum syrup by anaerobic seed sludge in a 1.3 L (1 L working volume) anaerobic sequencing batch reactor (ASBR) by supplementation with nutrients and vitamins. Four treatments, i.e. nutrient and vitamin supplementation, only nutrient supplementation, no supplements and only vitamin supplementation, were conducted using 30 g/L sweet sorghum syrup as the substrate with 1.45 g/L FeSO 4 in ASBR. The ASBR was operated at 24 hour hydraulic retention time at a controlled pH of 5.0. Results indicated that nutrient and vitamin supplementations could increase hydrogen production rate (HPR; 3.2 L H 2/L− d ) and hydrogen yield (HY; 1.6 mol H 2/mol hexose) up to 5 fold in comparison to the control (0.6 L H 2/L− d and 0.34 mol H 2/mol hexose, respectively). The polymerase chain reaction-denatured gradient gel electrophoresis analysis indicated that the predominant hydrogen producers were Clostridia species. The higher hydrogen production obtained from the treatments with nutrient supplementation might be due to the presence of Clostridia species together with Klebsiella sp. and Desulfovibrio sp. Lack of nutrients in treatments without the supplementation and in treatment where only vitamin solution was added could lead to the reduction of hydrogen production efficiency of Clostridia species. The presence of lactic acid bacteria, i.e. Enterococcus sp. and Lactobacillus sp., caused an adverse effect on hydrogen-producing bacteria, resulting in a low HPR and HY in these two treatments.

Physico-Chemical Properties and Antioxidant Potential of Syrup Prepared from ‘Madhura’ Sweet Sorghum (Sorghum bicolor L. Moench) Cultivar Grown at Different Locations in Kenya

The study was undertaken with the objective of producing sweet sorghum syrup, analyze its physical, chemical and antioxidant properties, and quantify the influence of environment on the properties of the syrup. The color coordinate values of Chroma and Hue angle were indicative of the dark brown coloration of the syrups and were most influenced by location compared to L* values. The density and the moisture content showed no significant difference while apparent viscosity and total acidity was significantly different between the syrup compared from two locations. The sweet sorghum syrups from the two locations had fructose levels of 12 and 2 %, sucrose at 66 and 88 % while and glucose levels were 17 and 6 %, respectively. Calcium was the macro-element with the highest concentration ranging between 108.0 and −272.33 mg/100 g of syrup and was significantly different (p ≤ 0.05) between the locations. For micro-elements, magnesium had highest (124 and 118 mg/100 g).The sweet sorghum syrups exhibited high level of total phenolic content and total flavonoid content at 261.31 mg Gallic acid equivalents and 197.50 mg quercitin acid equivalent per 100 g syrup respectively. Since the radical scavenging activity was greater than 50 % even at low syrup concentrations, indicates that the sweet sorghum syrups are potent free radical-scavengers. This study shows that the sweet sorghum syrup is comparable to sugarcane syrup. Because of its superior antioxidant properties the syrup may find application in the food industry.

Silver glyconanoparticles functionalized with sugars of sweet sorghum syrup as an antimicrobial agent

Bio-directed synthesis of metal nanoparticles is gaining importance due to their biocompatibility, low toxicity and eco-friendly nature. We used sweet sorghum syrup for a facile and cost-effective green synthesis of silver glyconanoparticles. Silver nanoparticles were formed due to reduction of silver ions when silver nitrate solution was treated with sorghum syrup solutions of different pH values. The nanoparticles were characterized by UV–vis, TEM (transmission electron microscopy), DLS (dynamic light scattering), EDAX (energy dispersive X-ray spectroscopy), FT-IR (fourier transform infrared spectroscopy) and XRD (X-ray diffraction spectroscopy). The silver glyconanoparticles exhibited a characteristic surface plasmon resonance around 385nm. At pH 8.5, the nanoparticles were mono-dispersed and spherical in shape with average particle size of 11.2nm. The XRD and SAED studies suggested that the nanoparticles were crystalline in nature. EDAX analysis showed the presence of elemental silver signal in the synthesized glyconanoparticles. FT-IR analysis revealed that glucose, fructose and sucrose present in sorghum syrup acted as capping ligands. Silver glyconanoparticles prepared at pH 8.5 had a zeta potential of −28.9mV and were anionic charged. They exhibited strong antimicrobial activity against Gram-positive, Gram-negative and different Candida species at MIC values ranging between 2 and 32μgml−1. This is first report on sweet sorghum syrup sugars-derived silver glyconanoparticles with antimicrobial property.

Synthesis and characterization of gold glyconanoparticles functionalized with sugars of sweet sorghum syrup

Gold glyconanoparticles were synthesized by a simple, rapid, and eco-friendly method by using sweet Sorghum syrup for application in biomedicine and biotechnology. The nanostructures of the prepared gold nanoparticles were confirmed by using UV-visible absorbance, TEM, SAED, FTIR, EDAX, XRD, and photoluminescence analyses. The formation of gold nanoparticles at both room and boiling temperatures and kinetics of the reaction were monitored by UV-visible spectroscopy and TEM studies. TEM analysis revealed that the obtained nanoparticles were mono-dispersed and spherical in shape with an average particle size of 7 nm. The size of the nanoparticles was influenced by the concentration of Sorghum syrup. The presence of elemental gold was confirmed by EDAX analysis. Based on the FTIR analysis, it was observed that the sugars present in the Sorghum syrup possibly acts as capping agents. The zeta potential analysis revealed that the glyconanoparticles were negatively charged with a potential of -25 mV. The XRD and SAED patterns also suggest that the nanoparticles were crystalline in nature and these particles were found to exhibit visible photoluminescence. Fructose and glucose present in sweet Sorghum syrup were demonstrated as responsible sugars for the reduction of gold ions, and sucrose stabilized the formed nanoparticles. The proposed mechanism for the formation and stabilization of gold glyconanoparticles is based on the phenomenon of "macromolecular crowding." This is the first report on the use of sweet Sorghum syrup for the green synthesis of gold glyconanoparticles at both room and boiling temperatures.

Biological hydrogen production from sweet sorghum syrup by mixed cultures using an anaerobic sequencing batch reactor (ASBR)

Continuous biological hydrogen production from sweet sorghum syrup by mixed cultures was investigated by using anaerobic sequencing batch reactor (ASBR). The ASBR was conducted based on the optimum condition obtained from batch experiment i.e. 25 g/L of total sugar concentration, 1.45 g/L of FeSO 4 and pH of 5.0. Feasibility of continuous hydrogen fermentation in ASBR operation at room temperature (30 ± 3 °C) with different hydraulic retention time (HRT) of 96, 48, 24 and 12 hr and cycle periods consisting of filling (20 min), settling (20 min), and decanting (20 min) phases was analyzed. Results showed that hydrogen content decreased with a reduction in HRT i.e. from 42.93% (96 hr HRT) to 21.06% (12 hr HRT). Decrease in HRT resulted in a decrease of solvents produced which was from 10.77 to 2.67 mg/L for acetone and 78.25 mg/L to zero for butanol at HRT of 96 hr–12 hr, respectively. HRT of 24 hr was the optimum condition for ASBR operation indicated by the maximum hydrogen yield of 0.68 mol H 2/mol hexose. The microbial determination in DGGE analysis indicated that the well-known hydrogen producers Clostridia species were dominant in the reacting step. The presence of Sporolactobacillus sp. which could excrete the bacteriocins causing the adverse effect on hydrogen-producing bacteria might responsible for the low hydrogen content obtained.

Optimization of biohydrogen production from sweet sorghum syrup using statistical methods

This study employed statistically based experimental designs to optimize fermentation conditions for hydrogen production from sweet sorghum syrup by anaerobic mixed cultures. Initial screening of important factors influencing hydrogen production, i.e., total sugar, initial pH, nutrient solution, iron (II) sulphate (FeSO 4), peptone and sodium bicarbonate was conducted by the Plackett–Burman method. Results indicated that only FeSO 4 had statistically significant ( P ≤ 0.005) influences on specific hydrogen production ( P s) while total sugar and initial pH had an interdependent effect on P s. Optimal conditions for the maximal P s were 25 g/L total sugar, 4.75 initial pH and 1.45 g/L FeSO 4 in which P s of 6897 mL H 2/L was estimated. Estimated optimum conditions revealed only 0.04% difference from the actual P s of 6864 mL H 2/L which suggested that the optimal conditions obtained can be practically applied to produce hydrogen from sweet sorghum syrup with the least error.

Ethanol Production from Sweet Sorghum Syrup for Utilization as Automotive Fuel in India

Ethanol demand is increasing drastically in the present time due to its blending in automotive fuels, which is desirable for getting clean exhaust and fuel sufficiency. The higher cost of cultivation of sugarcane/-beets, highly sensitive molasses rates, and ultimately instabilities in the price of ethanol have created grounds to search for an alternative source for ethanol production. Sweet sorghum has shown potential as a raw material for fuel-grade ethanol production due to its rapid growth rate and early maturity, greater water use efficiency, limited fertilizer requirement, high total value, and wide adoptability. Ethanol-producing companies, research institutions, and governments can coordinate with farmers to strategically develop value-added utilization of sweet sorghum. Fuel-grade ethanol production from sweet sorghum syrup can significantly reduce India's dependence on foreign oil and also minimize the environmental threat caused by fossil fuels.

DESTRUCTION OF MICROORGANISMS AND DEFORMATION OF PLASTIC JARS BY HOT SORGHUM SYRUP

ABSTRACT Sweet sorghum syrup was heated at 49° to 71°C and filled into glass jars of 200 mL capacity that contained each of four microorganisms (Bacillus subtilis; Byssochlamys nivea; Saccharomyces rouxii; and Aspergillus niger) at 0, 1,000 or 10,000 CFU/mL syrup. Counts were determined on syrup immediately after filling into the jars and after four months storage. The heated syrup at all temperatures significantly reduced the survival of bacteria and fungi at the time of filling. After four months, no bacteria could be detected in syrup at each temperature, and no fungi could be detected at 66° and 71°C. The heat of syrup at 71°C or lower did not cause single layer polypropylene jars to become deformed; however, at 77° and 82°C deformation occurred such that the jars were unsatisfactory for the packaging of syrup. Therefore, syrup can be filled at 66° and 71° into single layer polypropylene jars. At these temperatures, common spoilage microflora were destroyed or inactivated during storage, and the plastic jars did not become deformed.

Microbial Changes in Sweet Sorghum ( Sorghum bicolor ) Juices

Juice freshly expressed from Sorghum bicolor for making sweet sorghum syrup contained 10 microorganisms per ml. The dominant bacterium was Leuconostoc mesenteroides, followed by gram-negative rods. Lactobacilli, yeasts, and nonfecal coliform bacteria each comprised about 1% of the microbial population. Spoilage of juice, manifested by a sour odor, discoloration, and foaming, occurred between 5 and 12 h at ambient temperatures. Spoilage was correlated with a drop in pH from 4.9 to 4.5 L. mesenteroides was the dominant spoiling agent at 20 degrees C, and Lactobacillus plantarum was the dominant spoiling agent at 32 degrees C, as determined by pure culture studies. Juice may be stored for 14 days at 4 degrees C if promptly refrigerated.