CONVERSION OF SUGAR CROPS AND BY-PRODUCTS TO CHEMICALS WITH APPLICATIONS IN THE SUGAR, FOOD, PHARMACEUTICAL, AND NUTRACEUTICAL INDUSTRIES.

<b>Project Methods</b><br> Biomass PreparationSugarcane and by-products (juice, syrup, molasses, bagasse) will be collected from Louisiana sugar factories and both energy cane and sorghum by-products (juice, syrup, bagasse) will be processed/collected at research stations within the State and from Heckemeyer Biorefinery in Missouri.Analytical MethodsChemical composition and enzymatic hydrolysis of bagasse will be conducted following protocols developed by the National Renewable Energy Laboratory (NREL). Instrumental analytical support will be provided primarily by ASI's analytical laboratory, with some specialized analyses performed on the main LSU campus or subcontracted to other entities.Organic acids (e.g., formic, acetic, levulinic, fumaric) will be analyzed using a HPLC (Agilent 1100 Series) equipped with a Diode Array Detector (G1315B Agilent) at 210 nm and a Shimadzu VP-ODS column thermally controlled at 40°C. The mobile phase is 0.005 N sulfuric acid with a flow rate set at 0.35 mL/min.Sugars (e.g., glucose, fructose, sucrose, arabinose, cellobiose, xylose) will be quantified by HPLC (Agilent 1200 Series) equipped with a BioRad Aminex HPX-P87P (P) column set at 80°C and a differential Refractive Index Detector (G1362A Agilent). Sample volume is set at 20 μl with HPLC water used as the mobile phase at 0.8 mL/min.Cations (e.g., sodium, ammonium, potassium, magnesium, calcium) will be analyzed in a capillary high-performance ion chromatography (HPIC) (Thermo Scientific ICS 5000) equipped with a Dionex Ion Pac CG 16 guard column and a Dionex Ion Pac column CS 16 set at 40°C. Methanesulfonic acid and deionized water will be used as eluents at a flow rate of 0.5 mL/min.Xylo-oligosaccharides (XOS) will be analyzed by HPIC (Thermo Scientific ICS 5000) equipped with a Thermo Scientific CarboPac PA 100 analytical column (250 x 2 mm) and guard column (50 x 2 mm) set at 30°C. Sodium hydroxide and sodium acetate will be used as eluents at a flow rate of 0.4 mL/min.Total Phenolic Content (TPC) and phenols will be determined by the Folin-Ciocalteu method with minor modifications, using gallic acid as the standard [45]. A HPLC method is being developed at ASI for the identification and quantification of phenolic compounds present in sugar crops (e.g., sugarcane, energy cane, sorghum) and by-products (e.g., pressed juice, syrup, molasses, bagasse).Antioxidant Activities will be determined with two methods: (1) the DPPH radical scavenging activity method [46, 47], and (2) the ORAC (Oxygen Radical Absorbance Capacity) method using the ORAC Antioxidant Kit (Research Triangle Park, NC). Color and Indicator Value (I.V.) will be calculated according to the official ICUMSA method GS2/3-9 (1994) for sugarcane products, with slight modifications.Statistical analyses will be carried out (where applicable) by analysis of variance (ANOVA) and Tukey's honest significant difference (HSD) test at a 95% confidence level using SAS 9.4 software (SAS Institute Inc., Cary, NC, USA).