Statistical Optimization of Media Components for Xylanase Production by Aspergillus spp. Using Solid State Fermentation and its Application in Fruit Juice Clarification

Xylanases are enzymes that convert xylan into xylose, xylobiose, and xylotriose. The present study deals with the production and optimization of xylanase through Solid-State Fermentation (SSF) using different agricultural wastes by Aspergillus spp. The Plackett Burman (PB) design was used to screen significant media components affecting the xylanase production. The carbon sources screened were wheat bran, rice bran, sugarcane bagasse, corn cob, and orange peel. The nitrogen sources screened were yeast extract, peptone, (NH4)2SO4, Na2NO3, and urea. Also, nine different salts such as KCl, MgSO4, Na2HPO4, CaCl2, FeSO4, ZnSO4, Na2CO3, KH2PO4, and NaH2PO4 which act as trace elements were screened. The results showed that wheat bran, yeast extract, Na2NO3 and KCl are the significant factors that affect xylanase production. A 33 Full Factorial Design (FFD) was performed to optimize the significant media components (wheat bran, KCl, yeast extract) obtained from PB design using Response Surface Methodology (RSM). Statistical analysis of results showed that wheat bran, KCl, yeast extract, and interaction between wheat bran and yeast extract were found to be significant. The optimum concentration of wheat bran, KCl, yeast extract was 8 g/L, 0.1 g/L and 3 g/L. The Partial purification of xylanase was carried out using ammonium salt precipitation and dialysis. Gel filtration chromatography was performed to optimize the elution time, which was found to be 6 minutes. Application of xylanase in orange juice clarification was studied at 40 °C, 50 °C, and 60 °C. The optimum temperature obtained was 60 ºC.

Addressing Enzymatic Clarification Challenges of Muscat Grape Juice

Winemakers use technical enzymes to assist with clarification, extraction, and other processes in winemaking. In some cases, enzyme mixes are found to be ineffective for a variety of reasons. This study characterizes difficult-to-clarify juices from the Muscat family, examines the effects of pasteurization, and classifies these juices based on cultivar, harvest date, geographical location, and harvesting technique. In addition to studying the chemical compositions of different Muscat juices, enzyme testing was performed by creating enzyme cocktails and evaluating their functionality. The data suggest a distinct matrix effect on juice clarification that can be influenced during juice processing. Berry proteins, polysaccharides, and native enzymes play an important role during the clarification process, influencing the efficiency of technical enzymes. On the other side, high macromolecule extraction from the grape material, through excessive shearing forces in machine-harvested and processed fruit, for example, can have a negative effect, especially in ripe and overripe grape material. Based on these findings, the winemaking strategy and use of technical enzymes need to be adapted to the incoming grapes. Besides adjusting the mechanical forces to the level of ripeness, avoiding native fermentation prior to clarification should be prioritized. The enzyme mixes developed and tested in these experiments show a high degree of efficiency in the majority of juices that were evaluated.

Clarification of Sugar Cane Juice (Saccharum Officinarum) Through the Use of National Cocoa Muclago (Theobroma Cacao L)

The investigation was carried out at 980 m.s.n. in the San Ramón compound of the El Corazón Parish, Pangua canton, Cotopaxi province, Ecuador. The variables to be evaluated in the sugar cane juice clarification process were the viscosity (20, 25 and 30 cp) and the concentration of Ragnar variety cocoa shell mucilage (0.75, 1.5, and 2.25%), to determine the spectral color and saturation in the sugarcane juice. 10 liters of juice were used in each experimental unit, taking the clarified syrup samples in amber bottles and refrigerating them until further analysis on the colorimeter was conducted. For the statistical evaluation of the results of the saturation percentage, normality tests were performed according to the Shapiro-Wilk statistic; applying the Friedman and Holm test of multiple comparisons, allowed to identify the combination of a1b2 (25 cp * 2.25%) as the best juice clarification treatment, and, managing to establish the descriptive data, thus: spectral color at 576 nm, saturation 46.91%; standard deviation 2.75; median 46.36%; variance 7.6 and a range of 5.43. Keywords: syrup, spectral, flocculant, cachaza. Resumen La investigación se realizó a 980 msnm en el recinto San Ramón de la Parroquia El Corazón, cantón Pangua, provincia Cotopaxi, Ecuador. Las variables a evaluar en el proceso de clarificación de jugo de caña de azúcar fueron la viscosidad (20, 25 y 30 cp) y la concentración de mucílago de cáscara de cacao variedad Ragnar (0,75%, 1,5% y 2,25%), para determinar el color espectral y de saturación en el jugo de caña de azúcar. En cada unidad experimental se usó 10 litros de jugo, tomando las muestras de jarabe clarificado en botellas tipo ámbar y refrigerándolas hasta posterior análisis en el colorímetro. Para la evaluación estadística de los resultados del porcentaje de saturación, se realizaron pruebas de normalidad según el estadístico de Shapiro-Wilk; aplicando el test de Friedman y Holm de comparaciones múltiples, permitieron identificar como mejor tratamiento de clarificación de jugo a la combinación a1b2 (25 cp * 2,25%), y, logrando establecer los datos descriptivos, así: color espectral en 576 nm, saturación 46,91%; desviación estándar 2,75; mediana 46,36%; varianza 7,6 y un rango de 5,43. Palabras clave: jarabe, espectral, floculante, cachaza.