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Juice Clarification (juice + clarification)

Distribution by Scientific Domains

Chemistry	100%

Selected Abstracts

Juice Clarification by Thermostable Fractions of Marsh Grapefruit Pectinmethylesterase

JOURNAL OF FOOD SCIENCE, Issue 5 2002
M. Corredig
ABSTRACT: Orange juice clarification by thermostable pectinmethylesterase (TS-PME), isolated from grapefruit pulp by ammonium sulfate precipitation, and ion-exchange and affinity chromatography was investigated. TSPME, having different specific activities, induced different clarification behavior of reconstituted orange juice at 2 units/ml. Based on percent transmittance, TS-PME fraction with the lower specific activity clarified juices earlier than TS-PME at higher specific activity. Particle size distribution of the cloud-soluble fraction showed that TS-PME increased the average particle size from 0.7 ,m to 1 mm and maintained a monomodal distribution. After 27 d of storage at 4 °C, samples of clarified juice still showed a large population of small cloud particles when measured by diffraction light scattering. [source]

CLARIFICATION OF WATERMELON (CITRULLUS LANATUS) JUICE BY MICROFILTRATION

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 6 2008
Ch. CHHAYA
ABSTRACT Microfiltration of watermelon juice was conducted using stirred membrane cell in continuous mode. The experiments were conducted at operating pressures of 136.5, 204.7 and 276 kPa, and stirring speeds 1,200 rpm (Re = 1.40 × 105), 1,400 rpm (Re = 1.63 × 105) and 1,600 rpm (Re = 1.87 × 105). Permeate flux decline was analyzed using a first-order kinetic model, and correlations were developed for the steady-state polarized layer resistance with the operating conditions, e.g., transmembrane pressure difference, Reynolds number and membrane resistance. The permeate flux was calculated based on the developed correlation, and found to be in good agreement with the actual experimental flux. The change in quality parameters of clarified juice was marginal compared to that of original juice. PRACTICAL APPLICATIONS The application of membrane technology is one of the emerging areas in food industry. The major application includes fruit juice clarification and concentration. Because of the nonthermal nature of membrane separation, the juice can be clarified at room temperature and packed aseptically for a longer shelf life without the loss of its initial quality parameters. The major problem during clarification is decline in permeate flux of fruit juice with time. Identification of causes for flux decline is essential for designing of membrane modules to make the clarification process commercially viable. The quality of juice during storage is vital, and therefore, determination of variation of its physicochemical properties during storage is also important. [source]

EFFECTS OF CO-IMMOBILIZATION OF PECTINASE AND AMYLASE ON ULTRAFILTRATION OF APPLE JUICE SIMULATE

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 6 2001
MARÍA E. CARRÍN
ABSTRACT In view of its possible application in apple juice clarification, the potential of co-immobilized pectinase/amylase by physical adsorption on a polysulfone ultrafiltration hollow fiber was examined. Solutions containing different concentrations of pectin and starch were used. The effect of various operational parameters on the production of reducing compounds, mainly galacturonic acid and maltose, was investigated. Results indicated that relative permeate flux, during ultrafiltration of starch-pectin solutions, was up to 35% higher when commercial pectinase and amylase were co-immobilized on a hollow fiber membrane. Although the concentration of reaction products increased up to 50% with the pectin concentration, the same was not verified when the starch content changed from 3.85 to 5.00 mg/mL. However, the reference permeate flux was improved when starch was added to substrate, independently of its concentration. Considering the size of an average starch granule, this increase in permeate flux was attributed to the removal of pectin gel by dragging. Permeate fluxes were comparable for both batch and permeate recycling operations. [source]

Clarification of Citrus Juice is Influenced by Specific Activity of Thermolabile Pectinmethylesterase and Inactive PME-Pectin Complexes

JOURNAL OF FOOD SCIENCE, Issue 7 2002
J. Ackerley
ABSTRACT: Thermolabile pectinmethylesterase (PME) from Valencia orange pulp was extracted, partially purified by cation exchange chromatography (IEX), and added to reconstituted orange juice at 2 units/ml. Of the juices that clarified, %T increased, cloud particle size increased and % degree of esterification (DE) decreased in the 15 d storage study. The rate of clarification was most rapid for juices with added PME extracts that never bound Hi-Trap SP and contained 36 and 27 kDa peptide, intermediate for crude extracts of PME not applied to IEX, and lowest for PME extracts that bound Hi-Trap SP and contained 36 and 13 kDa peptide. These results suggest that PME-pectin complexes and low peptides moderate PME activity and juice clarification. [source]