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Secunderabad, India

Naga Padma P.,BVB Vivekananda College | Anuradha K.,BVB Vivekananda College | Reddy G.,Osmania University
Innovative Food Science and Emerging Technologies | Year: 2011

Pectin rich cold stored spoiled fruits, vegetables and cold soils were screened and different pectinolytic isolates were obtained by enrichment culturing and ruthenium red plate assay. Among the primary isolates 10-15% were yeast isolates. Six isolates with higher zones of pectin hydrolysis were selected and tested for polygalacturonase (PGU) production at room temperature (25 °C) and at 5 °C. One isolate identified as Saccharomyces sp. with highest polygalacturonase activity at 5 °C was used for enzyme production using raw fruit pectins as substrates. The isolate was identified by preliminary cultural, morphological and sugar fermentation tests. PGU production was high in raw pectin substrates like orange peel (21 U/ml), apple peel (20 U/ml ), mango peel (19 U/ml), grape must (18 U/ml) and guava peel (15 U/ml). Selected Saccharomyces sp. was found to grow at room temperature and produce good polygalacturonase active at 5 °C. Cold-active PGU could have ample application in fruit juice clarification as these conditions are milder and also prevent spoilage. The present study concentrated on enzyme production using the cheaper raw pectin rich substrates. Industrial relevance: The manuscript contains information on the cold active polygalacturonase produced by yeast at room temperature. It has industrial application for fruit juice clarification at cold (mild) conditions as it is a cold active enzyme. Also the enzyme is produced at room temperature by yeast considered as a GRAS organism. Therefore, it is a significant observation by the authors. © 2011 Elsevier Ltd. All rights reserved. Source

Anuradha K.,BVB Vivekananda College | Naga Padma P.,BVB Vivekananda College | Venkateshwar S.,Osmania University | Reddy G.,Osmania University
Indian Journal of Biotechnology | Year: 2014

Selection of the best nutrients is one of the most critical stage in media optimization for polygalacturonase production. Plackett-Burman design was used to screen various pectin substrates, nitrogen sources and mineral nutrients for polygalacturonase production by Aspergillus awamori MTCC 9166. Fifteen different pectin sources like crude pectin, polygalacturonic acid, orange peel, citrus peel, jackfruit peel, etc. were selected for polygalacturonase production using 16 experimental design of Plackett-Burman. Similarly, eleven nitrogen sources like yeast extract, tryptone, casein hydrolysate, sodium nitrate, ammonium chloride, etc. and eleven mineral nutrients like NaCl, MgSO4, KH2PO4, CaCl2, etc. were screened for polygalacturonase production using 12 experimental design of Plackett-Burman. The enzyme production was studied for 5 d, where the maximum production was observed on 3rd d and so this data was analyzed using Indostat software to obtain regression coefficients and t-values. Based on these values significant nutrients like seven pectin sources (orange peel, jack fruit rind, apple peel, pine apple peel, mango peel, banana peel & tomato pulp), four nitrogen sources (urea, yeast extract, casein hydrolysate & potassium nitrate) and four mineral nutrients (NaCl, KH2PO4, CaCl2 & KH2PO4) were selected for second level screening of efficient nutrients for polygalacturonase production using 16 experimental design of Plackett-Burman. Orange peel as pectin source, casein hydrolysate as nitrogen source and NaCl showed maximum enzyme production and so were selected for further quantitative optimization. Source

Anuradha K.,BVB Vivekananda College | Naga Padma P.,BVB Vivekananda College | Venkateshwar S.,Osmania University | Reddy G.,Osmania University
International Food Research Journal | Year: 2016

Pectin rich fruit juices need enzymatic treatment for clarification. As fruits are rich in pectin, pectinolytic treatment can efficiently reduce viscosity resulting in clarified fruit juice. Enzymatic treatment of mango pulp results in 80% recovery of total juice present in the fruit. Use of pectin degrading polygalacturonases increases both fruit juice extraction and clarification. Polygalacturonase (PG) produced by Aspergillus awamori MTCC 9166 is studied for mango juice clarification and conditions are optimized by Box-Behnken design. The conditions studied are incubation time (15-45 min), enzyme concentration (0.5-1.5 U/ml), and temperature (25-40°C). Significant regression model describing the change on viscosity with respect to independent variables was established. Based on surface plots and contour plots, the optimum conditions for mango juice clarification were obtained. The recommended enzymatic treatment conditions are enzyme concentration 1.5 U/ml, incubation time 30 min at 40°C. Significant (60%) reduction in viscosity was observed. © All Rights Reserved. Source

Anuradha K.,BVB Vivekananda College | Naga Padma P.,BVB Vivekananda College | Venkateshwar S.,Osmania University | Reddy G.,Osmania University
Biocatalysis and Agricultural Biotechnology | Year: 2014

Polygalacturonase enzyme has its industrial application in extraction and clarification of fruit juices. Growth as pellet is an important character for any industrial fungal strain as product recovery becomes easy and simple. The simultaneous effect of fermentation conditions like pH, temperature, agitation and inoculum size were studied on pellet morphology and polygalacturonase production by Aspergillus awamori MTCC 9166 in submerged fermentation using crude pectin. The studies were done by unidimensional approach in which conventionally one parameter was selected and studied at a time. Optimum fermentation conditions for maximum polygalacturonase production were at pH 5.5, temperature 28°C, agitation speed 200rpm and inoculum size 1×106 spores/ml. The highest enzyme production at these conditions was 17.8U/ml. The study revealed a significant fact that the same optimum fermentation conditions promoted both pellet formation and maximum enzyme production. © 2014 Elsevier Ltd. Source

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