Pectinases

Pectinases are a group of hydrolytic enzymes, usually referred as pectolytic enzymes, which find important applications in the food and beverages industries, in addition to various other industries. Pectolytic enzymes degrade pectic material and reduce the viscosity of a solution, making it easier to handle. They are used industrially in fruit processing to facilitate pressing and to help in the separation of the flocculent precipitate by sedimentation, filtration, or centrifugation in the extraction of the clarified juice (95). Pectinases are used for the elimination of pectin in wine making, coffee and tea processing plants, and maceration of vegetable tissue (93,94). Pectinases comprise hydrolases, lyases, and oxidases, and can be obtained from higher plants, microorganisms, and insects (96). Pectinases can be obtained from several fungi, bacteria (including alkalophilic), actinomycetes, and yeast, such as alkalophilic bacteria, actinomycetes, Aspergillus versicolor, A. niger, A. awamori,

Rhizopus stolonifer, Penicillium italicum, P. frequentans, Polyporus squamosus, Thermoascus aurantiacus, Clostridium thermosaccharolyticum, C. felsincum, Tubercularia vulgaris, Sclerotium rolfsii, Erwinia sp., Erwinia carotovora, Bacillus sp., B. subtilis,

B. bumilus, B. stearothermophilus, B. polymyxa, Pseudomonas syringae, Rhizoctonia solani, Xanthomonas compestris, Saccharomyces cerevisiae, Kluyveromyces marxianus, and Trichosporon penicillatum (89,93-97,100,101). Extracellular pectinases from Aspergillus sp. are of commercial interest and strains of A. niger, A. carbonarius, and A. foetidus are used. Among these, A. niger is considered as the most important for production in SSF. Various agro-industrial residues such as apple pomace (92), citrus waste, orange and lemon peels (91), soy bran (94), sugar cane bagasse (95), wheat bran (97), coffee pulp (87), cocoa pulp, (98) and cranberry and strawberry pomace (99) are used as the substrates. Citrus pulps or peels could be used as inducers for enzyme synthesis (91). In the case of pectinases, generally enzyme yields are higher and the enzyme is said to be more stable (over a wider range of pH and temperature) in SSF in comparison to SmF (88,89,93-97).

Making Your Own Wine

Making Your Own Wine

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