Effect of extracts of wastewater from olive milling in postharvest treatments of pomegranate fruit decay caused by Penicillium adametzioides

Autor: Giacomo Linoci, Giulia Cappelletti, Mara Quaglia, Martina Cerri, Chiaraluce Moretti, Agnese Taticchi, Stefania Urbani
Rok vydání: 2016
Předmět:
Zdroj: Postharvest Biology and Technology. 118:26-34
ISSN: 0925-5214
DOI: 10.1016/j.postharvbio.2016.03.012
Popis: Nonclimateric pomegranate ( Punica granatum L.) fruit harvested at full ripening are susceptible to attack by different genera of pathogenic fungi such as Alternaria , Aspergillus , Botrytis , Colletotrichum , Coniella , Nematospora , Penicillium , Pestalotiopsis , Pilidiella , Rhizopus and Syncephalastrum which can cause rot of the fruits thus compromising their organoleptic and nutritional value. Seven fungal species belonging to the genus Penicillium such as Penicillium expansum , Penicillium herquei , Penicillium implicatum , Penicillium glabrum , Penicillium minioluteum , Penicillium purpurogenum and Penicillium sclerotiorum have been previously identified as causal agents of postharvest pomegranate decay. Based on culture characteristics, molecular analyses on internal transcribed spacers, β-tubulin gene sequences, and pathogenicity tests, Penicillium adametzioides S. Abe ex G. Sm. is identified as a causal agent of pomegranate fruit rot. To the best of our knowledge, this is the first report of P. adametzioides as a pathogen of P. granatum . A phenolic concentrate obtained from olive-mill wastewater through a membrane filtration process, and its related purified phenolic extract that has a lower reducing sugar content, were produced and tested in vitro and in vivo against P. adametzioides . Both the phenolic concentrate and the purified phenolic extract significantly reduced mycelial growth and conidial germination of P. adametzioides when applied at 4 mg mL −1 and 8 mg mL −1 phenols. At the same content of phenols, the greater reduction of mycelial growth by the purified phenolic extract was related to its lower sugar content. Of note, the purified phenolic extract at 4 and 8 mg mL −1 phenols protected pomegranate fruit in vivo against P. adametzioides . Postharvest application of such by-products of the olive-oil industry might represent an alternative use of olive-mill wastewater, where its high content of phenols results in a disposal problem. This olive-mill wastewater also represents an alternative means for safe disease control of pomegranate fruit.
Databáze: OpenAIRE