Effects of Aspergillus niger Infection on the Quality of Jujube and Ochratoxin A Cumulative Effect.

The jujube is one of the most popular fruits in China because of its delicious taste and high nutritional value. It has a long history of usage as an important food or traditional medicine. However, the jujube is easily infected by fungi, which causes economic losses and threatens human health. When the jujube was infected by Aspergillus niger (H1), the changes in nutritional qualities were determined, such as the content of total acid, vitamin C, reducing sugar, etc. In addition, the ability of A. niger (H1) to produce ochratoxin A (OTA) in different inoculation times and culture media was evaluated, and the content of OTA in jujubes was also analyzed. After jujubes were infected by A. niger (H1), the total acid, and vitamin C contents increased, while the total phenol content decreased, and the reducing sugar content increased after an initial decrease. Although A. niger (H1) infection caused the jujubes to rot and affected its quality, OTA had not been detected. This research provides a theoretical foundation for maximizing edible safety and evaluating the losses caused by fungal disease in jujubes.

Isolation of Main Pathogens Causing Postharvest Disease in Fresh Codonopsis pilosula during Different Storage Stages and Ozone Control against Disease and Mycotoxin Accumulation.

Codonopsis pilosula is an important Chinese herbal medicine. However, fresh C. pilosula is prone to decay during storage due to microorganism infections, seriously affecting the medicinal value and even causing mycotoxin accumulation. Therefore, it is necessary to study the pathogens present and develop efficient control strategies to mitigate their detrimental effects on the herbs during storage. In this study, fresh C. pilosula was collected from Min County in Gansu Province, China. The natural disease symptoms were observed during different storage stages, and the pathogens causing C. pilosula postharvest decay were isolated from the infected fresh C. pilosula. Morphological and molecular identification were performed, and pathogenicity was tested using Koch's postulates. In addition, the control of ozone was examined against the isolates and mycotoxin accumulation. The results indicated that the naturally occurring symptom increased progressively with the extension of storage time. The mucor rot caused by Mucor was first observed on day 7, followed by root rot caused by Fusarium on day 14. Blue mold disease caused by Penicillum expansum was detected as the most serious postharvest disease on day 28. Pink rot disease caused by Trichothecium roseum was observed on day 56. Moreover, ozone treatment significantly decreased the development of postharvest disease and inhibited the accumulations of patulin, deoxynivalenol, 15-Acetyl-deoxynivalenol, and HT-2 toxin.

Acetylsalicylic acid treatment reduce Fusarium rot development and neosolaniol accumulation in muskmelon fruit.

Fusarium rot of muskmelon is a common and frequently-occurring postharvest disease, which leads to quality deterioration and neosolaniol (NEO) contamination. New strategies to control postharvest decay and reduce NEO contamination are of paramount importance. The effects of acetylsalicylic acid (ASA) treatment on the growth of Fusarium sulphureum in vitro, and Fusarium rot development and NEO accumulation in fruits inoculated with F. sulphureum in vivo were investigated. The results showed that ASA inhibited the growth of F. sulphureum, evident morphological and major cellular changes were observed under the microscope. In vivo testing showed that 3.2 mg/mL ASA significantly suppressed Fusarium rot development and NEO accumulation after 6 and 8 d of pathogen inoculation. Meanwhile, Tri gene expressions involved in NEO biosynthesis were down-regulated after treatment. Taken together, ASA treatment not only reduced Fusarium rot development by inhibiting the growth of F. sulphureum, but decreased NEO accumulation by suppressing NEO biosynthesis pathway.