Starch-based antifungal edible coatings to control sour rot caused by Geotrichum citri-aurantii and maintain postharvest quality of 'Fino' lemon.

Background: Two edible coating (EC) emulsions based on potato starch (F6 and F10) alone or formulated with sodium benzoate (SB, 2% w/w) (F6/SB and F10/SB) were evaluated to maintain postharvest quality of cold-stored 'Fino' lemons and control sour rot on lemons artificially inoculated with Geotrichum citri-aurantii. Previous research showed the potential of these ECs to improve the storability of 'Orri' mandarins and reduce citrus green and blue molds caused by Penicillum digitatum and Penicillium italicum, respectively.

Results: The coatings F6/SB and F10/SB significantly reduced sour rot incidence and severity compared to uncoated control samples on lemons incubated at 28 °C for 4 and 7 days.

Curative activity of postharvest GRAS salt treatments to control citrus sour rot caused by Geotrichum citri-aurantii.

The effectiveness of the "generally recognized as safe" (GRAS) salts potassium sorbate (PS), sodium benzoate (SB), sodium ethylparaben (SEP) and sodium methylparaben (SMP) to control sour rot, caused by Geotrichum citri-aurantii, was assessed by dipping economically important citrus species and cultivars in aqueous solutions for 30, 60 or 150 s at 20 °C, followed by examination after 8 d of storage at 28 °C. Curative activity was determined because the fruit were inoculated 24 h prior to treatment. Dipping fruit for 60 s in SMP (200 mM), SEP (200 mM) or SB (3% w/v) were very effective and reduced sour rot incidence and severity by up to 90%.

Distribution of Native Lactic Acid Bacteria in Wineries of Queretaro, Mexico and Their Resistance to Wine-Like Conditions.

Native lactic acid bacteria (LAB) are capable of growing during winemaking, thereby strongly affecting wine quality. The species of LAB present in musts, wines during malolactic fermentation (MLF), and barrels/filters were investigated in wineries from the emerging wine region of Queretaro, México using multiplex PCR and culture. The resistance to wine-like conditions (WLC): ethanol (10, 12, and 13%), SO (30 mg⋅l), and low pH (3.

DNA-based methodologies for the quantification of live and dead cells in formulated biocontrol products based on Pantoea agglomerans CPA-2.

Pantoea agglomerans strain CPA-2 is an effective biocontrol agent (BCA) against the major postharvest pathogens present on pome and citrus fruits. Dehydration, such as freeze-drying, spray-drying and fluidized bed drying is one of the best ways to formulate BCAs. In this work, the survival of CPA-2 cells after formulation was determined by dilution plating and molecular methods as qPCR alone and combined with a sample pretreatment with a propidium monoazide dye (PMA-qPCR) and they were used to calculate treatment concentrations in efficacy trials on postharvest oranges.

Development of PMA real-time PCR method to quantify viable cells of Pantoea agglomerans CPA-2, an antagonist to control the major postharvest diseases on oranges.

Dilution plating is the quantification method commonly used to estimate the population level of postharvest biocontrol agents, but this method does not permit a distinction among introduced and indigenous strains. Recently, molecular techniques based on DNA amplification such as quantitative real-time PCR (qPCR) have been successfully applied for their high strain-specific detection level. However, the ability of qPCR to distinguish viable and nonviable cells is limited.

Detection and quantification by PCR assay of the biocontrol agent Pantoea agglomerans CPA-2 on apples.

The registration of biological control agents requires the development of monitoring systems to detect and quantify the agent in the environment. Pantoea agglomerans CPA-2 is an effective biocontrol agent for postharvest diseases of citrus and pome fruits. The monitoring of CPA-2 in postharvest semi-commercial trials was evaluated by Rodac impression plates and the colonies isolated were confirmed by conventional PCR using the SCAR primers PAGA1 and PAGB1.