Clean Postharvest Technologies to Control Diseases in Fruit

Rosita Umar Ubong1*, Kofi Abrakadabra2 and Abdulahi Kolo3 

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1Food Technology Development Agency, 1001 Research Street, Kisumu, Kenya; ruubong@gmail.com 

2Department of Postharvest Management, University of Science and Technology, Akwa Iboma, Republic of Benin; taakum@usst.com

3International Organisation for Innovation, No-Food-Loss Street, Lilongwe, Malawi; akafrica@postharvestloss.com

*Presenting author

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(Abstract body text in 12-point Times New Roman, justified – maximum 500 words)

The susceptibility of papaya to postharvest diseases is high. Fungal growth and anthracnose are considered one of the most significant. Synthetic fungicides are the most commonly used for postharvest disease control. Nevertheless, these products have restricted application due to the negative effects on human health. The aim of this work was to study the effects of clean technologies as an alternative for quality and pathology control during postharvest handling of papaya. Fruit were selected and subsequently treated with several clean technologies: Mild Heat Treatment at 45°C for 5 minutes (MHT45), Mild Heat Treatment at 70°C for 1 minute (MHT70), Ultrasounds at ambient temperature for 10 minutes (USTA), and Ultrasounds at 50°C for 1 minute (US50). Additionally, non-treated fruit were used as a control. After treatment, fruit were dried and stored at 8°C. Weight loss, respiration rates, firmness, aerobic mesophilic bacteria, mould, yeast counts, and anthracnose incidence were monitored after 0, 5, 14, and 21 days of storage. Fruit treated with ultrasounds had an increase in respiration rate and weight loss, whilst the application of MHT led to a lower respiration rate and weight loss. Conversely, the treatments assessed, especially US50 and MHT70, resulted in fruit with higher firmness compared to the control. After US50, MHT45, and MHT70 treatments followed by 21 days of storage, bacterial counts were 6.45, 5.79, and 7.21 cfu.g-1, respectively, versus counts of 9,95 cfu.g-1 for control fruit. These treatments also resulted in lower fungal counts of 4.95, 2.00, and 3.30 cfu.g-1 versus counts of 6.93 cfu.g-1 detected for control fruit. Consequently, the anthracnose visual incidence was reduced by up to 80% following the application of MHT treatment. Thus, the application of treatments such as MHT at 70°C might be a suitable alternative for the control of pathogens and enhancing the postharvest quality of papaya fruit.