66047 - Postaharvest Pathology And Entomology Of Foodstuff

Learning outcomes

At the end of the course, the student is able to recognize the main biotic and abiotic agents responsible for postharvest disorders and the pests of stored food commodities; understand their biology, epidemiology and modes of spread; assess the consequences of disorders on food quality, storability and safety; identify and apply integrated strategies for the prevention, monitoring and protection of fresh, minimally processed and processed plant products and stored food commodities.

Course contents

The course is divided into two modules: Pathology of Products and Food Commodities (4 ECTS) and Entomology of Stored Food Commodities (2 ECTS).

PATHOLOGY OF PRODUCTS AND FOOD COMMODITIES – 4 ECTS

Principles of postharvest pathology

Importance of biotic diseases and abiotic disorders as causes of qualitative and quantitative losses during storage, transport and marketing. Main fungal and bacterial agents and mycotoxin-producing fungi. Role of product physiological status, wounds and latent infections in the development of postharvest diseases.

Review of general plant pathology: concept of disease and pathogenesis; biotic and abiotic diseases; disease triangle and disease pyramid; infectious disease cycle; diagnosis and Koch’s postulates; principles of epidemiology; plant–pathogen interactions.

Postharvest protection of plant products

Principles and applications of the main prevention and protection methods:

• physical methods: high and low temperatures, cold chain, controlled and modified atmospheres, management of relative humidity and ethylene, UV and ionizing radiation;
• chemical and physicochemical methods: disinfectants and sanitizers, with particular reference to ozone and electrolyzed water;
• biological and naturally derived methods: natural substances, essential oils, chitosan and beneficial microorganisms;
• integrated protection: combination of physical, chemical and biological methods for disease management during storage, transport and distribution.

For the different approaches, mechanisms of action, application methods, efficacy, compatibility, effects on the product and main limitations of use will be considered.

Diseases and disorders of specific products

Main postharvest diseases and abiotic disorders of:

• pome fruit;
• stone fruit;
• grapes;
• kiwifruit;
• strawberries;
• potatoes;
• citrus fruit;
• pomegranate.

For the main case studies, the following will be addressed: etiology, symptomatology, distribution and economic importance; biological cycle and epidemiology; qualitative and quantitative losses; prevention and protection strategies; effects on product quality and processing, including possible mycotoxin contamination.

Practical activities

Isolation and identification of the main fungal agents responsible for postharvest diseases using microbiological and/or molecular techniques.

ENTOMOLOGY OF STORED FOOD COMMODITIES – 2 ECTS

Pests of stored food commodities

Main characteristics of pests and their importance in stored commodities and food industries. Direct and indirect damage: product loss, contamination, transmission of microorganisms, reduction in nutritional value and alteration of the technological properties of foods. Causes and modes of spread of infestations.

Biology and identification of pests

Principles of morphology, systematics, biology, metamorphosis and developmental cycles of insects of interest in stored food commodities.

Main groups of pests:

• rodents and mites;
• cockroaches and dipterans;
• lepidopteran pests of stored commodities, with particular reference to Sitotroga cerealella, Plodia interpunctella and Ephestia kuehniella;
• coleopteran pests of stored commodities, with particular reference to Sitophilus spp., Rhyzopertha dominica, Tribolium spp., Tenebrio molitor and Stegobium paniceum.

Prevention and management of infestations

Principles of Integrated Pest Management (IPM) applied to stored food commodities.

Monitoring, prevention and main control strategies:

• mechanical and physical methods;
• high and low temperatures and controlled atmospheres;
• biotechnological methods and use of pheromones;
• biological control;
• chemical methods and fumigants.

Efficacy, application methods, limitations and the impact of the different methods on the quality and safety of stored commodities will be discussed.

Readings/Bibliography

Pathology of Products and Food Commodities

Recommended textbook

De Cicco V., Bertolini P., Salerno M.G. Patologia postraccolta dei prodotti vegetali. Piccin Nuova Libraria, Padova.

Atlases for disease identification

Snowdon A.L. A Colour Atlas of Post-Harvest Diseases & Disorders of Fruits & Vegetables. Vol. 1–2. Wolfe Scientific, London.

Tonini G. Atlante delle alterazioni microrganiche postraccolta (pomacee e drupacee). Bayer S.p.A., Milano.

Web resources

Postharvest Research and Extension Center, University of California, Davis.

Entomology of Stored Food Commodities

Süss L., Guerra P. Gli infestanti nelle industrie alimentari. La gestione sulle derrate e nell’industria. Riconoscimento, modalità di prevenzione, monitoraggio e lotta. Avenue Media, Bologna, 2021.

Süss L., Locatelli D.P. I parassiti delle derrate: riconoscimento e gestione delle infestazioni nelle industrie alimentari. Calderini Edagricole, Bologna, 2001.

Teaching methods

The course includes lectures and practical activities.

Lectures use presentations, images, diagrams and case studies to illustrate the main issues related to diseases, disorders and pests of postharvest products. Discussion during lectures is aimed at developing the ability to recognize problems and critically evaluate possible prevention and management strategies.

Practical activities include laboratory work for the isolation and identification of fungal agents, observation and identification of diseases, disorders and pests and, where scheduled, an educational visit to facilities within the agri-food supply chain.

Assessment methods

Assessment covers the entire syllabus of both modules and is aimed at evaluating the student’s ability to:

• recognize the main symptoms, causal agents and pests;
• understand their biology, epidemiology and modes of spread;
• identify appropriate prevention and protection strategies;
• assess their impact on the quality and safety of food products.

The examination takes place during the sessions published on AlmaEsami and includes a 40-minute written test, covering the entire course syllabus and taken without the use of notes or books.

Students who pass the written test are admitted, during the same examination session, to an oral discussion during which they may review their written test and discuss the answers provided. The discussion also includes further examination of selected topics from the syllabus and contributes to the determination of the final grade.

Teaching tools

PC, video projector, digital teaching materials and teaching laboratory.

Office hours

See the website of Annamaria Mincuzzi

See the website of Riccardo Baroncelli