66047 - Postaharvest Pathology And Entomology Of Foodstuff

Learning outcomes

At the end of the course the student will be able to make a diagnosis of the main postharvest diseases and disorders, and of the alterations induced by insects in stored plant products. He will be able to evaluate also their influence on processed plant products.

Course contents

The course is divided in two didactic units:

• Postaharvest pathology of plant foodstuff (4 CFU)
• Entomology of plant food stuff (2CFU)

POSTHARVEST PATHOLOGY OF PLANT FOODSTUFF (4 CFU)

Didactic units

General aspects (6 hours)

Importance of diseases and disorders on postharvest losses of raw and semi-processed fresh plant products. Influence of postharvest technologies on losses. Definition of disease and disorder. Outline of epidemiology, pathogenesis and control. Mechanisms of resistance of plant products to diseases: natural and induced, types of resistance. General characteristics of the main agents of diseases (fungi and bacteria), outline of taxonomy and toxin production. Influence of the physiological state, of wounds and of latent infections on post harvest diseases. Influence of disease and disorders on quality and on safety characteristic of raw and processed products.

Chilling injury, importance and limits to the use of cold chain, classification of horticultural products according to their susceptibility to chilling injury, symptoms, induced structural and physiological modifications, control.

Integrated protection of plant products (10 hours)

Integrated postharvest disease management of raw and semi-processed fresh products, during storage, transportation and distribution (physical, chemical and biological methods).

Physical methods

High temperatures: types of heat treatments (hot air and hot water), effects on the host and on the pathogen.

Low temperature (cooling): importance of the cold chain in the storage and distribution of raw and semi-processed fresh plant products, effects on the host and on the pathogen.

Oxygen and carbon dioxide: importance of controlled atmosphere (CA) , dynamic CA and modified atmosphere in storage and distribution of raw and processed fresh plant products, effects on the host and on the pathogen.

Ethylene scrubbing: influence of ethylene on ripening and senescence of the products, scrubbing technologies, effects on the host and on the pathogen.

Relative humidity (RH): importance and management of RH during storage and distribution, effects on the host and on the pathogen.

Ultraviolet light at low doses: management of the treatments, effects on the host and on the pathogen.

Ionizing radiation: sources, safety, limits, effects on the host and on the pathogen.

Chemical methods

Disinfectants: importance, types of disinfectants used on fresh plant products, how to apply, efficacy.

Chemical protectants: classification, hazard classes, technical limits, safety precautions, mode of application and of action, formulation types, residues, outlook of EC regulation of pesticide residues.

Biological methods

Natural susbstances: sources, activity, non-target effects, application limits.

Antagonistic microorganisms (fungi, bacteria and yeasts): mode of action, compatibility with other control methods, formulations, efficacy limits.

SPECIFIC PRODUCT DISESASES AND DISORDERS (18 hours)

Each disease and disorder is described from the point of view of:

- importance, distribution, qualitative and quantitative losses caused

- taxonomy, symptomatology, epidemiology and control

- influence on product processing (losses, mycotoxins, safety issues)

Pome fruits: Neofabrea, Penicillium, Botrytis, Mucor, Alternaria, superficial scald, soft scald, watercore, bitter pit. Stone fruits: Monilinia, Botrytis*, Rhizopus, Mucor*, internal breakdown (mealiness), abnormal ripening. Kiwifruit: Botrytis*, Phialophora. Grapes: Botrytis*, Aspergillus*. Strawberry: Botrytis*, Colletotricum. Tomato: Alternaria*, Colletotricum*, Botrytis* (mold count by Howard method), Pectobacterium, chilling injury. Potato: Fusarium, Pectobacterium*, greening, sweetening, sprouting. Onion: Botrytis*, Aspergillus*, Colletotricum*, Fusarium*, Pectobacterium*, Pseudomonas, sprouting. Leafy vegetables: Sclerotinia, Botrytis*, Pectobacterium*, Pseudomonas*, russet spotting, yellowing, senescence.

* Only symptoms and control.

Practices: Isolation and identification in the didactic laboratory of diseases caused by fungi, through observation under light microscope.

ENTOMOLOGY OF PLANT FOODSTUFFS (2 CFU)

Teaching units

Part 1 General (6 hours)

1.1 Types of insect damage

1.1.2 Direct: subtraction of products and commodities.
1.1.3 Indirect: transmission of infections, parasites, reduction of nutritional value and rheological capacity of flour and pollution.

1.2 Pests in food chains

1.2.1 Sequences of insect pests: primary, secondary and tertiary.

1.3 Characteristics of insects

1.3.1 Morphology: the structure of the body and its appendages, integument, chewing mouth parts (various types) and Diptera Brachiceri lambent sucking.
1.3.2 Anatomy: the different internal organs and their functions.
1.3.1 Biology: Reproduction, fertility and post-embryonic development.

Skills acquired by students from Unit 1

Knowledge of the relationships that insects have with the products and commodities.
Knowledge of the fundamental traits of the insect body and of its vital activities.

Part 2 Special (6 hours)

2.1 Generalities and and bio-ethology behavior of the main insect pests to products and foodstuffs listed below:

Blattodea (Blattidi: Blatta orientalis, Periplaneta americana; Blattellidi: Blattella germanica, Supella longipalpa); Psocoptera (Liposcelis decolor); Coleoptera (Dermestidae: Dermestes lardarius, Trogoderma granarium; Bostrichidae: Rhyzopertha dominica; Anobiidae: Stegobium paniceum, Lasioderma serricorne; Tenebronidae: Tenebrio molitor, Tribolium castaneum, Tribolium confusum; Bruchidae: Acanthoscelides obtectus; Curculionidae (Rincoforidae): Sitophilus granarius, S. oryzae, S. zeamais), Lepidoptera (Tineidae: Nemapogon granellus; Gelechiidi: Sitotroga cerealella; Pyralidae: Ephestia kuehniella, Plodia interpunctella), Diptera (Piophilidae: Piophila casei; Muscidae: Musca domestica).

Skills acquired by the student unit 2

Knowledge of the characteristics of insect pests useful for setting up prevention programs and struggle.

Applied Part 3 (8 hours)

3.1 Methods of analysis of food to detect the presence or traces of weed

3.1.1 X-ray, biological 3.1.2, acoustic 3.1.3, 3.1.4 respirometric, Calorimetric 3.1.5, 3.1.6 flotation, colorimetric 3.1.6, 3.1.6 filth-test.

3.2 Sampling of cereals according to the "official methods of analysis of grain."

3.3 Methods of insect pests interdiction

3.3.1 Prevention of infestation by insects.
3.3.2 Design and cleaning systems.
3.3.3 Inspection of the environments and monitoring of pests (trace analysis, use of traps).

3.4 Means and methods of struggle

3.4.1 Mechanical (diatomaceous earth ect.).
3.4.2 Physical (controlled atmosphere, low temperature, light radiation etc.).
3.4. 3 Biotechnical (pheromones, hormones similar ontogenetic).
3.4.4 Chemical: insecticides, characteristics of their main fumigant and residual activity groups.

Skills acquired by the student unit 3

Knowledge of the principles for proper management of the population of insect pests.
Knowledge of methods of analysis to properly assess the extent of the infestation.
Knowledge of methods of struggle required for the prevention and elimination of insect infestations.

Readings/Bibliography

Snowdon A.L. A colour atlas of postharvest diseases & disorders of fruit & vegetables. Vol. 1 & 2 . Wolfe Scientific ed. London, 1990. (Consultabile c/o Biblioteca "Campus Scienze degli alimenti"). Visibile nel sito WEB: http://books.google.com/books?id=WK-Scwl9skYC&pg=PA184&lpg=PA184&dq=pseudomonas+fluorescens+vegetables+rot&source=bl&ots=wSGByFca5i&sig=PLTrtJYPNRoAj-NTMIliB1-Zlzk&hl=en&ei=ZoGAToTiOKXH0QXwivnBCQ&sa=X&oi=book_result&ct=result&resnum=6&ved=0CEMQ6AEwBQ#v=onepage&q=pseudomonas%20fluorescens%20vegetables%20rot&f=false

Postharvest Technology Center - UNIVERSITY OF CALIFORNIA - Division of Agriculture and Natural Resources - [http://ucanr.edu/]http://postharvest.ucdavis.edu/Library/Selected_Postharvest_References_466/ [http://postharvest.ucdavis.edu/Library/Selected_Postharvest_References_466/]

Süss L., Locatelli DP, 2001 - Parasites of food. Recognition and management of pests in food industries. - Calderini Edagricole, Bologna, XIV +363 pp..

http://www.entom.unibo.it/Derrate% 20Cesena.zip

Lecture Notes

Teaching methods

1) Classroom lectures with power point presentations visualizing diagrams, figures, outlooks. Students' discussion, curiosity, and critical thinking on pstharvest diseases, disorders and pests of fresh horticultural products is stimulated. Their progresses and hurdles will be informally assessed through the talks.

2) Exercises by projection of disease, disorder and pests, by examination of collected specimens and a study visit to wholesale fruit and veg market.

Assessment methods

Verification of learning takes place in the sessions reported on Almaesami, through a written test lasting 40 minutes, concerning the entire program of both modules, without the help of notes or books. It consists of 26 questions, partly multiple choice and partly open-ended. Each question is awarded a maximum of one point. In the same session, students who have passed the written exam will be admitted to an interview to discuss with the teachers the answers provided in the assignment and deep some of the topics listed. In this phase, a further 4 points and eventually “laude” may be awarded.

Teaching tools

PC, projector, laboratory.

Office hours

See the website of Claudio Ratti

See the website of Paolo Radeghieri