Cereals and Cereal Products (Source of Contamination and preservations).pptx

Food Microbiology

1. VIVEKANANDHA ARTS AND SCIENCE COLLEGE FOR WOMEN Veerachipalayam - 637 303, Sankagiri, Salem Dt., Tamil Nadu India. Affiliated to Periyar University, Salem ; Recognised Under Section 2(f) & 12(B) of the UGC Act, 1956 ) SUBMITTED BY KEERTHANA SARAVANAN III-B.Sc. Microbiology Department of Microbiology VIAAS, Sankagiri . DEPARTMENT OF MICROBIOLOGY SUBJECT: Food Microbiology. Title: Cereals and Cereal Products. SUBJECT INCHARGE: Dr. R. DINESHKUMAR, Assistant Professor, Department of Microbiology VIAAS, Sankagiri

2. Index What is cereals? Importance of cereals. Types of cereals. What are cereal products? Source of contaminations: Physical Chemical Biological Prevention of contaminations. What is mean by food spoilage? Spoilage in cereals and cereal products: Grains Flours breads Preservations. Methods of preservations. Controls of microbes in cereals and cereal products.

3. What is cereals? It is commonly referred to as grain or cereal grain. They are a type of crop that belongs to the grass family (Poaceae) and are widely cultivated for their nutritional and versatile seeds. Examples: Wheat, Rice, Corn(Maize), Oats, Barley, Rye, Millet, Sorghum. They are a good source of carbohydrates, fibre and essential nutrients like iron, B vitamins and minerals. They are relatively low in fat and calories.

4. Importance of cereals: Primary source of energy. Nutrient rich. Supports healthy digestion. Help to manage weight. Reduce chronic disease risk. Support to animal nutrition. Local to global economics. And used as animals health supplements.

5. Types of cereals. Cereals come in great varieties. Here are the different types of cereals examples mentioned below: Wheat Rice Oats Barley Quinoa Millet Rye Sorghum

6. Types of cereals:

7. What are Cereal products?

8. Sources that are contaminate the products:

9. Physical Contaminations: The main pollutant of concern in pulses, wheat and rice milling facilities is particularly matter emission generated from: UnSanitizing Material handling. Cleaning. Milling. Packaging operations. Contaminated equipment's. Environmental sources. Storage conditions and storage temperature. Shipping containers. These operations are typically located inside the mill buildings. Dust released from these operations spread inside the shop floor environment of the factory.

10. Chemical contaminations: It refers to the presence of unwanted chemical substance that can affect the food safety and nutrition value of the product. Here are some examples of chemical contaminations that can affect the cereals and cereal products: Heavy metals (eg: lead, mercury, arsenic, cadmium) Polycyclic aromatic hydrocarbons(PAHs) Polychlorinated biphenyls (PCBs) Dioxins and furans Acrylamide Monochloroacetic acid (MCA) Chlorinated solvents(eg: trichloroethylene, perchloroethylene) Food additives (eg: excessive use of preservatives, colourings agents)

11. Biological contaminations: Biological contaminations is commonly based on the over growth of microorganisms. These microorganisms will grow when they have favourable conditions like pH, humidity, temperature and the nutritional value. Microbial contaminations of cereals and cereal products can occur through various microorganisms, including: Fungi. Bacteria. Moulds. Insects.

12. Preventions of contaminations: Proper handling Proper storage Proper sanitizing Regular cleaning Pest control measures Regular inspections Maintain testing Employee training Create awareness among employee Supply chain control and verifications Regulatory compliance and certifications

13. What is mean by food spoilage? Undesirable change in food appearance, formation of unpleasant odour and unpleasant taste. The unusable state of food is known as spoilage 99.9% organisms were involved in food spoilage.

14. Spoilage of Cereals and Cereal products : The cereals are often contaminated with soil, air(dust), insects as well as the natural microflora of the harvested grains. Freshly harvested grains are shown to possess a bacterial count of 10³-10⁶ bacterial cells/g and over 10,000 mould spores/g of grains. The common bacteria species are from Pseudomanadaceae, Micrococcaceae, Lactobacillaceae.

15. Cereals has a low moisture content thus cause most spoilage. Grains: The spoilage of grains is accompanied with the presence of moulds. The moulds attacking the grains are two types namely Field fungi and Storage fungi .

16. Grains: Field fungi: Field fungi are well adapted to rapid changing conditions on the surface of the grains. In these most commonly found in the genus, Cladosporium, Alternaria , etc. They survive in the hot conditions and desiccation and apparently need a high water activity to survive.

17. Grains: Storage fungi: These are well adapted to the more constant conditions of cereals in storage. They generally grow at low water activity . Examples of some storage fungi are Penicillium, Aspergillus, Furasium and some Xerophilic moulds like Eurotium spp. And Aspergillus restrictus grow very slowly at a very low water activity.

18. Flours: Normally in flours the water activity is very less, that is unfavourable for the microbial growth but once there is slightly moisturing may permit the growth of mould and bacteria. Types of spoilage of flours differs with the differential contaminating flora. If the acid forming bacteria are present, an acid fermentation begins, followed by alcoholic fermentation by yeast and acetic acid production by Acetobacter spp. Other bacteria include coliforms, species of bacillus and micrococci.

19. Breads: Certain kind of bread microbes are used for fermentation. The main type of spoilage in bread is mouldiness and ropiness commonly called mould and rope. The temperature attained in the baking process usually high enough to kill all the moulds and microbes. Main moulds involves in the spoilage of bread are Bread moulds – Rhizopus tolonifier Green spores – Penicillium expansum Yellow pigment – Aspergillus niger Reddish pigment – Monilla

20. Bread contamination cycle:

21. Breads: Rope mainly caused by Bacillus subtillis or β -licheniformis. The area of ropiness is yellow to brown and soft and sticky to the touch. Chalky bread: Caused by the growth of yeast like fungi, Endomycopsis spp. The swelling of moist macroni has been repeatedly caused by the gas production by bacteria, Enterobactercoacea

22. Preservation: Most of the cereals and cereal products have low moisture content that is difficulty in preservation. Storage temperature 4.4 to 7.2⁰C is recommended for dry products. There many types of preservations in the cereals and cereal products.

23. Methods of preservations :

24. Methods of preservations: Asepsis: Improperly sanitized equipment's may be source of rope bacteria and acid forming bacteria, that cause sourness to dough. Using sterilized equipment's and raw materials avoid contaminations. Use of heats: The complete baking process destroys all bacterial cells, yeasts, moulds, spores but not spores of rope-forming bacteria.

25. Methods of preservations: Use of low temperature: Baked products should be kept under cool conditions or refrigerated in home for preventions of food spoilage. These can be stored for months. Use of chemicals: A large number of chemicals used such as sodium, calcium propionate, sodium diacetate and sorbates mainly for moulds in breads, rolls and cakes. Acidification of dough with acetic acids has been used to control ropes. Radiations: Ionizing radiations, gamma rays and cathodes rays have been used in bakeries, uv lights are used to destroy or reduce the number of microbes from knives, machine, on surface of breads, cakes. Low level radiations can also be used to destroy moulds in stored grains.

26. Controls of microbes in cereals and cereal products: Pre-harvest control measures: Good agricultural practices Crop rotation and sanitation Irrigation managements Post-harvest control measures: proper drying and storage Cleaning and grading Disinfections Aeration and ventilations Processing control measures: Cleaning and sanitizing equipment's Heat treatments Moisture controls Packaging and storage

27. Controls of microbes in cereals and cereal products : Microbial testing: Regular testing for pathogens.(eg: Salmonella, E coli ) Testing for spoilage microorganisms(eg: mould, yeasts) Testing of mycotoxins.(eg: alfatoxins, achrotoxins ) Good manufacturing practices: Personal hygiene and training Cleaning and sanitizing schedules Equipment's maintenance and calibrations Pest control programs Haccp ( Hazard Analysis and Critical Control Points) Identify potential hazards Determine critical control points Establish monitoring and control procedures Verify and validate HACCP plan.

28. Reference: Food microbiology –K.Vijaya Ramesh Volume II –Food Processing and Preservation –DS.Warris. https://microbenotes.com/spoilage-cereal-products/ https://wingreensharvest.com/blogs/news/what-are-cereals-different-types-of-cereals-list-with-benefits https://en.m.wikipedia.org/wiki/Cereal#:~:text=Among%20the%20best%2Dknown%20cereals,buckwheat%2C%20quinoa%2C%20and%20amaranth https://www.vedantu.com/biology/cereals http://www.historyofcereals.com/cereal-facts/types-of-cereals/

29. Thank you..