Cereals and Cereals Products

1. Department of Microbiology
Submitted by:
Ms. Thanusri Rajendiran
III BSC., Microbiology
Vivekanandha arts and science
college
Sankagiri,salem.
Tamilnadu, India.

2. CONTENT
I
● INTRODUCTION
● SOURCES OF CONTAMINATION
● SPOILAGE OF CEREAL PRODUCTS
● CONTAMINATION
● PRESERVATION METHODS

3. INTRODUCTION
● Cereal grains, such as wheat, corn, rye, oat, rice, etc., are important nutrients and energy sources
for humans.
● Cereal grains are the most commonly consumed food group worldwide and they are grown on about
60% of the cultivated land in the world
● Cereals are consumed in various forms in the food industry.
● Cooked cereals are eaten directly after cooking (rice, maize).
● Flours are made by grinding cereals (such as wheat, maize, rice, and rye) and products processed
from them, e.g. biscuits, cookies, etc.
● Bread is usually made from flours of wheat and rye by yeast fermentation.
● Manufactured dried cereal products produced from wheat, maize, oats, and rice.
● These products are subject to physical, chemical, and microbiological spoilage that affects the taste,
aroma, leavening, appearance, and overall quality of the end consumer product.

4. CEREALS

5. Sources of contamination
● Air and dust
● Soil
● Water
● Insects
● Rodents
● Birds
● Animals
● Humans
● environmental conditions (such as drought, rainfall, temperature, and sunligh
● harvesting and processing equipment
● Contaminated equipment and unsanitary handling.
● Storage condition and storage temperature
● Shipping containers

6. ● Cereals usually contain 70–75% carbohydrates, 8–15% protein, fat, fiber, vitamins, and
minerals with near-neutral pH and hence are susceptible to microbial growth leading to
spoilage.
● Microbial growth is normally prevented due to sufficiently low water activity (i.e. below
0.70).
● Mold is considered the primary organism for causing spoilage in cereal.
● Bacteria can also cause spoilage of cereals, but yeasts cause few spoilage problems.
● The most commonly associated bacterial families with cereals are Bacillaceae,
Micrococcaceae, Lactobacillaceae, and Pseudomonadaceae.
● Yeast that is found in cereal includes Candida, Cryptococcus, Pichia, Sporobolomyces,
Rhodotorula, Trichosporon
● Mold spores in cereals and flour are chiefly Aspergillus, Penicillium, Alternaria, Mucor,
Cladosporium, Fusarium, Helminthosporium, Cladosporium, and Rhizopus.
SPOILAGE OF CEREALS

7. CONTAMINATION OF CEREALS AND CEREAL PRODUCTS
● The exteriors of harvested grains retainssome of the natural flora they had while
growing plus contamination
From soil,insect,other sources.
● Freshly harvested grains contain loads of a few thousands to million of bacteria /GM and
mold spores
● Bacteria are mostly in the families Pseudomonas ,Micrococci,Lactobacillus and Bacilli.
● Scouring and Washing the grains remove some of the Microorganisms are removed with
outer portions of the grains during milling. The milling processes especially bleaching
reduce no of organisms

8. ● The chemicals used to prevent and control the
occurrence of pests causing harm to crops that
includes including fungicides, herbicides, and
insecticides.
● The pesticides provide crop protection from the
damaging influences of pests, higher yields, and
better quality of cereals.
PRESERVATION OF CEREALS AND CEREAL PRODUCTS
PESTICIDES

9. ● Grains are dried to a low moisture content until
the moisture content level guaranteeing safe
storage conditions.
● Drying helps to create unfavorable conditions
for mold growth and the proliferation of
insects.
DRYING

10. ● It is a process that involves exposing cereal
food to a certain amount of ionizing
radiation.
● Irradiation has been successfully used for
the control of microorganisms on cereals and
flours.
IRRADIATION

11. ● Pulsed UV light treatment is a non-thermal
technology that can be used both for
decontamination of foods and food contact
surfaces.
● Pulsed UV light is considered to be more
efficient in microbial inactivation than UV
light, offering safer and faster
decontamination.
● The antimicrobial efficacy of this technology
against microorganisms occurring on stored
cereal grains has been studied.
PULSED UV LIGHT TREATMENT

12. ● Organic acids are used as food additives and
preservatives and can also be used for grain
preservation.
● Adding organic acids (acetic, citric, lactic, or
propionic) or a combination of organic acids and
NaCl added to tempering water is found to reduce
microbial contamination in cereal.
● It was reported that the combination of lactic acid
(5.0%) and NaCl (52%) was the most effective
against aerobic plate count and Enterobacteriaceae.
ORGANIC ACID