fermented cereal products 2
TRANSCRIPT
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Fermented Cereal ProductsBread
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Bread• A staple food prepared from a dough of flour and
water, usually by baking --- Wikipedia
• Food made of flour, water, and yeast or another leavening agent, mixed together and baked --- Google
• A staple food made from flour or meal mixed with other dry and liquid ingredients, usually combined with a leavening agent, and kneaded, shaped into loaves, and baked. --- Thefreedictionary
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Manufacturing Process
Mixing and kneading the dough Fermentation Cutting, "resting" and gas reproduction Molding Baking Slicing Packaging
Fermentation
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Yeast Lactic acid bacteria
Saccharomyces cerevisiae Leuconostoc mesentoroides
In breadmaking, fermentation involves two microorganisms
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Roles of Yeast
Increases dough volume Develops structure and texture Imparts distinctive flavor to the bread Enhances the nutritive
value of the product
Roles of Lactic Acid Bacteria
Produce lactic acid Produce flavoring compounds
BREADMAKING
Microorganisms involved Saccharomyces cerevisiae Leuconostoc mesenteroides
Leavening is performed by yeast Longer fermentation will produce more
acids, resulting in a tendency of dough collapse
During fermentation, dough "conditioning" takes place. Conditioning is a result of the action of gluten induced by the following:
a. proteolytic enzymes
b. pH reduction due to acid production
Dough Conditioners
Ammonium salts, which are sometimes used to stimulate the yeast
Sugars, which are usually added in the formulation for activity of yeast
NOTESThe rate of gas production by yeast can be increased by the addition of the following: More yeast Sugar or amylase-bearing malt Yeast food
On the other hand, gas production is decreased by the following: Salt addition Addition of too much yeast food Use of too high or too low a temperature
Production Steps
• (see separate handout about bread making)• Additional notes about Baking Step
Fermented Rice CakePUTO
Generally served with grated coconutBreakfast and snack foodTypes: plain and special
a leavened, steamed rice cake made from year-old rice grains which are soaked, ground with water, and allowed to undergo a natural acid and gas fermentation
Production Steps1. Initial Cooking2. Grinding3. Draining of ground “slurry” (galapong)4. Preparation of starter (lebadura)5. Fermentation (1st stage) – mixing of
lebadura and galapong6. Addition of sugar and lye7. Fermentation (2nd stage)
Control of Process1. Rice – high or medium amylose content
2. Soaking time or hydration factor of rice is 3 – 4 hours
3. Fermentation temperature of 28 – 30 °C in about 42 hours; can be shortened to about 21 hours using prepared starter
4. Addition of lye reduces acidity of the product
5. Use of proper cover during steaming.
Identified Fermenting Microorganisms
•The predominant organisms were always composed of:
Leuconostoc mesenteroides (45 – 89%)
Streptococcus faecalis (20 – 50%)
Saccharomyces cerevisiae ( 18% of the population at the end of fermentation.)
Changes in Microflora
1. Starter (a) aerobic colonies of bacteria and yeast (early stages), (b) predominant LAB and yeast (later stage)
2. Drained flour – absence of aerobic colonies; presence of acid-forming
3. 1st stage of fermentation – consists of LAB and few yeast colonies
4. 2nd stage of fermentation – dominated by yeasts.
Physical Changes1. Acid development – by S. faecalis2. Leavening – by S. cerevisiae and Leuconostoc
mesenteroides3. Amylose content – main factor affecting
gloss, cohesiveness, and tenderness of cooked rice
4. High amylose content rice varieties give higher yield and greater volume than low amylose content varieties.
Biochemical Changes
1. Changes in rice during storage• Old rice is more flaky than freshly harvested
rice• Fresh rice (upon cooking), loses more solids
to the cooking water than stored• Non-reducing sugar decreased while
reducing sugars increased.• Slight drop in pH for stored rice.a
2. Changes in pH and Total Acidity•Starter: pH decreases from 6.0 to 4.2
TA (%lactate) – 0.3 to 0.62- 0.66%•Drained rice flour after 24 hours
pH 3.9 to 4.12; TA (%LA) – 0.34 – 0.42%•Fermenting Mixture
1st stage – pH: 4.4 to 4.10%; %LA 0.40 – 0.59%2nd stage – pH 7.0 decreased to pH 6.12 – 6.25;
%LA (final) = 0.24 – 0.28%
Nutritional Value• 251 calories / 100g• 3.5% protein content• 56% carbohydrates
BIBINGKA
• Method of fermentation is the same as in puto• Cooked by baking or roasting• Cooked in a moulder (bibingkahan) lined with
banana leaves• Classified as ordinary and special types.