Microbiology of idly

detail information about the microbiology of idli

1. MICROBIOLOGY OF IDLY BY PALLE DHARANI

2. INTRODUCTION Idly is popularly taken as breakfast foods in India mainly South Indians. Idly has several variations, including rava idli, which is made from semolina. Regional variants include sanna of konkan. The spongy texture of steamed idli is imparted by the presence of surface active protein(globulin) and arabinogalactan. Idli is a cereal, legume based food . Idli is a small, white, acid leaved steam cake made by fermentation of thick idli batter. It is soft and spongy with desirable sour flavor and it is eaten with chutney, pickle and sambhar. The nutrient value of a single medium-sized (regular) idli is:  35-39 calories

3. MUDAY IDLI RAVA IDLI RAGI IDLI TATTE IDLI

4. RAW MATERIAL USED FOR IDLY PREPARATION The basic components of idli are u rad dhal, rice and fenugreek seeds. For proportion of these matter for the quality of the product and mix them in a 1:3.

5. PREPARATION OF IDLIS

6. MICROFLORA ASSOCIATED WITH FERMENTATION The microorganisms developing during the initial soaking of ingredients are sufficient to carry out fermentation. Both bacteria and yeast play important role in fermentation. During idli batter fermentation the predominant micro flora o f bacteria associated are Leuconostoc mesenteroidies, Streptococcus faecalis, pediococcus cerevisiae . Yeast associated with fermentation are Saccharomyces Cerevisiae, T orulopsis candida, T richosporon pullulans . The role of lactic acid bacteria is to reduce pH of batter to level 4.4 to 4.5 and this pH is optimum for yeast activity.

7. BIOCHEMICAL CHANGES There are two major changes – leavening and acidification. In the process of leavening during fermentation the volume of batter i ncreases from 1-3times of original and during acidification the lactic a cid is produced. The pH value decreases from 6 to 4.3-5.3. There is a slight increase in level of soluble salts and non protein nitrogen . The level of soluble nitrogen and free amino acid gets increased. The e ssential amino acid increase like choline, methionine, cysteine and vitC. The fermentation is performed by lactic acid bacteria especially the Heterofermantative strain like L euconostoc mesenteroidies and homofermantative strain like enterococcus faecalis (classified as streptococcus faecalis) Heterofermantative strain generate both lactic acid and carbon dioxide whereas homofermantative strain generate only lactic acid. Hence L. mesenteroidies tolerate high concentration of salt and suppress the growth of other undesirable microorganisms

8. B b   Leuconostoc mesenteroidies

9. HEALTH BENEFITTS It is easy to digest and get flushed out easily. It is highly nutritious and becomes more nutritious by adding vegetables to the sambhar. It is a light dish and is not all at difficult to digest. Fermented idly is rich in proteins, carbohydrates and vitamins. Rich in vitamins and encourages healthy gut flora. Idli contains no fat, no cholesterol, and no saturated fat. Since idli is a fermented food and fermentation increases bioavailability of minerals in food, helping to assimilate more nutrition. Idli fermentation enhanced B- vitamins specially thiamine, riboflavin, niacin, Pyridoxine & vitB12.

10. SHELF LIFE OF IDLY The steps have been taken to improve the shelf life by canning of idli and modified atmospheric packaging of idli batter The ready to cook idli batter has shelf life of 4-5 days at 4⁰C and Cooked idli can be stored for 1day and we can make idli upma from those. Due to the presence of high bacteria and yeast activity, the quality of idli batter gets deteriorated with increase of storage time.

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