Spoilage of Fermented Food and Soft Drinks

Spoilage of fermented food

The microorganism is used in main food industrial for the preparation of food. The process of preparation of food by using the discard microorganism under control condition is known as food fermentation . Fermentation can be called control degradation because under the specific condition the conversion of food take place . The various types of fermentation food SauerKet, softKrut, Kim hey pickles . fermentation dairy produced yoghurt ,cheese, some milk etc . Fermentationmilk and fermentation alcoholic beverages (wine , beer brandy). Fermentation foods are very less vulnerary(suitable) to spoilage by the microorganism . Because of their low pH production of alcohol and in some producers presence carbon dioxide prevented the growth of the microorganism . The source of contamination of the fermentation food depended on the type of food but the most importantly important source of contamination include air , water, ingredient use , various equipment , packaging container .

Spoilage of fermented vegetable

1. SauerKet : It is the product of lactic acid fermentation of cabbage with pH 3.4 -3.7 despises its very low pH ,undergoes following the type of spoilage .

• Soft Krut: Charatestices by softening of raw material (cabbage) due to degradation of pectin component of the raw material . It causes by Erwin species and mould Byssochlamys
• Slyme ropy Kurt :It is because by Encapsulated varieties of Lactobacillus planetarium.
• Pink Kurt : It is caused by Torula species,
• Rotted Kurt :It is caused by proteolytic organism including yeast and mold . In this type of spoilage of flavours produces due to proteolysis.

Spoilage of Pickles

It is the lactic acid fermentation of vegetable . The finished product has been pH at around four . Pickles undergoes following types of spoilage .

1. Floaters and Boaters :By Lactobacillus Plantarum and Coliform bacteria , which produce carbon dioxidein pickles .
2. Slippery pickles :It caused by capsulated bacteria such as Lactobacillus Plantarum .
3. Soft pickles : Dueto the growth of an organism that produces proteolytic enzymes . Organism like PenicilliumFusarium Cladosporium and Alternaria etc .
4. Black pickles :Due to the production of hydrogensulphite and the iron content of food react of giving black ferrous sulphide most often caused by Bacillus Nigeria

Spoilage of soft drinks

The typeof spoilage of soft drinks on them composition. Soft drinks are oftencarbonated and added with sugar along with different types of organic acid ( maleic acid , citric acid tartaric acid ) carbonation in present os such acids lower the pH of soft drinks and inhibit the growth of non-acidtolerant common types of spoilage are;

1. Cloudiness :Result from contains growth of yeast like Candida, Torulopsis etc.
2. Ropiness :Result from the growth of capsulated bacteria such s Gluconobacter species and sometimes may cause by Bacillus species.
3. Mushy odour :Caused by Achromobacter species . Molde may grow on the surface of non-carbonated beverages , that contains air above the liquid .

Spoilage of beer

The spoilage of beer caused by themicroorganism called beer infection or beer disease . Common type of microorganism involved in spoilage of beer include ;

Yeast :Saccharomyces , Hansenula etc.

• Spoilage caused by cloudiness yeast :Yeast produces turbidity when they grew beer . Yeast may be carried from the fermentation of contamination . Mainly caused by Saccharomyces pastures .
• spoilage caused by Off taste and off flavour :

1. Bitter flavour : Scahoromyces Pastries .
2. Ester like flavour
3. Most yeasts produce fruity odour and some produce hydrogen sulphite from hopextract .
4. Dextrin utilizen such as sacharomyces diasticus degrade dextin and produces off flavour .

Bacteria : Pediococcus , Lactobacillus , Flavobacterium , Acetobacter , Zygomas , Micrococci , Streptococcus , Bacillus etc .

• Spoilage caused by mash bacteria :Mash undergoes butyric acid fermentation by Clostridium species or Lactic acid fermentation by Lactobacillus species . These off flavour may be carried out to final product i.e beer.
• Spoilage cause by beer :It is characterised by sourness turbidity and ropiness of beer . Commonly caused by Peodicoccus cerevisiae.
• Sourness or turbidity :The acid tolerant Acetobacter , Gluconobacter, causes sourness under aerobic condition. Lactobacillus pastures caused sourness and turbidity .

References

Frazier, WC and Westhoff DC. Food Microbiology. 3rd. New Delhi: Tata McGraw-Hill Publishing Company Limited, 1986.

Jay, MJ. Moderen Food Microbiology. Ed. India. 3rd. Delhi: CBS Publications and Distributions, 1987.