Accessory food substances or vitamins, Biology

Assignment Help:

Q. Accessory Food Substances or Vitamins ?

Bacteria also vary in their need for vitamins or accessory growth factors. Some microorganisms are unable to synthesize some or all of the vitamins needed for their growth. For example, Staphylococcus aureus synthesizes part while Pseudomonas or Escherichia coli all of the factors needed. The lactics and many pathogens must have all of the vitamins furnished.

Microorganisms may require B vitamins in low quantities and most of the natural foods have an abundant quantity of these. Gram positive bacteria are the least synthetic and must, therefore, be supplied with one or more of these compounds before they will grow. Gram-negative bacteria and molds are able to synthesize most of their requirements. Consequently, these two groups of organisms may be found growing on foods low in B vitamins. Fruits tend to be lower in B vitamins than meats. Thus, the usual spoilage of fruits is by molds rather than bacteria since fruits also have a low pH and positive Eh, which favour mold growth.

Egg white contains biotin but also contains avidin, which ties it up, making it unavailable to microorganisms and thus eliminate spoilage of eggs through biotin requiring organisms. The processing of foods often reduces the vitamin content. For example, thiamine, pantothenic acid, folic acid and ascorbic acid (in air) are heat-labile. Drying causes a loss in vitamins such as thiamine and ascorbic acid. Even storage of foods for long periods, especially if the storage temperature is elevated, may result in a decrease in the level of some of these growth factors.


Related Discussions:- Accessory food substances or vitamins

Microfilament, Full Description about microfilament

Full Description about microfilament

Show nutrition guidelines for prevention of heart disease, Q. Show Nutritio...

Q. Show Nutrition guidelines for prevention of heart disease? Nutrition guidelines for prevention of heart disease as suggested by WHO are highlighted. Details regardin

What are neurodegenerative diseases, What are neurodegenerative diseases an...

What are neurodegenerative diseases and how might they be treated? Neurodegenerative diseases that include Alzheimer's, Parkinson's, Huntington's, and amyotrophic lateral scler

What is cartilage explain briefly, What is Cartilage explain briefly? S...

What is Cartilage explain briefly? Some bones, such as the bones in the skull, develop directly from membranous connective tissue, but in human fetal development, most of the s

Define the reduction of the activation energy, How does the formation of th...

How does the formation of the enzyme-substrate complex define the reduction of the activation energy of chemical reactions? The enzyme possibly works as a test tube within whic

Haemodynamics of tricuspid regurgitation, Q. Haemodynamics of Tricuspid reg...

Q. Haemodynamics of Tricuspid regurgitation? Right Atrial pressure tracing shows a prominent ‘v' wave and these cannot be appreciated in a patient with atrial fibrillation. RV

Explain clear liquid diet, Explain Clear Liquid Diet Clear Liquid Die...

Explain Clear Liquid Diet Clear Liquid Diet:  It is composed  of  foods with  low residue content which  help  to minimize  the  load of food needing digestion  in  the  int

Reproduction, site of fertilistion in human

site of fertilistion in human

Explain sol -gel transformation, Explain sol -gel transformation During...

Explain sol -gel transformation During sol -gel transformation, a three dimensional network is formed by the interlocking of dispersed particles. The liquid phase is entrapped

Define amino acid requirements for human, Define Amino acid requirements fo...

Define Amino acid requirements for Human? Data regarding the essential amino acid requirements of infants, children and adults are given in terms of egg protein and cow's milk

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd