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

Enzymes, what is rennin? how does it work? and what is its optimum pH level...

what is rennin? how does it work? and what is its optimum pH level and activity temperature?

What is end-to-end anastomosis subclavian flap aortoplasty, What is End-to-...

What is End-to-End Anastomosis with Subclavian Flap Aortoplasty ? The two operations can be combined as a single procedure. Medially end-to-end anastomosis is done between the

The identity and amounts of elements in the molecule, If the chemical formu...

If the chemical formula of a substance is C17 H 31 COOH, what can you tell about the identity and amounts of elements in the molecule? Can someone please explain me this?

Explain the wound breakdown, Wound breakdown With careful flap design a...

Wound breakdown With careful flap design and gentle tissue handling this is a rare complication. The healing which follows is by secondary intention and can be aided by chlorhe

Difference between the concepts of karyotype and genome, Normal 0 ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Define poverty alleviation to control under nutrition, Define Poverty Allev...

Define Poverty Alleviation to control under nutrition? There are a number of development programmes aiming at employment assurance to the landless and other labour with a focus

Define pectin, Pectin The word pectin is derived from a Greek word whic...

Pectin The word pectin is derived from a Greek word which means to "congeal or solidify". Pectin is an acidic structural polysaccharide, found in fruit and vegetables and mainl

Define intermediate level of the numeric pyramid, In the short term what wi...

In the short term what will happen to the levels above and below a population of secondary consumers of a numeric pyramid if a large number of individuals from this population dies

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