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

Explain about pre - diabetes, Q. Explain about Pre - Diabetes? Pre - Di...

Q. Explain about Pre - Diabetes? Pre - Diabetes is a condition where blood sugar level is above normal but below to be diagnosed as diabetes mellitus. It has been found that

Disability adjusted life years (dalys), Disability Adjusted Life Years (DAL...

Disability Adjusted Life Years (DALYs) DALYs is a measure for the overall ‘burden of disease’. Originally developed by the World Health Organization (WHO), it is being increas

How is respiration performed by the larva of amphibians, Q. How is respirat...

Q. How is respiration performed by the larva of amphibians? The larva of amphibians has exclusively branchial respiration this is one of the reasons why it depends on water to

Application of derivative, Give some real world sample problem involving us...

Give some real world sample problem involving use of derivative

Technological level - pollution control, Technological level - Pollution co...

Technological level - Pollution control Air pollution can be reduced by using bag filters, electrostatic precipitators and cyclone separators that separate large and small par

Carbohydrates, Carbohydrates Fifty five to seventy per cent of the re...

Carbohydrates Fifty five to seventy per cent of the required energy in animals is derived from carbohydrates. However, fats and proteins can also be broken down and used for

What is non specific defence, What is Non specific defence Non specifi...

What is Non specific defence Non specifi c:  These relate to  the  physical barriers  like  skin  and mucous membrane. They form the first line of defence against entry of mic

How to calculate the net protein utilization (npu), How to calculate the Ne...

How to calculate the Net Protein Utilization (NPU)? Mitchell (1922) introduced the term 'Net Utilization of Dietary Protein' which is a product of digestibility coefficient and

Fishes- regeneration in vertebrates, Fishes- Regeneration in Vertebrates ...

Fishes- Regeneration in Vertebrates Several different parts of the fish body will re-grow. Plucked scales are promptly replaced by new ones and amputated gill filaments can re

Most common opportunistic diseases in aids, Q. Moniliasis is one of the mos...

Q. Moniliasis is one of the most common opportunistic diseases in AIDS. What is the etiological agent of moniliasis and what is the other name of the disease? Why is monilia also c

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