Effect on microbial ecology and food spoilage of ph, Biology

Assignment Help:

Q. Effect on Microbial Ecology and Food Spoilage of pH?

The acidity of a product plays an important role in deciding the type microflora present in food and the rate and type of its spoilage. For example, most of the meats and seafoods have a final ultimate pH of about 5.6 and above. Thus, these products are susceptible to bacterial as well as to mold and yeast spoilage. Similarly, most vegetables have higher pH values than fruits, and thus vegetables would be more prone to bacterial than fungal spoilage since such pH values favour bacterial growth. Soft-rot producing bacteria such as Erwinia carotovora and pseudomonads play a significant role in their spoilage.

In fruits, however, a lower pH (below 4.5) prevents bacterial growth and yeasts and molds dominate spoilage. Fish is spoiled more rapidly than meat under chilled conditions. This is due to the fact that the pH of post-rigor mammalian muscle is around 5.6 and this contributes to the longer storage life of meat. On the other hand, fish have a pH between 6.2-6.5. Shewanella (formerly Alteromonas) mainly causes spoilage under chilled conditions. It is a pH-sensitive microbe and hence, plays a significant role in fish spoilage but not in normal meat (pH<6.0). Those fishes that have a naturally low pH such as halibut (pH~5.6) as a result have better keeping qualities than other fish. Thus, a food with inherently low pH would tend to be more stable microbiologically than a neutral food.


Related Discussions:- Effect on microbial ecology and food spoilage of ph

Explain fats in biological compound, Explain Fats in biological compound ? ...

Explain Fats in biological compound ? Fats :   Monoglycerides, diglycerides, and triglycerides are fats consisting of a backbone of the alcohol molecule glycerol, consisting of

What are the chief complaint and patient expectations, Chief Complaint and ...

Chief Complaint and Patient's Expectations It is extremely vital to know what the patient really wants. 1. The chief complaint should be recorded in patient's own words as f

Plant physiology, application of apical dominace in horticulture and agricu...

application of apical dominace in horticulture and agriculture short notes

Shapes - types of nursing units, Shapes: Nightingale Ward  In the 1...

Shapes: Nightingale Ward  In the 1940s,  this traditional nursing unit was based on  the long rectangle pavilion type ward and self-contained unit. This concept is establis

How are lipids used as an energy source by the organism, How are lipids use...

How are lipids used as an energy source by the organism? Carbohydrates are the major energy source for aerobic cell respiration. In the absence or deficiency of such substances

Dilute this concentration of cells to yield 300 cells, For a particular ass...

For a particular assay, you require cells at a concentration of 300 cells per ml. In your flask of cells growing you counted a sample using a hemacytometer and found that you have

Forebrain - diancephalon, DIANCEPHALO N - Less visible. Occupies on...

DIANCEPHALO N - Less visible. Occupies only 1% of brain's volume. Its lumen is diocoel or III ventricle. Roof is epithalamus . On it pineal body is present. Fl

Which statement is false, Which is FALSE? Diastereomers: Select one: ...

Which is FALSE? Diastereomers: Select one: a. Have the same molecular weight b. Have the same connectivity c. Are mirror images d. All of the above e. None of the

Define the term- adaptation, Define the term- Adaptation The terms sco...

Define the term- Adaptation The terms scotopic and photopic vision are relative to the lighting conditions of an individual place. Light adaptation is a very quick process and

Floral apex, Floral Apex Each plant must pass through a minimal 'ripe...

Floral Apex Each plant must pass through a minimal 'ripeness to flower' stage. That is, even to perceive and respond to a specific photoperiodic regime, a plant must be ready

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