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

Homeostasis solution, In biology, Homeostasis is the ability of an open pro...

In biology, Homeostasis is the ability of an open program to manage its internal environment to sustain constant circumstances through several energetic stability improvements mana

Principle of echocardiography, Echocardiography Utilizes principle of ultra...

Echocardiography Utilizes principle of ultrasound for visualization of heart and great vessels. It uses sound in the frequency of 1-10 MHz. As the frequency of probe increase

Tetrasaccharides, TETRASACCHARIDES The oligosaccharides are formed b...

TETRASACCHARIDES The oligosaccharides are formed by condensation of four monosaccharides. T rachyos e is a nonreducing tetrasaccharide found in plants as transport ca

Why is diabetes known as impairment to the homeostasis, Describe normal reg...

Describe normal regulation of blood glucose via the pancreatic hormones. How is this altered with Diabetes? Why is Diabetes called an impairment to the homeostasis of glucose? What

Assignment, Write short note onApplications of apical dominance in horticul...

Write short note onApplications of apical dominance in horticulture and agriculture

How would contrast single covalent bonds, 1. In modern blimps, the gas of c...

1. In modern blimps, the gas of choice used to inflate them is helium rather than hydrogen. Hydrogen would be lighter, but helium is safer. Compare and contrast the atomic structur

Explain the absorption of protein, Explain the Absorption of Protein? A...

Explain the Absorption of Protein? Although single amino acids are liberated in the intestinal contents, there is insufficient power in the enzymes of the pancreatic juice to r

What do you mean by inflammation, Q. What is inflammation? Inflammation...

Q. What is inflammation? Inflammation is the initial response of the unspecific defense system versus aggressions against the body the aggressions may be caused by trauma, infe

Response to heavy metal stress, Response to Heavy Metal Stress Severa...

Response to Heavy Metal Stress Several heavy metals emanating from industrial mining and sewage disposal operations contaminate the environment. Cadmium is a common contamina

In general what is the cause of the aneuploidies, In general what is the ca...

In general what is the cause of the aneuploidies? In general the aneuploidies are caused by impaired assortment of chromosomes during meiosis. For instance, when the homologous

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