Assessing The Quality Of Poultry Meat Biology Essay

Published:

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.

The meat composition includes a host of chemical compounds in muscles, they include free fatty acids, glycerol, triglycerides, phospholipids, non-protein nitrogenous components such as DNA, RNA, ammonia, amine groups, and vitamins, also There are glycogen granules and ATP .

In Europe, the average loss in quantity of fresh poultry meat is estimated to be 1Ñ3%, although some processing plants report up to 6% trimming loss in breast meat alone. At 1% loss, it can be estimated that 54,600 tonnes of prime broiler meat was lost during the year 1996. In December 1996, the producer price (pound sterling (£) equivalent) was 56 p kg-1 in the Netherlands, the lowest cost producer in Europe, and at this producer price, the actual loss for the year 1996 can be estimated at over £30 million. If the retail price of fresh turkey meat is considered to be £3 kg-1 and the minimal loss due to trimming happens to be 1%, then it is estimated that the European turkey industry had lost about £50 million worth of prime meat in the year 1996. Although the trimmings and downgraded portions or carcasses would have been sold at a reduced price, this certainly shows the importance of carcass and meat quality.

To address the concerns of poultry processors and retailers, scientists around the world are relentlessly pursuing research and development. ( A.B.M. Raj , 1997)

In meat and meat products during storage at refrigerated temperatures can develop a highly toxic substances such as ammonia, hydrogen sulfide, peroxidase, putrescine, and cadaverine formed by decarboxylation of amino acids in meat as a consequence of the process autolytic decomposition process in meat.

Qualities measurements of chemical or physico-chemical properties, which are directly relevant to food quality, are found less frequently for process

control in the meat industry (Nollet, L. M. L. Et al. 2006) To assess the quality and freshness of meat during storage was determined ammonia (easily hydrolyzable nitrogen) with Nessler reagent. Method consists in measure the quantity of nitrogen present in the form of dissolved ammonia and ammonium ions. The test involves dosing in the reaction medium with Nessler's reagent (solution of potassium tetraiodomercurate) Photocolorimetric method.

The products were purchased from the slaughter house immediately after slaughter and stored for 10 days at 4 0 C.

Materials and Method

Sample Preparation

Meat for analysis was minced twice after that was weighed 10 grams (10,000 mg) of the analytical balance and placed in a 100 volumetric flask and brought to volume with bidistilate water closed and with a lid to shake and leave to rest for 10 minutes.

Sample Preparation

Ammonia in aqueous extract of meat sample form with solution of potassium tetraiodomercurate (II) (K2[HgI4]) (Nessler reagent) complex colored, yellow-orange oximercury ammonium iodide, color intensity was read photocolorimeter to the wavelengths of 425 nm.

NH4+ + 2[HgI4]2− + 4OH− → HgO·Hg(NH2)I + 7I− + 3H2O

Reagents

Bidistilate water without ammonia.

Nessler reagent (tetraiodomercurate bipotasic solution in potassium hydroxide): 5 g potassium iodide dissolved in 5 cm3 of hot water in an Erlenmeyer flask. Add hot saturated solution of mercuric chloride until the precipitate formed is no longer dissolved. After cooling the solution separate, decant a 100 cm3 volumetric flask. Add 15 g potassium hydroxide dissolved in 30 cm3 water and bring to volume with water. Add 0.5 cm3 saturated solution of mercuric chloride, allow to make the solution above the precipitate and separated by decantation, pass in a clean and kept in the dark.

Alkaline mixture: 10 g sodium carbonate and 10 g sodium hydroxide dissolved in few ml of bidistilate water in a 100 ml volumetric flask and completed to volume with bidistilate water;

Standard stocks solution of ammonia is obtained by weighing the analytical balance 1000 mg ammonium chloride dissolved in a 100 volumetric flask, bring to volume with bidistilate water after a dilution is made by taking 1 ml of this solution and introducing it into a 1000 ml volumetric flask and bringing to volume with bidistilate

water so that the solution finally have a concentration of 0.01 mg / l ammonium chloride.

Seignette salt (potassium sodium tartrate): 392g salt Seignette

NaKC4H4O6 ∙ 4:20 dissolve in 784 ml 20% NaOH solution. Mix well and after two hours may be used without shaking the bottle.

Description of working procedures

100 ml aqueous meat extract were placed in a cylinder with a stopper and add 1 ml alkaline mixture and shaken. It was the supernatant 10 ml, was added 2 ml Seignette salt and 2 ml Nessler reagent was shaken and left to stand 10 minutes later which was centrifuged at 3500 rpm for 10 min with a rotating centrifuge ROTANTA model 460 then read color intensity in WTW photocolorimeter SpectroFlex model 6100 to 425 nm in 1 mm cuvette. Extinction values of the sample was interpolated from a standard curve which was performed after the scheme of Table no 1.

Table 1. Standard solution realization for photocolorimeter calibration

Concentration of ammonia solution

mg/l

0

0.02

0.04

0.06

0.08

0.1

standard solution

ml

0

2

4

6

8

0

Bidistilate water

ml

0

8

6

4

2

1

Seignette salt

ml

2

Nessler reagent

ml

2

Figure 1. Calibration curve

Table 2. Results of standard solution readings at photocolorimeter

Standard solution concentrations (mg)

Abs.1*

Abs.2*

Media

RSD**

%

0

0,002

0,002

0,002

0

0,02

0,156

0,155

0,155

0,454

0,04

0,287

0,282

0,284

1,242

0,06

0,436

0,434

0,435

0,325

0,08

0,553

0,555

0,554

0,255

0,1

0,671

0,673

0,672

0,210

* Absorbance; ** Relative standard deviation

Results and Discussion

During the 10 days in which meat was kept at 4 0 C was taken each day 10 g sample which was analyzed for ammonia content by reaction of ammonia with Nessler reagent.

The intensity of color formed following reaction similarly to the standard solution of ammonia reading. Extinction values of the sample was interpolated on the calibration curve.

In the table one can see the results content increases of the ammonia in meat during the 10 days.

Table 3. Results of experimental data

Day

Sample masses g

Abs.1*

Abs.2*

Media

RDS**

%

Concentration

mg NH3 / 100 g

1

10,018

0,105

0,104

0,105

0,676

23,484

2

10,022

0,141

0,142

0,142

0,499

24,736

3

10,025

0,172

0,174

0,173

0,817

26,509

4

10,002

0,185

0,186

0,186

0,381

26,942

5

10,008

0,201

0,202

0,202

0,350

29,229

6

10,003

0,215

0,216

0,216

0,328

31,399

7

10,013

0,224

0,227

0,226

0,940

35,824

8

10,016

0,243

0,247

0,245

1,154

37,224

9

10,011

0,268

0,262

0,265

1,600

37,242

10

10,010

0,275

0,273

0,274

0,516

38,212

* Absorbance; ** Relative standard deviation

From Table 3 we can see that the meat from of the 9th day the value exceeds the limit from 35 mg, g NH3/100 permitted by Romanian legislation, limit stipulated in article 12 of Order 975/1998 which provides that in the pork meat the easily hydrolyzable nitrogen over 35 mg NH3/100 g limit is unfit for human consumption through clear signs of deterioration (Order 975 1998)

Variation of hydrolysable nitrogen (mg NH3 /100g meat) during storage to de 40C can be seen in Figure 2.

Figure 2 Variation of hydrolysable nitrogen (mg NH3 /100g meat) during storage

to de 40C

Conclusion

The determination of ammonia (easily hydrolyzable nitrogen) in pork meat is critical for daily quality control of production and for specification in contracts.

The traditional ammonia methods (easily hydrolyzable nitrogen) see. SR 9065-7: 2007 is relatively accurate, but it is, time-consuming; exposes the analyst to toxic fumes, concentrated acid, and alkali; and produces chemical wastes that must be disposed compared with Photocolorimetric method of this paper which is somewhat quicker than the traditional method SR 9065-7: 2007.

Writing Services

Essay Writing
Service

Find out how the very best essay writing service can help you accomplish more and achieve higher marks today.

Assignment Writing Service

From complicated assignments to tricky tasks, our experts can tackle virtually any question thrown at them.

Dissertation Writing Service

A dissertation (also known as a thesis or research project) is probably the most important piece of work for any student! From full dissertations to individual chapters, we’re on hand to support you.

Coursework Writing Service

Our expert qualified writers can help you get your coursework right first time, every time.

Dissertation Proposal Service

The first step to completing a dissertation is to create a proposal that talks about what you wish to do. Our experts can design suitable methodologies - perfect to help you get started with a dissertation.

Report Writing
Service

Reports for any audience. Perfectly structured, professionally written, and tailored to suit your exact requirements.

Essay Skeleton Answer Service

If you’re just looking for some help to get started on an essay, our outline service provides you with a perfect essay plan.

Marking & Proofreading Service

Not sure if your work is hitting the mark? Struggling to get feedback from your lecturer? Our premium marking service was created just for you - get the feedback you deserve now.

Exam Revision
Service

Exams can be one of the most stressful experiences you’ll ever have! Revision is key, and we’re here to help. With custom created revision notes and exam answers, you’ll never feel underprepared again.