Etiket Arşivleri: FOOD QUALITY CONTROL

Determination of Acidity, Peroxide and Color Test of Fried Oil

FE 376 FOOD QUALITY CONTROL

DETERMINATION OF ACIDITY,PEROXIDE AND COLOR TEST OF FRIED OIL

PREPARED BY:   ŞEYMA MARANGOZ           

MEHTAP KEKLİK

İREM DEMET KODAŞ

DUYGU KÖKALP

EMİNE KÜÇÜKOĞLU

ŞEYMA KURTBEYOĞLU                                                              

SUBMITTED TO:PROF.DR.FAHRETTİN GÖĞÜŞ

WHAT IS THE FRYING?     

WHAT  ARE THE  QUALITY TESTS IN FRIED OIL?

FRYING

Frying is the cooking of food in oil or another fat, a technique that originated in ancient Egypt around 2500 BC.

Frying is used to improve quality of taste and consummability of the food.

DEEP FRYING

Deep frying is a cooking method in which food is submerged in hot fat, most commonly oil.

Deep-frying is a cooking process, with which water containing foodstuff is immersed into edible oils or fats at temperatures between 140 – 180 °C.

In the first phase, within a few seconds, a thin crust forms, whose structure crucially affects the deep-frying process and the quality of the food with regards to fat absorption and crispness.

Factors Affecting the Quality of Oil during Deep Frying

  • Replenishment of fresh oil

  • Frying time and temperature

  • Quality of frying oil

  • Types of foods

  • Types of fryer

  • Antioxidants

  • Dissolved oxygen contents in oil

PHYSICAL AND CHEMICAL PARAMETERS OF FRYING OIL

DETERMINATION OF ACIDITY  OF FRIYING OIL

WHAT IS THE ACIDITY?

Acidity is a result of hydrolysis of oil from the triglyceride structure.

WHY DOES ACIDITY INCREASE ?

  • Free fatty acid is an important index for oil quality and shelf life of the oil

Acidity increases as free fatty acids occur from the hydrolysis of oil.

  • The increase in free fatty acids means that oxidation stability decrease

  • It is one of the important indicators for that rancidity of oil will start

PROCEDURE OF ACIDITY

Weigh 5 g of oil and transfer it into 300 ml conical flask

Add 50 ml of alcohol -ether solution to the oil solution

At the end of the dissolution  add 1 or 2 drops of phenolphthalein indicator.

Titrate this against the 0.1 N KOH solution from the

burette.

The appearance of pink color indicates the end point

CALCULATION OF ACIDITY EXPERIMENT

                                    Vol. of KOH*2.8

Acidity(%oleic acid)=

                                    wt of sample (g)

DETERMINATION OF PEROXIDE IN FRYING OIL

  • The most common test for the determination of oil oxidation is peroxide value (PV).

  • It is a parameter representing the extent of oxidation

WHAT IS THE PEROXIDE ?

Peroxide is a compound that formed from triglyceride and not stable.

Oil oxidation is an undesirable series of chemical reactions involving oxygen that degrades the quality of an oil.

WHICH PARAMETERS EFFECT PEROXIDE VALUE?

Temperature

Oxygen exposure

Light

Moisture

Transition metals,

PROCEDURE OF PEROXIDE VALUE

Weigh 3,5 g of oil and transfer it into 250 ml erlenmayer flask

Add 30 ml of chloroform-acetic acid solution to the oil solution

Add 1 ml of KI into solution

Wait 5 min this solution at dark environment

After waiting,add 75 ml of distilled water and 1 ml starch

solution.(If dark color is observed,solution has peroxide)

Titrate this against the 0.002 Na2S2O3solution from the burette

until the red color observed.(brick red)

CALCULATION

                                        V*2.8

Peroxide value =

                               wt of the sample (g)

   V:Consumed 0,002 N Na2S2O3
Color

Color formation in oils during frying is one of the most noticeable degradation reactions that occur in the frying oil.

To control the condition of the natural color of the pigment in the composition of the oil.

To control the bleaching process perform correctly.

COLOR

  • Different oils darken at different rates

  • Oils with more natural anti-oxidants will darken more than oils with lower levels of natural anti-oxidants

Protein products caused both the fastest darkening and thermo-oxidative deterioration of the frying oil.

HOW TO COLOR MEASURED?

The HunterLab  L*,a*,b* commonly used in the food industry.

The systems measure the degree of lightness (L),

     The degree of redness or greenness (+/-a), and

     The degree of yellowness or blueness (+/-b).

ACIDITY AND PEROXIDE VALUES ACCORDING TO TSI

CONCLUSION 

Acidity increases depending on the frying time which causes the rancidity in oil. Result of the rancidity unpleasant odor and flavour occurs.

Peroxide shows variability depending on the time.

L value of color is different for standards.This may stem from added some sunflower oil during frying process.

EFFECTS ON HEALTH

  • Reusing oil is that can create free fatty acids, ketones, aldehyde etc. which cause ailments in the long run

  • This type of frying oil indicate mutagenic and carcinogenic effects which are caused the health problems .


Good Manufacturing Practice – GMP ( Leila KAKKO )

World Food Programme

 “Food quality control is necessary to ensure that food aid supplies are safe, of good quality and available in adequate amounts, in time, at affordable prices to ensure an acceptable nutritional and health status for all population groups”

 Food Quality Systems – HACCP, GMP, ISO & Codex Alimentarius

Source: http://www.mf.uni-mb.si/mf/instituti/IPweb/html/KakkoL%20GMP%20in%20food.pdf

Laboratory‎ > ‎Analysis of Flour ( Hüsametin KİRAZ )

FE 376 FOOD QUALITY CONTROL

LABORATORY REPORT

Experiment: Analysis of Flour

· Determination of Ash in Wheat Flour

· Determination of Crude Gluten in Flour

· Acidity of Wheat Flour (water extract method)

· Detection of Soy Flour in Wheat Flour

· Moisture Content of Wheat Flour

Submitted to: Asst.Prof.Dr. EMİNE (ALBEN) ERÇELEBİ

Submitted by: Hüsametin KİRAZ

Submitted date: 19/11/2012

Purpose:

The aim of this experiment we learning quality parameters of flour by looking amount of ash, calculate grude gluten, acidity flour,detection of soy flour, moisture content of flour in wholewheat, bread flour and cake flour.

Theory:

The wheat and flour tests described in this section are standardized testing procedures commonly used for quality control purposes. Results from these tests have a direct relationship to finished product quality. Wheat and flour specifications are communications between buyers and sellers. These specifications are requirements for particular wheat and flour characteristics. To meet these specifications, wheat and flour quality testing is necessary. Specifications for moisture content, ash content, protein content, and falling number are determined with basic tests.The laboratory millingtest is used to evaluate the milling performance of wheat and to produce flour for otherlaboratory tests. Wheat and flour specifications often require specialized testing to determine howflour will perform during processing. Several tests evaluate dough and gluten strength properties. The farinograph and mixograph tests measure the resistance of dough to mixing. The extensigraph test measures the resistance of dough to stretching. The alveograph test measures the resistance of a bubble of dough to expansion. The wet gluten test measures the amount of gluten protein in flour. The starch properties of flour are measured by the amylograph and the rapid visco analyzer tests.

Laboratory‎ > ‎Analysis of Wheat Flour ( Ahmet DEMİRCAN )

FE 376

FOOD QUALITY CONTROL

ANALYSIS OF WHEAT FLOUR 

                           Submitted to:     Emine ERÇELEBİ

                           Submitted by:      Ahmet DEMİRCAN

PURPOSE:

            The aim of this experiment was to consider the standard content of flour by doing main analysis.

THEORY:

         Wheat quality and methods in wheat quality determination is important. Determination of the quality of bakery products which have significant position in the food industry and nutrition is necessary from the point of product features and economic view. However, the choosing appropriate raw material according to that appropriate quality of wheat/flour/semolina is very important to produce products such as bread, biscuit etc. Beside that methods and analysis which are used to determine the quality must be applied exactly and results must be well evaluated by the aid of good qualified technical person and equipment. Nowadays the importance of technical person, equipment and methods for determination of quality is accepted by the consumers and producers.

Wheat is important than other grain. Because;

1-It is raised in large area due to fit different climate and earth condition.

2-high yield and easy agriculture

3-easy storage and high nutrition value

4-when wheat flour is contact with water, protein particles in flour form gluten (wet germ).No grain’s protein except wheat form wet germ.

Wheat Kernel

Wheat kernel contains some layers, germ, endosperm, aleuron layer, bran, outer kernel layer. The germ and bran are removed from the kernel when white flour is milled, even though they contain nearly all the fiber and B vitamins; they are removed because they also negate the elastic properties of the gluten, which is so vital to the texture and crumb of the bread.

The percentage of total product in any desired fraction of flour is called extraction. In other words, straight grade flour that is %72 of the total product is % 72 extraction flour. The composition of flour with various percent extractions is given:

Approximately composition of flour

Component

Flour

(72%)

Flour

(80%)

Whole meal

(95-100)

Wheat

Germ

Wheat

Bran

Moisture (%)

13-15

13-14.5

13-14

9-12

14

Protein (%)

8-13

8-14

10-15

25-30

12-16

Fat (%)

0.9-1.4

1-1.6

1.5-2.5

8.5-11

3-4

Carbohydrate (%)

65-70

64-70

60-68

39-45

Fibre(%)

0.1-0.3

0.2-0.4

1.8-2.5

2-2.5

9-12

Ash (%)

0.3-0.5

0.6-0.9

1.2-2.0

4.0-4.5

4-6

 

            Wheat that is between the bread and pastry types are used for cracker, doughnut, and all purpose flour. There are physical and chemical test of flour. These:

            Physical Tests: including test weight, kernel hardness, gluten washing, density, internal infestation evaluation, thousand kernel weight, pearling index, granulation and particle size.

            Chemical Tests: Moisture, ash, and protein tests are the most widely used on wheat. The kjeldahl protein test normally is made on al hard wheat. To report protein content on uniform moisture basis, the moisture lost is necessary. Miller and Johnson (1954) state that moisture is related to quality of wheat and flour in at least three ways:(1)flour yield varies inversely with moisture content (2)composition percentage are inversely related to percentages of moisture  present; and(3)deterioration of grain during storage may depend on the moisture relationships in the wheat kernel.

            The ash test is significant as a way to determine flour grade. Since the ash content of bran is about 20 times that of endosperm; the ash test indicates how thoroughly bran and germ were separated from the kernel endosperm. There is considerable variation in the amount of mineral matter in wheat, depending on the class of wheat and the area it was grown; therefore, the ash test is often applied to wheat as well as to flour.

            Color tests, such as the Pekar or the slick test, also are used to judge milling results or flour grade, and recently photo electric methods such as the Agtron for assessing flour color have come into use. Many attempts have been made to appraise wheat quality on the basis of the amino acid composition of wheat gluten. Determining the amino acid composition of wheat is no longer a tedious and expensive procedure, but pence 1950 failed to show essential differences in the amino acid content of 17 flours milled from different varieties and types of wheat.

            Starch damage is a subject of recent concern to wheat processors and to the baker. The extent of starch damage alters flour characteristics and end use.

            The amylase activity of wheat and flour are measured by the Falling Number test, Blish-Sandstedt method, and the amylograph. The description of those tests and other mentioned can be found in Cereal Laboratory methods (1962) and wheat and wheat technology.

            Variental Differences in Gluten Quality: Many techniques have been developed to separate gluten from the other constituents of wheat flour. The washing-out process can be done by hand or mechanically. A quantitative test consist merely of weighing the gluten either wet or after being dried, but estimating gluten quality is a more difficult matter.

            The measurement of gluten quality has been based on four general principles, namely; expansion by heat, recovery from compression, and gluten extension and gluten relaxation of gluten.

            Although there is agreement that many properties of dough are due to the gluten component of flour, most cereal chemist in the United States prefer to study the properties of dough rather than to separate gluten and thus attempt to appraise quality. Regardless of the methods used, differences in gluten properties between classes and varieties of wheat are obvious

The production of flour affects quality of making bread. Therefore, before production of flour, suitable wheat must be selected firstly and analyzed in laboratory. Hence, produced flour is both high in quality and suitable for quality.

The flour production is made three different type of wheat;

·         Triticum durum: for macaroni

·         Triticum aestivum: for bread

·         Triticum compactum: for biscuit

 Some criterions very important for flour;

·         amount of protein and quality

·         amount of normal starch and damaging starch

·         moisture content

·         amount of aflatoxin

·        amount of alpha amylase

 

MATERIALS:

·         Bunsen burner

·         Porcelen cruise

·         Desiccator

·         Oven

·         Flour

·         Analytical scale

·         Beaker

·         Conical flask

·         Water bath

·         Filter paper

·         Phenolphthalein

·         Test tubes

·         2 % urea solution

·         0,05M NAOH  solution

PROCEDURE: 

  • Determination of Ash in Wheat Flour

2 g of flour was weighed in to a well-dried porcelain evaporating dish.Then it was heated gently on a Bunsen burner and the dish was ashed at 550-570°C.After two hour the dish was transerred to a dessiccator,was cooled and weighed.Finally the total ash was calculated as a percentage of the sample.

  • Determination of Crude Gluten  in Flour

25 g of flour and 19 ml of water was added in a mortar,the mixture was worked with a spatula.The dough was kneaded gently under a water tap for 10-15 min.The solid matter under water was placed.Finally it was compressed as dry as possible,was rolled into a ball,and the moist gluten was weighed and it was expressed as a percentage of flour.Also its color,toughness and elasticity were noted.Then it was dreid at 100°C to a constant weight,it was weighed and expressed as a percentage of flour.

  • Determination of Acidity  in Wheat Flour

18 g of flour with 200 ml of CO2-free water was shaken in a conical flask.Then it was placed in a water bath at 40 °C for 0,5 h with the flask loosely stoppered.100 ml clear filtrate with 0,05 M NaOH solution was filtrated and titrated by using phenolphthalein as an indicator.:It was calculated as a lactic acid or KH2PO4.

  • Detection of soy flour in wheat flour

0,5 g sample with 5 ml of 2 % urea solution was mixed in a test tube.A strip of red litmus paper was immersed in the liquid.The test tube was stoppered and heat in a water bath held at 40 °C for 0,5 h.If soy flour is present in more than traces ,the litmus paper will turn to blue.

  • Mositure Content of Wheat Flour

  • 2 g of sample was weighed out accurately into a pre-dried nickel or steel dish ,spreading the sample as thinly as possiblke over the base of the dish.The dish was put and  the contents was maintaned at 105°C,and was dried for 2h.Then it was removed ,was cooled in a dessicators and was weighed.drying was continued until a constatn wight had been reached.FinallyThe moisture content was calculated from the weight loss of the sample.

 RESULT AND CALCULATİON:

 

 Moisture content of wheat flour:[(2-(57,6-55,874))/2]*100: 13,7 %

     

Ash content of wheat flour  : [(27,4152-27,3852)/2]*100 : 1,5 %      

              % wet gluten [(7,54)/[25*(100-13,7)]]*100 : 0,35 %

          % acidity(KH2PO4 in dry matter): [(1,36*1,4)/(18*(100-13,7))]*100:0,13 %

          % acidity (lactc acid in dry matter):[(0,9*1,4)/(18*(100-13,7))]*100:0,08 %

DISCUSSION:

            In this experiment, we made moisture, ash, crude gluten, detection of soy flour and acidity analysis of different types of flours. We should compare our samples with TS 4500.

But we should understand and learn limitation of quality standards and Why is important for human health. For instance; the moisture content of flour is an important point for us. Our sample is suitable for moisture content according to TS 4500 because it should not be over limit %14.5.

The reason of moisture content can be many such as climate, wet and temperature of warehouse or rain harvest. More wet amount cause a problem during milling.

One other way of quality determination is ash of sample. Obtained result by at the end of experiment is 0.85%. The percentage amount of Bran is higher with compare to normal flour. Because inorganic matter diffuses quickly into Bran, then they diffuse inside wheat particles. So, inorganic matter exists in low amount at center of wheat particles. Ash content of bran mixed is suitable for TS 4500 because maximum value is 0.85 for “under semolina flour”.

Also an important quality analysis is gluten amount determination of flour and bran. If gluten amount of flour is high sufficient, this is very well. Because this effect swelling of bread during fermentation of yeast in it. At the end of reactions CO2 gases is produced during fermentation. In this event, gluten service to hold to coming out CO2 gases. Dry gluten result of sample, according TS 4500 it should not be under 9%. Our result is much higher than this value.

The other important parameter is detection of soy flour. We analyzed the flour, and there was no change in color at litmus paper. So we can say that this flour does not contain soy flour which is illegal in Turkey.

Sensory Analysis ( Betül ÖZDEMİR )

T.C.

UNIVERSITY OF GAZİANTEP

FACULTY OF ENGINEERING

DEPARTMENT OF FOOD ENGINEERING

    FE 376 FOOD QUALITY CONTROL LABORATORY 

Experiment Name:  “Sensory Analysis”

Submitted to: Asst.Prof.Dr. ÇİĞDEM ( AYKAÇ ) SOYSAL

Submitted by: Betül ÖZDEMİR

                          Başak Koç

                          Hüsamettin KİRAZ

                          Mustafa MUTLU

PURPOSE

The purpose of this experiment was application of triangle test for different kind of yogurt to find out a detectable difference between two similar yogurt.

THEORY

Sensory analysis (or sensory evaluation) is a scientific discipline that applies principles of experimental design and statistical analysis to the use of human senses (sightsmell, taste, touch and hearing )for the purposes of evaluating consumer products. The discipline requires panels of human assessors, on whom the products are tested, and recording the responses made by them. By applying statistical techniques to the results it is possible to make inferences and insights about the products under test. Most large consumer goods companies have departments dedicated to sensory analysis.

All sensory testing methods are divided into three categories: hedonistic, comparative and descriptive testing. Hedonistic tests are always used within the scope of consumer tests and serve to characterize consumer behavior. On the other hand, comparative and descriptive sensory tests are referred to as “expert tests” because they may only be carried out by trained persons and can give very detailed information about individual product parameters. Selection of a sensory testing method must always take into account the test objective.

The most common sensory testing method is triangle test. The triangle test is a discriminative method with many uses in sensory science including:

·         gauging if an overall difference is present between two products

·         selecting qualified panelists for a particular test

·         determining whether shifts in processing or ingredients have significantly changed a product.

During a triangle test, a panelist is presented with one different and two a like samples. If possible, all three samples should be presented to the panelist at once, and the panelist should be instructed to taste the samples from left to right. The six possible order combinations should be randomized across panelists. For samples A and B, the six possible order combinations are: AAB, ABA, BAA, BBA, BAB, and ABB. The panelist is instructed to identify the odd sample and record his answer.

DISCUSSION

      Sensory is an analytical method where the human senses are a sample of testers. Sensory analysis testing is used considerably in the food industry for product development. It also plays a key role in quality control and in the marketing of products.  Many types of sensory analysis tests have been devised to fulfil a number of specific objectives.  These tests are grouped into three categories. Preference test, Difference test, Descriptive test.

         Preference tests are used in the food industry to determine: if consumers like a product, if one product preferred over another and if consumers intend to use a product. Difference test are used to detect small differences in foods. Difference tests are used in food industry to answer some of the following questions: Does a difference exist? Would people notice the difference? How would you describe the difference? . Descriptive tests are used to describe the perceived sensory characteristics of products. Descriptive tests can be used in the food industry to answer some of the following questions: what does the product taste like? What are its perceived sensory characteristics / attributes? How does a change in processing / packaging / storage conditions affect the sensory quality of this product? And Triangle test; Tester is presented with three coded sample, two samples are the same, one is different, tester is required to identify the sample that is different.

We did triangle test in this experiment. A triangle test is a discriminative form of a sensory analysis. its results first’ Indicate whether or not a detectable difference exists between two samples.’ For this reason it is often used to ”in quality control to determine if a particular production run meets the quality control standard.”. To carry out the experiment the panelists must be provided with three coded samples of the products being tested. Two of the samples must be from the same product and panelists must pick the odd one out. The panelists must also be provided with another food or beverage to cleanse their palate and to minimize the cross contamination of different sample flavors in the mouth. In addition, there are nine possible errors which could influence a triangle test: · Expectation error: This error occurs when the panelists are given more than enough information about the test before actually doing it. Too many facts or hints cause panelists to make a judgment on expectation rather than intuition. For this reason it is important provide only the facts necessary to complete the test. 

            As a result this test (triangle test) is depends on the people. For this reason, we can taste different from the same sample. For example someone feels salty but someone feels spicy on the same sample. According to some people find strong acidic, some people find low acidic. For these result we should choose panelist very carefully.

References:

*http://www.sensorysociety.org/ssp/wiki/Triangle_Test/

*http://www.wildflavors.com/?fuseaction=home.viewpage&page_id=D7EA3E55-D949-D6C2-A8022A4387E6C37B&r=1

*http://en.wikipedia.org/wiki/Sensory_analysis

Licorice Syrup

FE 376 FOOD QUALITY CONTROL LICORICE SYRUP

Licorice is the root of glycyrrhiza glabra from which a somewhat sweet flavor can be extracted. The licorice plant is a legume that is native to Southern Europe and parts of Asia. It is not botanically related to anise, star anise, or fennel, which are sources of similar flavouring compounds.
The licorice plant is part of the pea family and is found in Turkey and Greece, although it is propagated in many parts of the world.

This herb contains

FLOW CHART OF LICORICE SYRUP

ANALYSIS OF LIQUORICE

Determination of moisture
Determination of total sugar
Determination of ash
Determination of BRIX
Determination of number of diastase
Microbiogical determination

HMF ANALYSIS BY SPECTROPHOTOMETER

REFERENCES