Quality Test of Flour

FST 202 FOOD QUALITY CONTROL

TITLE NAME ID NUMBER

: QUALITY CONTROL OF TEST FLOUR : NURFADHILAH BINTI JAAFAR : 2013698078

GROUP

: AS 1165A2

SUBMITION DATE

: 31TH JUNE 2015

LECTURER’S NAME: MADAM MARDIANA BT AHAMAD ZABIDI

INTRODUCTION

The production of flour has been discovered from a long time ago and there is variety of flours sold in the market. Wheat is a grass that is cultivated and harvested worldwide and scientifically known as Triticumm spp which is the second most essential food after rice. It is also commonly distributed in the form of packed cereal grains or for the production of flour which the grains will undergo the grinding and sifting process to obtain the powdery form of flour. A kernel of wheat consists of kernel, endosperm, bran and germ and the type of wheat is classified according to the texture of endosperm and the protein content. The breakdown of grain during milling process depends on the texture of endosperm while the protein content plays an important role related to the properties of flour. Wheat flour provides the several essential nutrients that can fulfil the requirements to our body; however people nowadays are more concern about the high protein and gluten-free flour which is low in carbohydrate. Carbohydrate is the major components in the wheat flour and it also rich with vitamin, minerals and protein. Source of the energy can be provided from carbohydrates and the protein content in the wheat flour serves as the amino acid as the sign for the chemical in body systems. Micronutrient, such as vitamin B helps to improve the body metabolism, cell and body tissue. Convenient store, hypermarkets or supermarket provide the consumer with various type of flours for a different purpose. Type of flour that available in the market are hard wheat flour, soft wheat flour, whole wheat flour, rice flour that is comes with specific usage. The flour is chosen based on several factors which are based on the protein content and the gluten texture that may affect the production quality of baked goods and other food products. Wheat flour needs to undergo the physical and chemical test which is important for the quality control purposes. The chemical analysis conducted consists of pH determination and the acidity of the wheat flour and the microscopic examination, flour infestation are for the physical tests. The wheat hardness influences the protein content. The harder the wheat the higher its protein content in the flour and hard wheat flour is suitable for bread making. Besides that, the soft wheat flour is best used for cakes, cookies and pastry making which produce tender and crumple textures with lower protein content compared to the food products made up from hard wheat flour.

Whole wheat flour is rich in fibre and vitamin such as potassium, zinc and magnesium. Regular whole wheat flour can also be used for the baked goods such as pizza, flatbreads and

cookies. However, when making those, the amount of whole wheat flour must be used in the appropriate amount since not all the baked goods ideal with the whole wheat flour. Rice flour is completely gluten- free and gives a slightly sandy texture to the baked goods which is commonly used as a base ingredient for bakery products. The small usage of rice flour in baked goods can give a crumbly, tender and a mouthful taste.

RESULTS A. pH of the wheat flour

Types of wheat flour Cap Sauh Cap Lili

pH 5.95 6.17

B. Acidity Cap Sauh Wheat Flour 1 mL 0.05 M Na OH = 0.0068 g KH2PO4 KH2 PO4

=

61.7 . × 0.0068 ×100 18 g

=2.331 Cap Lili Wheat Flour 1 mL 0.05 M Na OH = 0.0068 g KH2PO4 KH2 PO4

==

47.9 ×0. 0068 ×100 18 g

=1.809

C. Microscopic Examination (Wheat, rice, corn and tapioca flour. a) Wheat flour

Wheat starch granules surrounded in a continuous matrix with oval and spherical shape. The striations present are slightly visible in large granules while the hilum is shown as a circular spot.

b) Rice flour Starch granules of rice flour are very small with oval and round shape. It tends to agglomerate in round and irregular to form a cluster.

c) Corn flour The granules are irregular, round and may have irregular shape and aggregations. Striations are very distinct and the hilum shown in the centre of granules and it may be shown in a crack form.

d) Tapioca flour It belongs to medium size granules with irregular shape. It can also be D. Flour Infestations seen from spherical, polygonal to dispersed shape. There is a few discrete the hilum Types of flour Cap Sauh hilum, and many CapofLili is stellately fissured. Infestation No No

DISCUSSIONS Flour is commonly described as a fine powder, made from wheat that is being used for cooking especially for the production of baked goods. Flour is being customized on the processing industry or for grocery trade. The quality of flour need to be control, therefore, in this practical we conducted the physical and chemical test. The physical tests conducted are the microscopic examination and the flour infestations while the chemical test are whereby the determination of pH and acidity. Cap Sauh and Cap Lili flour were being used for both tests. Based on the pH results it shows that Cap Lili with pH 6.17 while Cap Sauh is 5.95. The wheat flour usually have the pH ranging between 6.0- 6.8 and the average pH of fresh flour is 6.12. The pH of flour is distinctly differing due to the chlorination stage during the flour production. Both Cap Sauh and Cap Lili are slightly acidic as white flour usually undergoes the chlorination process. Some unbleached flour may become acidic over time and additional of additives in bleached flour keep them fresh over a long period. The freshness of the flour depends on its acidity. Next, we did the determination of acidity on both flours by titration process. Cap Sauh has the slightly higher acidity with value (2.331) compared to Cap Lili (1.809). During the storage of the flour, fat and phosphotides are broken down enzymatically and promotes by the factor of high water content, temperature and high degree of extraction. This enzymatic breakdown activity is acceptable for maturation of the flour to a certain extent, however once the tolerance exceed, the flour may become inedible for usage. The results of microscopic examination for the wheat, rice, corn and tapioca flour are simply described on the results attachment. A very dilute iodine solution is added to the sample under the cover slip when there is any doubt to determine the particular grain or starch. The illumination need to be modified in order to observe more clearly image of striations and hilum. Based on the result, there is no presence of infestations on both flours after leaving them flattened after 2 minutes. There was no evidence of pimpling or surface distribution on the flours. Pimpling on the flour indicates the presence of mites breaking the surface due to the lack of the oxygen in flour thus; the mites are looking out for more oxygen.

CONCLUSIONS In conclusions, Cap Sauh flour has the higher acidity value (2.331) with low pH (5.95) compared to Cap Lili flour with acidity value (1.809) and high pH (6.17) which closes to natural pH. From microscopic examination, wheat flour consists of spherical and oval shape of granules and rice flour have smaller granules aggregates in irregular and spherical shape. Both corn flour and tapioca have irregular and spherical shape and belong to medium class size of granules but tapioca flour granules have few discrete hilum, and many of the hilum is stellately fissured. Lastly, there is no infestation evidence such as pimpling and surface disturbance by mites on both Cap Sauh and Cap Lili flours.

QUESTIONS 1. What are the major functional ingredients in flour which gives strength and structure to baked products? The major functional ingredient in flour is the gluten protein which gives strength and unique elastic properties and the structure to baked products. Gluten consists of gliadin and glutenin which when they bind together due to chemical reaction, they stretch and become harden. The amount of gluten can be simply measured by washing out the starch from a small ball of dough under running water and the remaining left is the gluten protein.

2. Why does incoming flour should have a moisture content of not more than 14%? The incoming flour should have moisture content of not more than 14% to reduce the risk of moulds, insect infestation and to avoid the rancidity during storage. Lowering the moisture contents can made the flour safe to store and the mould would have only minimum requirement for their growth to produce the mycotoxins. 3. What is starch gelatinization? What happens to the starch granules at very high temperature? Starch gelatinization is a reaction when the starch and liquid is combined together with heated conditions, the individual starch granules absorb the liquid and swell, which causes the liquid to thicken Gelatinization, occurs at different temperatures for different types of starch. Root-based starches such as potato thicken at lower temperatures but

break down more quickly, whereas cereal-based starches like corn and wheat thicken at higher temperatures but break down more slowly. Gelatinization can be inhibited by the high levels of sugar or acid while the presence of salt can promote the reaction.

REFERENCES 1. Fellows, P., & Axtell, B. (1995). Quality assurance for small-scale rural food industries (p. 44). Rome: Food and Agriculture Organization of the United Nations. 2. Pant Sharma, V. (2011, May 19). Bakery Series : 3: Chemical Analysis of Wheat Flour. Retrieved June 27, 2015, from http://foodpathshala.ning.com/profiles/blogs/bakeryseries-3-chemical 3. Food Science Basics: Effects of Heat on Starches and Sugars. (2014, March 13). Retrieved June 27, 2015. from http://chefsblade.monster.com/training/articles/215-foodscience-basics-effects-of-heat-on-starches-and-sugars

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