Img 203: Food Chemical analysis
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This document discusses the analysis of ingredients and processing of dry yellow noodles. It outlines the main ingredients of wheat flour, salt, and colorant. Tests described include analyzing wheat flour for sulphur dioxide, oil used during frying for acid content, moisture content and pH of the final product. Suggested additional tests include determining gluten content using the AACC method and protein content using combustion nitrogen analysis.
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Img 203: Food Chemical analysis
- 1. IMG 203: Food Chemical Analysis Group Members: 1. Siti Nadzirah Binti Md Supar 2. Nurul Alia Binti Nordin 3. Amalia Haziqah Binti Khairuddin 4. Wan Nur Hafzan Binti Wan Musa
- 2. DRY YELLOW NOODLE Main ingredients: 1. wheat flour 2. salt 3. colorant permitted (tartarazine) Product Description -firm and elastic texture -have a chewy in texture -before cooking - have hard and dry texture
- 3. Flow processing Solution preparation Mixing Sheeting/ Cutting Frying Draining Weighing Packaging
- 4. Raw Ingredients 1. Wheat flour 2. Salts 3. Tartazine
- 5. Test on Raw Ingredients Wheat flour Modified Monier-William Method To ensure that the sulphur dioxide content in the wheat flour is within the range considered suitable for consumption. Principle As in the Monier-Williams method, samples are treated with acid and heated to release SO2. A nitrogen carrier gas sweeps the SO2 through a reflux condenser and into the S Coulometer cell. The S Coulometer automatically titrates the SO2 and digitally displays the amount.
- 6. Test during Processing Oil used Why? Because the lipid polymers in fried oils, and recently acryl amide formed in high carbohydrate fried foods has joined the scare-wagon. Principle Free fatty acids of the sample, at pH<7.0, react with a chromogenous compound and decrease its colour. The decreasing of colour, read at 630 nm, is proportional to the acid concentration of the sample, expressed as % of oleic acid. The acid content of edible fats is given by the quantity of free fatty acids deriving from the hydrolytic rancidity of triglycerides.
- 7. Test on Final Product Moisture Why? To determine the water activity of the dried noodles to ensure it is stable and will not spoil easily while in storage and make sure that the moisture content of dried noodles does not exceed the safety value of 10%. Using oven drying method.
- 8. Test on Final Product pH value Test acidity using Mettler-Toledom Delta 320 pH meter. pH meter measures the pH by using an electrode cell composed of two electrodes dipped into the sample solution. A voltage develops due to the ionic concentration of the sample Why? To make sure the pH value of dried noodles does not exceed 6.0-6.5.
- 9. Test on Final Product Shelf life By sensory evaluation. To determine how long dried noodles can be stored. Tested by a sensory evaluation assesses a food’s smell, appearance, flavour, and texture. It can be used to monitor and record obvious changes that occur over time. Useful when determining the shelf life of a food. The food should be assessed under the conditions at which it is designed to be stored and consumed.
- 10. Suggestion method 1. Gluten – AACC method 38.10.01 2. Test on protein - Combustion Nitrogen Analyses (CNA)
- 11. Method Gluten – AACC method 38.10.01 1. 25 gram flour is kneaded with about 15 ml water to make a dough ball. 2. The dough ball is allowed to immersed in water for one hour to ensure hydration. 3. After this the starch is washed out by kneading gently in a gentle stream of water over a fine sieve of silk till the washed liquid is clear. 4. The cohesive gluten obtained is pressed as dry as possible & then weighed. 5. The wet gluten so obtained is then dried at 1000 C for 24 hr. and weighed again to get the value for dry gluten.
- 12. Test on protein - Combustion Nitrogen Analyses (CNA) Method 1. A sample of flour or ground wheat (0.15 to 0.20 grams) is weighed and placed into a CNA protein analyzer. 2. This process is fully automated and begins by dropping the sample into a hot oven where it is burned at 952 degrees Celsius. 3. The amount of nitrogen gas released during burning is measured and a formula is applied to convert this measurement to protein content in the sample.
Editor's Notes
- According to Food Act 1983(ACT 281) & Regulations, the sulphur dioxide or sulphites as a permitted food conditioner not exceeding 200 mg/kg. For this food product, sulphur dioxide act as bleaching of sugars.
- Results Gluten in a sample can be estimated by washing the dough free of starch, sugars, water soluble proteins, and other minor components. The wet cohesive mass obtained is wet gluten while the dried product obtained from it is called dry gluten Importance It helps to understand the gluten content in flour and thereby selection of flour as per the product to be manufactured.
- Results • Protein content is determined through high temperature combustion in a protein analyzer. Since protein is the major wheat compound that contains nitrogen, the protein content can be determined by measuring the amount of nitrogen released during burning. • Protein content results are expressed as a percentage of the total sample weight; for example, 10 percent protein content on 12 percent moisture basis for wheat or 8.5 percent on 14 percent moisture basis for flour. Why is this important? Protein content is a key specification for wheat and flour purchasers since it is related to many processing properties, such as water absorption and gluten strength. Protein content also can be related to finished-product attributes, such as texture and appearance. Low protein content is desired for crisp or tender products, such as snacks or cakes. High protein content is desired for products with chewy texture, such as pan bread and hearth bread. Bakers use protein content results to anticipate water absorption and dough development time for processes and products, because higher protein content usually requires more water and a longer mixing time to achieve optimum dough consistency. Combustion Nitrogen Analysis (CNA) is often used to develop calibrations for other protein methods, such as Near Infrared Transmittance (NIRT) or Near Infrared Reflectance (NIRR). Adapted from Method 46-30, Approved Methods of the American Association of Cereal Chemists, 10th Edition. 2000. St. Paul, MN.