Experiment 2: Food Test Introduction Food is a type of chemical test that use to determine the chemical molecule which commonly found in the food. These biological molecules include sugar, protein and starch. Sugar can be classified in to 2 groups which are reducing sugar and non reducing sugar. Examples of reducing sugar are glucose, fructose, galactose and maltose. While the non reducing sugar in this experiment is sucrose.
It can be expected that once amylase reacts with the starch, maltose will then be broken down and less starch will be visible and more sugar will be apparent thus causing the solution mixed with iodine to become lighter and lighter. Materials and Methods Materials included: · · Rack of test tubes · Three spot plates · Hot plate · Large beaker for water bath · Amylase · Disposable droppers · Marker · Starch solution · Distilled water · IKI(dropper) · Benedict’s solution Method/Procedure 1. Identification of Starch To be able to identify the presence of starch, it was necessary to make a sample test by using IKI in wells on the spot plate. Three wells on the spot plate were filled with one drop of IKI each. In the first well two drops of water was mixed with the IKI to show what a negative
Escherichia Coli is a large, diverse group of bacteria of the Enterobacteriaceae family. A German physician named Dr. Theodore Escherich discovered it in 1885. The genus is composed of gram-negative, aerobic, facultatively anaerobic, non-spore forming rods. The organism’s usual habitat is the digestive tracts of humans and animals. Escherichia Coli is a beneficial function in the human body because it synthesizes useful vitamins such as Vitamin K. E. coli also acts as competition in the intestine by suppressing the growth of pathogenic bacteria that may be present or ingested.
It is produced by the fermentation of sugars with yeast and is concentrated by distillation to be used as fuel. The fermentation of starch involves the starch being converted into a sugar so it needs to be broken down to simpler glucose molecules through hydrolysis. Starch is converted enzymatically to glucose by an enzyme called amylase. The enzyme is a biological catalyst which speeds up the rate of the reaction. The resulting dextrose from the starch is then fermented into ethanol with the aid of yeast which produces carbon dioxide.
Introduction PART 1 In 1883 Hans Christian Gram discovered an important differential staining method that is used extensively today. The stain is called the Gram Stain. This staining procedure differentiates microbes into two basic groups: Gram positive microbes and Gram negative microbes. Gram staining consists of four components: * Primary stain (Crystal violet, methyl violet or Gentian violet) * Mordant (Gram's Iodine) * Decolourizer (ethyl alcohol, acetone or 1:1 ethanol-acetone mixture) * Counterstain (Dilute carbol fuchsin, safranin or neutral red) Procedure : 1. Prepare the smear and heat fix it.
Introduction: As implied by the name "lactic cultures," belong to a category of microorganisms that can digest the milk sugar lactose and convert it into lactic acid. For the cells to utilize lactose, deriving carbon and energy from it, they must also possess the enzymes needed to break lactose into two components sugars: glucose and galactose. Some representative strains are Streptococcus lactis, S. cremoris, thermophilus, Lactobacillus bulgaricus, L. acidophilus, and L. plantarum. These cultures can be purchased directly from local health food and drug stores in tablet form. These tablets, taken orally during the intake of dairy products, help those people who have digestive tract disorder and cannot tolerate lactose.
Aim: To investigate on the activity of catalase. Introduction Catalase, an enzyme found in many different tissues, catalyses the breakdown of hydrogen peroxide into water and oxygen. 2H₂O₂ → 2H₂O + O₂ Hydrogen peroxide is a toxic substance that can be formed during aerobic respiration and catalase removes this product. The activity of catalase can be measured by finding the rate of oxygen release from hydrogen peroxide. Minced potato provides a suitable source of catalase and the pH is varied in this experiment using citric acid-sodium phosphate buffer solutions at pH values of 4.4, 5.2, 6.5, 7.5 and 9.
The most common probiotic bacteria come from two groups, Lactobacillus or Bifidobacterium, although it is important to remember that many other types of bacteria are also classified as probiotics. Each group of bacteria has different species and each species has different strains. This is important to remember because different strains have different benefits for different parts of your body. For example, Lactobacillus casei Shirota has been shown to support the immune system and to help food move through the gut, but Lactobacillus bulgaricus may help relieve symptoms of lactose intolerance, a condition in which people cannot digest the lactose found in most milk and dairy products. In general, not all probiotics are the same, and they don’t all work the same way.
The peroxide value (PV) test, which is one of the most common tests used to evaluate the extent of lipid oxidation, is based on measuring peroxides. Objective: To measure the PV or a number of food samples, and to evaluate the meaning of the results. Reagents: Acetic acid (glacial) Chloroform (CCl4) 15% Potassium iodide (KI) 0.01 N (0.01M) sodium thiosulfate (Na2S2O3) Starch indicator 0.5 % concentrated hydrochloric acid HCl 0.01 N (0.00167M) potassium dichromate K2Cr2O7 (fix.) Procedure Determination of the titre of the sodium thiosulfate solution Measure off 10 ml of 0.01N K2Cr2O7 solution to a 200 ml conical flask. Add 0.5 ml concentrated HCl and 1.0 ml 15% KI solution.
| Practical Report | | | | Practical Report Introduction This specific experiment will demonstrate both the efficiency and the disinfecting capabilities of the various disinfectants used and if the experiment is followed correctly the results deemed should be noted that if the substance possess a chemical substances that inhibits the growth of the bacterial culture placed onto the agar (E.Coli) that inhibition zones will be created and we can tabulate and record the observation thus walking away with an understanding of the efficiency of the tested disinfectants used and their success rate. What is known about E.Coli is that it is normally found in food it is a Gram negative, rod shaped bacterium that can help the body break down and assists the body in digestion of food (Dowshen, 2009).Although certain strains of the E.Coli are pathogenic to humans such as the serotype O157:H7, this specific strain of E.Coli is known to cause food poising and can escalate and become life threatening (Nordqvist, 2011). Domestos is chlorine based bleaching agent (Directa, 2009) and is a common household cleaning substance that is used. Handy Andy is a common and popular general house hold cleaner. Dettol is trusted antiseptic and disinfectant and is widely used to fight unwanted bacteria (Thompson D. M.) It has a distinct and characteristic phenolic odour.