University:
Buffalo State University
Course:
CHE 111 | Fundamentals of Chemistry
Academic year:

2024
Views:

472

Pages:

2
Author:

ethan vicor

EXPERIMENT IV Determination of Oil Quality Oil Quality Fats that have become rancid have an unpleasant odor and taste it may be toxic for some people, as well as being damaging nutritional content of other food substances. rancidity incident (rancidity) can occurs due to the oxidation and hydrolysis processes in fat, both physically enzymatic or non-enzymatic. Among the various possible causes of fat breakdown, it turns out the process Autooxidation has the greatest influence on taste. The fat oxidized to form peroxides which can decompose again to form aldehydes, ketones and fatty acids. The presence of aldehydes and ketones is what causes this rancidity. The peroxide number is the number of milligrams of peroxide per 1000 grams oil/fat. This peroxide number is useful to determine the presence of autooxidation from oil/fat. To prevent and inhibit the oxidation process in fat Usually, antioxidants need to be added to oil. Meanwhile, rancidity caused by hydrolysis often occurs because too long storage factors and poor storage methods, thus causing the growth of certain capable microorganisms produces lipase enzymes (can hydrolyze triglycerides, diglycerides, and monoglycerides to glycerol and free fatty acids). Amount of fatty acids The free products produced by the hydrolysis process can be determined using measure the degree of acidity of the fat. Generally very rancid fats has a low acidity value. 1. Determination of Peroxide Value Reactor : - Rancid oil/fat - Acetic acid-chloroform solution (3 : 2) - Saturated KI solution; Standard solution of 0.1 N Na-thiosulfate and 1% starch solution Procedure : - Weigh 5.00 ± 0.05 grams of sample (rancid oil/fat) in an Erlenmeyer flask, and add 30 mL of acetic acid-chloroform solution. - Shake until the ingredients are completely dissolved. Add 0.5 mL of KI solution fed up. - Leave for 1 minute, shaking occasionally add 30 mL of distilled water. - Titrate with 0.1 N Na2S2O3until the yellow color is almost gone (yellow young). Add 0.5 mL of 1% starch solution. Titrate again with Na2S2O3 0.1 N until clear. Note the volume used. - The peroxide value is expressed in milliequivalents of peroxide in 1000 grams of sample. 2. Determination of Free Fatty Acids in Oil (FFA = Free Fatty Acid) Reactor : - NaOH 0.1 N - 0.1 N oxalic acid standard solution - PP indicator 1% - Ethanol 96% Procedure : - Take 10 mL of coconut oil with a deep volume pipette (BJ = 0.92). Erlenmeyer, add 10 mL of 96% ethanol, then add 5 drops of pp 1%. Titrate with 0.1 N NaOH.