Izlaganje sa skupa
Preparation and Determination of the Physical and Chemical Properties of Margarinen
Z. Weihnacht
; Prirodoslovna škola Vladimira Preloga, Zagreb, Hrvatska
S. Rupčić Petelinc
; Prirodoslovna škola Vladimira Preloga, Zagreb, Hrvatska
S. Habazin
; Prirodoslovna škola Vladimira Preloga, Zagreb, Hrvatska
Sažetak
Nutrition is one of the most basic needs of the human body. It ensures the introduction of substances needed to sustain life of the organism, its growth and proper development. In the food pyramid, fats together with carbohydrates are at the very top. One source of fat in human nutrition is margarine. Margarine comprises at least 82 % vegetable fats and 16 % water. The remainder consists of lecithin, sugar, salt, colours, and vitamins.
The margarine production process involves hydrogenation of vegetable fats, assembling the margarine mixture, emulsifying, crystallization and packing.
The objective of this study was to show that margarine could be prepared in a school laboratory under conditions that are applicable for such laboratory. Meaning:
a) In a school laboratory at normal pressure and at elevated temperature with nickel as catalyst, i.e. without the use of an autoclave, carry out the reaction of hydrogenation soybean and palm oil in order to obtain a vegetable fat that is the basic ingredient of margarine. During the preparation of margarine, the hydrogenation reaction was carefully monitored by determining the iodine value.
b) Preparation of margarine obtained from vegetable fats.
c) Determination and comparison of selected physical and chemical properties of the product with the same properties of several types of margarines available on the market. The following properties were determined:
– Melting point, in order to obtain composition of fat phase and determine suitability for human
use.
– Acid value, as an indicator of the amount of free fatty acids that influence the taste.
– Peroxide value, for insight into the oxidative stability of fats.
This work has shown that it is possible to make vegetable fat in a school lab by hydrogenation of vegetable oils. Unlike the industrial process of hydrogenation carried out under a pressure of 0.36 to 2 atm, which takes about two hours, our reaction was carried out at atmospheric pressure but with a greater amount of catalyst, and took six hours for soybean oil, and four hours for palm oil. To the resulting vegetable fats we added water, salt, lecithin and pure soybean oil, and thus prepared margarine, also without complete and detailed simulation of the industrial process, and using readily available materials and equipment usually found in every laboratory.
Ključne riječi
making of vegetable fat in a school lab; hydrogenation of vegetable oils; physical and chemical properties of margarinen
Hrčak ID:
77150
URI
Datum izdavanja:
6.2.2012.
Posjeta: 3.633 *