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Encapsulation and oxidation of fat in recombined milk powder

Jayakumar, Jitesh LU (2017) KLGM01 20171
Food Technology and Nutrition (M.Sc.)
Abstract
Fat-filled milk powders are manufactured by blending skim milk powder with vegetable oil and these powders have gained a great economic importance. Sensible selection of vegetable oil can help in satisfying both nutritional features and functional characteristics of fat for dairy application. The stability of milk powders can be affected by its composition, mainly the composition of fats which can lead to lipid oxidation. The stability of fats depends on various parameters, some of which are, the composition of the fat, crystal form of fat, the composition of powder etc. The parameter which was mainly focused in this study was the crystal form of the fat. The rate of oxidation to some extent depends directly on the fraction of unsaturated... (More)
Fat-filled milk powders are manufactured by blending skim milk powder with vegetable oil and these powders have gained a great economic importance. Sensible selection of vegetable oil can help in satisfying both nutritional features and functional characteristics of fat for dairy application. The stability of milk powders can be affected by its composition, mainly the composition of fats which can lead to lipid oxidation. The stability of fats depends on various parameters, some of which are, the composition of the fat, crystal form of fat, the composition of powder etc. The parameter which was mainly focused in this study was the crystal form of the fat. The rate of oxidation to some extent depends directly on the fraction of unsaturated lipids and hence this parameter was also used to calculate the measurable oxidation rate. The primary goal of this thesis was to encapsulate vegetable oil in skim milk powder and determine the influence of different crystal forms of fats on the stability of milk powder. The different fats selected were based on the form in which they crystallize. These fats also varied in the fraction of unsaturation. Milk powder was encapsulated with highly unsaturated fat (liquid fat), fat with a very low fraction of unsaturation (hard fat) and in combination of both the kinds of fat, keeping in mind the objective to investigate the effect on the properties of milk powder by the addition of hard fat to liquid fat. Numerous techniques such as DSC, particle size determination, surface free-fat extraction, quantifying the extent of oxidation, X-ray crystallography and SEM were carried out. The results obtained shows that the addition of hard fat to liquid fat brings about changes in the properties and the stability of the fat-filled milk powder. With respect to oxidation, the addition of hard fat reduces the rate of oxidation compared to the rate of oxidation of just the liquid fat in milk powder. But varying the concentration of hard fat did not show a significant difference. (Less)
Popular Abstract
Fat-filled milk powders are made my mixing milk powder with vegetable oil. Over the past few decades, fat-filled milk powders have gained a great economic importance. When milk powders are stored over a long period of time, they can get spoilt and give out unpleasant odour. There are various factors which could be responsible for this spoilage. Some of the main factors are the composition of milk powder, composition of fat, the conditions in which the milk powder is stored etc. In this study, the effect of fat on the stability of milk powder was studied. The fats oxidize and contribute towards the spoilage of the milk powder. The main parameters which were focused was the crystalline state of the fat and the fraction of unsaturation of... (More)
Fat-filled milk powders are made my mixing milk powder with vegetable oil. Over the past few decades, fat-filled milk powders have gained a great economic importance. When milk powders are stored over a long period of time, they can get spoilt and give out unpleasant odour. There are various factors which could be responsible for this spoilage. Some of the main factors are the composition of milk powder, composition of fat, the conditions in which the milk powder is stored etc. In this study, the effect of fat on the stability of milk powder was studied. The fats oxidize and contribute towards the spoilage of the milk powder. The main parameters which were focused was the crystalline state of the fat and the fraction of unsaturation of fat. The primary goal of this project was to encapsulate vegetable oil in skim milk powder and the determine the effect of different vegetables oils used on the stability of milk powder. The different fats selected were based on the form in which they crystallize in. The hypothesis was that the crystallization process might affect the oxidation sensitivity of fat and in-turn affect the stability of milk powder.
Fat was encapsulated in milk powder by the process of spray drying. The powders obtained were stored at 35°C and 20% humidity and over the storage period, the analysis were carried out on the powder. The different analysis done were determination of primary and secondary oxidation, determination of emulsion droplet size in the recombined milk powder, determination of melting point and melting enthalpy, quantification of surface free fat, X-ray crystallography and scanning electron microscopy.
Milk powder was encapsulated with highly unsaturated fat (liquid fat), fat with a very low fraction of unsaturation (hard fat) and in combination of both the kinds of fat, keeping in mind the objective to investigate the effect on the properties of milk powder by the addition of hard fat to liquid fat. The results obtained shows that the addition of hard fat to liquid fat brings about changes in the properties and the stability of the fat-filled milk powder. With respect to oxidation, the addition of hard fat reduces the rate of oxidation compared to the rate of oxidation of just the liquid fat in milk powder. But varying the concentration of hard fat did not show a significant difference. From the hypothesis, it was expected the crystallizing fat will make the powder more sensitive to oxidation, but it was observed that it rather had a stabilizing effect on the powder. (Less)
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author
Jayakumar, Jitesh LU
supervisor
organization
course
KLGM01 20171
year
type
H2 - Master's Degree (Two Years)
subject
keywords
food technology, livsmedelsteknologi
language
English
id
8927013
date added to LUP
2017-10-31 08:41:58
date last changed
2017-10-31 08:41:58
@misc{8927013,
  abstract     = {Fat-filled milk powders are manufactured by blending skim milk powder with vegetable oil and these powders have gained a great economic importance. Sensible selection of vegetable oil can help in satisfying both nutritional features and functional characteristics of fat for dairy application. The stability of milk powders can be affected by its composition, mainly the composition of fats which can lead to lipid oxidation. The stability of fats depends on various parameters, some of which are, the composition of the fat, crystal form of fat, the composition of powder etc. The parameter which was mainly focused in this study was the crystal form of the fat. The rate of oxidation to some extent depends directly on the fraction of unsaturated lipids and hence this parameter was also used to calculate the measurable oxidation rate. The primary goal of this thesis was to encapsulate vegetable oil in skim milk powder and determine the influence of different crystal forms of fats on the stability of milk powder. The different fats selected were based on the form in which they crystallize. These fats also varied in the fraction of unsaturation. Milk powder was encapsulated with highly unsaturated fat (liquid fat), fat with a very low fraction of unsaturation (hard fat) and in combination of both the kinds of fat, keeping in mind the objective to investigate the effect on the properties of milk powder by the addition of hard fat to liquid fat. Numerous techniques such as DSC, particle size determination, surface free-fat extraction, quantifying the extent of oxidation, X-ray crystallography and SEM were carried out. The results obtained shows that the addition of hard fat to liquid fat brings about changes in the properties and the stability of the fat-filled milk powder. With respect to oxidation, the addition of hard fat reduces the rate of oxidation compared to the rate of oxidation of just the liquid fat in milk powder. But varying the concentration of hard fat did not show a significant difference.},
  author       = {Jayakumar, Jitesh},
  keyword      = {food technology,livsmedelsteknologi},
  language     = {eng},
  note         = {Student Paper},
  title        = {Encapsulation and oxidation of fat in recombined milk powder},
  year         = {2017},
}