1.
The Effect Of Date Palm Fruit (Phoenix Dactylifera L.) Extract On Oxidative Stabilization Of Butter At Ambient
by Fazal Rehman | Dr. Muhammad Nadeem | Dr. Saima Inayat | Dr. Yasir Zahoor.
Material type: ; Format:
print
; Literary form:
drama
Publisher: 2013Dissertation note: This investigation aimed to explore the antioxidant potential of date fruit extract using butter as an oxidation substrate on the basis of certain instrumental, orthodox analytical techniques and sensory characteristics. The objectives of this study were to characterize the date extract for polyphenolic compounds, free radical scavenging activity and inhibition of nitric oxide macromolecules and to study the effect of various concentrations of the date palm extract on oxidative stability and sensory characteristics.
The butter was added 200, 400 and 600-ppm respectively date palm extract and compared with a control, stored at refrigeration and ambient temperature during winter months for 90-days at the interval of 30-days. Peroxide value, anisidine value, iodine value, conjugated dines, totox value, free fatty acids and sensory evaluation were performed in the fresh and three month stored butters. Sensory evaluation of supplemented butter added with various concentrations of date palm extract stored revealed the effect of treatments, storage period and their interaction to be significant. Taste, Color and overall acceptability score was non-significant up to 30-days of storage. After this sensory score started to deteriorate and went on decreasing the rest of storage period. The decline in taste score was not due to the addition of date palm extract rather it was due to the generation of peroxides and other oxidation products. Oxidation products and peroxides are found to be in direct relation with temperature; with rise in temperature the decline in sensory evaluations was more pronounced. This connection between taste score and peroxide value was highly correlated (R= 0.9982).
The results of triplicate treatments and triplicate analysis (n=3x3; ±SD n=3x3) was analyzed by using one way analysis of variance techniques (ANOVA) to find out the effect of the date palm extract to the storage conditions. Differences among treatments were compared by Duncan Multiple Range Test.
Supplementation of butters with date palm fruit extract did not revealed any significant effect on the inhibition of free fatty acids (P>0.05). The free fatty acid content of fresh and 90 days stored treatments and control were at par with each other. The peroxide value of all the treatments and control increased during the storage period but to varying degree. The addition of date palm extract revealed a significant effect on inhibition of peroxide value (P<0.05). The peroxide value of fresh supplemented, control and 90 days stored samples showed a significant difference. The difference in control and treatments were in order of To > T 1 > T2 > T3 in 90-days stored experimental samples and control. T3 revealed a maximum resistance towards the increase of peroxide value during storage period of 90-days over the control at refrigeration temperature. It is evident from the result that the addition of date palm extract significantly inhibited the auto-oxidation phenomenon in butter stored at room temperature, however the concentration of oxidation products were higher as compared to butter stored at refrigeration temperature. The iodine value decreased during the storage period in control experimental samples throughout the storage period of 90-days but to varying extents at refrigeration temperature. Control (T0) showed highest decrease in iodine value while T3 showed least change in iodine value during the storage period.
The anisidine value of control and treatments stored at refrigeration temperature were in the order T0 > T1 > T2 > T3. Control revealed significant increase in anisidine value as compared to treatments. After 90 days of storage period the extent of secondary oxidation products in control and T3 was 22.24 and 8.35 at refrigeration temperature respectively. The classical rise of anisidine value was observed in all the treatments to varying degree, supplementation of natural antioxidant offered a great deal of resistance towards the rise of anisidine value. Supplementation of butter with date palm fruit extract revealed significant effect on the generation of oxidation products. Conjugated dienes for control and all the treatments increased throughout the storage time slowly and steadily.
Analysis of variance revealed that the effect of treatments, storage period and their interaction was significant. Taste, Color and overall acceptability score was non-significant up to 30-days of storage. After this sensory score started to deteriorate and went on decreasing the rest of storage period. The results indicate that ethanolic date palm extract at 600-ppm concentration can be used as natural antioxidant source for the long term storage of butter at ambient temperature during winter months. The outcome of this study will help the food industry for preservation of fats and oils.
Availability: Items available for loan: UVAS Library [Call number: 1800,T] (1).
2.
Photo-Oxidation Of Pasteurized Milk In Polyethylene Pouch Packs
by Asif anwar | Dr. Muhammad Nadeem | Dr. Imran javed | Prof. DR. Masroor ellahi.
Material type: ; Format:
print
; Literary form:
not fiction
Publisher: 2014Dissertation note: Abstract Availability: Items available for loan: UVAS Library [Call number: 1938,T] (1).
3.
Fractions Of Milk Fat On Lipolysis In Cheddar Cheese
by Shakeel Ahmad (2008-VA-426) | Prof. Dr. Muhammad Ayaz | Dr. Muhammad Nadeem | Dr. Muhammad Hayat Jaspal.
Material type: ; Literary form:
not fiction
Publisher: 2014Dissertation note: Lipids are heterogeneous group of biological compounds, soluble in fat and insoluble in water. Oils and fats mainly comprise of triglycerides and has great importance in Food systems. Fats and oils are completed through ester of three fatty acids and a glycerol molecule (Stolyhmo, 2007; McClement and Decker, 2010; Nichols et al. 2011). Fats have a primary importance for the texture of Foods (Rao, 2003).
Fat has more energy values as compared to other Foods nutrients (Wu et al. 2013), presently, one of the major developments is declining the cholesterol contents and fat in the Foodstuffs (Ma and Boye, 2013). Sensory attributes like appearance, flavor, texture and physicochemical properties of the Foods depend upon the fat because it is very important for the Foodstuffs improvement. For these properties, there should be practical strategies which can reduce fat contents only in the Foodstuff (Wu et al. 2013) and should not effect on nutritious and sensory properties (Boff et al. 2013).
Milk fat can be transformed into various fractions such as very high melting fraction (>50°C), high melting fraction (35-50°C), middle melting fraction (25-35°C), low melting fraction (10-25°C) and very low melting fraction (<10°C). Low melting fraction (<15°C) has strong butter flavor and can be incorporated into milk powder to improve functionality. It can be used in confectionery products and can increase spread ability of butter at low melting temperature (Gunstone, 2001).
It has been investigated that melting point of butter oil decreased with C18:2 and increased with C16:0 and C14:0 fatty acids. It has also been investigated that melting point is negatively correlated to C40, C38, C30 and C28 tri-acylglyceride while positively correlated with C48, C46 and C44 tri-acylglycerides (Ortiz-Gonzalez et al. 2007).
The anhydrous milk fat has a higher fraction of low melting tri-acylglycerids due to more unsaturated fatty acids (Smet et al. 2010).
Fatty acids are composed of carbon and hydrogen atoms having one carboxyl (COOH) group at one side of the chain (Ghatak and Bandyopadhyay, 2007). Fatty acids are divided into short, middle, long chain fatty acids and also in saturated and unsaturated fatty acids. Unsaturated fatty acids are further categorized as monounsaturated, poly unsaturated fatty acids and saturated fatty acids. Almost 65-68% saturated fatty acids of milk fat possess many health concerns (Richmond, 2007). More than 4 hundred types of fatty acids are present in milk fat of different bovine breeds. Plasma cholesterol and incidence of coronary heart disease is increased by medium chain saturated fatty acids of milk fat lauric acid (C12:0), myristic acid (C14:0) and palmitic acid (C16:0) (Jensen, 2002). Fatty acid composition of diet has a great impact on health. Considerable attention has been given on the saturated fatty acids present in diet (Astrup et al. 2011). Nutritionists recommend that saturated fatty acids should be replaced by unsaturated fatty acids to decrease the incidence of cardiovascular disease (Erkkila et al. 2008).
Medium chain fatty acids C12:0, C14:0 and C16:0 are atherogenic (Parodi, 2004; Kris-Etherton and Innis, 2007). The coronary heart diseases and atherogenic fatty acids are highly correlated (Moss and Reed, 2003; MacRae et al. 2005; Mensink, 2006). As compared to other lipids sources dairy products are well known to increase the cardiovascular diseases in human beings, because dairy products contain lower proportion of unsaturated fatty acids and higher proportion of saturated fatty acids especially palmitic and myristic fatty acids (Sacks and Katan, 2002). Dairy Foodstuffs are the sources of dietary cholesterol which increases the serum cholesterol (Collins et al. 2003).
Modification in milk fat can be carried out by chemical and enzymatic interesterification (Pal et al. 2000). Physical modification (fractionating of bovine milk fat into different fractions) of milk fat can be carried out by fractionation (Ali and Dimick, 1994). Commercial dairy industries commonly use dry fractionations to improve the texture and flavour properties of dairy products (Grall and Hartel, 1992). Nadeem et al. (2013) found in a study that long chain and short-chain fatty acids can be increased by fractionation of milk fat. Fractionation improves the functional properties of milk fat. Low melting fractions of milk fat can be used in a wide range of functional dairy products.
Cheese is worldwide extensively used dairy product. Researchers have tried to improve the unsaturated fatty acid composition of milk fat by blending with vegetable oil but the use of vegetable oils in cheese has a negative impact on texture, functional properties, excessive lipolysis and flavor characteristics of cheese (Wijesundera and Watkins, 2000;Yli-Jokipii et al. 2001; Dinkci et al. 2011). There are many factors which affect the texture and rheological properties of the cheese. These factors also effect the appearance, functional properties of the cheese and also effect the flavor of the cheese which are very important for consumer. On the base of texture varieties of cheeses are differentiated. Important property for the determination of differences in the cheeses is texture as compared to other flavor and taste property (Wendin et al. 2000)
Free fatty acids of cheddar cheese produced in the result of lipolysis are the precursors of flavor compounds (Smit et al. 2002; McSweeny, 2004). The suitability of low melting fractions of milk fat as a substrate in the manufacturing of cheddar cheese has not been previously investigated.
Availability: Items available for loan: UVAS Library [Call number: 2205,T] (1).
4.
Enhancement Of Omega Fatty Acids In Margarine Through Chia (Salvia Hispanica L.) Oil
by Hafiza Anam Baig (2010-VA-355) | Dr. Muhammad Nadeem | Dr. Saima Inayat | Dr. Muhammad Hayat Jaspal.
Material type: ; Literary form:
not fiction
Publisher: 2016Dissertation note: The higher incidents of deaths from cardiovascular diseases have led to the identification
and modification of risk factors for atherogenesis; it is regarded as the number one reason of
deaths in developed and underdeveloped countries. Chia contains about 40% edible oil, with
fairly high content of unsaturated fatty acids, oil contains about 60% omega-3 fatty acids on
weight basis. Margarine will be prepared from palm oil, palm kernel oil, butter and chia oil
blends by varying the concentration from 5% to 20%.
Margarine was prepared by blending butter, palm oil and Chia seed oil in various
proportions. Market margarine (Blue Band) was used as a positive control. Butter, Palm oil and
Chia Seed oil was characterized for free fatty acids, moisture content, saponification value,
unsaponifiable matter, iodine value, refractive index. Solid fat index was determined at 0, 10,
20, 30 and 40˚C by the dilatometric method, melting point was determined by open capillary
tube technique. Colour, free fatty acids, iodine value, peroxide value, anisidine value,
conjugated dienes and trienes was determined. Fatty acids composition of margarines was
determined by the transformation into fatty acid methyl esters. Margarine was stored at 6±1oC,
for 2 months, iodine value, peroxide anisidine values, free fatty acids, conjugated dienes and
trienes was determined. Sensory evaluation was performed by a panel of ten trained panel of
judges, samples was evaluated for color, smell, taste and overall acceptability on a 9-point
Hedonic scale.
Peroxide value of 60 days old control and T4 (12% chia oil) were 7.06 and 12.10
(MeqO2/kg). After 60 days of storage period, peroxide value was in the order of T4> T3> T2>
T1> control. Free fatty acids increased with the storage period in all the treatments. They are
also increasing with the treatments having higher concentration of chia oil. At 60 day, control
Summary
68
and T4 are 0.16 and 0.19% respectively. Anisidine value trend is considerably accelerating
along the treatments as well as with the storage time. At 60 day, control and T4 is 24.42 and
44.78 respectively. Conjugated Dienes have the increasing trend throughout the treatments.
They also have higher values from 0 to 60 days of time period. At 6o day, the control and T4
are 2.47 and 3.34 respectively. Conjugated Trienes of all the samples increased throughout the
storage period of 60 days. At 60 day, the control and T4 are 2.60 and 3.28 respectively. Iodine
value is in the decreasing trend throughout the storage period and the treatments. They are in the
order of T0>T1>T2>T3>T4. Fat content of all the treatments and the control went on decreasing
throughout the storage period of 60 days. At 60 day, control and T4 were 68.61 and 90.91
respectively. The order of the fat content in all the treatments were T0>T1>T2>T3>T4. Moisture
content of all the treatments and the control went on decreasing throughout the storage period of
60 days. At 0 day, Moisture content of all the treatments were virtually the same. At 60 day,
control and T4 were 27.52 and 7.64 respectively. Salt content of all the treatments at the end of
the storage period were increased. At 60 day, control and T4 were 4.18 and 1.42 respectively.
The taste score of all the treatments along the treatments having different concentrations of
unsaturated fatty acids and also along with the storage period of time is decreased. The taste
score of the control and T4 were 8.06 and 6.90 respectively. The order of the taste score is in the
descending order of T0>T1>T2>T3>T4. Results of this evidenced that concentration of omega
fatty acids can be enhanced in margarine through chia oil with acceptable sensory
characteristics. Major changes in fatty acid composition were observed around C18:2 and C18:3
(omega 6 and 3). Concentration of trans fatty acids in control, T1, T2, T3 and T4 was 24.75%,
6.67%, 5.49%, 4.71% and 3.19%. Availability: Items available for loan: UVAS Library [Call number: 2578-T] (1).
5.
Antioxidant Charactristics And Lipolysis Of Gouda Cheese Fortified With Mango (Mangifera Indica L.) Kernel Oil
by Sadaqat Ali (2010-VA-374) | Dr. Muhammad Nadeem | Dr. Muhammad Ayaz | Dr. Naveed ul Haq.
Material type: ; Literary form:
not fiction
Publisher: 2016Dissertation note: Oil from mango kernels was extracted by mechanical expression and solvent extraction (nhexane).
Mechanically expressed and solvent extracted oil was pooled for using in Gouda
cheese. Mango kernel oil was added in cheese milk at 5%, 10%, 15% and 20% concentration;
control was comprised of 100% milk fat. Mango kernel oil and freshly prepared Gouda cheese
fortified with mango kernel oil was characterized for total phenolic contents, DPPH free radical
scavenging activity, antioxidant activity in linoleic acid, nitric oxide free radical scavenging
activity and total flavonoids. Ripening of Gouda cheese was carried out for 3 months at 8±2oC;
fat, protein, ash, moisture content were estimated at 0, 45 and 90 days of ripening Fat, protein
and moisture content in cheese were determined at 0, 45 and 90 days of ripening. Free fatty
acids, peroxide value, iodine value and cholesterol in Gouda samples were analyzed for interval
of 45 days by using the standard methods. Fatty acid composition of fresh and 3 months stored
Gouda cheese was determined on a Gas Chromatograph.
Each treatment was replicated three times, each sample was analyzed three times and Experiment
was planned in a completely randomized design, two ways analysis of variance technique was
used to determine the effect of treatment, storage and their interaction. Duncan Multiple Range
Test was used to denote the significant difference among the treatments (Steel et al. 1997).
This novel research work opened a new strategy for the development of functional foods,
application of mango kernel oil in complex food substrates with efficient waste utilization.
Fortification of Gouda cheese with mango kernel oil significantly improved the 2, 2-diphenyl-1-
picrylhydrazyl free radical scavenging activity and total phenolic contents, increased total
flavonoids. Cheese fortified with mango kernel oil revealed the existence of mangiferin,
Sammary
44
catechin, quercetin caffeic acid and chlorogenic acid. Lipolytic changes in the cheese fortified
with mango kernel oil up to 10% concentration was similar to that of control with no difference
in sensory attributes. So Antioxidant characteristics of cheese can be improved through mango
kernel oil fortification. Availability: Items available for loan: UVAS Library [Call number: 2638-T] (1).
6.
Extraction Of Functional Polysaccharides From Chickpea (Cicer Arietinum) And Application As Edible Coating On Cheddar Cheese
by Muhammad Ali Sabir (2008-VA-433) | Dr. Muhammad Nadeem | Dr. Saima Inayat | Prof. Dr. Muhammad Abdullah.
Material type: ; Literary form:
not fiction
Publisher: 2016Dissertation note: Cheddar cheese was collected from the market and coated with three different coatings. All the reagents used in this study were High Performance Liquid Chromatography grade and obtained from Sigma Aldrich, USA. Experiment were performed in completely randomized design. Cheddar cheese was ripened for 60-days for lipolysis and was analyzed at the interval of 30-days interval. Composition of cheese milk and cheese, peroxide value, Iodine value, free fatty acids and changes in fatty acids (short chain and unsaturated fatty acids) composition were determined.
Fat content of all the treatments and control went on decreasing throughout the storage period of 60-days. There was not-significant difference in the protein content of cheddar cheese coated with different coatings.Moisture contents of cheddar cheese coated with different coatings decreased with the decreased ripening period of the cheddar cheese (P>0.05). Free fatty acids increased in all the treatments during the entire ripening period from 0 day to 60 days, the concentration of free fatty acids in all the treatments at all the determination time points were not different from each other and control. There was also increase the peroxide value of control sample from 0 day to 60-day time period of cheese ripening. All the determination frequencies showed that peroxide value of control and experimental samples were not different.Iodine value decreased in control sample day 0 to day 60 continuously, the decline in iodine value of control and experimental samples was not different.Concentration of short-chain, medium-chain and long-chain fatty acid decreased during the ripening period of 60 days but the decline in all the treatments was non-significant.Anisidine value increased in control sample day 0 to day 60 continuously. There also increased the Anisidine value higher in all treatments and control (P>0.05).
These results suggest that galactomannas based coating can be used for the coating of cheddar cheese.
Availability: Items available for loan: UVAS Library [Call number: 2701-T] (1).
7.
Effect of aqueous date palm (Phoenix dactylifera L.) fruit extract on antioxidant characteristics of ice cream
by Nadeem Abbas (2008-VA-412) | Dr. Muhammad Nadeem | Mr. Muhammad Junaid | Dr.Shahid Mehmood.
Material type: ; Format:
print
; Literary form:
not fiction
Publisher: 2017Dissertation note: The application of antioxidants extracted by the organic solvents have limited applications in foods due to their toxicity. Most of the antioxidants of date palm fruit (Phoenix dactylifera L.) are soluble in water. Antioxidant activity of water soluble natural antioxidants of date palm fruit using ice cream as an oxidation substrate has not been studied previously. This study has been planned with the objective to study the antioxidant characteristics and oxidative stability of ice supplemented with aqueous date palm fruit extract.
Date palm fruit extract were prepared by extracting 20 g date with 100 ml distilled water, followed by concentration and filtration. Ice cream were supplemented with date palm fruit extract at 200, 400, 600, 800 ppm and tertiary butylated hydroxy quinone 200 ppm concentrations. Ice cream were filled in plastic cups and stored at -18oC for 60 days.
Antioxidant characterization of date palm fruit extract was performed by yotal phenolic contents, DPPH free radical scavenging activity. Oxidative stability of ice cream was determined by peroxide value, anisidine value, changes in fatty acid profile sensory evaluation were performed at 0, 30 and 60 days of storage period.
Date palm fruit extract was characterized for antioxidant capacity, total phenolic contents of date palm fruit extract were 7.51% (GAE).DPPH free radical scavenging activity of date palm fruit extract was 78.8% as compared to 80.5%. Supplementation of ice cream with date palm fruit extract did not have any significant impact on fat, protein and total solids content.
Results indicated that peroxide value increased during the storage of 60 days in all the treatments and control. Rise in peroxide value was strongly correlated with the addition and dose of date palm fruit extract. Control had the highest peroxide value, followed by T1, T2, T3 and T4. Peroxide value of control and ice cream samples added with TBHQ (200 ppm) were not different
from each other (p<0.05). After 60 days of storage, anisidine value of control, T1, T2, T3, T4 and TBHQ added samples were 13.62, 10.58, 8.49, 7.36, 6.89 and 6.39, respectively.Flavor score of control, T1, T2, T3, T4 and TBHQ added ice cream were 8.2, 8.1, 8.0, 8.0, 8.1 and 8.2.
Date palm fruit extract 600 and 800 ppm can be sued for the long term stabilization of ice cream.
Availability: Items available for loan: UVAS Library [Call number: 2862-T] (1).
