Effects Of Storage And Processing Condition On The Quality Of Whola Milk Powder
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Publisher: 2009 Dissertation note: Milk is a complex mixture of fat, proteins, carbohydrates, minerals, vitamins and other miscellaneous constituents dispersed in water. Milk production in flush season is much more than the requirement. Milk production and supply fluctuate through out the year and during winter it is surplus to its demand. Dairy is one of the expanding industrial sectors in Pakistan; about 17 units are engaged in the production of various dairy products. Surplus milk is available in winter and this is the normal practice of dairy industry in Pakistan that surplus milk is converted in to different types of milk powders. The objectives of the study were to evaluate the physico- chemical and keeping quality of whole milk powder commercially available in the market and comparative study of functional properties among different brands of whole milk powders, evaluate the storage stability of different brands of whole milk powder atl5°C, 25°C and 40°C temperature and study the effects of processing conditions indicator like Hydroxymethyl Furfural (HMF) during storage.
Project was undertaken to study the effect of storage temperatures (15, 25 and 40°C) and processing conditions on physico chemical and sensory characteristics of whole milk powder. Statistical analysis of whole milk powder samples indicated during storage non significant changes in protein, ash, fat, lactose, acidity, burnt particles within the treatments as a function of storage was observed. Significant changes were recorded in free fatty acids, solubility index and per oxide value within the treatments and during storage period of 120 days. At 120 days of storage minimum increase in free fatty acids and peroxide value was noted in T3. Acidity, free fatty acids and peroxide value increased throughout the storage period of 120 days but at 15 °C the effect of storage on free fatty acids and peroxide value was comparatively less than 25 and 40 °C.
Hydroxy methyl furfural was found significant within the treatments and effect of storage period and temperature was also significant. Hydroxy methyl furfural almost remained same at 15 °C, with the increase of temperature it increased significantly. Sensory evaluation was carried out by a panel of six trained judges it was noted that score for color, taste; smell and mouth feel decreased with the increase of temperature and storage period. The highest score for color, smell, taste and mouth feel was obtained by T3 during 120 days of storage. Chemical analysis of whole milk powder samples showed that whole milk powder samples stored at 40 °C were most affected in terms of physico chmeical and sensory quality.
Overall results indicated that physico chemical quality and sensory properties of T3 was found best and it was comparatively less affected by storage temperatures. On the basis of this study it is recommended that for proper storage of whole milk powder 15 °C temperatures is suitable.
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Comparative Study On Physico-Chemical ,Microbiological & Chemical Adulterants Of Raw & Processed Milk.
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Publisher: 2009 Dissertation note: Milk production, handling, storage, transportation and marketing of milk is handled in a primitive way in Pakistan. Mostly middle man and contractors are involved in the collection, marketing and distribution of milk. Most of the milk is produced in rural sareas and transported to cities where it is supplied to milk plants and also to house consumers. During transportation and distribution there is no refrigeration involved. Middle man adds ice to keep the milk cool and prevent from spoilage. In addition, they also add chemical to kill bacteria and prevent spoilage of milk.
Adulteration of milk is one of the most serious issue in the dairy sector of Pakistan, causing not only major economic losses for the processing industry, but also major health risks for the consumers. Milk is a perishable item and to prevent the spoilage of milk various chemicals are added. In addition to that microbiological quality of milk is very important which directly concern not only with milk spoilage but also consumer health
Keeping in view this study the main object of this study is to determine the hysico-chemical, microbiological and adulterants in raw and processed milk available in Lahore. The raw milk samples ware collected from local market of Lahore city Gawalas, Retail milk shops, Small Dairy Farms sale points and Milk Plants collection centers. A total of 80 samples of raw and 40 samples of processed milk were collected from Lahore
Raw milk samples were collected from Retail milk shops and Gowalas at four different locations of Lahore city i.e. Defence, Allama Iqbal Town, Samanabad and Inside the wall city, from Small Dairy Farms sale points Sakhian pul and Shadera Town areas. Five samples were also collected from experimental dairy farm of UVAS and collection centers of 4 companies.
UHT and Pasteurized milk samples of five different brands were collected from Lahore. A total of 120 milk samples were collected for Physico-chemical, Microbiological and Chemical Adulterants study.
Physico-chemical, microbiological analysis and adulterants detection tests were performed in WTO Laboratory , University of Veterinary and Animal Sciences, Lahore. Color, Taste and flavor of most of the samples were found normal in color, taste and flavor except a few samples of raw milk from shops and Gawalas. Temperature of raw milk was ranged from 4.80±0.096 °C to 30.48±0.611 °C. UHT brands were at ambient temperature and Pasteurized milk brands were stored at refrigeration temperature.
Density in raw milk was ranged from 18.100±0.575 to 27.738±0.16203, lowest in Gawalas and highest in UVAS Dairy. In UHT milk ranged from 26.142±0.088 to 28.222±0.3 15 and in pasteurized milk ranged from 26.280±0.527 to 27.377±0.147.
The highest mean of freezing point recorded was -0.325±0.0 10 °C in Gawalas and lowest -0.542±0.003 °C observed in UVAS Dairy milk. URT milk ranged from -0.487±0.006 °C to -0.463±0.007 °C and in pasteurized milk brands ranged from -0.480±0.002 °C to - 0.455±0.008 °C.
Fat in raw milk ranged from 4.038-0.056% to 6.340±0.060% lowest was in shops and highest in UVAS Dairy milk. UHT fat ranged from 3.472±0.006% to 3.492±0.006% and in Pasteurized milk fat ranged 3.452±0.020% to 3.495±0.005%.
SNF in raw milk ranged from 5.386±0.13745% to 8.226±0.026% lowest in Gawalas and highest in UVAS Dairy. In UHT milk fat ranged from 7.465±0.033% to 8.082±0.09151% and in Pasteurized milk SNF ranged from 7.563±0.125% to 7.905±0.023%.
Protein in raw milk ranged from 2.131±0.060% to 3.162±0.017%, lowest was in shops and highest was in UVAS Dairy. In UHT milk protein ranged from 2.99 1±0.026% to 3.2 10±0.038%, in Pasteurized milk protein ranged from3.001±0.053 to 3.146±0.009. Lactose in raw milk ranged from 2.768±0.067% to 4.364±0.041%, lowest was in Gawalas and highest in UVAS Dairy. In UHT milk lactose ranged from 3.827±0.011% to 4.107±0.050%, in Pasteurized milk lactose ranged from 3.870±0.070 to 4.020±0.044.
Ash in raw milk ranged from 0.512±0.017% to 0.786 ±0.004%, lowest was in Gawalas and highest in UVAS Dairy farm. In UHT ash ranged from 0.698±0.0 1 1% to 0.739±0.007%, in Pasteurized milk ash ranged from 0.689±.008% to 0.739±0.007%.
Water added in raw milk ranged from 0 to 36.527±1.945%, lowest was in UVAS Dairy farm and highest Gawalas milk. In UHT water added ranged from 5.939±1.094% tol2.229±0.407% in Pasteurized milk water added ranged from 6.975±0.045% to 12. 150± 1.769%.
pH in raw milk ranged from 6.726±0.019 to 7.052±0.027, lowest was in UVAS Dairy and highest was in Gawalas milk, In UHT milk pH ranged from 6.839±0.019 to 6.870±0.0 19, in Pasteurized milk pH ranged from 6.800±0.024 to 6.886±0.03 1.
Acidity in raw milk ranged from 0.147±0.001% to 0.161±0.000%, lowest was in Gawalas and highest was in Dairy plant collection centers. In UHT milk acidity' ranged from 0.158±0.003% to 0.161±0.003% and in Pasteurized milk acidity ranged from 0.158±0.003% to 0.161±0.003%.To study the microbiological quality, total plate count (TPC), coliform count and S. aureus count were made.
TPC in raw milk ranged from 2.9 x iO± 2.2 x i04 to 1.7 x l0 ± 8.1 x 10± 8.1 x 106. Lowest was in UVAS Dairy farm and highest was in Gawalas milk, in Pasteurized milk TPC ranged from 5.0 x 10±l .2 x i04 to 6.8 x 10±2.3 x 104.
Coliform count in raw milk ranged from 3.1 x i0± 3.0 X 102 to 4.4 x i05 ± 4.3 X i03.
Lowest was 3.1 x i± 3.0 X 102 in UVAS dairy farm and highest was in Gawalas milk.
In Pasteurized milk Coliform count ranged from 58±3.856 to 344±161.272.
Staph aureus Count in raw milk ranged from 6.4 X l0±6.7 X 102 to 8.7 X 10±2.2 X i0
Lowest was in UVAS Dairy farm and highest was in Shops milk, in Pasteurized milk Staph aureus Count ranged from 61.87lO.901 to 276.62±105.178.
All UHT brands were found negative for TPC, Coliform count and Staph aureus count.
The qualitative tests adulterants were performed by (M.A.T). Kit.
In raw milk the major adulterants found were Urea, Formaldehyde, Hydrogen peroxide,
Neutralizers, Boric acid and QAC. All adulterants were found negative in the milk of
UVAS dairy farm.
In UHT and Pasteurized brands the adulterants found were Salt, Sugar, Starch and
On the basis of present finding, it is concluded that multiple factors can markedly affect the quality of milk. Water addition was one of the major adulteration present in every step of milk marketing. All the raw milk samples were found inferior for their Phsicochemical quality. In processed milk the fat percentage was in the normal range while other parameters were inferior. Microbiological contamination was also higher in raw and pasteurized milk samples. Adulteration of milk with chemicals such as caustic soda, urea, formalin, hydrogen peroxide, sugar and salt were also detected in raw and processed milk. The high microbiological contamination and presence of chemical adultrants in raw and processed milk showed that the milk constitutes a potential public health hazard.
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Effect Of Various Concen Trayious Of Hydrogen Pereoxide On Chemical And Microbiogical Quality Of Raw Buffalo Milk
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Publisher: 2011 Dissertation note: Milk is a complex mixture of fat, proteins, carbohydrates, minerals, vitamins and other miscellaneous constituents dispersed in water. Milk production in flush season is much more than in the normal. Milk production and supply fluctuate through out the year and during winter it is surplus to its demand. Surplus milk is available in winter due to new calving, less consumption of milk by the consumer. In winter season ample amount of green fodder is available to the animals which in turn increase the milk production.
Milk and milk products being very delicate and perishable food require special handling prior to the consumption and further treatment. Pakistan due to its harsh climatic conditions people are using different methods, for the preservation of milk. They are using different chemicals, additives and antibiotics to enhance the keeping quality of milk. Present study was planned to investigate the various concentration of hydrogen peroxide or raw buffalo milk and its effect on chemical and microbiological quality of raw buffalo milk.
Raw buffalo milk samples were collected from Dairy Animal Training and Research Centre, University of Veterinary and Animal Sciences, Ravi campus Pattoki Fifty samples of raw buffalo milk (100ml each) were collected to studied the nutritional composition and microbiological quality of the milk after adding the hydrogen peroxide. The hydrogen peroxide of different concentration i.e. 0.025%, 0.05%, 0.075%and 0.1% were used in this study. There was no significant change in the result regarding various nutritional composition of raw buffalo milk after adding the various concentrations of hydrogen peroxide. There is a slight change in the lactose % during study of 48 h storage of milk at different temperature. Statistically the change which occurred in lactose during storage is significant whereas over all decrease in Solid Not Fat is non significant
Mean value of TPC of raw buffalo milk treated with different concentrations of hydrogen peroxide storage at the three different temperatures indicated that at 10° C TPC was very less as compared to control. TPC at 30° C after 48 h was 9.83x106.Which was very less as compared to TPC of control i.e. 1.195 x107.
The effect of H2O2 on the quality of the milk is negligible as compared to the losses suffered without it. The hydrogen peroxide definitely have its effect as a preservative.. The use of preservative in milk and dairy products are not new in the countries where ambient temperature remains quite high. Our study suggests that the concentration of hydrogen peroxide to be used for the preservation of raw milk is 0.05 % to 0.1 %
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Incidence Of Spore Former Microbes In Pasteurized Milk Available In Lahore Disteict
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Publisher: 2014 Dissertation note: Abstract
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Development Of Cheddar Cheese By Using Crude Flowers Extract Of Citrus Aurantium (Sour Orange) As A Milk Coagulant
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Publisher: 2015 Dissertation note: Presently in Pakistan a few dairy companies are producing Cheddar cheese. Several
alternative proteases obtained from different vegetable and fruit sources such as fruits,
roots, latex and flowers have been recommended as rennet coagulant replacer in cheeses
processing. As there is now decrease in slaughtering of young calves, natural rennet
shortage occurs, so to fill it, sometimes alternates of rennet used in cheese production
This research project was designed to implement and introduce the use of Citrus
aurantium crude flower extracts (CFE) as an economical, easily available and rennet
substitute in Cheddar cheese production. CFE was evaluated for its first time usage as
coagulant in Cheddar cheese production and compared with rennet for its physicochemical
characteristics and sensory evaluation.
Cheddar cheese was made from buffalo milk. Standardized buffalo milk was pasteurized
and then cooled to inoculation temperature. It was inoculated with addition of 2% of
starter culture and given stay of 20-50 minutes. Then control sample was coagulated with
0.002% rennet and other samples were coagulated by Citrus aurantium crude flower
extracts (CFE) at different levels of 1%, 2 %, 3% and 4% at coagulation time. After
curdling, curd was cut, stirred and whey was drained. Then milling and cheddaring of
cheese blocks was done. Salting was done at the rate of 2.5%. After pressing, cheese was
stored in hygienic packaging and left for ripening at 10°C for 2 to 3 months.
Acceptability of newly developed Cheddar cheese using crude flower extracts (CFE) as a
coagulant was evaluated by sensory evaluation using criteria of color, Cheddar cheese
samples were analyzed for physico-chemical characteristics and sensory evaluation at 63
days of storage. The statistical analysis was carried out by using one way Analysis of
Variance (ANOVA) techniques under (CRD) Completely Randomized Design (Steel et
al. 1987). Duncan’s Multiple Range (DMR) Test was used for significant difference
comparisons (SAS 9.1 Statistical Software).
The cheese prepared from using 1% and 4% CFE cheese showed higher fat contents from
0 to 63 days while CFE cheese prepared with 1% and 3% have significant fat contents
and less than control sample prepared with rennet. Cheddar cheese with %, 2% and 3%
showed similar 25% protein content respectively but less than 4% and rennet coagulated
standard Cheddar cheese. Cheddar cheese made from 2% and 1% CFE showed slightly
higher moisture content while 3% and 4% showed moisture content of 33% almost
similar to the rennet coagulated Cheddar cheese which showed 32% of moisture content.
The cheese prepared from using 4% CFE cheese showed highest pH of 5.57 at 0 days
while after storage at 63 days pH decreased to 5.52. CFE Cheddar cheese prepared with
1%, 2% and 3% showed pH of 5.55 at 0 days and decreased to 5.52 which is standard pH
of the Cheddar cheese. Salting of all cheese samples was done at the rate of 2.5%. The
cheese prepared from using 2% and 3% CFE showed decrease in salt but it was higher
than 1% and controlled Cheddar cheese. While 4% showed lower salt contents than all
cheeses. Results showed that cheeses were made with 1% and 2% of CFE had a longer
and slightly softer texture. While cheeses contained 3% and 4% CFE had semi-hard
textural properties of curd similar to rennet added cheese which is similar to the standard
Cheddar cheese made with rennet. Cheddar cheese with 3% and 1% were preferred by
consumers instead of 2% and 4% for their better taste, texture/appearance and overall
acceptability but it was less preferred over standard Cheddar cheese (controlled) due to
the presence of bitter and intense aroma compounds of Citrus aurantium flowers.
It will give a benefit to the cheese industry by introducing a new economical, nutritional
and easily available rennet substitute source of milk coagulation. Pakistan is producing
largest amount of Citrus aurantium, so it will improve its export in other countries for
usage as an alternate of rennet and to provide economic benefits to our country.
Furthermore, it will open new ways for researchers to find out the characterization of
extract and enzyme of CFE.
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