1.
Development And Sensory Evaluation Of Flavored Probiotic Acidophilus Milk
by Muhammad Junaid | Dr. Imran Javed | Prof. Dr. Muhammad Ayaz.
Material type: ; Format:
print
Publisher: 2011Dissertation note: Fermented milk products are the foods that have been fermented with lactic acid bacteria includes Lactobacillus, Lactococcus, Leuconostoc, bifidobacterium etc. These are of great significance as they not only preserve the surplus milk but also provide vast quantities of nutritious and healthy foods in a wide variation of flavors, aromas and textures. Acidophilus milk is one of the fermented milk products in which probiotic starter culture is used for fermentation. This probiotic product not only adds to the taste but also improves the digestibility of milk. This value added product helps in maintaining the normal mocroflora of GIT by boosting the number of friendly intestinal bacteria. Decreasing the incidence of pediatric diarrhea, reducing serum cholesterol concentration, reducing the risk of coronary heart diseases are some of health promoting benefits of this value added product.
Presently in Pakistan none of the dairy company is producing value added flavored acidophilus milk product using probiotic culture so the research project was designed in a way to develop flavored probiotic acidophilus milk which has its health benefits along with fulfilling the nutritional requirement with acceptable organoleptic characteristics. Consumer acceptability was found to be important for product development and its marketing.
The aim of the present study was the development the probiotic acidophilus milk having health promoting benefits of probiotics and to appeal its consumer recognition by flavoring the product. For flavoring purpose different food grade flavors like strawberry, chocolate and vanilla at different levels was used with the purpose of providing our people with good, nutritional, healthy and value added product through research and development. Flavored probiotic acidophilus milk is a product in which the milk a perishable commodity was fermented using the pure culture of Lactobacillus acidophilus as a starter culture.
The freshly drawn raw milk used in the study was obtained from Dairy Animal Training and Research Center (DAT&RC), UVAS, Ravi campus, Pattoki. The whole milk was pasteurized at 72 °C for 15 minutes to kill the pathogenic microorganism and ensuring the safety of consumer. It was then standardized to 3.5% fat and 8.5% SNF and cooled at 4 ±1°C. This standardized milk was used for preparation of flavored probiotic acidophilus milk.
The microbiological identification and confirmation of Lactobacillus acidophilus starter culture procured from starter culture collection center (Danisco) was carried out in the postgraduate laboratory of Department of Dairy Technology UVAS, Ravi campus, Pattoki. The freeze dried culture was activated by inoculating and growing it in sterile whole milk at 40 ±1ºC and then maintained at 4 ± 1ºC.
Preliminary studies were performed to optimize and standardize the conditions like culture concentration (to be added in the milk for acidification and fermentation), temperature of incubation and time duration for incubation during the preparation of probiotic acidophilus milk. This task was accomplished by using culture varying in concentration form 1-5%. Similarly temperature variations were studied at 30°C, 35 °C and 40 °C. Time for incubation was given 04hrs and 08hrs for each culture concentration at different temperatures. The results of preliminary studies showed the development of probiotic acidophilus milk by inoculating with Lactobacillus acidophilus culture at 01% concentration incubated at 40 °C for 04hrs as the best choice.
The actual product development phase started after finding the best combination of culture concentration with temperature of incubation and time for incubation. During this phase the standardized and pasteurized milk (200ml) equilibrated for one hour at the fermentation temperature (40ºC) in a water bath was inoculated with overnight fresh culture of Lactobacillus acidophilus at the rate of 1%. Thereafter it was flavored using three different flavors e.g., mango, strawberry, and pineapple. Fermentation time was given 4hrs and the temperature of milk was maintained at 40ºC. The flavored probiotic acidophilus milk after its development was cooled and stored at 4±1 °C up to six days.
During storage the prepared flavored Probiotic acidophilus milk was evaluated for its sensory attributes. A panel of 10 judges evaluated the product for color, taste, aroma, appearance, acidic flavor and overall acceptability on 9-point hedonic scale (9 = like very much; 1 = dislike very much). The sensory evaluation of the product at day-1 and day-6 of its production was carried out in the Department of Dairy Technology University of Veterinary and Animal Sciences, Ravi Campus, Pattoki. The sensory evaluation performa was prepared and distributed to the panelist along with the consent form to participate in this sensory evaluation.
The flavored probiotic acidophilus milk, prepared, was evaluated regularly for physico-chemical analysis, based on pH and titrateable acidity (expressed as lactic acid %) during its storage up to six days with one day interval. The total viable count of the product was also determined microbiologically at day-1 and day-6 to study the viability of culture in the probiotic product.
All the results obtained were analyzed thorough analysis of variance technique (ANOVA). The significant differences were compared using Duncan's Multiple Range (DMR) test with a probability P ? 0.05.
Availability: Items available for loan: UVAS Library [Call number: 1296,T] (1).
2.
Qualitative Comparison Of Yoghurt Prepared From Conventional And Probiotic Culture
by Muhammad Ali | Prof. Dr. Muhammad Ayaz | Mr. Muhammad Junaid | Mr. Nisar.
Material type: ; Format:
print
Publisher: 2013Dissertation note: Abstract Availability: Items available for loan: UVAS Library [Call number: 1626,T] (1).
3.
Isolation And Molecular Identification Of Enterotoxigenic Escherichia Coli Strains Isolated From Raw And Pasteurized Milk
by Rahman Ullah | Dr. Imran Javed | Mr. Muhammad Junaid | Prof. Dr.
Material type: ; Format:
print
Publisher: 2013Dissertation note: Abstract Availability: Items available for loan: UVAS Library [Call number: 1816,T] (1).
4.
Development And Evaluation Of Mozzarella Cheese Influenced By Type Of Starter Culture And Fat Content Of Milk
by Imran Taj Khan (2013-VA-866) | Mr. Muhammad Junaid | Dr. Muhammad Ayaz | Mr. Muhammad Saadullah.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: Pakistan is the 4th largest milk producing country in the world having 50.99 million tons/year in which buffalo and cow add 61% and 35% share, respectively to total milk production in Pakistan, while the rest 5% of the total milk is contributed by other species like small ruminants and camel. Out of the total produced milk only 7-8% of the milk is processed and passes via milk supply chain while the remaining is distributed as raw milk (GOP, 2013-14). Processing of milk into cheese is a small segment in Pakistan, moreover the eating habits are not developed in Pakistani population along with the increase in price of local as well as imported cheese.
The manufacturing of cheese is one of the best examples of preserving milk, dating back from 6000-7000 BC till now. Cheese like other value added dairy products are among the highly nutritious diet of the world. Cheese comes in great variety of tastes and flavors, in a wide array of shapes, and are highly healthful and nutrimental (Walstra et al. 2006). The utilization of cheese in the form of pizza garnishes, cheese mixes, salads, sandwiches, stuffing has expanded because of dietary resemblance, ease and extensibility being used and cheese quality (Fox et al. 2000). Cheese manufacturing is increasing worldwide at the rate of 4.9% every year (Valhovic et al. 2014).
Cheese is the value added dairy product acquired by the seepage (of fluid) after coagulation of milk proteins through utilization of rennet and starter. Cheese is a mainstream nourishment because of its differing qualities in application, wholesome quality, accommodation and appealing taste. The assorted qualities are because of an expanding information of the innovation of cheese making and the natural chemistry and microbiology of cheese maturing (Sulieman et al. 2013). There are 500–800 assortments of cheese accessible in the universal business sector (Razzaq, 2003).
Mozzarella cheese is placed in the group of “Pasta filata” or stretched cheeses. Stretching is a treatment that gives the curd elasticity which is a dominating functional characteristic of Mozzarella cheese. Melting and stretching are the most important characteristics of Mozzarella cheese which is highly acknowledged in the making of Pizza as it is a chief ingredient (Owni et al. 2009).
Mozzarella cheese is a standout amongst the most prominent cheese varieties on the planet, in light of its essential use in the pizza topping (Kindstedt et al., 2004). The funtional attributes of Mozzarella cheese like shape, composition, meltability, stretchbility and color are changed by the components like milk composition, culture source or type and maturing environment dominating in the midst of the cheese availability (Luecy et al. 2003).
Mozzarella cheese is produced utilizing a paired lactic acid bacteria starter cultures of Streptococcus salvarius ssp. thermophilus and Lactobacillus delbrueckii ssp.bulgaricus (Ahmed et al. 2011).
At a certain point, Mozzarella was made just from water buffalo milk. Presently, it is normally produced using milk of bovine, goat and sheep. There are two types of Mozzarella cheese; i.e. regular Mozzarella which is accessible in low-fat and nonfat structures and has a semi-delicate in texture, versatile composition and is drier than fresh Mozzarella while, Fresh Mozzarella is produced using entire drain and has a gentler texture and sweet pleasing flavor and is commonly pressed in water or whey (Ibrahim, 2003).
Mozzarella cheese also has numerous therapeutical advantages; it is a decent wellspring of protein, vitamins and minerals. Utilization of Mozzarella cheese may secure against gout, an agonizing condition that outcomes in the development of uric acid stones in the joints. The calcium found in Mozzarella cheese additionally has its commitment in body weight reduction and gives insurance against breast tumor and metabolic disorder, which is a gathering of conditions that build the danger of creating cardiovascular disease or stroke (Ibrahim, 2003).
Low fat Mozzarella cheese is a nice wellspring of protein and calcium, furthermore it is non calorie-dense and less in saturated fat, which can prevent from cardiovascular illness, type 2 diabetes, joint inflammation, and memory loss, also block weight reduction endeavors upon consumption. Eating low fat ("part-skim") or fat-free Mozzarella cheese is an extraordinary approach to gain by its alimental advantages while minimizing unfortunate additional items. The calcium in Mozzarella cheese aides keep up healthy pulse rate and blood pressure (Bauer, 2014).
Mozzarella cheese production in the country in demand based being its most use in the pizza sector while its limited use as fresh product. Moreover the industry is using commercial imported culture for production of this cheese. The high price of the culture is one of the factor in the high price of the final product. Therefore the present study was designed with an objective to utilize the local culture for production of Mozzarella cheese. The idea was to maintain the quality of product at its higher regime. Furthermore its quality attributes were compared with the standard cheese produced from commercial culture. In addition the effect of change in fat level of milk on the quality and overall acceptability of the produced Mozzarella cheese was assessed.
Availability: Items available for loan: UVAS Library [Call number: 2266-T] (1).
5.
Quality Enhancement Of Buffalo Milk Yoghurt By Using Glutathione Treated Transglutaminase Enzyme As A Gelatin Replacer
by H. M. Arslan Amin (2009-VA-486) | Dr. Saima Inayat | Dr. Muhammad Junaid | Prof. Dr. Khalid Javed.
Material type: ; Literary form:
not fiction
Publisher: 2016Dissertation note: Yoghurt is a fermented dairy product and intensively used in all over the world. It is very popular in sub-continental region due to its high consumption as compare to other regions of the world. Fermentation of milk is carried out by mixture of lactic acid bacteria. Synergistic effect of Streptococcus thermophillus and Lactobacillus delbrueckii ssp. bulgaricus is a key factor which determines the rate of fermentation process and quality of yoghurt. In traditionally made set yoghurt, protein gel is stabilized by weak non covalent interactions (hydrogen bonding, electrostatic interactions and hydrophobic bonds). Addition of Transglutaminase enzyme (TGase) can provide opportunities to increase covalent bonding and cohesiveness which ultimately enhances the gel consistency with reduction of syneresis.
For the production of yogurt standardized buffalo milk of 5.5% fat and 9.5% SNF contents were used. Milk was pasteurized for 15 seconds at 72°C to kill the pathogenic bacteria and cooled to 42°C. After cooling the Glutathione treated Transglutaminase enzyme was added in the milk with different concentrations (1.25g/250ml, 2.50g/250ml, 3.75g/250ml and 5g/250ml) and cooled to 42°C. While the control sample was prepared without the addition of Glutathione treated Transglutaminase enzyme. After that each treatment was inoculated with standard yoghurt culture (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus) at the rate of 2% at 42°C for 3-4 hours and each sample was stored at 4°C in a refrigerator for 28 days. The physico-chemical parameters such as pH, acidity %, fat %, protein % and syneresis % were observed weekly till 4 weeks.
The quality comparison of prepared yoghurt was carried out by using Two Way Analysis of Variance (ANOVA) technique under Completely Randomized Design. Significant means were compared using Duncan’s Multiple Range (DMR) Test with the help of SAS 9.1.
Results showed variations in pH, acidity %, fat%, protein %, snf% and syneresis % values due to the production of Yoghurt with Glutathione treated Transglutaminase in different percentages. pH in different treatments decreased from 4.71 – 4.61. Acidity % during storage period increased from 0.40 % to 0.43 %. Fat % also showed some variation during storage period decreased from 5.37% – 4.49 %. Protein % in different treatments increased from 4.10 % – 4.27 % and SNF % in different treatments increased from 9.81% – 10.00 % . Syneresis % in different treatments decreased from 5.17% - 3.48 %. Sensory evaluation was carried out by a panel of 06 semi trained people, using criteria of appearance, taste, color, flavor and whole acceptability on a 9 points hedonic scale. Color, taste, aroma, acidity, appearance and overall acceptability showed non-significant results as compared with controlled sample after 28 days.
Results of the present study showed that yoghurt prepared with Glutathione treated Transglutaminase enzyme reduced the syneresis and enhanced the nutritional aspects of yoghurt.
Availability: Items available for loan: UVAS Library [Call number: 2483-T] (1).
6.
Balqees Mehmood Shakhsiat aur fun
by Muhammad Junaid Ikram.
Edition: 1stMaterial type: Publisher: Lahore Adara al awais 1998Availability: Items available for loan: UVAS Library [Call number: 920 Junaid 22187 1st 1998 Biographies] (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).
