Research Symposium-2015

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Browsing Research Symposium-2015 by Subject "Animal Production Technology"

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    Development of drinking yoghurt by incorporating corn (Zea mays) milk and corn seeds
    (Uva Wellassa University of Sri Lanka, 2015) Mendis, R.I.W.; Abesinghe, A.M.N.L.; Samaraweera, A.M.; Gunawardhane, L.K.A.
    Cereal grains are considered as important sources of dietary proteins, carbohydrates, vitamins, minerals and fiber for people all over the world (Chavan and Kadam, 1989). Corn (Zea mays) is locally grown cereal that can be purchased at low price from several areas in Sri Lanka. Corn milk is considered as a new innovation, especially in making yoghurt based products. Vegetable based corn milk yoghurt is an alternative to substitute the cow milk based yoghurt. Drinking yogurt is the fastest growing food and beverage category in worldwide (Yasni and Maulidya, 2013). However, still value added drinking yoghurts are rare in Sri Lankan market. Adding cereal grains is a perfect way to upgrade a drink to a nutritious breakfast. Therefore, this study was conducted to develop yoghurt by incorporating corn (Zea mays) milk and corn seed to cow milk. Methodology The study was carried out at Lucky Lanka Milk Processing Com. Ltd (LLMP), Matara and Uva Wellassa University. Six experimental trials with different treatments were conducted. In trial I, mature fresh corn seeds, mature boiled corn seeds and germinated corn seeds were separately used to extract corn milk and the best extract of corn milk was evaluated by sensory properties (odor, taste, color and mouth feel) using untrained panelist. In trial II the most compatible sugar (8%, 9% and 10% w/v) and gelatin (0%, 0.2% and 0.4% w/v) levels for different corn milk percentages (5%, 10%, 15% and 20% w/v) were identified. After selection of appropriate combinations of sugar and gelatin levels, trial III was done to select the best corn milk incorporation level by narrow downing the corn milk percentages (6%, 8%, 10%, 12% and 14%). Preserved in sugar syrup and boiled corn seeds were crushed into two sizes (> 3.15 mm and 2 mm –3. 15 mm) to prepare different types of corn seeds. Trial IV was carried out to select best corn seeds particles on the textural basis and trial V was done to assess the consumer acceptability for the presence of corn seeds in the corn milk incorporated drinking yoghurt. Finally three treatments (trial VI) were prepared and evaluated on sensory, chemical and microbiological properties. The sensory evaluation was done using 35 untrained panelists. In chemical analysis, proximate analysis (moisture content, crude fat, total solid, crude protein, ash and crude fiber content) was conducted. pH value and titratable acidity were evaluated and microbiological analysis was done for Yeast and Moulds, and Escherichia coli for three weeks in one day interval. The sensory data were analyzed using Friedman nonparametric test. Complete Randomized Design was conducted and data obtained from chemical and microbiological tests were analyzed by Analysis of Variance using the General Linear Model procedure of SAS. Significant means of treatments were separated using the Least Significant Difference test (P< 0.05). Result and Discussion In trial I, boiled corn seeds (mature) based method was selected to extract corn milk. Other two methods were rejected due to the unpleasant odour and taste which may be due to the activation of various food enzymes and breaking down the higher molecular components to simple molecules during germination. Eight per cent sugar (w/v) for 5% corn milk (w/v) and 10% sugar (w/v) for other 10%, 15% and 20% corn milk (w/v) incorporation levels were selected due to desirable sweetness. The gelatin level (w/v) was selected as 0% due to the presence of appropriate drinking yoghurt properties including texture, mouth feel, appearance and viscosity. The whey separation has been prevented by stabilizing effect of corn starch in corn milk. In sensory evaluation, 8% corn milk incorporation level was significantly highly preferred by panelist with respect to mouth feel, taste and overall acceptability (P<0.05). However, there is no significant difference in color and aroma of the three treatments (P>0.05) (Figure 01). Addition of corn milk had no influence to change colour and aroma of the product. Overall acceptabilty 6 4 2 0 Aroma 7% corn milk incorporation level 8% corn milk incorporation level Taste Mouth feel 9% corn milk incorporation level Figure 01. Web diagram for level of corn milk incorporation in sensory evaluation In trial IV, sugar syrup based method was rejected due to hardness of the seeds and crushed boiled corn seeds were selected. Further, the sensory results revealed that the preference (taste, aroma, mouth feel, color and overall acceptability) for corn seeds >3.15 mm or 2 mm to 3.15 mm particles incorporated drinking yoghurt is less whereas preference for corn milk incorporated drinking yoghurt without corn seeds was high. The observed difference is due to the disturbance for the drinkable property of product by presence of corn seed particles. The composition of the selected corn milk incorporated drinking yogurt is given in Table 01. There was a significant difference between treatments for change in pH with the storage period (P<0.05). pH values of the T8 (with preservative) and control were not changed dramatically. Control of pH by potassium sorbate could be due to inhibition of the activity of starter culture by inhibiting various enzymes in microbial cell (Rajapaksha et al., 2013). There was a significant difference between treatments with respect to acidity (P<0.05) and titratable acidity increased significantly with storage period and in treatments without preservatives. According to Rajapaksha et al. (2013), titratable acidity of yogurts increased over the time and acidity of yoghurt without potassium sorbate increases drastically than other treatments reflecting the inhibitory activity of potassium sorbate on post fermentation. Table 01. Composition of select corn milk incorporated drinking yoghurt Raw material Percentage Quantity (g) Milk 79.54% 867.03 Dairy cream 1.03% 11.33 SMP 1.42% 15.49 Corn milk 8.00% 87.20 Sugar 10.00% 109.00 Total 100.00% 1090.00 There were no contaminations with Coliform and Escherichia coli and thus safe for human consumption. There were no yeast colonies in T8 and control sample. At day 11, yeast colonies were exceed the SLS standards of <1000 only in T7 (without preservative). Proximate analysis revealed all the physiochemical characteristics of corn incorporated drinking yogurt (protein, fat, ash, fiber and total solid), except moisture significantly higher compared to plain drinking yoghurt (P<0.05). Usually drinking yoghurt does not contain fiber. However, due to addition of corn, milk fiber was increased up to 0.5%. Conclusion Eight per cent corn milk incorporation level with selected sugar (10%) and gelatin (0%) level has best consumer preference with respect to the taste, mouth feel and overall acceptability (P<0.05). Moreover, drinking yoghurt without corn seed particles is preferred by the panelists. Shelf life of product without potassium sorbate is around 11 days at 4 ºC with respect to microbiological analysis and physiochemical analysis.
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    Quail egg consumption: patterns, preferences and perceptions among consumers in Galle district, Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2015) Abeyrathna, H.M.W.N.
    Owing to the changing life style and food availability, Quail egg is being used as analternate potential and acceptable egg source in many parts of the world. Regular consumption of quail eggs helps fight against some diseases such as digestive tract disorders, tuberculosis, asthma, diabetes and stomach ulcers, strengthen the immune system, promote memory health, increase brain activity and stabilize the nervous system. Nutritional value of quail eggs is higher than those offered by other eggs and contain high amount of antioxidants, minerals, and vitamins and less amount of cholesterol (Tanasornet al.,2013).Compared to chicken eggs, there is a limited body of scholarly literature in related to consumer behavior of quail eggs. Most literature to do with quails and their eggs has focused on production and processing issues, not consumer market studies. Therefore, present study was aimed to determine the quail egg consumption patterns, preferences and perception among consumers in Galle district, Sri Lanka. Methodology Ten Divisional secretariats (Akmeemana, Ambalangoda, Baddegama, Balapitiya, Bope- poddala, Elpitiya, Galle four gravates, Habaraduwa, Thawalama and Yakkalamulla) in Galle districts were purposively selected as the research area. 200 consumers, who toured to local markets and supermarkets in those areas were purposively selected and interviewed.Information related to consumers’ age, sex, education, occupation, income, consumption pattern and attitude towards quail eggs were collected using a pre-tested questionnaire with havingboth open and closed form questions. Primary data were processed and analyzed using the Microsoft Office Excel (2003) and SPSS 20 package. The association between demographic data and egg consumption pattern was tested using chi square, with a p-value of less than 0.05 considered statistically significant. Result and Discussion As to present study produced data it is revealed that majority of the respondents (57%) did not consumed quail eggs, while 43% consumed. Table 01, shows the relationship between demographic data with the quail egg consumption. These demographic indices did not significantly (p>0.05) influence the quail egg consumption, except gender, with female respondents consuming less eggs. Findings of the study is revealed that purchasing frequency is not satisfied, because most of the respondents who consume quail eggs (81%) rarely purchasedeggs every month. Most of them had purchased quail eggs once or twice during the past year. Findings revealed, quail eggs were not a regular food item in their diet. Boiled eggs were most preferred (61%) as egg serving method than any other preparations (Figure 01). This can be expected because of the small size of quail eggs,it is inconvenient to prepared comparing withother poultry eggs especially chicken eggs. Consumers had purchased quail eggs from Food Cities (34%), from Farm shops (30%), from grocery stores (20%) and directly from farms (11%). 5% of consumers had supplied quail eggs by home production.
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    A study on microbial contaminations, sources and preventive measures in salted butter production in a commercial dairy plant
    (Uva Wellassa University of Sri Lanka, 2015) Wickramanayaka, T.D.G.; Abeyrathne, E.D.N.S.
    Dairy fat spreads are milk products relatively rich in fat in the form of a spreadable emulsion principally of the type of water-in-milk fat that remains in solid phase at a temperature of 20 °C (Codex Standard for Dairy Fat Spreads, 2006). There are two kinds of butter as sweet cream and ripened-cream. Sweet cream butter may or may not contain salt (Fernandes, 2008). To overcome the high demand of butter, a reputed dairy company in Sri Lanka engages in manufacturing salted butter. However, finish product frequently contain high microbial load before releasing to the packing which leads to quick rancidity. Consequently, it has become a problem to the company to obtain a profit. Therefore, this research was carried out to assess microbiological quality at different production steps to determine the sources of microbial contamination in salted butter production. Methodology A preliminary study was carried out to identify possible sample collection points including swab sampling points during production process. Samples were collected from raw cream, before and after pasteurization, after aging, during churning, final product, and wash water of butter granules and the churner. Swab samples were collected from cream and aging vats, hands of permanent workers (randomly), and inside and outside of the churner. Time and temperature during storage of cream in the cream vat, pasteurization and aging were recorded. Sample collection procedure was repeated for every batch up to identification of the contamination points. Quality of samples was evaluated by performing microbiological tests (total colony count, Coliform and fecal Coliform). According to the test results, contamination points were identified and microbiological (E. coli, yeast, and moulds), chemical (free fatty acid level of the final products) and physical (foreign matter observed from naked eye) properties were further analyzed. Entire tests were conducted in triplicate according to the analytical testing procedure of company. Data were finally analyzed by mean value comparison using Microsoft Excel 2013. Further, analyzed data were compared with the standards (SLS 279:1988). Results and Discussion According to the preliminary analysis, raw cream was stored for 4-5 hours at 7-8 °C in a cream vat. Mean total colony count in raw cream of seven batches was ranged from 110×10 to 127×10 cfu/g and Coliform and fecal Coliform bacteria were detected in all samples tested. After pasteurization (95 °C, 20 minutes), mean total colony count of all samples were lower than 10 cfu ⁄g and after aging (5-7 °C, 12 hours) (Table 01). Coliform and fecal Coliform bacteria were detected in all samples tested however, after pasteurization and aging, Coliform and fecal Coliform bacteria were not detected in any of the samples.