Protein Concentration in Food: Changes over Time

Protein Concentration in Food: Changes over Time Sou, Oi Ying   Food processing practical report Ultra filtration UF Experimental data Medium inlet pressure(bar) exit pressure(bar) Average pressure(bar) Pressure Difference(bar) Temperature Retentate flow rate(Ls-1) Flux rate(Ls-1) A. Flux rate with water Cold water 3 1 2 2 18.7 0.053 12.8 4 2 3 2 19.7 0.053 20.3 5 3 4 2 20.5 0.0605 29.3 6 4 5 2 21.4 0.053 37.6 7 5 6 2 22 0.0605 46 4 3 3.5 1 22.6 0.0189 22.6 4.5 2.5 3.5 2 23.5 0.0151 30 5 2 3.5 3 24 0.098 27.3 5.5 1.5 3.5 4 24.6 0.1286 26.6 6 1 3.5 5 25 0.1428 27 Discussion During ultrafiltration, molecules in solution are separated based on size using membranes (filters) of different pore sizes. Also, the feed stream is continuously re-circulated across the membranes with the primary objective of removing excess water and buffer from the feed stream. The simplest ultrafiltration setup consists of a vessel to hold the retentate and a pump to recirculate the product over the membranes. According to the experimental results, temperature increased when average pressure and pressure different are increasing. About retentate flow rate, it only affected by increasing the pressure different but not average pressure. Also, flux rate of cold water only affected by increasing average pressure while it seems remain constant by increasing pressure different. Ultrafiltration of skim milk Because rejection = , Cf is the concentration of any component in the feed and Cp is the concentration of that component in the permeate. So, the result is in below table.       Concentration of skim milk time(min) pressure(bar) temp(oC) permeate flux rate(Ls-1) Retentate solids% Retentate protein % Retentate lactose % 0 6,2 42 10 0.5 3.38 4.67 15 6,2 38.6 8.666666667 4 4.02 4.66 30 6,2 36.1 7 4.5 5.04 4.76 45 6,2 37.8 6.666666667 5 6.5 4.87 60 6,2 41.7 6 5 8.6 4.82 75 6,2 45.2 5.333333333 5.5 11.4 4.8 Calculation: 4   (initial factor for protein) Use this information to show protein concentration changes with time and how the flux rate change with protein concentration, and explain any other findings. With respect to flux behaviour, the retentate and permeate fluxes decrease over time at different operating pressures during filtration. The filter medium resistance increases linearly with the filtration time at different operating pressures during concentration. Therefore, the permeation flux rate of skim milk will decrease with times. The major problem in membrane separation process is decline in flux over time of operation. This flux decline is attributed to the fouling (In this case, retentate solids and protein accumulated) through ultrafiltration of membrane. Membrane fouling is affected by three major factors, namely, the membrane material properties, the feed characteristics and the operating parameters (Platt Nystrà ¶m, 2007). Since we have known that retentate and permeate fluxes decline during concentration of milk was measured with time of process, the possible reason has been suggested. In early staged of milk ultrafiltration, the characteristics of proteinaceous foulants and flux, and adsorption fouling is probably the primary mechanism of flux decline. Reverse Osmosis RO experimental data Medium Pressure (bar) Temp(oC) return flow(Ls-1) Flux rate(Ls-1) Feed conductivity(uS) Permeate conductivity(uS) Cold water 10 17.7 0.312 0.012666667 920 44 20 19.1 0.028666667 958 29 30 20.3 0.075384615 999 19 40 21.7 0.072 1041 13 50 22.7 0.224 0.065333333 915 9 Estimate the power consumption for the highest pressure 1. Because pressure head = , g = 9.81m/s2, p1 = 0 and = 1ÃÆ'-103kg/m3 So, power = mass flow rate ÃÆ'- pressure head ÃÆ'- g = mass flow rate ÃÆ'- ÃÆ'- g = mass flow rate ÃÆ'- Because 1bar = 14.7psi = 105N/m-2 So the lowest power = 10bar = 10ÃÆ'-105N/m-2 = 1ÃÆ'-106N/m2, the highest power = 50 bar = 50ÃÆ'-105N/m-2 = 5ÃÆ'-106N/m2 P10 = mass flow rate ÃÆ'- =   = 312W P50 = mass flow rate ÃÆ'- = = 1120W Because rejection = , Cf is the concentration of any component in the feed and Cp is the concentration of that component in the permeate. So, the result is in below table.       Juice Pressure(bar) Temp.(oC) Flux rate(Ls-1) Retentate solids(%) Permeate solids(%) 10 15.7 0.017333333 5 0 20 18.7 0.016666667 5 0 30 20.1 0.110666667 5 0 40 21 0.116666667 5 0 50 22.6 0.278571429 5 0 0 min 50 26 0.257142857 5 0 5 50 26.2 0.03 13 0 10 50 23.6 0.02 15 0 15 50 23.2 0.013333333 22 0 20 50 25.7 0.014 21 0 25 50 29.7 0.009333333 26 0 30 50 33.3 0.005 30 0 35 50 36.4 0.002166667 22 0 Plot 1: flux rate curve of water and juice with pressure The flux of a RO membrane is directly proportional to temperature and pressure. According to the diagram, the flux rate pf water and juice are increasing because of the risen of pressure. In addition, the flux rate of water should be higher than the flux rate of juice at the same pressure condition because of the viscosity. However, it is not an experiment in ideal condition. In these two trial, the temperature of two sets of experiments are slightly different which might affect the result and difficult to compare. Plot2: Temperature of juice and cold water against pressure Is there any change of temperature during this procedure? If so, why? The effect of temperature on membrane performance is the vital indicator. Energy consumption is increased as the applied pressure increases (Elimelech, M., Phillip, W. A, 2011). Under the same pressure, temperature of juice and cold water are both increasing with the risen pressure, therefore, we can state that pressure increased, temperature increased at the same time. It is because the energy for processing juice have been dissipated. How do the permeate flux rate and retentate solids change with time? Plot 3: flux rate curve of juice with time Plot4: Retentate solids of juice against time Base on the result, the osmotic pressure of a solution is related to the concentration of the solute and temperature. They are in proportional relationship. The flux rate of juice decreases with increasing retentate solid concentration. However, the acidic properties of juice might lower the rate of process. Because it would cause the membrane imperfections. From some studies, it revealed that higher the number and concentration of low molecular weight water soluble components in the raw juice, higher processing loss in reverse osmosis (Jiao, B., Cassano, A., Drioli, E., 2004). Permeate flux is a function of feed concentration. Feed concentration differs with membrane and permeate flux is a function of feed concentration. As feed concentration increases, permeate flux decreases and vice versa (Jayaraman, K. S., Das Gupta, D. K., 1992). Given by graph, the flux rate of juice is almost approach zero after 35mins. It is because the concentration of retentate solids have been accumulated by time. The reason is that the increase of retentate solids (foulants), which accumulated on the membrane would stop the process until it cleans. Plot 5: Temp of juice against time The average processing capacity can be increased by temperature rise of feeding material. Relationship of soluble solids and sugar was slightly increased. At higher temperature, the membrane permeability coefficient is higher, the diffusivity coefficient in the solution increases and the viscosity coefficient decreases. The average processing capacity can be increased with the increased temperature of feeding material. The relationship between soluble solids and sugar increased slightly under higher temperature condition. At higher temperatures, the membrane permeability coefficient is higher, the diffusion coefficient in the solution increases and the viscosity coefficient decreases (Ghosh, A. K., Jeong, B. H., Huang, X., Hoek, E. M., 2008). Therefore, in our experiment, the temperature of juice is increasing by times. Use the sugar concentration data to estimate the rejection for sugar and compare this to the ideal situation In ideal condition, the speed of permeation of solvent depends upon the pressure applied, provide that the concentration of the solute constant and thus the osmotic pressure of the solution remains constant. For an ideal situation, the flux is linear to the pressure of feed. Also, requirements of ideal membrane are as follows: (i). The highest possible water permeability (ii). Greatest possible selectivity (iii). High pressure resistibility (iv). Reasonably long life when using in production (Martin, M., Eon, C., Guiochon, G, 1975) However, in our experiment, that is not in an ideal condition. The concentration of retentate solids are increasing and the membrane blocked to stop the process after 40 mins. Therefore, the rejection for sugar would happen when the foulants are on the membrane and not allow the juice pass through anymore. In this case, it happened at 40 minutes in the process. The flux rate is almost dropped to 0%. In normal industry, there are cleaning process to ensure the whole process are keep running and would not be stopped. References:         Ã‚   Bahnasawy, A. H., Shenana, M. E. (2010). Flux behavior and energy consumption of ultrafiltration (UF) process of milk. Australian Journal of Agricultural Engineering, 1(2), 54. Younos, T., Tulou, K. E. (2005). Energy needs, consumption and sources.  Journal of Contemporary Water Research Education,  132(1), 27-38. Jimenez-Flores, R., Kosikowski, F. V. (1986). Properties of ultrafiltered skim milk retentate powders.  Journal of Dairy Science,  69(2), 329-339.1 Jiao, B., Cassano, A., Drioli, E. (2004). Recent advances on membrane processes for the concentration of fruit juices: a review. Journal of food engineering, 63(3), 303-324.Al-Mutaz, I. S., Al-Ghunaimi, M. A. (2001, October). Performance of reverse osmosis units at high temperatures. IDA. Jayaraman, K. S., Das Gupta, D. K. (1992). Dehydration of fruits and vegetables-recent developments in principles and techniques. Drying Technology, 10(1), 1-50. Ghosh, A. K., Jeong, B. H., Huang, X., Hoek, E. M. (2008). Impacts of reaction and curing conditions on polyamide composite reverse osmosis membrane properties. Journal of Membrane Science, 311(1), 34-45 Elimelech, M., Phillip, W. A. (2011). The future of seawater desalination: energy, technology, and the environment. science, 333(6043), 712-717. Martin, M., Eon, C., Guiochon, G. (1975). Study of the pertinency of pressure in liquid chromatography III. A practical method for choosing the experimental conditions in liquid chromatography. Journal of Chromatography A, 110(2), 213-232. Contamination Level of Mold: Entero Bacteriaceae Family Contamination Level of Mold: Entero Bacteriaceae Family Chapter III   METHODOLOGY 3.1. Introduction The research methodology used a qualitative approach. The study has been conducted in November 2016 in Bandung city. The survey, observe and microbiology contaminant sampling was collected from food vendors premises as the study population. The study design used to evaluate knowledge, attitude, and practice (KAP) and contamination level of mold also Entero Bacteriaceae family. In addition, socio-demographic questions and others premise information that can be predicted factors for understanding the relationship between food vendors characters.   Furthermore, support from the local government as a regulatory role on food street activities was investigated to identify and to understand how to enhance better implementation in food hygiene. 3.2 Methodology Design and Study Instrument 3.2.1 Methodology design The data survey presented the understanding, behavior, and implementation of hygiene practice by food vendor premises. The aspects were all assessed as follow: Knowledge; an assessment of hygiene practice knowledge was carried out using an interview survey. Attitude; Likert 5 points agree-disagree questions were asked for measuring the food handlers attitude. Practice; an observational study of food hygiene was used in the assessment. This audit used the score for measuring of its implementation. Microbiological contaminations sampling; an investigate study of cleanliness of cooking utensil. The presence of an implementation of regulatory aspects of street foods. The social demographic questions and food premises information were also surveyed to explore the characteristics of respondents. 3.2.2 Study Instrument In this present study, we used a constructed questionnaire based on the references. This questionnaire consist of (1) General questions regards to social demographic characteristics, (2) Food premises information (3) Knowledge, Attitude, Practice questions (4) The presence of an implementation of regulatory aspects. Socio-demographic questionnaire as a complementary questionnaire consists of factors predicted that influence on respondents (food street vendors) knowledge, behavior and practice on food safety and hygiene which are constructed based on literature such as age, sex, marital status, education level, number of employment, employee type (self employer/ employee), how long they have been a seller and also their profit per day. Food premises information showed the premises condition and type of food that sale, food preparation, food packaging material, type of facilities (i.e stall, mobile street vendors, tend, stand, or handed), and also hour length of sale. The knowledge questionnaire, consists of 10 questions containing multiple choices questions, was giving to respondent for reviewing their awareness on food hygiene. The questions concerning knowledge about food hygiene from storage, cleanness, preparation and personal hygiene linked to transmission of microorganisms, and respondents were asked to choose one answer from among three options. The questions of attitude consist of 10 questions. The answer options for these question used Likert scales ranging from 1 (very disagree) to 5 (very agree) to show a subjective response on their agreement on food hygiene implementation. The scores for attitude were similar with the range from 1-5, the higher score represents better manner on food hygiene. The scores for practice on food hygiene were calculated from 50 questions based on an audit that observed on premises. The appearance of reducing cross contamination on food handlers/vendors was noted e.g. personal hygiene, food storage, pest control and utensil/ equipment. The source of water supply was investigated also the ice (whether commercially bought or self-made). The presence of food exterior facilities and sanitary utilities was determined e.g. availability of toilets, adequate washing facilities, sink, surface, waste, and food packaging. The availability of cool storage/refrigeration storage was also checked. For microbial contaminant testing, VBRG dip slide type was used to determine whether there is evidence of entero bactericeae and mold in the food street premises e.g. cutting board, utensil, plate, glass and other food equipment. 3.3 DataCollection An interview survey was carried out in one sub-district in Bandung city in November 2016. The minimum number of food street vendors was randomly selected as much as the result from prior validation questionnaire tests. The validation of questionnaire process has been conducted in July 2016 in Bandung city for improving the questionnaire and determining the appropriate sampling size also an area which should be chosen. The sample size minimum required for the study are calculated based on as the result of the prior validation study. Based on the level of significant of 5% with a confidence interval of 95%, 253 premises/ respondents are needed for this study. In this cross-sectional study, we surveyed 272 respondents from one sub-district. Face to face interview was conducted in November 2016 by using Bahasa/Indonesian language and common Sundanese language as an ethnic language in the study area. All study instruments were in Bahasa/ Indonesia version and interview were taken on their premises. The study was supported by assistant researchers, as interviewers, who had food science background and understood both languages. The interviewer had been trained with regard to study such as food safety in a brief view, how to conduct the survey, interview method, study instrument, and ethical requirement including informed consent. The interviews were set in respondents premises to easier for answering the questions and to observe their practice on food hygiene. Informed consent form was read out by the interviewer. The interview taken as well as the respondents   were agreed to participate, questions were read out   by interviewers, and interviewers also marked the answer on the questionnaires instruments. The interviewe rs also acted as an auditor for observing the hygiene practice on their premises and recorded into practice audit sheet. Sampling for determining microbial contamination used a dip slide that consists two agar sides, the first side the red side was used to confirm the presence of Entero Bacteriaceae family and the second side that flaxen color for mold. The sampling procedures were: Remove the dip-slide from the tube by pulling the plastic tab at the top of the dip-slide. Take care not to allow the dip-slide agar (the jelly type substance on each side) to hit the edge of the clear plastic tube. Place dip slide agar down onto the surface, and make sure the entire agar has full contact with the surface.   Keep the agar applied to the surface for approximately 20 seconds, then turn over to the other side and apply the other agar to the surface. Replace the dip-slide into the sterile plastic tube taking care not to damage the agar. Next, place the dip-slide tube into a dip slide incubator at 37 0C or warm place. The incubation period is 2- 3 days for bacteria. The optimum temperature for most mold/yeast is from 27 0C to 30 0C and the incubation time is 2 7 days. After 3 days, generally, both of results were read and recorded. Bacteria present in the sample liquid will grow and form colonies. The selective agar for Entero Bacteriaceae colonies will appear in red. A bacterial reference chart is used to determine the number of bacteria in the sample. The bacteria reference level has five charts that showed how many colony-forming-unit( CFU)/cm2 e.g. 2.5 (very slight growth), 12 (slight growth), 40 (moderate growth), 100(heavy growth) and 250 (very heavy growth). While the evidence of mold form appears in the furry colony. The chart of mold consists of slight (0.4), moderate (1.6) and heavy (4). 3.4 Statistical analysis Food safety knowledge scores for the respondents were, calculated based on the multiple choice answer from   each question, only for the items of correct answers was assigned a score: +1 and 0 in the case of dont know/wrong option. For ten attitude questions were calculated from the Likert scale point 1-5, for question number 2, 6 and 9, the reversible point was used to calculate the point because it was a negative question. The answers were classified as +1 point when the auditor/interview found out the correct evidence on respondents premises and 0 points when they failed to find it. However, not available marked for a respondent who did not have the correlation item with the type of food. The total percent score for the respondents attitude was then calculated by sum up all score in total. Statistical analysis of the association between Knowledge, Attitude and Practice (KAP) questionnaire answers, social demographic characteristics and food information also microbial contamination level were carried out to determine the relationship between them and explore the pattern. Data were analyzed by SPSS version 20. Based on the level of significant of 5% with a confidence interval of 95%, all analyses were considered statistically significant at P ≠¤ 0.05. The descriptive analysis, Fishers χ square test, was performed to describe socio-demographics characteristics of the respondents. Analysis of variance (ANOVA) and t-test was used for comparing mean scores between all factors and observing the relationships between KAP and predicted factors that may influence on KAP. Furthermore, to investigate whether this relationship systematically varied by specific socio-demographic characteristics for Independent variables included age, gender, and education level, and work experience, type of job which was full time or part time and having attended courses on food hygiene were conducted. Ethicalconsiderationreview This study has approved by Ethics Committee of the University of Birmingham, School of Chemistry Engineering, United Kingdom. The identity of respondents will be treated securely and the outcome only will be used for academic purpose. The researcher and university supervisor will keep all data collection with confidential care. Chapter IV RESULT 4.1 Sociodemographic We obtained 272 responses from one area, 269 participants have completed the questions (response rate= 98.89%). Distribution of some socio-demographics characteristics respondents described in Table 1. Variable category Number % Gender Male 205 76.21 Female 64 23.79 Age group (years) Teen(15-24) 42 15.61 Young people (25-40) 102 37.92 Mature (41-60) 119 44.24 Elderly (> 60) 6 2.23 Marital Status Married 216 80.30 Unmarried 53 19.70 Education Level No Schooling 5 1.86 Elementary school 71 26.39 Junior High School 99 36.80 High school 78 29.00 Diploma 10 3.72 Graduate 6 2.23 Profit per day (IDR) < 50 K 17 6.32 50   100 K 131 48.70 101   200 K 64 23.79 201 300 K 26 9.67 301 400 K 9 3.35 > 401 K 22 8.18 Eat your own product Never 13 4.83 Rarely (1 4 times a month) 68 25.28 Sometimes (1-4 times a week) 75 27.88 Often (> 4 times a week) 35 13.01 Very often (every day) 78 29.00 Job type Part time 5 1.86 Full time 264 98.14 4.2 Food premises information