Department of Food Processing Technology Research Projects 2007-2009

Design of a Processing Plant for Production of Banana Chips / Crisps

¹P.Marandure; ²P.Muredzi; ³C. Winini

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
³Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; cwinini@hit.ac.zw
²Dean – School of Industrial Sciences & Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; pmuredzi@hit.ac.zw

A study was carried out on the design of a processing plant for production of savoury banana chips/crisps. The aim of the project was to improve the existing processing designs, which are into production of savory banana chips. This design was done to improve the quality of banana chips and maximize their production i.e. commercialization and increasing their acceptability on the market. This design was completed after some research on designs available for processing of banana chips. The existing designs have setbacks like failing to meet standards of products expected by consumers.

Banana chips products are not satisfying customers and have no desirable quality attributes expected by consumers both local and internationally. After a thorough research and close look into existing designs it was concluded that there are some inadequacies in existing designs. Inadequacies seen include processing steps like immersion of green bananas in warm water, cooling of banana chips prior to packaging, drying and cleaning / washing. A processing plant for production of savoury banana chips was designed. Improving the existing designs was found to yield better results in terms of product quality. TRIZ and Axiomatic were used as design methodologies.

Redesigning of Suncrest (Pvt) Ltd Poultry Processing Plant

¹N.Tamirepi; ²P.Muredzi;

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Dean – School of Industrial Sciences & Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; pmuredzi@hit.ac.zw

The main aim of the study was to redesign Suncrest factory so that it meets standards and enable it to be HACCP certified. This involved drawing and analysis the existing factory ground floor layout and coming up with a modified layout using AutoCAD. The major areas of concern included a possible location of toilets for female factory workers and laboratory. Other suggested changes that could not be represented diagrammatically include installation of pallets in the cold rooms, changes to be made to the floors, walls, internal drainage. The layouts have been included in the appendix section.

Design of a Soymilk continuous processing plant with suitable HACCP system. (Case of INSTIFOODS, Harare Institute of Technology, Belvedere, Harare)

¹N.Mashoko;²M.Mudyiwa; ³P.Muredzi

¹ Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
² Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; mmudyiwa@hit.ac.zw
³Dean – School of Industrial Sciences & Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; pmuredzi@hit.ac.zw

INSTIFOODS has a small food processing plant with very low production volumes resulting in its products being unable to penetrate the local market. Thus designing a suitable plant that would result in increased production margins and quality products would help put its name on the map. The study project involved designing a production plant capable of commercial production. The project was carried out at the Harare Institute of Technology where the company is located. The company has since developed some products from Soya beans. Currently on production is soymilk, soy -yoghurt, soy- drinks and soy -ice cream all being soy based products.

Designing a Banana Winery

¹V.F. Matiyenga, ² A. Musengi; ³P.Muredzi

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
² Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; amusengi@hit.ac.zw
³Dean – School of Industrial Sciences & Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; pmuredzi@hit.ac.zw

Winery design is a careful blend of art, engineering and science; it requires a very clear vision of what is to be achieved in the new plant and proper planning. The main aim was to establish optimal design solutions for the development of alternative industries in wine making processes so as to reduce post-harvest losses in banana production.

Wine making poses many quality and safety hazards. In this work, an effort is made for quality and safety production of banana wine by describing and outlining the movement of raw materials through to the end product from reception. The study reveals the design of a relevant factory design that promotes production of equality and safe product.

Like most horticultural crops, there is considerable wastage due to post – harvest handling hence the need for commercial equipment and sufficient technology for processing of bananas. It is through an in-depth understanding of winemaking practice and processes that the most innovative and appropriate design solutions can be found. To ensure functionality of a winery, logistics of raw material reception should be defined, specific requirements of the processes to suit the style of wine to be produced, efficient workflows, and occupational health and safety matters and efficient energy systems. The challenge encountered in the research work was to plan, design and construct cost effective processes

Design modification of chiller cabinets at Commercial Refrigeration (Pvt) Ltd Company, Harare.

¹T. Chasara; ²E.Z. Ganha, ³P.Muredzi

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Box Be 277, Belvedere, Harare; eganhai@hit.ac.zw
³Dean – School of Industrial Sciences & Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; pmuredzi@hit.ac.zw

The main thrust of the study project was the simultaneous and systematic approach to the design and production of thermally efficient and reliable refrigeration cabinets. The simultaneous approach entails the concurrent performance of the product design and process design activities through the use of cross – functional teams. The essential ingredients of the systematic approach are (1) the establishment of the primary need of a product /service, (2) well detailed design specifications,(3) logical thought processes e.g. brain storming, (4) the address of regulatory and statutory requirements and (5) the importance of evaluating a variety of possible solutions to a problem. Cost considerations and market competition dictate the need to produce designs that are both functionally sound and economically viable. The increasing importance of the human aspect in engineering design has been addressed through ergonomic considerations.

Development of Vegetable Cream from Trichilia Emetica (Natal Mahogany) Seeds.

¹M.Chipungu; ²P.Muredzi

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Dean – School of Industrial Sciences & Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; pmuredzi@hit.ac.zw

Development of the vegetable cream was mainly based on the current indigenous way of obtaining the Trichilia Emetica extract, which is currently used for cooking green vegetables as well as extraction of oil. This project however involved intensive laboratory investigations a well as observed aimed at evaluating and producing the best quality possible.

Design of a Miniature Pectin Processing Plant

¹1F.Shawarira; ²D.N.Moyo; ³P.Muredzi

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; dmoyo@hit.ac.zw
³Dean – School of Industrial Sciences & Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; pmuredzi@hit.ac.zw

The study project involved the design of a process plant for production of commercial grade pectin from citrus peels and apple pomace both of which are waste products of commercial fruit juice extraction. The study involved research into the background of the production, and the benefits of the product in various food products. A critical assessment of the existing pectin process plant designs was conducted so as to facilitate process improvement. The critical evaluation was vital in the design project as it gave an insight into the environmental, capital and technical issues that existing designs fail to address. The design was thus molded from this evaluation.

Design of a mini plant for extraction of essential oils from Citrus fruit peels.

¹M.Nyabani, ²C.Winini

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
² Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; cwinini@hit.ac.zw

Through technological evolution, essential oils have become of much significance in food companies, soft drink companies as well as the fragrance industries, just to say the least. Used as a source of flavor and aroma, it has raised the need to commercially produce essential oils since the bulk of the market requires reliable supplies of consistent high quality product.

Apparently, essential oils have been imported into the country and there has been a small scale production of crude essential oils in Msasa, Harare. Now, such a big market and available resources, why not maximize what we have and optimize the simple extraction equipment available. This project aimed at optimizing equipment that is used to extract concentrated perfumes, now to extract concentrated essential oils from citrus peels. The mini equipment designed caters from breaking down of peels to the concentration of the essential oil. During the project, it was discovered that the equipment can also generate steam that can be made into hydrosol

Optimization of degumming process in soybean oil Extraction at National Foods Aspindale,Harare

¹Mupunga.L.; ² P.Muredzi

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Dean – School of Industrial Sciences & Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; pmuredzi@hit.ac.zw

Fats and oils contain complex organo-phosphorus compounds referred to as phosphatides, or more commonly as gums. They are removed during processing by a variety of treatments collectively referred to as degumming. The process involves treatment with water, or phosphoric acid, or polybasic organic acids, either individually or in combination, followed by its absorption on a bleaching earth or filter. The degumming method which is done at National Foods is acid-water degumming method in which crude oil is mixed with 0.0005-0.1% of phosphoric acid and 1-2% water at 70º C. The mixture is then cooled to 45º C and allowed to hydrate for 60 minutes. The water-soluble substances are then separated from the oil by sedimentation method which takes three hours. In this project the degumming process was optimized through the separation of phosphatides from oil by centrifugation method.

Automation design of the sugar mixing process in a soft drink manufacturing plant.

¹S.Chiringa; ²C.Winini; ³P.Muredzi

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; cwinini@hit.ac.zw
³Dean – School of Industrial Sciences & Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; pmuredzi@hit.ac.zw

The design aims to improve an existing sugar mixing process by automating it. The existing system is manual and is carried out in batches which are repeated as required by an order, hence the process is slow and quality consistency is also low. Since a lot of manual materials handling is involved, the system requires of a lot of labour. The system to be designed consists of a continuous process of dissolving sugar with water in a tank to a pre-determined concentration level. The automation design of the system comprised of basically three goals. These were (1) concentration control (2) flow rate control (3) fluid level control. The design comprises of a fluid level sensor connected in cascade with an inline refractometer to a throttling control valve in order to maintain the sugar concentration at the desired set point. The mass flow rate of the sugar and the volumetric flow rate of the inlet water are predetermined by calculations and set at that rate in a Programmable Logic Controller (PLC). The concentration of the sugar level is measured by an inline refractometer. The sugar mixture at the desired Brix level is released through an output line and pumped to the desired location. The design procedure was done in five stages which were: defining or establishing goals, preparation of information, formulation of models, and determination of the solution and finally a description of the controller system. Components of the control system were chosen in such a way that they were in sync with the holistic control design.

Design of a mini-plant for extraction of oil from Adansonia Digitata

¹S.P.Nyarugwe; ²P.Muredzi

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Dean – School of Industrial Sciences & Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; pmuredzi@hit.ac.zw

The project was aimed at designing a mini-plant for the extraction of oil from ADANSONIA DIGITATA (Baobab seeds). Oil is produced on a small scale by other people especially in rural parts of countries like Madagascar. There is no optimum extraction of oil as the methods used e.g. kneading and use of Ghanis is not very effective. The oil produced is prone to degradative processes such as autozidation. Because of the high oil content as compared to other oil seed such as soybean, sunflower and cottonseed the seed presents a better and commercially viable source of oil. Baobab oil is stable and it stores longer than other oils and can blend easily with other edible and essential oils. Above all it is edible and can be used as cooking oil and used in cosmetics. Baobab oil has a small amount of antinutrional properties which are removed during oil processing.

Some seeds even contain up to 37% edible oil (FAO, 1988a; 1988b) which could be extracted easily using modern technologies. To date, there are not any efforts made by government authorities concerned to utilize these resources. The processing of seed includes; size reduction, conditioning, flaking, solvent extraction, oil refinery (degumming, alkali refining, bleaching and deodorization) and oil enrichment.

An evaluation of the effect of starch quality on the Viscosity of opaque beer.

¹J.Ndikudze; ²P.Muredzi

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; jndikudze@hit.ac.zw
²Dean – School of Industrial Sciences & Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; pmuredzi@hit.ac.zw

Sorghum beer viscosity is an important quality attribute, which affects the body of the product. The starch content of three samples of cereal adjuncts that were to be used for brewing was determined by hydrolysis in the laboratory.

The samples were: Red Sorghum, White Sorghum and Maize. Brews whose adjunct starch content was determined were closely monitored (according to the Delta Beverages Sorghum Beer Manufacturing Quality Manual). Viscosities of the brews were recorded. The product viscosity was found to be affected by the starch content and quality. In this project, the chemistry and physical chemistry of starch are discussed with an emphasis on how structure (molecular and super molecular) and quality influence the functionality of this polysaccharide. Even more important to processing and quality attributes of starch products is the recognition that the super molecular structure and interactions between starch and other food constituents area governed by the mobility of amorphous phase of each particular system. In this respect water acting as a plasticizer depresses the glass transition temperature and thereby alters the kinetics of state transformations (e.g., gelatinization, retro gradation and reactivity of starch ).

Design of a Finger Millet Malting Plant

¹J.Tongonya; ² P.Muredzi

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; jndikudze@hit.ac.zw
²Dean – School of Industrial Sciences & Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; pmuredzi@hit.ac.zw

The study project involved the design of a malting plant for the production of finger millet malt on a small scale. Finger millet (Eleusine coracana), is a drought resistant, brown and tiny grain. The facility consists of raw material and finished goods storage areas that supply the production line with finger millet grain as the main input to the process. The plant layout consists of basically four workstations. A facility floor plan and diagrams of processing equipment are provided in the research. In addition,, four points in the processing sequence are suggested as material tracking points.

Development of HACCP System in the manufacture of Peanut butter. The Case of Nutresco Foods, Harare

¹P.Marandure; ²D.N.Moyo

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; dmoyo@hit.ac.zw

The study was undertaken to develop HACCP quality system in the peanut butter plant. HACCP is an abbreviation for Hazard Analysis and Critical Control Points. It is defined as a system which provides the framework for monitoring the total food system, from harvesting to consumption, to reduce the risk of food borne illness Taylor (2001). The system was developed as an alternative to traditional control systems such as finished product analysis and process controls. The objective of this project was to develop HACCP quality system in the manufacture of peanut butter. Quality systems like HACCP facilitate efficient in production there by reducing production costs and facilitate the production of peanut butter which is safe for human consumption.

Initially, prerequisites programs such as good manufacturing practice (GMP), personal hygiene, standards operating procedures, and personnel training among others were put in place so as to build a solid foundation for development of HACCP. The HACCP team was then assembled and provide with necessary training although most of them were trained before. The HACCP team was multidisciplinary and includes representatives and experts from production, sanitation, quality assurance, food microbiology, maintenance and engineering. Before the application of the seven HACCP principles five preliminary tasks have been accomplished.

Seven HACCP principles were applied and they included hazard analysis, CCP identification, establishing critical limits, monitoring procedures, corrective actions, verification procedures, and record keeping and documentation. In identification of hazards associated with the production of peanut butter questionnaires were used. The results obtained indicated that after development of HACCP system there was reduction of contamination of peanut butter. Processing steps like inspection, screening and roasting were identified to be critical control points

Design of an Environmental Management System for the Beverage Industry (Case of Schweppes Zimbabwe Ltd, Harare)

¹M.Nyabani; ²M.Nyahada;

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; mnyahada@hit.ac.zw

The project involved practical visits to the plant in order to gather information relevant to design the system. The main objective s of this project were to ensure that the company comply with laws and regulations, to identify the causes of environmental problems and provide means to eliminate them, to help the company save money, and to improve efficiency and effectiveness in performance. The results of the research showed that production of drinks resulted in wastewater that did not conform to local regulations, for which the company was made to pay a heavy fine. The main causes were the high pH of the wastewater and a high level of contaminants presents. The system designed targeted this area and came out with results to help solve this problem, hence achieve the objectives.

Investigating the use of reverse osmosis in the Standardization of milk which is used in the production of Yoghurts.

¹L.Mupunga; ²M.Nyahada

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; mnyahada@hit.ac.zw

Reverse osmosis (RO) is a membrane process that can be used in standardizing the dry matter content in milk that is used in the production of yoghurts. The aim of the project was to improve the quality of the yoghurts and to reduce the costs of the ingredients used in yoghurts production, through the use of reverse osmosis. No effects of reverse osmosis were observed on acidification period of yoghurts. It was observed that the use of membrane system in standardization of milk has no effect on viscosity, Flow index and yield stress of the yoghurts as long as the density of the yoghurt mixes were within specifications the rheological properties of the yoghurts were not affected. High quality yoghurts were produced using milk, which was standardized using reverse osmosis.

Application of Six Sigma A Case Study of Dairibord Holdings Zimbabwe (Ltd) Chimombe Line.

¹S.T.Chiringa; ²C. Winini; ³O.Chimusoro; ⁴P.Muredzi

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
² Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; cwinini@hit.ac.zw
³Department of Industrial & Manufacturing Engineering, Harare Institute of Technology, Box Be 277, Belvedere, Harare;
⁴Dean – School of Industrial Sciences & Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; pmuredzi@hit.ac.zw

The Ultra Heat Treated product, Chimombe, has been recording high customer complaints arising from pre-mature deterioration of milk, low production yields as well as packing yields. Waters produced by the process were also high and their averages were well beyond the acceptable ranges. The overall effect is an increase in the costs of non-conformance. The objectives of the project were: to investigate the root causes of milk deterioration before the anticipated shelf-life, to measure and quantify the losses in terms of financial and no-financial terms and to apply the first three phases of the Define- Measure – Analyse – Improve – Control methodology and to suggest solutions.

The methods used included performing interview facilitated by open-ended questionnaires. Data collected was both primary and secondary. The secondary data collected included customer complaints, amounts of waste produced, number of units sold as well as packaging yields. For customer complaints no sampling was done. Primary data collected was that of defects produced on a single shift and systematic sampling was used. Analysis included use of run charts, cause and effect diagrams and Pareto charts. The results were presented using line and bar graphs as well as pie charts.

On average 139 units of Chimombe were defective per every million units sold to customers. This translates to sigma level of 5.1. Wastes produced by the process were at an average of 286.63 kilograms per month. This equates to an equivalent loss of 71 160 units. Customer complaints were at average of 10 complaints a month and the corresponding number of units returned each month were at an average of 161 units. In dollar value terms, the company was losing R1290 per month with regards to packaging waste. The main root causes of milk deterioration were attributed to post UHT contamination which occurred during breakdowns (machine related) and differences in packaging film thickness. Other causes established were that of the age of milk against bacterial load. On analysis 53.7% of the problems were machine related. Solutions and support measures were suggested and a means of controlling and sustaining improvement results if implementation follows were suggested.

Design of a continuous conveyor oven dryer for a corn snacks manufacturing plant

¹W.Gwala; ²A. Musengi; ³P.Muredzi

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
² Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; amusengi@hit.ac.zw
³Dean – School of Industrial Sciences & Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; pmuredzi@hit.ac.zw

The study project sought to design a continuous dryer for the drying and conditioning of corn snacks in order to attain textural crispiness and the required moisture content of 3% and below as required to attain textural crispiness and the required quality specifications. The design parameters were that the dryer would have to with an 8 hour feed rate 3200kg of snacks. The existing dries could not meet the production volume requirement.

The design came as an improvement to the existing dryer by changing to rotary drum system of drying which employed conductive drying as the mode of heat transfer. The drum was substituted with a continuous mesh conveyor belt that transported snacks over a hot heating tray in a ‘drying hood’. In this case the mode of heating became radiation heating aided by convection heating from the drying air circulating in the hood by natural convection currents.

Justification of the new design came in the increased capacity of 3200kg of snacks as demanded by the constraints. This would be feed rate of snacks as they were discharged from the extrusion section when the factory ran at full capacity.

The design was able to meet the feed rate of 2300kg /8 hours of snacks, which was a 62.5 kw with the rotary dryer. The residence time of snacks in the new dryer, as mass flow rate was 6.67kg/min as compared with 2.5kg/min with the rotary dryer.
The success of the new dryer enabled the Technical Department’s goal to reduce the production costs by 23.2% to be achievable as well as to increase production levels by 62.5% at Zap snacks (Innscor Snacks Division).

Design of a continuous processing system for mixed dried Vegetables.

¹Mashoko.N.; ²A. Musengi

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; amusengi@hit.ac.zw

In order to ensure continuous food supply to the growing population and to enable farmers to produce high quality marketable products, efficient and at the same time affordable drying methods are necessary. This research project on the design of a continuous processing system for mixed dried vegetables stands to give the opportunity to produce high quality marketable products. The design came as an improvement of the existing production method at Intertec Foods Division of dried vegetables and Soya based products, whose operations are carried out manually and products are sun dried to a continuous drying system.

It is anticipated that the new design will result in increase in the production rate to 162kkg/h, 70.2kg/h and 5kg/h for cabbage, covo, and carrots respectively in proportion to the packaged ratio of 6:3.5:0.5 Increase in the post harvest losses to the perishable product. The design on the arrangement and location of processing equipment was illustrated on auto-cad drawings. Design analysis on the product properties and parameters suitable for continuous drying were carried out.

Production of a biodegradable plastic from chicken feathers.

¹N.Tamirepi; ²A.Musengi; ³P.Muredzi

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
² Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; amusengi@hit.ac.zw
³Dean – School of Industrial Sciences & Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; pmuredzi@hit.ac.zw

Poultry feathers were utilized in an attempt to produce a plastic from chicken feathers. This was done in an effort to reduce land pollution from waste plastics due to their non-biodegradability nature. Chicken feathers were pulverized and mixed with glycerol which was used as the plasticizer. Different combinations of feather and glycerol were applied. Sodium sulphate was also added in some of the samples to increase viscosity. All the samples were heated to 60◦C then left to air dry. One sample had pressure and heat applied simultaneously and another, just pressure. Some of the samples did not solidify, while others became hard brittle substances and one turned into gel like substance.

Optimisation of peas processing method for a fruit and Vegetable Processing Plant: Case of Cairns Foods – Mutare

¹P.A. Mapfurira; ²D.N.Moyo

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; dmoyo@hit.ac.zw

Cairns Foods – Mutare processes peas which have both local and export market but some inefficiencies are currently being encountered during the production process. The project was aimed at coming up with a process that produces a high quality product that satisfies product and customer requirements, coming up with means of reducing losses and improving yield of the final product, increasing utilization of currently unutilized workstations and proposing an appropriate finish for the process line so as to minimize health hazards since the current finish is wearing out.

To solve the inefficiencies currently being encountered, simple material balance problem solving techniques were used to make sure an acceptable yield of final product was produced. Flexible Manufacturing Systems application techniques were used to increase utilization of currently unutilized workstations. The engineering and maintenance department was requested to repair the grader and adjust its rotational speed so as to produce consistent grades of peas. Implementing the suggested above ideas, the yield was increased from 61.17% to 69.90%. Unutilized machines had their production rates adjusted so that they began to be fully utilized. Production costs were reduced as a result of the reduction of downtime

Design of a Whey Treatment Process at Dairibord Kadoma Manufacturing Plant

¹F.Shawarira; ²D.N.Moyo

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; dmoyo@hit.ac.zw

The study project involved the design of a whey treatment process designed to utilize the whey volumes produced from the manufacturer of hard chesses at Kadoma Dairy. The design was aimed at reducing the biological oxygen demand (BOD) of whey (=60g oxygen/litre), whilst recovering some nutrients from the whey. The study involved research into whey processing applied in foreign dairy industries and process and equipment design.

Based on material balances on one batch production of Cheddar cheese at the aforementioned dairy (employing 12,000L of whole milk), the raw whey quantities expected were determined to be 10,961.20 L. From these volumes, mass balances for whey process unit operations were calculated. The final product is expected to be a whey protein and lactose concentrate (60% solids). This product could be of benefit to Dairibord Zimbabwe Pvt Ltd since, (i) it helps avoid any legal law suits concerned with the pollution of the environment due to the reduced BOD of the resulting effluent stream and (ii0 it can be added to other products such as ice cream and yoghurt to increase total solids.

Investigating the Accumulation of iron in Cereal Products.

¹G.Makore; ²D.N.Moyo

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; dmoyo@hit.ac.zw

Many processing machines in food industry are made from different alloys where iron is the major component. Due to excessive heating and interaction of machine components, the wearing rate is very high as a result, metal particles gradually accumulate in the food. In this study, accumulation of iron was determined using Atomic Absorption Spectrophotometer (AAS). Through the use of AAS, iron accumulation was determined and the results reflect that iron accumulates as processing proceeds.

Design of mixing machine for a vegetable freezing plant The Case of Exhort Enterprises (Pvt) Ltd.; Harare

¹M.Chipungu; ²D.N.Moyo

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; dmoyo@hit.ac.zw

Homogeneity and consistency of individually Frozen Vegetable mixes can be achieved by the use of an appropriately designed mixer. The impellers and agitators as well as mixing vessels that already exist can be developed to suit the delicate nature of frozen vegetables. As the products are agitated heat may be dissipated which may result in undesirable temperature rise, thus a mixer with the ability to maintain product temperature can eliminate the problem of clumping, reactivation of microbial activity which may later lead to shortened product shelf life.

Optimization of the cleaning and sterilization of reusable Plastic bottles in a Sorghum beer packaging plant (Case Study – Delta Beverages, Harare)

¹J.Ndikudze; ²M.Nyahada

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
²Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; mnyahada@hit.ac.zw

Optimization of the cleaning / sterilization process of reusable plastic bottles has been investigated. Sterilization effect of NaoH (0.5-1.0% and Nitric acid (0.25-1%)at different pressure and time frames temperature (50; 55; 60; 65; 70; 75; 80) 0C was investigated. Effect of Nitric acid and NaoH was dependent on time and temperature of exposure and concentration of sterilants. At all temperatures, concentrations and pressure investigated, inactivation of microorganisms increased with increase in temperature, and concentration of sterilants and pressure of water applicant. As the product whose container is being treated has an acidic background due to primarily to the eventual fermentation process and also because lactic acid is used in the production of sorghum beer as raw material, the influence of metric acid on microbial inactivation depended on concentration mostly. At temperature investigated nitric acid was more significantly more effective than NaoH. Successful reduction of microbial population was registered with the targeted reduction of 99% being achieved, as evidenced by the statistical analysis of results.

Design of a quality management system model for the Production department of a snack foods manufacturing Company: Case of Zap Snacks Pvt Ltd, Harare

¹J.Tongonya; ² D.N.Moyo; ³A.Musengi

¹Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare
² Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; dmoyo@hit.ac.zw
³Department of Food Processing Technology, Harare Institute of Technology, Box Be 277, Belvedere, Harare; amusengi@hit.ac.zw

The adoption of Quality Management System as a quality management procedure has been on the rise for the past decade in the country. The purpose of this project was to design a Quality Management System model in compliance with ISO9001:2000 for the out desktop research to find literature around this area, gap analysis was done using a questionnaire, process, and personal interviews were used for the development of work instructions. Currently, there is no workable quality system at Zap snacks. A quality Management System model, consisting of a Quality Policy, Quality Manual, Documented Quality Procedures and Work Instructions was designed. In coming up with the design, the major limitation was the economic environment in which the company is operating in, which is in recession.