Department of Food Processing Technology

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Start date: 2013

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Now showing 1 - 10 of 17
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    Microbiology and Immunology
    (HIT, 2018-05-15) HIT
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    A concise review of yam (Dioscorea spp.) starch: extraction, chemical composition, physicochemical properties and its potential food applications
    (Taylor & Francis, 2024-12-30) Mawoneke, Kurai Gareth; Kwiri, Raphael; Ndemera, Melody
    Substantial studies have been conducted on the starches derived from various yam species. These studies have examined numerous extraction methods, including acid, alkali, ammonia, water and enzymatic techniques, each yielding between 10–20% starch. The physicochemical properties of yam starches have been extensively characterized, evaluating factors, such as granule size, amylose content (ranging from 0 to 40%), gelatinization behavior and rheological profiles. Notably, the yam species D. esculenta and D. dumoterum exhibit lower amylose levels, while D. trifida can present as a waxy starch with less than 2% amylose. Minimal variation has been observed in the composition, patterning and characteristics across D. cayenensis and D. rotundata starches. Yam tubers are composed of 60–80% starch by dry matter, playing a fundamental role in the quality of yam-based foods. Yam starches have demonstrated potential as thickeners, fat replacers and edible film formers due to their physicochemical attributes, particularly their gelling properties which enhance texture and functionality. However, the industrial utilization of yam starches remains limited due to a lack of systematic data and standardized isolation methods. Further research is needed to optimize extraction protocols and expand the food applications of this versatile starch.
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    Development and evaluation of a plantain-peanut sandwich for the Nigerian market
    (. International Journal of Nutrition and Food Sciences, 2014-06-19) Malomo, Olu; Uche, E; Adekoyeni, O. O; Alamu, E. A
    Protein-energy malnutrition is a common nutritional disorder in developing countries and constitutes a major public health problem in young children and elderly people. This project is aimed at evaluating the acceptability of plantainpeanut sandwich and roasted at different temperatures. A plantain-peanut sandwich consists of minced protein stuffed into a carbohydrate source made into a roll as a food product. The plantain was roasted at two different temperatures then later enriched with 5%, 10% and 15% peanut butter. The crude protein and crude fibre contents of the plantain samples roasted at 200oC and 240oC showed no significant difference (P˃0.05) while the ash, fat and carbohydrate contents showed that there was a significant difference (P˂0.05). Results of the proximate composition showed that there was significant difference (P˂0.05) at the two different roasting temperatures of 200oC and 240oC when enriched at 5%, 10% and 15% levels with peanut butter. This pattern of significant increase was also observed with the amino acid profiles at the two different roasting temperature levels.
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    Selected Articles in Food Science & Technology for College Graduate Students
    (Science Publishing Group, 2015-04-05) Muredzi, Perkins
    Food Science represents the application of the basic sciences, biotechnology, and engineering to the production, processing, packaging, distribution, and evaluation of foods. Food science and food technology complement production agriculture by developing methods that minimize waste and improve the quality, utility, safety, attractiveness, and shelf life of foods. Food scientists strive to improve the efficiency of food processing while ensuring high quality, nutritious, safe, and convenient food products. To this end, they employ the principles of chemistry, physics, biochemistry, microbiology, engineering, nutrition, and management in an integrated manner. Food scientists require specialized education and technical training. Advanced studies in food science and technology taken by graduate students provide a broader, more varied education than is possible in the other study programmes. Graduate students are more often expected to take courses in food chemistry, food engineering and processing, food microbiology, nutrition, and food marketing as well as in the supporting disciplines and commodity areas in their special interests. Graduate students therefore require exposure to information regards immerging and critical topics in the various areas offered in their studies. To complement taught courses some programmes offer seminars on advanced topics or food research areas. This collection of articles serves to give the graduate student a varied portfolio of articles as reference material for the various disciplines of food science and technology under study thus enriching knowledge in selected critical topics
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    Grewia bicolor seed oil: Putative pharmaceutical, cosmetic and industrial uses
    (South African Journal of Botany, 2015-06-12) Nyakudya, Trevor,T; Magwa, Michael,L; Chivandi, Elton; Nosenga, Noseiphi; Erlwanger, Kennedy L; Gundidza, Mazuru; Gundidza, Ernegy; Muredzi, Perkins
    The physicochemical characterisation, seed oil content and fatty acid profile of oil extracts from Grewia bicolor seeds collected in Zimbabwe were performed using standard extraction and chromatographic techniques. The main objective was to determine the potential domestic and industrial usefulness of the G. bicolor seeds. The G. bicolor seeds yielded 4.80% of brownish-orange oil that had an acceptable odour. The seed oil consisted of saturated (20.20%), monounsaturated (25.10%) and polyunsaturated (54.41%) fatty acids. Palmitic acid (11.46%), stearic acid (5.77%), oleic acid (19.33%) and linoleic acid (54.41%) were the main fatty acids in G. bicolor seed oil. The oil had a high acid value (0.53 mg KOH/g), iodine value (39.21 g I2/100 g oil) and saponification value (130.43 mg KOH/g) compared to published data on other nutritionally and ethnomedicinally important plant seed oils. We conclude that the G. bicolor seeds are low oil yielding, whose oil could be used as a potential source of palmitic, stearic, oleic and linoleic acids and may potentially be utilized as an industrial ingredient in the manufacture of soaps, pharmaceutical products, and cosmetics. Further studies are required to explore the possibility of using this seed oil in industry.
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    Comparative Study of Degradation Kinetics of Ascorbic Acid (Vitamin C) in Tray Drying, Solar Drying and open Sun Drying of Pineapple Slices
    (Austin Journal of Nutrition & Metabolism, 2015-06-01) Gwala, W; Padmavati, R
    A comparison of degradation kinetics of ascorbic acid was done on tray, solar and open sun drying of pineapples. Thin slices of 10mm±3 thickness were equally weighed and divided into three samples of 300g each. One 300g sample was placed in a tray dryer and dried at a temperature of 60oC, the next 300g sample was placed in the solar dryer and another 300g sample was placed on a tile for open sun drying and dried under fluctuating temperatures. Samples were taken at half hour intervals and analysed for vitamin C content over the drying period using the 2,6 dinitrophenolindophenol dye titration method. The residual vitamin C content in tray drying was least at 11.25 mg/100g of sample. This was followed by sun drying with a residual vitamin C content of 19.5mg/100g of sample. Solar dried sample showed the highest vitamin C retention with 29.25mg/100g of sample weight. The degradation kinetics were analysed using the first order fractional Model and the Weibull Model. The correlation coefficient (R2) was calculated for goodness of fit. The Weibull model had the best fit. However deviation from first order degradation kinetics of vitamin C was noted.
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    Preparation of Adansonia digitata flavoured Soy Milk based yoghurt
    (Harare Institute of Technology, 2014-05-22) Muredzi, Perkins
    An Adansonia digitata flavoured Soy Milk based yoghurt is prepared by leaching soybean meal with aqueous solution having a pH of 4 to 5 to remove sugars without removing protein, leaching a resultant residual sugar free cake with an aqueous solution having a pH above 7 to dissolve protein material, adjusting the pH of a resulting protein containing filtrate to 6.5 to 7.0 adding sucrose to the filtrate, flavouring with Adansonia digitata powder and homogenising to produce a flavoured Soy Milk, sterilising at about 116 0C and fermenting with a mixed bacterial culture comprising in addition to Lactobacillus delbrueckii, a strain capable of stimulating growth of Lactobacillus delbrueckii , in an incubator (at 37-40 0C) to produce Soy Yoghurt.
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    Novel Non Thermal Preservation Techniques in Meat Processing: High Hydrostatic Pressure as a Model Technology
    (Science Publishing Group, 2014-01-30) Muredzi, Perkins
    Consumers demand high quality and convenient meat products, with natural flavour and taste, and very much appreciate the fresh appearance of minimally processed food. To harmonize or to blend all these demands without compromising safety, it is necessary to implement new preservation technologies in the meat industry and in the food industry in general. High hydrostatic pressure (HHP) represents an attractive non-thermal process for meat products to avoid post-processing contamination. This review paper discusses the pivotal role played by HHP in meat processing and gives a general analysis of shelf life extension in meat products treated with HPP, the main technological effects of HHP in meat and a study case on “Mechanically recovered poultry meat sausages manufactured with High Hydrostatic Pressure”
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    Microbiological safety of cooked vended foods in an urban informal market:
    (International Journal of Nutrition and Food Sciences, 2014-05-30) Mpofu, Enock; Tongonya, Jeritah; Gwala, Shannon,T; Makarichi, Lydia; Kwiri, Raphael; Winini, Clive; Mujuru, Felix; Muredzi, Perkins
    The study presents an investigation of the microbiological safety of cooked vended foods in an urban informal market in Harare, Zimbabwe. Analyses were performed on 200 samples of mostly vended ready to eat foodstuffs (comprising chicken and beef stew, egg rolls, doughnuts and boiled mealie cobs) between the month of October and November 2012. Samples were analyzed against different types of indicator micro-organisms namely total aerobics, coliforms and Escherichia coli and pathogens (Salmonella spp. and Staphylococcus aureus). Significantly, early morning samples were less contaminated than afternoon samples (p<0.05). No Salmonella spp. was detected in any of the foodstuffs analysed, though S. aureus and E.coli were present (respectively ranges from 3-62x102 cfu/g and 6-49x101 cfu/g). Respectively, nearly 85.5% and 53% of the samples were highly contaminated with S. aureus and E. coli. Correspondingly, total aerobic plate count ranged from 11-172x103cfu/g, while coliform count ranged from 8-85 x102 cfu/g. Subsequently, the study showed that informally vended foods might contain pathogenic microorganisms which signify a risk for human health. The importance of adequate measures to guarantee food safety was underscored.
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    Microbiological quality of Gonimbrasia belina processed under different traditional practices in Gwanda, Zimbabwe
    (International Journal of Current Microbiolgy Applied Sciences, 2014-01-02) Mujuru, Felix; Winini, Clive; Kwiri, Raphael; Nyambi, Clarice; Moyo, Dinga.N
    TheaimofthisstudywastoinvestigatethemicrobiologicalqualityofMopaniWorms(MW)(Gonimbrasiabelina)processedunderdifferenttraditionalpracticesin Gwanda,Zimbabwe.FreshlyharvestedMopaneworms(MW)weredeguttedusingbarehandsorglovedhands.Thedeguttedwormsweresub-dividedinto4equal portions and subjected to different traditional drying methods namely, boiling insaltedwater(5%w/wsalt)for30minutesandsolardrying,openpanroasting,drumroastingandhot-ashdryingtoapproximately15%moisturecontent.Thereafter,driedMWsweremicrobiologicallyanalysedagainstindicatormicro-organisms(totalbacteriacounts,coliformsandEscherichiacoli)andpathogens(Salmonella spp.andStaphylococcusaureus)aswellasspoilageorganisms(yeastandmolds).Microbiologicaltestsconductedshowedthat,totalbacteriacounts(TBC)wererelativelylowwithvaluesrangingfrom10-2500CFUg-1. Significantly,deguttingMWsusingbarehandsfollowedbydrumroastingandboilinginsaltwatercoupledwithopenpanroasting,hadtheleastTBC(10CFUg-1and30CFUg-1)respectively.ColiformsandE.coliwerealsodetectedinMWswithvaluesrangingfrom0-43CFUg-1and0-30CFUg-1respectively(barehandsdegutted)whilstinglovesdeguttedMWscoliformscountswere0-45CFUg-1andE.colicountswere0-35CFUg-1.Furthermore,someMWsespeciallyashindriedsamplesthatcontainedvaryinglevelsandtypesofyeastsandmoldsthatincludedFusariumandPenicillium.NoSalmonellaspecieweredetectedinallsampletested.Thestudyshowedthat,MWprocessingmethodandsubsequenthandlingareimportantparametersindeterminingthetypeandlevelsoftheircontamination.Assuch,itisimperativeforharvestersandprocessorstoobservegoodharvestingandmanufacturingpracticesandfollowprotocolsthatdonotresultinre-contamination of produce as this might present a danger to the public consumers.