Browsing by Author "Kwiri, Raphael"

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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.
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.
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.
Proximate composition of pumpkin gourd (Cucurbita pepo) seeds from Zimbabwe ,
(International Journal of Nutrition and Food Sciences., 2014-06-30) Winini, Clive; Kwiri, Raphael; Musengi, Amos; Mudyiwa, Misheck; Nyambi, Clarice; Muredzi, Perkins; Malunga, Abigail
Curcubita pepo seeds have been widely consumed in Zimbabwe way back in the 1970s, but still locally, there is no data on the nutritional quality of Curcubita pepo seeds, hence the study attempted to avail this information. Curcubita pepo seeds from selected places in Zimbabwe were analysed. The proximate analysis including major nutrients and minerals were determined. The C. pepo seed had a moisture content of 5.662±0.016gkg-1. Significantly, Curcubita pepo had high amounts of crude oil and proteins as compared to other edible oil rich seeds. The crude oil content and protein were 43.460±0.098gkg-1 and 32.860±0.103gkg-1 respectively. Other components such as carbohydrates, crude fibre and energy were 12.160±0.142gkg-1, 2.578±0.007gkg-1 and 562.82±0.132gkg-1 correspondingly. Ash content was 3.324±0.010gkg-1 which was further analysed into various major minerals giving analysed means as Na (67.956±0.037gkg-1), Zn (1.244±0.010gkg-1), P (1040.8±0.663gkg-1), Fe (11.980±0.086gkg-1), Ca (141±0.316gkg-1) and Mg (344.6±0.245gkg-1). The findings indicated that C. pepo seeds are a good alternative source of highly nutritious food for instance proteins and lipids as well as minerals (Mg, Ca, Zn, P and Fe) that could greatly contribute to human nutritional requirements. However, it still remains important to further profile the quality of the lipids and proteins from C. pepo seed so as to verify their essentiality and availability to the human body as well as evaluating the presence of other bioactive and antinutritional factors that might be present in these seeds.