Thesis (MSc Food Sc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Cassava flour is recommended for substitution with wheat flour in composite flour for
baking. The potential use of cassava flour in the food and pharmaceutical industries is attributed
to its gluten-free nature and excellent functional properties. However, optimum packaging
solution and storage conditions for cassava flour is critical in maintaining the quality attributes
and shelf-life stability during storage. Therefore, this study focused on investigating the effects
of package types (plastic buckets, low density polyethylene (LDPE) bags and brown paper
bags) and storage conditions (cool condition (15 °C, 90% RH); ambient condition (23 °C, 60%
RH); and higher condition (38 °C, 60% RH)) on the functional properties, quality attributes and
shelf-life stability of cassava flour (cvs. ‘TME 419’ and ‘UMUCASS 36’) developed at the
National Root Crops Research Institute, Umudike, Nigeria. Proximate composition,
physicochemical attributes, functional properties, and microbial safety of flour were analysed
every 4 weeks for 12 weeks storage duration.
Flour stored under cool condition with paper bags became moist and sticky with
appearance of mould growth before 4 weeks of storage. However, at the end of 12 weeks
storage, a decline in moisture content of 11.00 ± 0.02 and 7.05 ± 0.01% flour of ‘TME 419’ was
observed at ambient and higher conditions, respectively. Rate of moisture decline was similar in
flour of ‘UMUCASS 36’. A slight decrease in protein content of flour was observed during the 12
weeks storage from 1.9 ± 0.07 to 1.30 ± 0.001% for cv. ‘TME 419’ and 3.0 ± 0.05 to 2.27 ±
0.001% for cv. ‘UMUCASS 36’; however, no significant difference was observed under ambient
and higher conditions. Cassava flour packed in paper bags and stored under higher condition
(38 °C, 60%) had the highest loss (50%) of carotenoid content from 1.84 ± 0.10% to 0.91 ±
0.08%, while a minimal loss (24%) of carotenoid was observed in flour packed in plastic buckets
under ambient condition. The concentration of hydrogen cyanide (HCN) decreased across all
treatments and was below the safe cyanide level of 50 µg/ mL for food products. After the 12
weeks of storage, flour packed in plastic buckets had the highest aerobic mesophilic bacterial
counts (3.43 ± 0.04 log cfu/ g) followed by flour in LDPE bags (3.37 ± 0.03 log cfu/ g) and paper
bags (3.35 ± 0.01 log cfu/ g). No significant difference was observed in the package types;
however the counts observed were within the acceptable microbial limit
Swelling power (SP), solubility and peak viscosity were used to characterise the
changes in functional and pasting properties of cassava flour relevant in food industries. Flour
packed in plastic buckets under ambient condition had the lowest swelling power (8.48 ± 0.55%)
and peak viscosity (260 ± 0.51 RVU) compared to flour packed in LDPE and paper bags with (9.10 ± 0.13 and 9.32 ± 0.41%) SP and (263.67 ± 4.04 RVU and 302 ± 9.52 RVU) peak
viscosity, respectively. The essential minerals (sodium, potassium, copper, and iron) were
significantly higher in flour of ‘TME 419’ compared to ‘UMUCASS 36’.
In summary, for the production of high grade foods such as bread where higher swelling
power and viscosities are required, flour from ‘TME 419’ packed with paper bags under higher
condition could be desirable. In addition, for infant formulation, flour from ‘UMUCASS 36’
packed in plastic buckets and stored under ambient condition which best maintained nutritional
contents (protein and fat) and had the lowest peak viscosity would be more suitable. Flour from
both cassava cultivars could be stored up to 12 weeks duration under ambient and hot tropical
conditions using all package types evaluated. However, storage with paper bag under higher
condition offers the chances of better shelf -life stability of cassava flour. / AFRIKAANSE OPSOMMING: Daar word aanbeveel dat kassavameel in plaas van koringmeel in saamgestelde meel
by gebak gebruik word. Die potensiële gebruik van kassavameel in die kos- en farmaseutiese
industrieë word toegeskryf aan die glutenvrye aard en funksionele kenmerke daarvan. Optimale
verpakking en stoortoestande is egter belangrik vir die instandhouding van die gehalte
kenmerke en raklewe stabiliteit tydens stoor. Daarom is die fokus van hierdie studie op die
effek van verskillende tipes verpakking (plastiekemmers, lae densiteits politelien (LDPE) sakke
en bruin papiersakke) en stoortoestande (koel toestande (15 °C, 90% RH); omringende
temperature (23 °C, 60% RH); en hoër temperature (38 °C, 60% RH) op die funksionele
kenmerke, gehalte kenmerke en raklewe stabiliteit van kassavameel (kultivare. ‘TME 419’ en
‘UMUCASS 36’) wat by die Nasionale Wortelgewasse Navorsingsinstituut, Umudike, Nigerië
ontwikkel is. Die komposisie, fisiochemiese kenmerke, funksionele kenmerke en mikrobiale
veiligheid van meel is elke vier weke tydens die 12-weke stoortydperk ontleed.
Meel wat onder koeltoestande in papiersakke gestoor word, word klam en taai en
swamme maak by vier weke van stoor ’n verskyning. Teen die einde van 12 weke stoortydperk
is daar ’n afname in klammigheid van 11.00 ± 0.02 en 7.05 ± 0.01% in ‘TME 419’ meel by
onderskeidelik omgewings- en hoër temperature. Die afname in klammigheid is soortgelyk by
‘UMUCASS 36’ meel. ’n Effense afname in die proteïen inhoud van die meel is tydens die 12-
weke stoortydperk vanaf 1.9 ± 0.07 tot 1.30 ± 0.001% by die kultivaar . ‘TME 419’ en 3.0 ± 0.05
tot 2.27 ± 0.001% vir kultivaar ‘UMUCASS 36’ opgemerk. Geen noemenswaardige verskil is
egter onder omgewings- en hoër temperature opgemerk nie. Kassavameel wat in papiersakke
en onder hoër temperature (38 °C, 60%) gestoor is het die hoogste verlies (50%) aan karotien
inhoud vanaf 1.84 ± 0.10% tot 0.91 ± 0.08% getoon , terwyl ’n minimale verlies (24%) by meel
wat in plastiekemmers onder omgewingstemperature verpak is, opgemerk is. Die konsentrasie
van waterstof hidrosianied (HCN) het tydens alle behandelinge afgeneem en was onder die
veilige vlak van 50 µg/ mL vir kosprodukte. Na ’n 12-weke stoortydperk het die meel wat in
plastiekemmers verpak is, die hoogste mesofiliese bakterië telling getoon \ (3.43 ± 0.04 log cfu/
g) gevolg deur die meel in die LDPE sakke (3.37 ± 0.03 log cfu/ g) en papiersakke (3.35 ±
0.01 log cfu/ g). Daar was geen merkbare verskil ten opsigte van verpakkingstipes nie; die
tellings wat geneem is, was almal binne die aanvaarbare mikrobiale perk.
Swelkrag (SP), oplosbaarheid en piek viskositeit is gebruik om die veranderinge in
funksionele kenmerke van kassavameel wat betrekking het op die kosindustrie, te ondersoek.
Meel wat onder omgewingstemperature in plastiekemmers verpak is, het die laagste swelkrag (8.48 ± 0.55%) en piekviskositeit getoon (260 ± 0.51 RVU) getoon vergeleke met meel wat in
LDPE- en papiersakke (9.10 ± 0.13 en 9.32 ± 0.41%) swelkrag en (263.67 ± 4.04 RVU en 302
± 9.52 RVU) piekviskositeit, onderskeidelik toon. Die belangrike minerale (natrium, kalium,
koper en yster) was noemenswaardig hoër in die ‘TME 419’ meel vergeleke met ‘UMUCASS
36’.
Ten slotte, vir die produksie van hoëgraad kossoorte soos brood waar hoë swelkrag en
viskositeit belangrik is, is In ‘TME 419’ meel onder hoër toestande verpak in papiersakke, die
beste keuse. In die geval egter van babakosse is ‘UMUCASS 36’meel wat in plastiekemmers
verpak en onder omgewingstemperature gestoor is, en wat dus koswaardes (proteïen en vette)
behou en wat die laagste piek viskositeit het, meer geskik. Meel van albei kultivaars kan vir tot
twaalf weke onder omgewings- en hoë, tropiese temperature in al die verpakkingstipes wat
evalueer is, gestoor word. Stoor in papiersakke onder hoër temperature verbeter egter die
kanse op beter raklewe stabiliteit.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/97142 |
| Date | 04 1900 |
| Creators | Uchechukwu-Agua, Amarachi Divine |
| Contributors | Opara, Umezuruike Linus, Manley, Marena, Caleb, Oluwafemi, Stellenbosch University. Faculty of Agrisciences. Dept. of Food Science. |
| Publisher | Stellenbosch : Stellenbosch University, 2015. |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | viii, 150 pages : colour illustrations |
| Rights | Stellenbosch University |
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