Effects of packaging and storage condition on functional properties and quality attributes of cassava flour (CVS. ‘TME 419’ AND ‘UMUCASS 36’)

Uchechukwu-Agua, Amarachi Divine (2015-04)

Thesis (MSc Food Sc)--Stellenbosch University, 2015.

Thesis

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.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/97142
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