Evaluation of different approaches to ensuring the quality of HQCF and its products in the value chain Cassava Gmarket Food Safety/Quality Team (FUNAAB) OBADINA, A.O. and ADEGUNWA, M.O. Department of Food Science and Technology, P.M.B. 2240, Abeokuta Presented at 39 th NIFST Conference, Owerri, Nigeria

INTRODUCTION This can be achieved if producers of HQCF comply with the requirements of standard bodies and reduce Food hazards according to ISO Approaches to quality management in cassava value chains involve a number of key factors that may influence or contribute to overall quality of the finished product.

Approaches to quality management in cassava value chains The field before the fresh roots are harvested Management of the roots after harvesting Environment in which processing takes place Equipment and quality of water used for processing Processing flow all the way to storage

Methodology Systematically the principles of HACCP Good Agricultural Practice (GAP) … Good Manufacturing Practice (GMP)

Factors that constitute food hazards in HQCF Type of hazardHazardCritical limits Biological Mesophilic aerobic bacteria10 6 max Coliform bacteria10 2 max Salmonella0 Yeast and moulds10 3 max Chemical Cyanogens<10mg/kg RustNone PaintNo peeled paint Fumigation chemicalsNone Physical SandNone DustNone GrassNone Any other foreign matter3%

HQCF Quality Attributes White in colour Bland in taste, not sour Low in cyanide (<10mg/Kg) Particle size <0.25mm Odourless Free of foreign matter Free of mould, with low microbial count Has a moisture content of 10-12% Not fermented (pH >5.5)

Critical Points and Hazards in HQCF processing Critical PointsHazards Addressed ARemoval of rots during peeling of cassava rootsBiological BWashing peeled roots in clean waterBiological CProduction of a wet mash by gratingChemical (cyanogens) D Drying pressed cassava cake as quickly as possible (6 hours) Biological and Physical EpH measurementChemical (to address fermentation) FSieving to produce fine free flowing flourPhysical GBagging in polypropylene bags with liner and keeping in hygienic dry aerated store Biological & Physical

Study of the impact of different unit operations on safety and quality of cassava flours Processing cassava into flour involved different approaches of two unit operations, namely; i.size reduction ii.drying size reduction chipping and grating Drying methods sun, solar vs. flash drying

Effect of grating on removal of HCN from cassava flour Stage of processingHCN-ppm % cumulative reduction of total cyanogens Fresh roots73.16± In peeling roots51.03± After grating48.43± In pressed wet cake18.84± Dried grits6.73± HQCF4.99±

Effect of chipping/slicing cassava roots on HCN reduction Stage of processing HCN-ppm % cumulative reduction of total cyanogens Fresh roots73.16± After peeling roots51.03± After chipping41.58± Dried chips22.67± Flour20.99±

Effect of drying methods on removal of HCN from cassava products Stage of processing Drying Method Sun dryingSolar dryerFlash dryer mgHCNeqkg-1 dry weight % reduction of total cyanogens mgHCNeqkg-1 dry weight % reduction of total cyanogens mgHCNeqkg-1 dry weight % reduction of total cyanogens Wet slices/chips 14.01± ± ± Flour18.32± ± ±

Conclusion Effect of chipping/slicing cassava roots on HCN reduction shows that chipping and slicing were not efficient in reducing HCN to safe levels of 10ppm as recommended by WHO High cyanogens levels remained in the chips both sundried and solar dried.. These products still contain cyanogens levels much higher than the recommended safe levels of 10mgHCNeqkg-1 dry weight Results show that FLASH dryer was the most drying method for reducing HCN levels in flour reducing by (96%) followed by SOLAR dryer (88%) and sun drying (85%) respectively

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