A RESEARCH PRESENTATION

Titled:

Investigation of the storage stability of -carotene in βgari processed from yellow fleshed cassava (Manihot esculenta Crantz)

Cosmos I. Onyiba* and Simeon I. Egba

14th August, 2015

Biofortification, the process of adding nutritional value to a crop has been used to

increase the concentration of Pro-vitamin A (β-carotene) in cassava through

convectional breeding and modern biotechnology. This is a promising tool in the

fight against health issues resulting from Vitamin A deficiency (VAD); many thanks

to the efforts of HarvestPlus Nigeria, International Institute of Tropical Agriculture

(IITA), Ibadan and National Root Crop Research Institute (NRCRI), Umudike.

Gari, a product of the Pro-vitamin A cassava has been picked as a case study for

this research work since it serves as the major staple food in Nigeria and West

Africa. Degradation of β-carotene in gari (processed from yellow flesh cassava) has

been a major challenge to research; and has been linked with cooking, processing

and storage under conditions such as heat, light and oxygen (Bechoff et al., 2010).

Thus, of what use would it be if significant amount of this nutrient is lost during

storage prior to consumption by the target population (especially the VAD

population)?

Introduction

Aim and Experiment DesignAim

This research work was aimed at determining the best storage conditions that will

allow maximum retention of β-carotene in gari obtained from two different yellow

fleshed cassava roots (TMS 01/1371 and TMS 01/1412). Experimental Design

The experimental gari samples processed from each clone were paired (i.e. TMS

01/1371 and TMS 01/1412) into four groups with respect to four different storage

conditions. The storage conditions for each sample group were as follows: Exposure

to sunlight and oxygen; Exposure to electric bulb light (yellow light) and oxygen;

storage in black polyethylene bag (light exclusion only); and Exclusion of light and

oxygen. Gari samples for the β-carotene determinations were collected from each

group on weekly basis for a total period of four (4) weeks. T-test, ANOVA and

Summary Charts were done using IBM SPSS Statistics version 20.

Figure 1: Changes in β-carotene content of TMS 01/1371 samples

Results

Figure 2: Changes in β-carotene content of TMS 01/1412 samples

Figure 3: TMS 01/1371 weekly percentage retention of β-carotene

in stored gari

Figure 4: TMS 01/1412 weekly percentage retention of β-carotene

in stored gari

Key Research Findings During processing of the β-carotene cassava to gari, a very significant

amount of the nutrient was lost especially during garification; and this was due to the high temperature applied at the gelatinization phase of the garification (roasting).

The degradation (loss) of β-carotene in the experimental gari follows the first order kinetics; and this Loss could be caused by thermal degradation, auto-oxidation and photo-degradation.

Exposure of the β-carotene gari to direct sunlight has higher detrimental effects than storage under electric bulb light (60watt yellow light).

The exclusion of the β-carotene gari from light and oxygen retains more appreciable amount of the nutrient.

High temperature and oxygen acts as an activating catalyst for photo-degradation of β-carotene in the experimental gari.

The stability and retention rates of β-carotene in gari during processing and storage may vary according to the genetic differences in the yellow fleshed varieties. some varieties may show better stability (when stored in certain conditions) than the others.

There may be other factors that affect the storage stability of the β-carotene gari; thus further research is required.

The experimental gari samples obtained from the yellow fleshed cassava variety TMS 01/1371 showed better stability during storage (for a duration of 4 weeks) when compared with TMS 01/1412 experimental gari samples.

Conclusions This research study has been able to prove that conditions for storage

of the experimental gari from TMS 01/1412 and TMS 01/1371 significantly affect the stability of their β-carotene contents. Gari samples from both varieties stored in light and oxygen exclusion (Group D) showed better stability during the period of storage; and TMS 01/1371 gari samples had significantly higher percentage retention than those of TMS 01/1412. Fortunately, this study has given an insight to food technologist on the best conditions for packaging the β-carotene gari. However, this means of packaging should be cost efficient enough to allow maximum retention of the nutrient; aid market distribution and delivery among the vitamin A deficient (VAD) population.

Thanks for

listening

Theory guides…..but Experiment decides!!!