ORANGE-FLESHED SWEET POTATO (OFSP) – CASSAVA COMPOSITE GARI: EFFECTS OF PROCESSING VARIABLES AND STORAGE ON BETA-CAROTENE AND SENSORY QUALITIES

ABSTRACT

Incorporating orange-fleshed sweet potato (OFSP) into gari could increase the

nutritional value of gari. This work sought to improve the nutritional quality of

gari by incorporating OFSP into the gari. Multivariate response surface was

used for the optimization of the optimum amount of OFSP and the

fermentation duration required in producing a good quality gari. The results

showed that beta-carotene content increased with increasing fermentation

duration and increasing OFSP percentage. However, OFSP amount did not

affect the swelling capacity while a longer fermentation period reduced the

swelling capacity of the OFSP–cassava composite gari. Incorporation of OFSP

into gari lowered its sensory attributes, while attributes such as texture and

overall acceptability increased with fermentation duration. Furthermore, the

OFSP amount and fermentation duration affected the lightness (L*) and

redness (a*) of the gari, but did not influence the yellowness (b*) of the gari.

Producing gari by using 90% cassava and 10% OFSP (9:1 ratio of cassava to

OFSP) and fermenting for 2.21days gave the best quality gari based on the

beta-carotene content of 19.8 μg/ml, swelling capacity of 3.2 and sensory

attributes. Moreover, both storage conditions and storage durations influenced

the beta-carotene content of the gari but did not affect the swelling capacity,

bulk density and colour of OFSP–cassava composite gari significantly. The

profit on the OFSP–cassava composite gari was determined to be higher than

that of 100% cassava gari. Orange-fleshed sweet potato could therefore be

incorporated into gari to improve the vitamin A content of gari and thereby

improve the economic status of gari processors.

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