In- vitro CARBOHYDRATE DIGESTIBILITY OF SOME PEARL MILLET HYBIDS AND COUSCOUS

PRODUCED FROM THEM

Nkama, I; B. C. Hamaker; I. Angarwai; .Shelleng, A.B; Diarra.M and B. Bababe

INTRODUCTION

• Pear Millet (Pennisetum glaucum) is a staple food for countries in Asia and Africa. Nigeria, Mali, Burkina-Faso, Senegal and Niger account for the major quantity of pearl millet produced in West Africa.

• Millet is an excellent source of energy and a relatively good source of protein, some vitamins and minerals (Nkama et al., 2003).

• Millet hybrids refer to the offspring of two different specie where single cross hybrids are made with cytoplasmic/genic male sterile seed parent and pollen parents that restore male fertility.

• Digestibility is the breakdown of proteins, carbohydrates and lipids in a food system by enzyme either in vitro or in vivo.

• The rate of digestibility of a substrate can be accelerated or slowed even impeded by enzymes and their inhibitors.

• Couscous is an agglomerated, steamed – cooked product processed from millet, sorghum, maize and wheat (Galiba et al., 1987.

The objective of this study

• To determine the effects of processing of pearl millet hybrids into couscous on their in vitro carbohydrate digestibility.

MATERIALS AND METHODS

• Nine pearl millet hybrids, two improved varieties and one Farmers’ Local usedin the study were obtained from Lake Chad Research Institute, Maiduguri.

• Shekib’s et al. (1988) method was used for in vitro carbohydrate digestibility determination.

• The grains hardness and dimensions was determined using grain hardness tester (Model l Euweka. TBH 30, Germany). The grains were placed into the machine and mechanical force applied on them and readings obtained were recorded on the recorder.

MATERIALS AND METHODS

• Couscous was made from cleaned dehulled millet grain by grinding, sieving to obtain fine flour.

• The flour was mixed with water to form dough which was passed through a coarse sieve to obtain agglomerates.

• The agglomerates was steamed on a perforated pot and then dried to safe moisture levels.

Sample Hardness (N) Diameter (mm)

Digestibility (%)

Pearl Millet Hybrids Couscous

Time (min) Time (min)

10 30 60 10 30 60

LCIC MH 99-39 45.20abc 2.261abc 3.205f 11.22g 29.48i 17.50fe 49.17c 82.50a

LCIC MH 99-23 36.80c 2.482 a 3.436f 12.09g 38.14i 13.21f 36.47f 61.00g

LCIC MH 99-31 34.40c 2.432 ab 12.50bc 29.04b 47.58f 14.78ef 42.26de 71.13de

LCIC MH 99-25 40.40bc 2.187cd 13.65b 41.24 a 50.44 e 27.33ab 43.17d 69.17e

LCIC MH 99-26 37.80c 2.068cd 9.717d 39.81a 55.80 d 25.59bc 51.19c 76.84c

LCIC MH 99-10 52.90a 2.084cd 13.50b 2926c 61.74b 21.76d 39.61e 80.20ab

LCIC MH 99-33 42.20abc 2.253abc 13.04 bc 31.67b 44.09a 29.78a 56.04b 72.33d

LCIC MH 99-12 49.40bc 2.152cd 19.09a 30.91f 64.09a 20.58d 59,81a 79.42b

LCIC MV-1 39.30cb 1.973d 12.46bc 25.23d 62.30b 24.53d 49.05c 73.58d

FARMERS LOCAL

40.30bc 2.167cd s.898b 19.991e 46.90g 27.52ab 41.28de 56.51b

SOSA1-C88 44.10abc 2.065cd 6.514a 16.15f 46.17 g 13.13f 26.25g 63.13g

LCIC 9702 34.50c 2.211bcd 11.689c 40.59a 58.58c 17.20a 50.81c 66.40f

Table 1: In- vitro carbohydrate digestibility of pearl millet hybrids and couscous produced from them

RESULTS AND DISCUSSION

• Processing increased the in vitro digestibility of carbohydrate no matter the initial digestibility of the hybrid.

• Generally most of the hybrids had better digestibility compared to the improved cultivars and farmers’ Local when processed into couscous.

• Couscous from a low digestibility hybrid can be more digestible than that made from a high digestibility hybrid.