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.

Table 1: In- vitro carbohydrate digestibility of pearl millet hybrids and couscous produced from them Sample Hardness (N) Diameter (mm) Digestibility (%) Pearl Millet Hybrids Couscous Time (min) 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

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.