Steep-Out Moisture, Malting Loss, and Diastatic Power of Pearl Millet and Sorghum as Affected by Germination Time and Cultivar

Abstract

Ten pearl millet cultivars and sorghum (control) were steeped for 12 hours with one hour air rest and germinated for 96 hours. The germinative properties and steep-out moisture content of the grain were determined. Green malt moisture, malting loss, vegetative loss, total malting loss, and diastatic power were also determined during germination at intervals of 24 hours. Data obtained from the study were statistically analyzed using analysis of variance of a randomized complete design and 11 × 5 factorial experiments to determine differences among germination time and cultivar. Means were separated using Duncan Multiple Range Test. Correlation analysis was determined with computer using statistix, version 4.1. Results indicated that grains had good germinative properties and wide variations of steep-out moisture content among the cultivars. Green malt moisture, metabolic loss (malting loss), vegetative loss (seedling yield), total malting loss, and diastatic power increased significantly (P < 0.05) with an increase in germination time and varied widely among cultivars. This information could serve as a guide for selection of suitable pearl millet cultivars for malting.

Keywords:

• Pearl millet cultivars
• Sorghum
• Steep-out moisture
• Germinative properties
• Malting loss
• Diastatic power

INTRODUCTION

There has been a rapid increase in population of people living in the semi-arid region of Nigeria. The semi-arid region is characterized by drought and poor sandy soil.[1] To feed the teeming population in the region, there is the need to develop and improve crops that can withstand the harsh weather and cultural conditions. Pearl millet is the common crop grown by farmers in this region. It grows well in the poor sandy soil and matures within the short time rainfall period, avoiding drought.[2] Pearl millet grain can be processed into many products. One method that transforms the grain to nutritious foods for children and adult is malting.[3] Malting is synonymous with barley but other grains have been malted to produce high quality malt based food products. Sorghum has been malted[4,5,6–13] to produce alcoholic beverages and weaning foods. Other grains that have been found satisfactory for malting are wheat and maize, although the high fat content of the latter[14] puts it at a disadvantage.

Information required for screening of grains for malting, such as physicochemical characteristics, germinative properties, metabolic loss, vegetative loss, malting loss and diastatic power has been documented.[15,16] The physicochemical characteristics of pearl millet cultivars grown in northern Nigeria have been reported by Badau et al.,[17] but most of the information required for screening of grains for malting is under reported in this environment. Therefore, the objectives of this study were to determine the effect of germination time and cultivar on the malting properties of peal millet.

MATERIALS AND METHODS

Ten pearl millet cultivars and one sorghum cultivar (control) were obtained form Lake Chad Research Institute, Maiduguri. Chemicals and reagents used were of analytical grade.

Sample Preparation

The cereal grains were cleaned manually of broken seeds, dust and other extraneous materials. Experimental samples were taken using the quarterly procedures of Lees.[18]

Germinative Properties

Germination energy, germination count, water sensitivity and germination capacity of the pearl millet cultivars and sorghum were determined.[4,14,19,20]

Steeping

The cleaned grains were steeped in water for 12 hours at 30°C[21–25] with grain to water ration of 1:10 (w/v),[24] with one hour air rest after every 6 hours of steeping. For each air rest, the steep water was changed. At the end of the 12 hours of steeping, the steeped grains were sterilized by immersing in a solution of 1% sodium hypochlorite for 20 minutes[4,12] before it was drained and weighed. Surface moisture was blotted with blotting paper and moisture content was determined in oven (Schutzart Din 40050-1p 20 Memmert-854, Schwabach, Germany).[26]

Germination

The steep grains were spread on sterilized wet jute bags to sprout at room temperature (32 ± 2°C) for 0, 24, 48, 72, and 96 hours.[27]

Kilning (Drying)

After germination, the green malt was weighed, followed by drying in fan fitted oven (Gallenkamp Oven BS MODEL OV-160 made in England) at 50°C for 24 hours and finally polishing, to remove shoots and rootlets.

Analysis of Malt

The steep-out moisture, green malt moisture, malting (metabolic) loss, vegetative loss (seedling yield) and total malting loss were determined as described by Gomez et al.,[26] Diastatic power of malt was also determined as described by IOB,[20] Agbo,[19] and Gomez et al.[26]

STATISTICAL ANALYSIS

The mean and standard deviations were calculated for steep-out moisture content based on ten pearl millet cultivars and one sorghum cultivar (control). Analysis of variances (ANOVA) of a randomized complete design was used to determine differences among cultivars. Means were compared using Duncan multiple range test (DMRT). The mean and standard deviation of green malt moisture, malting loss, vegetative loss, total malting loss, and diastatic power were also determined. Analysis of variance (ANOVA) from 11 × 5 factorial experiments in a randomized complete block design was used to determine differences among germination time and cultivar. In each case, means, were compared using Duncan multiple range test (DMRT) with a computer using statistical programmes, statistix version 4.1, USA.[28] The correlation coefficients among the green malt moisture, steep-out moisture and malting loss were also determined with computer using statistical programme statistix, version 4.1, USA.

RESULTS AND DISCUSSION

Germinative Properties

The germinative properties of pearl millet cultivars and sorghum are presented in Table 1. The germination capacity ranged from 98.3 to 99.0%. Germination energy and germination count ranged from 95.0 to 97.0% and 94.5 to 97.0%, respectively. The water sensitivity of the grains ranged from 0.0 to 1.0% and therefore, the grains were not water sensitive. The germinative properties are useful in selecting grains for malting.[29] In brewing industries, it is necessary to carryout a test on the viability of the grains by making germination counts. If germination falls below 65%, the grain is not viable enough to malt, because diastatic enzymes are activated only during germination.[26] Therefore, all the pearl millet cultivars have good germination percentage and were not water sensitive; hence based on this information, they are good for malting. Water sensitivity is used to control steeping program.[29] Maltsters avoid water sensitive grains or have to adjust the steeping regime to overcome the condition.[30]

Table 1 Germinative capacity, germinative energy (4.0 ml), germinative count (8.0 ml) and water sensitvity of various pearl millet cultivars and sorghum.

	Parameter
Material	Germinative capacity (%)	Germinative energy (%)	Germinative count (%)	Water sensitivity (%)
Pearl millet cultivars
SOSAT C-88	98.0	96.0	95.0	1.0
ZANGO	99.0	96.0	96.0	0.0
EX-BORNO	98.0	95.0	94.7	0.3
LCRI-IC 9701	99.0	95.7	95.0	0.7
ICMV-IS 94206	98.3	96.3	95.6	0.7
ICMV IS 94208	99.0	97.0	97.0	0.0
GWAGWA	99.0	96.7	96.0	0.7
G.I – 14.9	99.3	96.5	96.5	0.0
GB 8735	98.3	95.6	94.7	0.9
G.I 297-1	99.0	96.5	94.5	1.0
Sorghum cultivar
ICSV III	95.5	95.4	95.0	0.4
All values represent the average of several determinations.

Steep-out Moisture and Green Malt Moisture

The steep-out moisture content and green malt moisture of various pearl millet cultivars and sorghum cultivar are shown in Table 2. The steep-out moisture ranged from 37.66 to 47%. Sorghum had higher value than the pearl millet cultivars. The steep-out moisture of G.1-297-1 was higher than the rest of the peal millet cultivars. This result confirmed earlier report of Sopade et al.[31] that sorghum absorbed more water than millet. The green malt moisture increased (P < 0.05) with increase in germination time for all grains. It increased (P < 0.05) progressively from 0 hour to the 96^th hour of germination. The green malt moisture content of the grains reached their peak at 72^nd hour of germination. There were significant (P < 0.05) variations of green malt moisture among the cultivars as from 0 hour of germination up to the 96^th hour. The variations increased with increase in germination time. The initial green malt moisture indicates the quantity of water in the fresh grain. It is being influenced by quantity and frequency of water sprinkled during germination.[4] Therefore, the need to sprinkle water uniformly at regular intervals of time on the grains during germination cannot be over emphasized. This is necessary for the development of enzyme systems in the grains.

Table 2 Steep-out Moisture content (%) and percent green malt moisture of pearl millet and sorghum as affected by germination time and cultivar ¹ .

	Germination Periods (hours)
Material	Moisture content	0^f	24	48	72	96
Pearl millet cultivars
SOSAT C-88	42.13 ± 1.53 ^yz	34.56 ± 0.95 ^e ^yz	43.09 ± 1.33 ^d ^yz	49.38 ± 1.38 ^c ^xyz	55.16 ± 1.29 ^b ^xy	63.60 ± 0.87 ^a ^wx
ZANGO	42.83 ± 1.57 ^xyz	34.03 ± 1.52 ^e ^yz	41.98 ± 1.04 ^d ^yz	47.70 ± 0.97 ^c ^yz	54.32 ± 1.08 ^b ^xyz	66.10 ± 1.06 ^a ^w
EX-BORNO	38.48 ± 1.43 ^z	32.76 ± 0.85 ^e ^z	39.23 ± 1.51 ^d ^z	50.82 ± 0.90 ^c ^xyz	59.23 ± 1.78 ^b ^wx	65.48 ± 1.27 ^a ^w
LCRI – IC 9701	37.66 ± 1.81 ^z	31.80 ± 0.99 ^d ^z	39.38 ± 1.02 ^c ^z	46.77 ± 1.01 ^b ^yz	49.20 ± 1.01 ^ab ^z	52.77 ± 0.98 ^a ^z
ICMV – IS 94206	40.68 ± 1.36 ^yz	33.02 ± 1.60 ^d ^yz	41.71 ± 1.00 ^c ^z	46.32 ± 0.90 ^bc ^yz	51.59 ± 0.99 ^b ^yz	60.98 ± 0.94 ^a ^wxy
ICMV – IS 94208	44.19 ± 1.62 ^x ^y	36.68 ± 1.35 ^d ^yz	42.89 ± 1.01 ^c ^yz	54.08 ± 1.04 ^b ^wx	62.77 ± 2.17 ^a ^w	63.20 ± 1.01 ^a ^wx
GB. 8735	40.98 ± 1.54 ^yz	33.91 ± 0.89 ^c ^yz	37.98 ± 1.00 ^c ^z	45.08 ± 1.52 ^b ^z	53.60 ± 0.87 ^a ^xyz	56.53 ± 1.05 ^a ^yz
G.I – 297–1	44.94 ± 0.89 ^xy	35.46 ± 1.00 ^c ^yz	40.56 ± 1.01 ^b ^z	54.29 ± 1.01 ^a ^wx	57.95 ± 1.62 ^a ^wx	58.88 ± 1.00 ^a ^xy
Sorghum cultivar
ICSV 111	47.89 ± 2.13 ^x	38.74 ± 1.71 ^e ^y	47.68 ± 2.26 ^d ^y	61.56 ± 3.77 ^c ^v	70.42 ± 0.76 ^b ^v	78.266 ± 2.34 ^a ^v

Metabolic (Malting) Loss

Table 3 shows the metabolic loss of the various pearl millet cultivars. The metabolic loss increased (P < 0.05) with increase in germination time with maximum peak at the 96^th hour of germination. The grains showed differences of metabolic loss among the cultivars at various germination times. At 0 hour germination, the metabolic loss ranged from 5.77 to 9.08% (which is also the steeping loss) and in the 24 hour, it ranged from 8.87 to 12.27%. The metabolic loss at 48^th and 72^nd hour of germination ranged from 11.39 to 15.59% and 14.89 to 19.57% respectively. While at 96^th hour of germination, it ranged from 15.99 to 22.27%. Sorghum had the highest metabolic loss, for most of the periods of germination except at 48^th and 72^nd hours of germination. The malting loss of sorghum is within the range reported by other researchers.[12,16,32]

Table 3 The metabolic loss (%) of pearl millet and sorghum as affected by germination time and cultivar ¹ .

		Germination Periods (hours)
S/No	Material	0^e	24	48	72	96
	Pearl Millet Cultivars
1	SOSAT C-88	6.90 ± 0.46 ^d ^yz	10.80 ± 1.01 ^cd ^yz	13.15 ± 0.52 ^bc ^xyz	16.46 ± 0.79 ^ab ^xyz	20.84 ± 0.72 ^a ^wx
2	ZANGO	5.77 ± 0.06 ^d ^z	9.86 ± 0.15 ^cd ^yz	12.29 ± 0.53 ^bc ^xyz	15.54 ± 1.79 ^ab ^yz	19.99 ± 0.34 ^a ^wxyz
3	EX-BORNO	6.54 ± 0.05 ^c ^yz	9.40 ± 0.09 ^bc ^yz	15.59 ± 0.02 ^ab ^x	18.19 ± 0.10 ^a ^xyz	19.27 ± 0.06 ^a ^wxyz
4	LCRI – IC 9701	6.21 ± 0.03 ^d ^yz	9.59 ± 0.08 ^cd ^yz	11.93 ± 0.05 ^c ^yz	15.08 ± 0.13 ^bc ^z	19.35 ± 0.10 ^a ^wxyz
5	ICMV – IS 94206	5.78 ± 0.08^e ^z	9.24 ± 0.02 ^bc ^yz	11.39 ± 0.04 ^ab ^z	15.28 ± 0.12 ^a ^yz	18.46 ± 0.71 ^a ^wxyz
6	ICMV – IS 94208	8.45 ± 0.05 ^b ^yz	10.44 ± 0.04 ^b ^yz	13.76 ± 0.10 ^ab ^xyz	16.71 ± 0.22 ^a ^xyz	16.79 ± 0.20 ^a ^yz
7	GWAGWA	7.63 ± 0.15 ^b ^yz	10.41 ± 0.12 ^b ^yz	22.67 ± 0.54 ^a ^w	27.30 ± 0.36 ^a ^w	27.27 ± 0.23 ^a ^v
8	G.I. – 14.9	8.69 ± 0.80^e ^yz	11.50 ± 0.79 ^c ^yz	15.50 ± 0.89 ^ab ^x	19.57 ± 0.83 ^a ^x	20.52 ± 0.96 ^a ^wxy
9	GB. 8735	6.83 ± 0.85 ^b ^yz	8.87 ± 1.53 ^b ^z	11.42 ± 0.73 ^ab ^z	14.89 ± 1.08 ^a ^z	15.99 ± 1.32 ^a ^z
10	G.I – 297-1	6.45 ± 0.57^e ^yz	8.95 ± 0.82 ^bc ^z	13.28 ± 1.16 ^ab ^xyz	16.18 ± 1.44 ^a ^xyz	17.94 ± 1.04 ^a ^xyz
	Sorghum Cultivar
11	ICSV 111	9.08 ± 1.12 ^b ^z	12.27 ± 0.93 ^b ^y	15.26 ± 1.12 ^ab ^xy	19.12 ± 0.95 ^a ^xy	22.23 ± 0.76 ^a ^w

Vegetative Loss (Seedling Yield)

Vegetative loss of the pearl millet cultivars increased (P < 0.05) with increase in germination time. Vegetative loss was not detected at 0 hour of germination. The vegetative loss differ among the cultivars significantly (P < 0.05). It can be deduced from this result that vegetative loss of millet cultivars and sorghum increased with increase in germination time. At the onset of germination, there was negligible growth and therefore vegetative loss was more at the 24^th hour and beyond (Table 4).

Table 4 The vegetative loss (%) of malted pearl millet and sorghum as affected by germination time and cultivar ¹ .

		Germination Periods (hours)
S/No	Material	0^d	24	48	72	96
	Pearl Millet Cultivars
1	SOSAT C-88	ND	3.92 ± 0.96 ^by	6.57 ± 0.54 ^b ^xyz	12.29 ± 1.21 ^a ^xy	17.72 ± 1.21 ^a ^vw
2	ZANGO	ND	3.30 ± 0.89 ^c ^yz	5.96 ± 1.24 ^bc ^xyz	11.06 ± 1.52 ^b ^xyz	19.92 ± 1.52 ^a ^v
3	EX-BORNO	ND	3.10 ± 0.15 ^b ^yz	9.76 ± 1.51 ^a ^x	12.58 ± 1.29 ^a ^xy	12.73 ± 1.26 ^a ^xyz
4	LCRI – IC 9701	ND	3.83 ± 0.20 ^c ^y	5.61 ± 1.14 ^bc ^yz	9.84 ± 0.69 ^ab ^yz	17.67 ± 0.52 ^a ^vw
5	ICMV – IS 94206	ND	3.34 ± 0.56 ^c ^yz	5.97 ± 0.34 ^bc ^xyz	9.79 ± 0.83 ^b ^yz	14.85 ± 0.76 ^a ^wxy
6	ICMV – IS 94208	ND	2.18 ± 0.21 ^b ^yz	5.69 ± 1.08 ^ab ^yz	8.94 ± 1.02 ^a ^yz	9.84 ± 0.93 ^a ^x
7	GWAGWA	ND	2.20 ± 0.22 ^b ^yz	8.97 ± 1.49 ^a ^xy	9.95 ± 1.51 ^a ^yz	11.69 ± 0.99 ^a ^xyz
8	G.I. – 14.9	ND	3.14 ± 0.11 ^b ^yz	8.51 ± 0.70 ^b ^xy	14.79 ± 1.19 ^a ^x	15.47 ± 0.37 ^a ^wx
9	GB. 8735	ND	1.33 ± 0.33 ^b ^z	3.76 ± 1.22 ^ab ^z	7.33 ± 0.43 ^a ^z	8.88 ± 0.90 ^a ^z
10	G.I – 297–1	ND	2.02 ± 0.03 ^b ^yz	6.92 ± 0.90 ^ab ^xyz	9.99 ± 1.06 ^a ^yz	10.94 ± 1.49 ^a ^yz
	Sorghum Cultivar
11	ICSV 111	ND	3.55 ± 0.47 ^c ^y	5.53 ± 0.35 ^bc ^yz	10.34 ± 0.45 ^ab ^yz	11.39 ± 0.51 ^a ^yz

Total Malting Loss

In a similar pattern, the total malting loss (Table 5) of the various grains studied increased significantly (P < 0.05) with increase in germination time. Wide variations of total malting loss among the cultivars existed at various periods of germination.

Table 5 The total malting loss (%) of pearl millet and sorghum as affected by germination time and cultivar ¹ .

		Germination time (hours)
S/No	Material	0^e	24	48	72	96
	Pearl Millet Cultivars
1	SOSAT C-88	6.90 ± 0.76 ^d ^yz	4.30 ± 0.22 ^c ^x	18.86 ± 1.32 ^c ^xy	26.73 ± 0.87 ^b ^y	34.87 ± 1.20 ^a ^vw
2	ZANGO	5.77 ± 1.12 ^d ^z	12.81 ± 0.77 ^c ^xy	17.51 ± 0.31 ^c ^xyz	25.66 ± 0.87 ^b ^y	35.63 ± 0.88 ^a ^v
3	EX-BORNO	6.54 ± 0.59 ^d ^yz	12.21 ± 0.19 ^c ^xyz	23.79 ± 1.17 ^b ^v	28.48 ± 0.53 ^ab ^xy	33.36 ± 0.41 ^a ^vw
4	LCRI – IC 9701	6.21 ± 0.70 ^d ^yz	13.05 ± 0.05 ^c ^xy	16.89 ± 0.86 ^c ^yz	23.44 ± 0.38 ^b ^z	33.60 ± 0.05 ^a ^vw
5	ICMV – IS 94206	5.78 ± 0.82 ^d ^z	12.26 ± 0.23 ^c ^xyz	16.68 ± 0.98 ^c ^yz	23.57 ± 0.70 ^b ^z	30.57 ± 0.65 ^a ^wxy
6	ICMV – IS 94208	8.45 ± 0.48 ^c ^y	12.39 ± 0.43 ^c ^xyz	18.67 ± 0.52 ^b ^xy	24.16 ± 0.04 ^ab ^yz	24.26 ± 0.04 ^a ^z
7	GWAGWA	7.63 ± 0.56 ^b ^yz	12.38 ± 0.36 ^b ^xyz	22.67 ± 0.56 ^a ^vw	26.25 ± 0.30 ^a ^y	27.13 ± 0.09 ^a ^yz
8	G.I. – 14.9	8.69 ± 0.69 ^d ^y	14.28 ± 0.17 ^c ^x	22.70 ± 0.13 ^b ^vw	31.46 ± 0.52 ^a ^x	32.28 ± 0.19 ^a ^vwx
9	GB. 8735	6.83 ± 0.11 ^d ^yz	10.08 ± 0.07 ^cd ^z	14.74 ± 0.95 ^c ^z	21.13 ± 0.08 ^b ^z	27.59 ± 0.61 ^a ^yz
10	G.I – 297–1	6.45 ± 0.37 ^c ^yz	10.79 ± 0.97 ^c ^yz	196.28 ± 0.12 ^b ^wxy	24.55 ± .10 ^ab ^yz	26.24 ± 0.19 ^a ^yz
	Sorghum Cultivar
11	ICSV 111	7.43 ± 0.42 ^c ^yz	11.68 ± 0.39 ^c ^yz	20.49 ± 0.49 ^b ^vwx	25.56 ± 0.52 ^ab ^yz	28.09 ± 1.04 ^a ^xyz

Diastatic Power

The diastatic power of the pearl millet cultivars is shown in Table 6. The diastatic power increased significantly (P < 0.05) with increase in germination time. The 0 hour of germination recorded the lowest diastatic power and gradually increased with increase in germination time up to the 96 hours of germination. There were significanct (P < 0.05) variations of diastatic power of the grains at 48 to 96 hours of germination. Subramanian et al.[8] reported similar findings for sorghum. Diatase is important in brewing as it acts on the starch present in the grain to alter its properties during malting as well as mashing.[33,34] The diastatic power of SOSAT C-88, ZANGO and EX-BORNO were not significantly (P > 0.05) different from sorghum at 96 hours of germination. It appears that these cultivars, due their ability to produce high diastatic power during germination, have good potential for malting and for specific end uses such as porridges, opaque or larger beer.[8] Demuyakor and Ohta[9] malted Sorghum vulgare from Ghana and results showed that the diastatic power increased with increase in germination time, reaching its peak on the 96 hours of germination. The data obtained in this article suggest that cultivar variation exists for diastatic power development during germination, which confirms the observations of Olaniyi and Akinrele[35] and Subramanian et al.[8]

Table 6 The diastatic power (°L) of pearl millet and sorghum as affected by germination time and cultivar ¹ .

	Germination time (hours)
Material	0^e	24	28	72	96
Pearl millet cultivars
SOSAT-C88	22.03 ± 1.70 ^d ^w	25.06 ± 1.19 ^d ^y	39.79 ± 2.30 ^c ^v	45.40 ± 2.37 ^b ^x	59.11 ± 1.03 ^a ^v
ZANGO	20.45 ± 2.36 ^d ^w	23.95 ± 2.36 ^d ^y	36.64 ± 1.40 ^c ^vw	42.26 ± 3.39 ^b ^xy	54.85 ± 2.73 ^a ^vw
EX-BORNO	18.66 ± 1.40 ^d ^wx	20.45 ± 1.70 ^d ^yz	32.10 ± 4.18 ^c ^vwxy	38.44 ± 1.17 ^b ^xy	47.43 ± 1.70 ^a ^vwxy
LCRI-IC 9701	12.14 ± 1.35 ^d ^z	13.94 ± 1.03 ^d ^z	20.32 ± 2.16 ^c ^yz	26.96 ± 3.59 ^b ^z	38.88 ± 3.83 ^a ^xyz
ICMV-IS 94206	15.29 ± 1.40 ^c ^xyz	16.64 ± 1.70 ^c ^z	25.40 ± 1.40 ^b ^wxyz	36.86 ± 1.03 ^a ^xyz	40.91 ± 3.83 ^a ^wxyz
ICMV-IS 94208	12.82 ± 2.30 ^c ^z	15.06 ± 1.03 ^bc ^z	19.11 ± 1.03 ^b ^z	30.12 ± 1.40 ^a ^yz	35.07 ± 4.21 ^a ^yz
GWAGWA	15.06 ± 1.03 ^c ^xyz	17.08 ± 1.03 ^c ^z	20.23 ± 2.02 ^bc ^yz	26,75 ± 1.70 ^b ^z	42.71 ± 2.72 ^a ^wxyz
G.I-149	13.45 ± 1.79 ^b ^yz	15.06 ± 1.03 ^b ^z	27.63 ± 1.79 ^a ^wxyz	27.90 ± 1.78 ^a ^z	29.43 ± 1.04 ^a ^z
GB 8735	13.94 ± 1.03 ^d ^xyz	17.08 ± 1.03 ^cd ^z	22.92 ± 2.03 ^c ^xyz	29.67 ± 1.35 ^b ^yz	34.17 ± 5.15 ^a ^yz
G.I-297-1	17.08 ± 1.03 ^c ^wxyz	16.41 ± 2.72 ^c ^z	33.94 ± 1.03 ^b ^vwx	44.95 ± 2.80 ^a ^x	45.76 ± 2.02 ^a ^wxy
Sorghum cultivar
ICVS 111	17.98 ± 1.03 ^d ^wxy	20.45 ± 1.70 ^d ^yz	40.24 ± 0.77 ^c ^v	45.85 ± 2.02 ^bc ^x	53.50 ± 6.12 ^a ^vwx

Correlation Analysis Between Malting Properties

There was good correlation between green malt moisture, steep-out moisture and malting loss (Table 7). Green malt moisture was positively correlated (r = 0.97, P < 0.05) with malting loss and total malting loss (r = 0.82, P < 0.05) and diastatic power (r = 0.88, P < 0.05). Vegetative loss correlated (r = 0.91, P < 0,05) with total malting loss. There was no significant correlation (r = 0.35, P > 0.05) between malting loss and vegetative loss. It has been reported that the optimum germination time of pearl millet is 72 hours.[36,37] Therefore, most of the pearl millet cultivars had moderate malting loss compared with the values for sorghum obtained in this research and published reports.[16,12] Singh and Sosulki[15] reported that malting losses are depended more on the duration of germination. Many researchers have attempted to reduce malting losses by shortening the length of rootlets and shoots using potassium bromate at concentration of 125 mg/litre.[38] However, Aisien and Muts[5] found out that neither gilberellic acid, nor bromate, can affect amylase and protease levels in sorghum.

Table 7 Correlation Analysis between steep-out moisture, green malt moisture, malting loss, and diastatic power of various pearl millet cultivars.

	Green malt moisture	Steep-out moisture	Malting loss	Vegetative loss	Total malting loss
Steep-out moisture	0.62
Malting loss	0.97 ^a	0.80 ^a
Vegetative loss	0.63	0.58	0.35
Total malting loss	0.82 ^a	0.79 ^a	0.88 ^a	0.91 ^a
Diastatic power	0.83 ^a	0.77 ^a	−0.71 ^a	−0.83 ^a	−0.82 ^a

CONCLUSION

Steeping grains for 12 hours has shown that sorghum absorbed more water than pearl millet cultivars. G.I-297-1 absorbed more water than the other pearl millet cultivars. The grains had good germinative properties. Green malt moisture, malting loss, vegetative loss, total malting loss, and diatsatic power increased with increase in germination time up to the 96 hours of germination and varied among the cultivars. The diastatic power of SOSAT C-88, ZANGO AND EX-BORNO were not significantly (P > 0.05) different from sorghum at 96 hours of germination and therefore, these pearl millet cultivars could be considered for malting. There was positive correlation between green malt moisture, steep-out moisture and malt loss of the pearl millet cultivar.

ACKNOWLEDGMENTS

The authors acknowledged the assistance rendered (in form of published articles) by Professor E.B. Agbo of Biological Sciences Programme, Abubakar Tafawa Balewa University; Bauchi, Nigeria. The grain was supplied by Lake Chad Research Institute Maiduguri and is gratefully acknowledged.

Notes

¹Mean ± Std of triplicate determinations;

^a-eMeans within each row not followed by the same superscript are significantly different (P < 0.05);

^v-zMeans within each column not followed by the same super script are significantly different (P < 0.05);

0^fhour is the time just after steeping and before germination, while 24, 48, 72, and 96 hours are samples taken at 24 hours intervals.

¹Mean ± Std of triplicate determinations;

^a-dMeans within each row not followed by the same superscript are significantly different (P < 0.05);

^v-zMeans within each column not followed by the same super script are significantly different (P < 0.05);

0^ehour is the time just after steeping and before germination, while 24, 48, 72, and 96 hours are samples taken at 24 hours intervals.

¹Mean ± Std of triplicate determinations;

^a-dMeans within each row not followed by the same superscript are significantly different (P < 0.05);

^v-zMeans within each column not followed by the same super script are significantly different (P < 0.05);

ND = Not detected;

0^dhour is the time just after steeping and before germination, while 24, 48, 72, and 96 hours are samples taken at 24 hours intervals.

¹Mean ± Std of triplicate determinations;

^a-dMeans within each row not followed by the same superscript are significantly different (P < 0.05);

^v-zMeans within each column not followed by the same super script are significantly different (P < 0.05);

0^ehour is the time just after steeping and before germination, while 24, 48, 72, and 96 hours are samples taken at 24 hours intervals.

¹Meand standard of triplicate determinations;

^a-dMeans with each row not followed by the same super script are significantly different (P < 0.05);

^v-zMeans with each column not followed by the same superscript are significantly different (P < 0.05);

0^eh is the time after steeping and before germination, while 24, 48, 72, and 96 h are times which samples were taken for analysis.

^aSignificant at 5% (P < 0.05).

19. Agbo, E.B. Studies on the malting properties of sorghum varieties used for larger production. PhD Thesis. Abubakar Tafawa Balewa University, Bauchi, 1995.