Previous PageTable Of ContentsNext Page

Pre-release characterisation of the malting profile of WI-3102

S. Roumeliotis1, S.J.Logue1, C. Hunt2 and A.R.Barr1

1Adelaide University, Department of Plant Science, PMB 1, Glen Osmond, SA, 5064, Australia
2
Biometrics SA, Waite Campus, Glen Osmond, SA, 5064, Australia

Introduction

Improvement in malt extract is an important goal of the South Australian Barley Improvement Program (SABIP), since high levels of malt extract are highly desired by the malting and brewing industries. In order to match the quality of Canadian and European barley varieties, breeders have used strategies such as mapping populations, doubled haploids, summer nurseries and marker assisted selection. As a result, promising high malt extract lines are now in advanced stages within the SABIP.

WI-3102 is a doubled haploid line derived from the cross WI2808// (Skiff/Haruna nijo). It has a semi-dwarf plant type conferring good standing ability and resistance to head loss. It is also resistant to cereal cyst nematode – a trait which previously had proven difficult to combine with high malt extract. It is best adapted to the medium and higher rainfall areas of SA and the Wimmera where it outyields Schooner but produces lower yields than Gairdner.

In variety trials since 1996, it has consistently averaged 1% higher malt extract than Franklin and 2-3% higher than Schooner. Viscosity and wort beta glucan are excellent, although diastatic power and fermentability are low. These characteristics however, indicate potential for the domestic brewing market, probably for low-mid alcohol beer production. It has a characteristic crinkled husk, which is thin. Recent research has shown an association between high levels of malt extract and thin husk. However, there can be potential problems associated with thin husk, including pre-harvest sprouting and embryo and skinning damage. The Malting and Brewing Industry Barley Technical Committee (MBIBTC) in its guidelines, has a 5% maximum upper limit for skinned grain per weight on a litre sample (MBIBTC, 1998). NACMA has a skinning limit of 10% (NACMA, 1996) and ABB Grains had a limit of 15% maximum count for the 1999/2000 season (ABB Grain, 1999). In Canada, Harrington barley is often criticized for ‘peeling”, or “skinning” as it is known in Australia. The Canadian breeders consider peeling resistance as one of their highest priority traits (Edney, 1999). In European varieties there is a wide range in skinning susceptibility, including popular varieties such as Alexis and Scarlett, which are prone to this problem (Baumer et al, 1998). In contrast, this has not been an issue with malting varieties well adapted to southern Australia such as Schooner, Sloop or Stirling. It is important for the Australian industry to assess the benefits (i.e., higher extract) and risks of this attribute of WI 3102 before its release. This paper reports a series of experiments conducted over two seasons to investigate the possible relationships between husk content, skinning, germination and malt quality in WI 3102 and its progeny.

Materials and Methods

Barley Samples

a) Husk studies

A total of 37 barley genotypes were chosen from 23 sites grown across South Australia. This data set was comprised of:

  • 34 samples from the 1998 season Brinkworth SABIP Stage 2 and 3 breeding trials
  • 16 samples from the 1999 season Brinkworth SABIP Stage 3 breeding trials
  • 16 samples from the 1999 season Yeelanna SABIP Stage 3 breeding trials
  • WI-3102 and Schooner from 21 SARDI Stage 4 sites from the 1999 season

Data from 23 of the genotypes are presented in this paper (Table 1).

b) WI-3102 commercial crop evaluation

A total of 11 barley samples were analysed from crops grown for the commercial malting and brewing evaluation of WI-3102 (Table 2). There were 4 crops grown in South Australia and 2 crops in Victoria, however samples from different paddocks were analysed separately. Crops were later pooled for commercial evaluation.

c) WI-3102 crosses

One hundred and seventeen barley samples were chosen from a number of experiments from the 2000 Stage 1 trials grown at Pinery in South Australia. Included in this sample set were 86 selections of the cross WI-3102//Keel/Fitzgerald and 17 selections of the cross Keel/Gairdner//WI3102. There were also seven commercial varieties including Barque, Franklin, Gairdner, Keel, Mundah, Schooner and Sloop used as controls. These samples were analysed for a range of quality parameters including percent skinning, husk content and IOB malt extract. These selections were also visually assessed for husk type (smooth or wrinkled husk) and whether they had excellent, good or poor hull adherence.

Table 1. Selected barley varieties included in 1998 and 1999 husk experiments

Variety/Line

1998 trials

1999 trials

Arapiles

x

x

Barque

x

x

Chebec

x

 

Fitzgerald

x

 

Franklin

x

x

Gairdner

x

x

Galleon

x

 

Monarch

x

x

SA93013 = SBWI-1 = Lofty Nijo

x

x

Schooner

x

x

Skiff

x

 

Sloop

x

x

Venture

x

x

Vic 9524 = Arapiles/Franklin

x

x

WA5040 = Kinukei-21 = Unicorn

x

 

WB190R = Wyalong

x

 

WI-2976 = Keel

x

 

WI-3102 = (WI-2808*(Skiff *Haruna Nijo))/D40

x

x

Harrington

x

x

Haruna Nijo

x

x

BX92;037-26 = ((Haruna Nijo/Skiff)-72)/Heran

x

 

BX92;042-27 = ((Haruna Nijo/Skiff)-72)/Natasha

x

 

BX92;026-89 = WI-3284 = ((Haruna Nijo/Skiff)-42)/Natasha

x

x

Table 2. WI-3102 commercial crop evaluation samples

ID

Line

Farmer

State

Details

1a

WI3102

Day

SA

Paddock 1

1b

WI3102

Day

SA

Paddock 2

1c

WI3102

Day

SA

Paddock 3

2a

WI3102

Crawford

SA

Fordvale Pastoral 3102a

2b

WI3102

Crawford

SA

Fordvale Pastoral 3102b

3

WI3102

McCormack

SA

Tarlee

4

WI3102

Johns

VIC

 

5a

WI3102

Jasper

VIC

Irrigation 1

5b

WI3102

Jasper

VIC

Irrigation 2

5c

WI3102

Jasper

VIC

Paddock 9

6

Arapiles

Jasper

VIC

 

Barley and Malt Quality Analysis

All barley and malt quality parameters were assessed using standard analytical methods, typical of the analysis conducted on Stage 4 variety trials in the SABIP (Barley Quality Report, 1999 season). Samples were micromalted using the standard protocol used by the Waite Barley Quality Evaluation Laboratory (Barley Quality Report, 1999 season). NIR Hot Water Extract (HWE) was assessed using calibrations developed on a NIRSystems 6500 scanning spectrophotometer (Roumeliotis et al, 1999). Thousand grain weights, and the germinative energy of barley were assessed using standard European Brewing Convention (EBC) methods (Analysis Committee of the EBC, 1998). Germinative energy was assessed directly after harvest in December, in March and just prior to malting in April. Germination counts were also carried out August, October, December and February of the following season. The husk content of barley and malt was determined using a scaled down version of the standard EBC method (Analysis Committee of the EBC, 1998). To assess husk damage, percent skinning was determined using the Australian Barley Board classification skinning protocol (ABB Grain, 1998). Milling energy was determined using a Comparamill. Hardness, diameter, weight and moisture were assessed using a Single Kernel Characterization System (SKCS 4100). Grain hydration during the malting process was assessed using the boiled grain method (Landau et al., 1995).

Statistical Analysis

For the husk study, multiple linear regression models were used to test the relationship between husk content, skinning, germination and malt quality. Fitted regression coefficients for each quality trait were tested for significant differences between coefficients and zero. All non-significant terms were systematically removed to obtain a model that contained all traits that significantly contribute to the overall multiple regression model for either husk content, skinning or germination.

Results and Discussion

Husk studies

For percent skinning, analysis of variance showed significant differences between average skinning between 1998 and 1999 seasons, however there was no significance between sites within each year. There are also significant variety effects, however no significant variety interactions for varieties across years or sites. Mean percentage skinning over 2 years (1998-1999) is shown in Table 3. WI-3102 was not significantly different to Schooner. Haruna nijo, which is also a thin husked variety, had an average skinning of 11.2% and Skiff 4.0%. In Haruna nijo crosses percent skinning ranged between 3.0 and 43.0. Feed varieties such as Barque, Chebec, Galleon and Skiff all had low percent skinning. A multiple linear regression model was applied to determine the key associations between skinning and malt quality. The following malt quality parameters were shown to be affected by skinning: grain hardness, grain diameter, micromalter moisture at 48hours, malt loss, b (grain colour intensity), WBG, SP, KI and HWE-NIR.

Table 3. The mean percentage skinning and husk content of 23 selected barley genotypes in 1998-1999

Variety/Line

% Skinning

% husk

Arapiles

9.7

8.63

Barque

5.0

11.22

Chebec

5.5

12.25

Fitzgerald

6.0

10.10

Franklin

23.0

8.12

Gairdner

7.3

8.53

Galleon

5.0

12.10

Monarch

20.8

8.62

Lofty Nijo

3.7

8.70

Schooner

17.3

8.31

Skiff

4.0

10.35

Sloop

12.7

9.62

Venture

14.0

8.57

Vic 9524

9.7

9.60

WA5040

19.0

9.10

Wyalong

4.0

10.85

Keel

7.0

14.35

WI-3102

25.9

6.86

Harrington

35.2

9.42

Haruna Nijo

11.2

7.88

BX92;037-26 = ((Haruna Nijo/Skiff)-72)/Heran

38.0

10.60

BX92;042-27 = ((Haruna Nijo/Skiff)-72)/Natasha

3.0

8.60

BX92;026-89 = WI-3284 = ((Haruna Nijo/Skiff)-42)/Natasha

18.2

7.22

LSD 5%

15.6

1.38

Analysis of variance showed that there were significant differences in husk content between the 1998 and 1999 seasons. Rainfall statistics from Brinkworth in 1998 (311mm, average husk content 10.66%) and in 1999 (368mm, average husk content 7.23%) show that environment may play a role in determining the husk content between seasons. There were also significant differences in husk content between sites, with site averages ranging between 5.85 at Brentwood and 10.66 at Brinkworth in 1998(data not shown). Significant differences were also found in husk content between varieties (Table 3). WI-3102 had on average 1.5% less husk content than Schooner and 7.5% less than the feed variety Keel. In terms of key associations with malt quality, the parameters found to be most affected by husk content were milling energy, grain moisture, DP, AA, Beta, MP, Viscosity, HWE-NIR and EBC HWE. Regression analysis also showed a significant negative linear relationship between skinning and husk content.

WI-3102 commercial crop evaluation

In 2000, MBIBTC Stage 2 evaluation of WI-3102 barley pilot brewing trials carried out by Carlton and United Breweries, showed no obvious processing problems or product quality issues. This trial assessed 8kg of malt, and produced very high malt extract with good beta glucan levels. As a result of these trials it was recommended that WI-3102 be evaluated on a commercial scale. WI-3102 is currently undergoing Stage 3-4 MBIBTC evaluation and commercial brewing results this year which will enable industry to make a decision on its future release.

Laboratory malt quality analysis of the WI-3102 commercial crop samples (MBIBTC Stage 3-4) confirm the findings of laboratory analysis within the SABIP (since 1996) as well as industry testing (Table 4). Malt extract is high whilst viscosity and WBG is excellent. DP and fermentability (AAL) are low. In the Victorian crops in particular, WI-3102 (samples 5a, 5b, 5c) was on average 3.9 % higher in malt extract than Arapiles and 1.5% higher than sample 4.

Table 4. Malt quality analysis of WI-3102 commercial crop samples from the 2000 harvest

ID

Line

State

DP

AA

Beta

MP

SP

KI

HWE

VISC

FAN

WBG

AAL

FRI

1a

WI3102

SA

466

125

341

11.3

5.2

45.6

82.2

1.63

213

193

78.9

67.5

1b

WI3102

SA

460

123

337

11.0

4.9

44.5

81.8

1.63

182

199

79.2

69.8

1c

WI3102

SA

381

113

268

9.9

4.8

48.4

82.1

1.65

192

193

78.2

78.6

2a

WI3102

SA

406

107

299

9.9

4.7

48.0

80.8

1.59

183

70

79.0

80.5

2b

WI3102

SA

419

120

299

9.9

4.8

48.7

81.4

1.57

180

78

78.0

80.1

3

WI3102

SA

440

127

313

9.7

5.2

52.9

83.6

1.55

224

3

80.7

84.1

4

WI3102

VIC

659

134

525

15.1

6.0

39.5

79.9

1.56

202

130

78.1

47.8

5a

WI3102

VIC

486

139

347

10.8

5.3

49.2

82.1

1.58

219

19

n/a

72.2

5b

WI3102

VIC

343

109

233

10.7

5.6

52.3

82.1

1.60

217

33

78.2

85.3

5c

WI3102

VIC

376

127

249

11.2

6.1

54.0

82.7

1.58

246

3

80.7

86.2

6

Arapiles

VIC

711

102

609

12.2

5.7

46.6

78.4

1.57

228

125

81.2

62.9

Analysis of the skinning, grain colour, grain weight, germination and husk characteristics of the WI-3102 commercial crop samples was also carried out (Table 5). Percent skinning ranged from 4-21% in the SA crop samples. In the Victorian crops, skinning ranged from 16-30%, however this was comparable to Arapiles, which had 18% skinning. Husk contents were varied, but generally lower in the Victorian samples. The husk content of the WI-3102 samples did not differ greatly after the malting process. In the germination analysis, WI-3102 showed no dormancy and low water sensitivity.

Table 5. Skinning percentage, husk content, grain colour, grain weight and germination data for the WI-3102 commercial crop samples

ID

Line

State

%
skinning

%
grain
husk
cont

%
malt
husk
cont

L*

1000
grain
weight

4ml
germ
Jan

4ml
germ
April

8ml
germ
Jan

8ml
germ
April

1a

WI3102

SA

17

7.7

7.3

61.8

43.6

100

100

90

99

1b

WI3102

SA

13

7.4

7.5

62.3

43.7

100

100

98

100

1c

WI3102

SA

16

7.1

7.6

59.1

44.2

100

100

96

100

2a

WI3102

SA

5

8.1

8.9

58.4

41.1

100

100

85

99

2b

WI3102

SA

4

9.9

9.2

58.0

41.8

100

100

86

100

3

WI3102

SA

21

7.8

7.8

63.9

51.8

100

100

100

100

4

WI3102

VIC

28

4.5

4.9

60.1

38.7

100

100

97

100

5a

WI3102

VIC

18

6.3

6.7

62.7

45.9

100

100

99

100

5b

WI3102

VIC

16

6.7

6.4

62.5

44.3

100

100

99

100

5c

WI3102

VIC

30

6.8

6.8

61.0

44.8

100

100

100

99

6

Arapiles

VIC

18

7.9

7.6

60.0

40.1

99

100

69

93

Maltsters and brewers have indicated strong interest in WI-3102. A 60 tonne batch of WI-3102 barley commercially grown was recently malted by Adelaide Malting Co. Batch analysis showed very high malt extract, excellent viscosity, good wort beta glucan and low DP. Coopers Brewery subsequently used this malt to produce “Pale Ale” with no obvious processing problems to date (Doug Stewart, personal communication).

WI-3102 crosses

WI 3102 is a very attractive prospect as a parent because of its combination of high malt extract, plump grain, semi-dwarf plant type and CCN resistance. However, it is crucial to know if its malt extract and thin husk are inextricably linked to wrinkled husk, which lowers hectoliter weight and increases the risk of skinning and poor hull adherence. In this study which included 86 selections of the cross WI-3102//Keel/Fitzgerald and 17 selections of the cross Keel/Gairdner//WI3102, a wide range of husk contents (6.3 – 11.7%), skinning percentage (2 – 53%) and IOB malt extract (74.5 – 81.0%) was observed. By grouping selections according to husk type, it was shown that a wrinkled husk led to slightly higher skinning (3% more) and lower husk content (0.4% less) which resulted in 0.25% lower malt extract (Table 6). Furthermore, selections characterized by poor hull adherence, had on average 15% higher skinning, 0.8% lower husk content, and only added 0.6% to malt extract levels. The key finding however is that husk type and husk adherence segregate independently and therefore confirm the findings of Roumeliotis et al. that it is possible to breed for varieties with smooth husk, low husk content, good hull adherence and high malt extract. Correlation coefficients between husk content, skinning and malt extract were calculated and the results validate the findings of Collins et al. and Roumeliotis et al., namely, there is a significant correlation between either husk content or skinning percentage and malt extract (-0.566, P<0.001; 0.304, P<0.001, respectively). Furthermore, there was a significant negative correlation (-0.328, P<001) found between skinning and husk content, which was also found in the husk study.

Table 6. The effect of husk type (smooth vs wrinkled) and hull adherence on the skinning percentage, husk content and IOB extract in a study of 103 selections from WI 3102 crosses.

Husk trait

Class

Mean % skinning

Mean %
husk content

Mean %
IOB HWE

Number in each class


Husk type

Wrinkled

15

9.21

78.3

62

Smooth

12

9.64

78.5

41

LSD 5%

NS

0.39

NS

 


Hull adherence

Excellent

8

9.76

78.2

24

Good

13

9.41

78.3

55

Poor

23

8.94

78.8

24

LSD 5%

3.51

0.471

NS

 

1LSD refers to comparing the minimum and maximum value. Other comparisons require a different LSD calculation.

Conclusion

WI 3102 was evaluated in small plot studies and from commercial scale crops. The analyses conducted confirm that WI 3102 has considerable potential as a malting barley for the domestic market, in the first instance, because of its combination of high malt extract, low viscosity, moderate diastatic power and low attenuation limit. Farmers and maltsters will have to carefully handle the harvest and processing of WI 3102 as its hull is more prone to damage than traditional Australian varieties like Schooner, although it is similar to other premium malting varieties grown overseas. Finally, the potential of WI 3102 as a parent has been established and it seems possible to breed for varieties with smooth husk, low husk content, good hull adherence and high malt extract.

Acknowledgements

This work acknowledges the support of the Malting Barley Quality Improvement Program, a program including Australian university, state government research investment corporations and foundations and malting and brewing companies. The authors would like to thank the members of the South Australian Barley Improvement Program for their assistance with sample preparation and analysis. Many thanks to Silja Home from VTT Finland for milling energy results and Cassandra Black and Joe Panozzo from VIDA for use of their SKCS. Thanks also to Mark Goldsmith from Carlton and United Breweries and MBIBTC for providing the Stage 2 evaluation report on WI-3102 and Doug Stewart from Adelaide Malting Co for personal communication.

References

1. ABB Grain Ltd., (1998) Barley Classification Manual, Version 2.0

2. ABB Grain Ltd., (1999) South Australia Barley Delivery Specifications Season 1999/2000, Ver. 1.0

3. Analysis Committee of the EBC (1998) Analytica EBC, Verlag Hans Carl Geranke-Fachverlag

4. Baumer M., Grossman O., Miedaner H., Graf H. and Sacher B. (1998) Monatsschrift fur Brauwinssenschaft. 51(11-12): 176-188

5. Collins, H.M., Logue, S.J., Jefferies, S.P., Stuart, I.M. and Barr, A.R. (1999) Proceedings of the

6. 9th Australian Barley Technical Symposium, Melbourne, Victoria, p. 2.44.1-2.44.6

7. Edney, M.J. (1999) Proceedings of the Canadian Barley Symposium’99, Winnipeg, Manitoba, Canada, p.117-123

8. Landau, J.B., Chandra, G.S. and Proudlove, M.O. (1995) Proceedings of the 7th Barley Technical Symposium, Perth, Western Australia, p.269-271

9. MBIBTC (1998) Industry Guidelines for Australian Malting Barley, Volume IV

10. NACMA (1996) Commodity Standards Grain, NACMA 530 Wilberforce Rd., Wiberforce, 2756

11. Roumeliotis S., Collins H.M., Logue S.J., Willsmore K.L., Jefferies S.P. and Barr A.R. (1999)

12. Proceedings of the 9th Australian Barley Technical Symposium, Melbourne, Victoria,

13. p. 3.5.1-3.5.6

14. Roumeliotis, S., Logue, S.J., Jefferies, S.P. and A.R. Barr (2000) The Development and

15. Implementation of NIR Calibrations for Predicting Malting Quality in Barley. In: Near Infrared Spectroscopy: Proceedings of the 9th International Conference, pp. 673-678, Eds. A.M.C. Davies and R. Giangiacomo. NIR Publications, UK

16. S.A Barley Improvement Program, (2001) Barley Quality Report 1999 Season, Adelaide University, Waite Campus

Previous PageTop Of PageNext Page