INVESTIGATION OF COMPONENTS OF BAKING QUALITY OF WHEAT IN ESTONIA Anne Ingver Reine Koppel. Jõgeva Plant Breeding Institute

Transcription

1 INVESTIGATION OF COMPONENTS OF BAKING QUALITY OF WHEAT IN ESTONIA Anne Ingver Reine Koppel Jõgeva Plant Breeding Institute

2 INTRODUCTION Estonia is situated at degrees north under long days and relatively short summers, with cold winter and precipitation between mm/year. The summer period is approximately 160 days. Average conditions during harvesting in Estonian conditions are satisfactory. Suitable for combine harvesting are in average days, from which days during the second 10 days period in August and days during the third. In the first decade of September only days are suitable for combine harvesting. Wheat in Estonia should satisfy the needs of baking industries. Therefore good baking quality has been one of the priorities in wheat breeding at Jõgeva Plant Breeding Institute (PBI). Breeding for baking quality is hampered by its complexity. For predicting baking quality we assessed protein content, gluten content, gluten strength (gluten index), Zeleny value, falling number, baking test parameters (including farinogram and extensiogram parameters) and combination of HMW glutenin subunits. Quality requirements for our breeding program are: protein content>12%; gluten content>25%; gluten index 50 90; high Zeleny value, falling number > 250 sec, stability of dough at least 6 min, composition of HMW subunits with high quality score by Payne.

3 MATERIAL AND METHODS The study was carried out with 12 spring and 13 winter wheat varieties of the Estonian Variety List from the trials of the Jõgeva PBI during Baking tests from 250g flour according to the long fermentation process were carried out with all the mentioned material by the method of Finnish State Granary. Protein and gluten content, gluten index and Zeleny value were determined by standard procedures. α-amylase activity was determined according to standard method by Hagberg Falling Number equipment. Additionally sprouting resistance after 3, 5 and 7 days was measured by data of moisture chamber test. SDS-Page electrophoresis for the Estonian Variety List varieties was carried out at the Institute of Experimental Biology.

4 RESULTS Comparing two types of wheat, spring wheat had better baking quality than winter wheat during the testing period. Spring wheat had higher protein (Fig. 1) and gluten content (Fig. 3) and higher Zeleny value (Fig. 5). Protein content had a greater influence on overall processing quality than any other single factor. Strength of gluten depended on the year (Fig. 4). Three years of five spring wheat had higher gluten index values. Spring wheat had higher farinograph absorption (Fig. 7) and better dough stability (Fig. 8). Winter wheat had shorter dough development time and stronger resistance to stretching. Spring wheat produced higher valorimeter value, dough elasticity and bigger loaf volume (Fig. 6). Differences in crumb structure and elasticity between different wheat types were not noticeable. Winter wheat was harvested before rainy period and had higher Falling number values in the most of the years (Fig. 2). According to Spearman Rank Correlations protein and gluten content influence both the farinogram and extensiogram parameters. Extensiogram parameters were more depending on gluten index values. Correlations between different quality parameters were found. Biochemical fingerprints by electrophoresis of the most of the Estonian Variety List varieties have Glu-1 subunits 2*, 7+9 (winter), 7+8 (spring) and 5+10.

5 prot. content % 18,0 16,0 14,0 12,0 10,0 Falling number, sec Figure 1. Protein content, % Figure 2. Falling number, sec gluten cont., % gluten index, % Figure 3. Gluten content, % Figure 4. Gluten index, %

6 Zeleny value, mm SPRING WHEAT WINTER WHEAT loaf volume, cm Figure 5. Zeleny value, ml Figure 6. Loaf volume, cm 3 60,0 20,0 water absorbtion, % 58,0 56,0 54,0 52,0 50,0 dough stability, min 15,0 10,0 5,0 Figure 7. Water absorption, % Figure 8. Dough stability, min

7 COMPOSITION of HMW GLUTENIN SUBUNITS by SDS PAGE Variety Country of Glu-A1 Glu-B1 Glu-D1 Glu-1 origin allele protein allele protein allele protein score 1 Kosack winter wheat Sweden b 2* d 6+8 a Kalvi winter wheat Estonia b 2* c 7+9 d Kalle winter wheat Norway a 1 c 7+9 d Portal winter wheat Germany a 1 c 7+9 d Sirvinta winter wheat Lithuania a / b 1 / 2* c 7+9 d Ramiro winter wheat Germany a 1 c 7+9 d Sani winter wheat Estonia b / c 2* / - b/c/a 7+8/7+9/7 d / a 5+10/ /8/5 8 Gunbo winter wheat Sweden b 2* b 7+8 a Tarso winter wheat Germany b 2* c 7+9 d Residence winter wheat The Netherlands c - a 7 a Lars winter wheat Germany b 2* c 7+9 d Bjorke winter wheat Sweden b 2* c 7+9 d Bill winter wheat Germany c - c 7+9 a Baldus spring wheat The Netherlands c - b 7+8 a Helle spring wheat Finland/Estonia b 2* b 7+8 a Mahti spring wheat Finland a 1 b 7+8 d Manu spring wheat Finland b 2* b 7+8 d Meri spring wheat Finland/Estonia b 2* c 7+9 a Munk spring wheat Germany c - c 7+9 d Reno spring wheat Norway a 1 c 7+9 d Runar spring wheat Norway b 2* b 7+8 d Satu spring wheat Sweden b 2* b 7+8 a Tjalve spring wheat Sweden b 2* c 7+9 d Triso spring wheat Germany c - b 7+8 a Vinjett spring wheat Sweden b 2* b 7+8 d

8 SPEARMAN RANK CORRELATIONS BETWEEN DATA OF BAKING QUALITY GC GI PC FAR A FAR DT FAR ST FAR S10 FAR S20 FAR V EXT AC EXT RS EXT E LV SV EV W GC 1 GI -0,26*** 1 PC 0,88*** 1 FAR A 0,62*** 0,65*** 1 FAR DT 0,74*** 0,87*** 0,64*** 1 FAR ST 0,50*** 0,24** 0,65*** 0,35** 0,70*** 1 FAR S10-0,66*** -0,79*** -0,57*** -0,85*** -0,87*** 1 FAR S20-0,58*** -0,16* -0,70*** -0,46*** -0,73*** -0,89*** 0,91*** 1 FAR V 0,72*** 0,86*** 0,62*** 0,94*** 0,81*** -0,93*** -0,87*** 1 EXT AC 0,66*** 0,33*** 0,62*** 0,39*** 0,62*** -0,50*** -0,54*** 0,48*** 1 EXT RS -0,44*** 0,65*** -0,31*** -0,21** -0,20** 0,16* 0,62*** 1 EXT E 0,63*** 0,74*** 0,33*** 0,68*** 0,54*** -0,57*** -0,51*** 0,65*** 0,43*** -0,37*** 1 LV 0,65*** 0,70*** 0,38*** 0,67*** 0,52*** -0,60*** -0,58*** 0,66*** 0,18* -0,31*** 0,53*** 1 SV -0,32*** -0,34*** -0,35*** -0,24** -0,19** 0,25*** 0,29*** -0,25*** -0,17* -0,16* -0,36*** 1 EV 0,18* -0,16* 1 W 0,45*** 0,46*** 0,72*** 0,44*** 0,28*** -0,43*** -0,37*** 0,46*** 0,21** 0,28*** -0,28*** 1 GC - gluten content; FAR S10 - softening 10 min LV - loaf volume GI - gluten index FAR S20- softening 20 min SV - crumb structure value Strong correlation r = > 0,70 PC - protein content FAR V - valorimeter value EV - crumb elasticity value Medium correlation r = 0,50-0,69 FAR A - farinograph absorbtion EXT AC -area under extensiogram curve W - loaf weight Weak correlation r < 0,50 FAR DT - dough developing time EXT RS - resistance to streching FAR ST - dough stability EXT E - extensibility

9 CONCLUSIONS In the northern part of Europe, where Estonia is situated, growing of wheat with satisfactory baking quality is possible if adapted varieties have been selected. Spring wheat grown in Estonian climate has usually better baking quality than winter wheat. By the trial results we received the average data ( ) for spring and winter wheat (SW/WW) as follows: protein content 14,7/13,5 %, gluten content 34,9/31,0 %, gluten index 73/67 %, Zeleny value 75,9/63,2 ml, falling number 305/317 sec, flour water absorption 57,2/55,7 %, dough stability 10,4/5,7 min, loaf volume 1495/1339 cm 3. Biochemical fingerprints by electrophoresis of the most of the Estonian Variety List varieties have Glu-1 subunits 2*, 7+9 (winter), 7+8 (spring) and Most of the listed varieties are suitable as bread wheats. From the Listed varieties the best baking quality had winter wheat varieties Sani (Estonia), Ramiro (Germany), Tarso (Germany) and spring wheat varieties Manu (Finland), Vinjett (Sweden), Helle (Estonia-Finland).