Sourdough fermentation of wholemeal wheat bread reduces glycemic responses in subjects with insulin resistance

Jenni Lappi, Emilia Selinheimo, Pekka Lehtinen, Ursula Schwab, Hannu Mykkänen, Marjukka Kolehmainen, Kaisa Poutanen

Research output: Contribution to journalOther journal contributionScientific

Abstract

Intake of wholegrain foods, as well as foods with slow glycemic response, is associated with reduced risk of chronic diseases. Since glycemic responses to breads made of wholemeal flour are high, retarding the glycemic response of a wholemeal bread would further increase its health benefits. The aim was to study postprandial glucose and insulin responses of wholemeal wheat breads in relation to baking technology. Breads were baked using 100% flour from peeled (2%) wheat kernels by straight dough or sourdough fermentation method, and with or without addition of xylanase during mixing of dough. Standard white wheat bread was used as reference. Eleven subjects with insulin resistance and features of the metabolic syndrome were served the breads in random order. Each test bread portion contained 50g of available carbohydrate. Blood samples for measuring glucose and insulin concentrations were drawn at eight time points over four hours. Nutrient composition and the content of soluble protein of the test breads were determined. In vitro hydrolysis of protein and molecular weight of the protein hydrolysates were also performed. The wheat bread produced using sourdough fermentation had the lowest postprandial glucose and insulin responses. Plasma glucose concentration was lower at time points 45, 60, 90 and 120 min (p<0.05) and higher at 240 min (p<0.01) as compared with the reference. Furthermore, serum insulin concentration was lower at the time point 90 min (p<0.05). The postprandial responses were not improved by addition of xylanase. Sourdough fermentation and xylanase treatment increased the amount of water-extractable arabinoxylan, while the latter also led to increased depolymerisation of water-extractable arabinoxylan. In the sourdough fermented bread, the content of soluble protein was the highest and the MW of the hydrolysed proteins the smallest. In conclusion, sourdough fermentation resulted in a bread with the most favourable postprandial glucose and insulin responses among the three tested wheat breads made of peeled kernels. Possible mechanisms by which fermentation produces this effect are low pH, increased arabinoxylan solubilisation, and proteolysis. The reduced postprandial response achieved by sourdough fermentation may further encourage the use of wholemeal wheat bread by persons with insulin resistance.
Original languageEnglish
JournalCereal Foods World
Volume54
Issue number2
Publication statusPublished - 2009
MoE publication typeB1 Article in a scientific magazine
EventC&E Spring Meeting 2009 : Whole Grain Global Summit - Newcastle upon Tyne, United Kingdom
Duration: 25 Mar 200927 Mar 2009

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sourdough
Bread
insulin resistance
breads
Triticum
Fermentation
Insulin Resistance
fermentation
wheat
insulin
arabinoxylan
xylanases
glucose
protein hydrolysates
dough
Insulin
Glucose
whole wheat bread
whole grain flour
proteins

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Lappi, Jenni ; Selinheimo, Emilia ; Lehtinen, Pekka ; Schwab, Ursula ; Mykkänen, Hannu ; Kolehmainen, Marjukka ; Poutanen, Kaisa. / Sourdough fermentation of wholemeal wheat bread reduces glycemic responses in subjects with insulin resistance. In: Cereal Foods World. 2009 ; Vol. 54, No. 2.
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title = "Sourdough fermentation of wholemeal wheat bread reduces glycemic responses in subjects with insulin resistance",
abstract = "Intake of wholegrain foods, as well as foods with slow glycemic response, is associated with reduced risk of chronic diseases. Since glycemic responses to breads made of wholemeal flour are high, retarding the glycemic response of a wholemeal bread would further increase its health benefits. The aim was to study postprandial glucose and insulin responses of wholemeal wheat breads in relation to baking technology. Breads were baked using 100{\%} flour from peeled (2{\%}) wheat kernels by straight dough or sourdough fermentation method, and with or without addition of xylanase during mixing of dough. Standard white wheat bread was used as reference. Eleven subjects with insulin resistance and features of the metabolic syndrome were served the breads in random order. Each test bread portion contained 50g of available carbohydrate. Blood samples for measuring glucose and insulin concentrations were drawn at eight time points over four hours. Nutrient composition and the content of soluble protein of the test breads were determined. In vitro hydrolysis of protein and molecular weight of the protein hydrolysates were also performed. The wheat bread produced using sourdough fermentation had the lowest postprandial glucose and insulin responses. Plasma glucose concentration was lower at time points 45, 60, 90 and 120 min (p<0.05) and higher at 240 min (p<0.01) as compared with the reference. Furthermore, serum insulin concentration was lower at the time point 90 min (p<0.05). The postprandial responses were not improved by addition of xylanase. Sourdough fermentation and xylanase treatment increased the amount of water-extractable arabinoxylan, while the latter also led to increased depolymerisation of water-extractable arabinoxylan. In the sourdough fermented bread, the content of soluble protein was the highest and the MW of the hydrolysed proteins the smallest. In conclusion, sourdough fermentation resulted in a bread with the most favourable postprandial glucose and insulin responses among the three tested wheat breads made of peeled kernels. Possible mechanisms by which fermentation produces this effect are low pH, increased arabinoxylan solubilisation, and proteolysis. The reduced postprandial response achieved by sourdough fermentation may further encourage the use of wholemeal wheat bread by persons with insulin resistance.",
author = "Jenni Lappi and Emilia Selinheimo and Pekka Lehtinen and Ursula Schwab and Hannu Mykk{\"a}nen and Marjukka Kolehmainen and Kaisa Poutanen",
year = "2009",
language = "English",
volume = "54",
journal = "Cereal Foods World",
issn = "0146-6283",
publisher = "AACC International",
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Sourdough fermentation of wholemeal wheat bread reduces glycemic responses in subjects with insulin resistance. / Lappi, Jenni; Selinheimo, Emilia; Lehtinen, Pekka; Schwab, Ursula; Mykkänen, Hannu; Kolehmainen, Marjukka; Poutanen, Kaisa.

In: Cereal Foods World, Vol. 54, No. 2, 2009.

Research output: Contribution to journalOther journal contributionScientific

TY - JOUR

T1 - Sourdough fermentation of wholemeal wheat bread reduces glycemic responses in subjects with insulin resistance

AU - Lappi, Jenni

AU - Selinheimo, Emilia

AU - Lehtinen, Pekka

AU - Schwab, Ursula

AU - Mykkänen, Hannu

AU - Kolehmainen, Marjukka

AU - Poutanen, Kaisa

PY - 2009

Y1 - 2009

N2 - Intake of wholegrain foods, as well as foods with slow glycemic response, is associated with reduced risk of chronic diseases. Since glycemic responses to breads made of wholemeal flour are high, retarding the glycemic response of a wholemeal bread would further increase its health benefits. The aim was to study postprandial glucose and insulin responses of wholemeal wheat breads in relation to baking technology. Breads were baked using 100% flour from peeled (2%) wheat kernels by straight dough or sourdough fermentation method, and with or without addition of xylanase during mixing of dough. Standard white wheat bread was used as reference. Eleven subjects with insulin resistance and features of the metabolic syndrome were served the breads in random order. Each test bread portion contained 50g of available carbohydrate. Blood samples for measuring glucose and insulin concentrations were drawn at eight time points over four hours. Nutrient composition and the content of soluble protein of the test breads were determined. In vitro hydrolysis of protein and molecular weight of the protein hydrolysates were also performed. The wheat bread produced using sourdough fermentation had the lowest postprandial glucose and insulin responses. Plasma glucose concentration was lower at time points 45, 60, 90 and 120 min (p<0.05) and higher at 240 min (p<0.01) as compared with the reference. Furthermore, serum insulin concentration was lower at the time point 90 min (p<0.05). The postprandial responses were not improved by addition of xylanase. Sourdough fermentation and xylanase treatment increased the amount of water-extractable arabinoxylan, while the latter also led to increased depolymerisation of water-extractable arabinoxylan. In the sourdough fermented bread, the content of soluble protein was the highest and the MW of the hydrolysed proteins the smallest. In conclusion, sourdough fermentation resulted in a bread with the most favourable postprandial glucose and insulin responses among the three tested wheat breads made of peeled kernels. Possible mechanisms by which fermentation produces this effect are low pH, increased arabinoxylan solubilisation, and proteolysis. The reduced postprandial response achieved by sourdough fermentation may further encourage the use of wholemeal wheat bread by persons with insulin resistance.

AB - Intake of wholegrain foods, as well as foods with slow glycemic response, is associated with reduced risk of chronic diseases. Since glycemic responses to breads made of wholemeal flour are high, retarding the glycemic response of a wholemeal bread would further increase its health benefits. The aim was to study postprandial glucose and insulin responses of wholemeal wheat breads in relation to baking technology. Breads were baked using 100% flour from peeled (2%) wheat kernels by straight dough or sourdough fermentation method, and with or without addition of xylanase during mixing of dough. Standard white wheat bread was used as reference. Eleven subjects with insulin resistance and features of the metabolic syndrome were served the breads in random order. Each test bread portion contained 50g of available carbohydrate. Blood samples for measuring glucose and insulin concentrations were drawn at eight time points over four hours. Nutrient composition and the content of soluble protein of the test breads were determined. In vitro hydrolysis of protein and molecular weight of the protein hydrolysates were also performed. The wheat bread produced using sourdough fermentation had the lowest postprandial glucose and insulin responses. Plasma glucose concentration was lower at time points 45, 60, 90 and 120 min (p<0.05) and higher at 240 min (p<0.01) as compared with the reference. Furthermore, serum insulin concentration was lower at the time point 90 min (p<0.05). The postprandial responses were not improved by addition of xylanase. Sourdough fermentation and xylanase treatment increased the amount of water-extractable arabinoxylan, while the latter also led to increased depolymerisation of water-extractable arabinoxylan. In the sourdough fermented bread, the content of soluble protein was the highest and the MW of the hydrolysed proteins the smallest. In conclusion, sourdough fermentation resulted in a bread with the most favourable postprandial glucose and insulin responses among the three tested wheat breads made of peeled kernels. Possible mechanisms by which fermentation produces this effect are low pH, increased arabinoxylan solubilisation, and proteolysis. The reduced postprandial response achieved by sourdough fermentation may further encourage the use of wholemeal wheat bread by persons with insulin resistance.

M3 - Other journal contribution

VL - 54

JO - Cereal Foods World

JF - Cereal Foods World

SN - 0146-6283

IS - 2

ER -