Use of sourdough lactobacilli and oat fibre to decrease the glycaemic index of white wheat bread.
This work was aimed at decreasing the glycaemic index (GI) of white wheat bread. Breads made with wheat flour (WF) or wholemeal flour (WMF) and fermented with baker's yeast had similar values of resistant starch (RS; 1.4-1.7 %, starch basis). Sourdough Lactobacillus plantarum P1 and Lactobacillus brevis P2 favoured the highest formation of RS (approximately 5 %) when fermented with WF and WMF. The mixture (1:1) of WF and WMF (WF/WMF) was selected. The effect of dietary fibres, chemical or sourdough acidification on the hydrolysis index (HI) of WF/WMF bread was determined. Among fibres, only the addition of oat fibre (5 %) decreased the HI to 90.84 %. Lactic acid determined the lowest HI, and the effect was related to the decrease of pH. For the same decrease of pH, breads fermented with L. plantarum P1 and L. brevis P2 (sourdough WF/WMF) showed values of HI lower than chemical acidification. The glucose response and GI of WF bread or sourdough WF/WMF bread enriched with oat fibre was determined by using fifteen healthy volunteers. Anhydrous glucose was used as reference. The area under the glucose response curve and the value of GI (72 %) of WF bread were significantly (P < 0.05) higher than sourdough WF/WMF bread enriched with oat fibre (GI = 53.7 %). The decrease of GI of the sourdough WF/WMF bread may be due to both fibre content and decreased pH. Compared to WMF bread, sourdough WF/WMF bread, enriched with oat fibre, had higher specific volume, better cell crumb structure and more appreciated acidulous smell, taste and aroma.
De Angelis
Maria
M
Dipartimento di Protezione delle Piante e Microbiologia Applicata, Università degli Studi di Bari, Via G. Amendola 165/a, 70126 Bari, Italy.
Rizzello
Carlo G
CG
Alfonsi
Giuditta
G
Arnault
Philip
P
Cappelle
Stefan
S
Di Cagno
Raffaella
R
Gobbetti
Marco
M
D000328:Adult; D000704:Analysis of Variance; D019540:Area Under Curve; D018554:Avena; D001939:Bread; D003258:Consumer Behavior; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004043:Dietary Fiber / Q000008:administration & dosage*; D019612:Fagopyrum; D005260:Female; D005433:Flour; D005524:Food Technology / Q000379:methods; D038321:Glycemic Index; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007778:Lactobacillus; D008297:Male; D008875:Middle Aged; D009753:Nutritive Value; D013213:Starch; D014908:Triticum
D004040:Dietary Carbohydrates; D004043:Dietary Fiber; D013213:Starch