Effects of enzyme-resistant starch obtained from rice starch by autoclaving-retrogradation method on the rheology of bread dough and some chemical properties of bread

This study was aimed to investigate the effects of enzyme resistant starch (ERS)which is rapidly growing product in recent years obtained by autoclaving-retrogradation (AR)method, on the rheological properties of bread dough and some chemical properties of bread. In pure rice starch, while there was not ERS found at the beginning, 0.57% ERS was occurred after AR application. moisture, ash and total starch content of AR applied ERS (A-ERS) were found as 8.74%, 0.50%, 70.82% respectively.A-ERS was added in to wheat flour at 0%, 2%, 4% and 6% levels replacement with wheat flour. Effects of A-ERS on dough rheological properties was evaluated by using amylograph, Kieffer dough and gluten extensibility rig (KER) and Chen–Hoseney Dough Stickiness Rig tests (CHT). The lowest amylograph peak viscosity (782 BU) was observed when A-ERS was added at 6% concentration and the maximum force (Rmax) measured with KER was shown the highest value as 65.96 g by the addition of 2% A-ERS. The extensibility increased with the addition of 4% and 6% A-ERS while at 2% addition level it was given the similar values with control sample.. CHT tests showed that inclusion of 2% A-ERS did’nt cause any significant change on the stickiness, work of adhesion and dough strength but significant increase on these parameters were observed as the level of A-ERS increased from 2 to 4 and 6% respectively. The amount of resistant starch present in the chemical composition of the bread increased proportionally with the addition rate of A-ERS. As a result; RS was occurred with AR application, substitution at 2% of A-ERS gave rheological values at least as good as the control sample. However, in order to achieve significant dietary fiber increase in bread, it was concluded that A-ERS should be added at least 6% level.Thus it can be suggested that A-ERS can be used as a valuable ingredient to enhance the functional properties of bakery products.

Otoklavlama-Retrogradasyon yöntemi uygulanarak pirinç niþastasýndan elde edilen enzime dirençli niþastanýn ekmek hamuru reolojisi ve ekmeðin bazý kimyasal özellikleri üzerine etkisi

Bu çalýþma ile son yýllarda popüleritesi hýzla artan ürünlerden olan enzime dirençli niþastanýn (EDN) otoklavlama-retrogradasyon (OR) yöntemi ile eldesi ve ekmek hamurunun reolojik özellikleri ile ekmeðin bazý kimyasal özellikleri üzerine etkisinin belirlenmesi amaçlanmýþtýr. Baþlangýçta bileþiminde EDN bulunmayan saf pirinç niþastasýna OR yöntemi uygulandýðýnda içeriðinde %0.57 oranýnda EDN oluþmuþtur. OR uygulanmýþ END (ORN)’nin nem, kül ve toplam niþasta içeriði sýrasýyla %8.74, %0.50, %70.82 olarak bulunmuþtur. Elde edilen ORN, ekmeklik buðday unu ile yer deðiþtirme prensibine göre %0,%2,%4 ve %6 oranlarýnda buðday ununa ilave edilave edilmiþtir. Amilograf, Kieffer hamur ve gluten uzayabilirlik testi ve Chen-Hoseney hamur yapýþkanlýk testleri (CHT) ile farklý oranlarda ORN eklenerek oluþturulan ekmek hamurunun reolojik özellikleri ölçülmüþtür. Jelatinizasyonun maksimum noktasýndaki vizkosite %6 ilave oranýnda en düþük deðeri (782 BU) alýrken %2 ilave oranýnda maksimum kuvvet (Rmax) en yüksek deðeri (65.96 g) almýþtýr. Uzayabilirlik yeteneði %2 ilave oranýnda kontrol örneðine benzer deðerde iken %4 ve %6 oranlarýnda artmýþtýr. Yapýþkanlýk, adezyon kuvveti ve hamur gücü parametreleri üzerine %2 oranýnda eklenen dirençli niþastanýn etkisi olmazken eklenme oraný %4 ve %6’ya çýkarýldýðýnda deðerler yükselmiþtir.%0,%2,%4 ve %6 oranlarýnda ORN eklenerek üretilen ekmeklerin dirençli niþasta miktarý ilave oranýyla orantýlý olarak artmýþtýr. Sonuç olarak OR yöntemi ile pirinç niþastasýndan EDN elde edilebileceði ve %2 oranýnda ekmek hamuruna eklenen bu ORN’nin reolojik özellikler bakýmýndan kontrol örneðe yakýn deðerler içerdiði, ancak ekmekte önemli düzeyde diyet lif artýþý saðlanabilmesi için ORN’nin en az %6 oranýnda ilave edilmesi gerektiði sonucuna ulaþýlmýþtýr. Elde edilen EDN fýrýncýlýk ürünlerinin fonksiyonel özelliklerini geliþtirmede deðerli bir bileþen olarak kullanýlabilir.