Effect of the Addition of Soluble Dietary Fiber and Green Tea Polyphenols on Acrylamide Formation and In Vitro Starch Digestibility in Baked Starchy Matrices

Abstract

Starch digestibility may be affected by food microstructural changes, as well as by specific interactions with some biomolecules, such as soluble dietary fibers (SDFs). It is well-known that acrylamide (AA) is a toxic and potentially carcinogenic compound formed in starchy food products processed at temperatures above 120 °C. This study aimed to investigate the effect of the addition of SDF and green tea polyphenols (GTP) on AA formation and in vitro starch digestibility in baked starchy matrices. The formulations were prepared using gluten and wheat starch, ensuring ~40 ± 2% (wet basis, w.b.) moisture in the doughs. In some samples, 7.5% (dry basis, d.b.) of starch was replaced with inulin (IN), polydextrose (PD) or partially hydrolyzed guar gum (PHGG), and/or with GTP at 1% (d.b). Acrylamide was determined by gas chromatography–mass spectrometry, and the in vitro starch digestibility using the Englyst method. The GTP was able to reduce AA content by ~48%, and a combination of IN-GTP allowed it to be reduced by up to ~64%, revealing the lowest rapidly available glucose content (~17 mg/g glucose). While a PD-GTP mixture reduced the AA content by around ~57% and gave the highest unavailable glucose fraction (~74 mg/g glucose) compared to the control. This study showed how functional ingredients could be used to develop successfully healthier starchy bakery foods.

Acrylamide in Bakery Products: A Review on Health Risks, Legal Regulations and Strategies to Reduce Its Formation

“…The addition of antioxidants also inhibits the blocking of acrolein to a certain level, which can lead to lower AA levels. The effects of polyphenols on the Maillard reaction have been given particular attention by various researchers [ 155 , 156 , 157 , 158 , 159 ]. The use of different extracts obtained from buckwheat seeds and sprouts reduced the AA level in bread by 16.7–27.3% [ 160 ].…”

In Vitro Starch Digestibility and Glycaemic Index of Fried Dough and Batter Enriched with Wheat and Oat Bran

“…This implies that magwinya with low initial moisture content (fried dough) are medium GI food. This reduction in eGI of fried dough samples may be attributed to the combined effect of dietary fibre and limited water in the food matrix, which would have caused incomplete starch gelatinisation, and of a consequence resistance to amylolytic enzymes in the digestion time frame [ 3 ]. In a food matrix such as magwinya, which has other components such as sugar (sucrose), salt, protein (gluten) and fibre, coupled with low initial water in the dough, these components compete with the starch granules for water.…”

“…The GI-lowering effect of bran types used in this study can be linked to their dietary fibre content which is composed mostly of non-starch polysaccharides such as β glucans (soluble fibre) in OB and arabinoxylan in WB [ 19 , 32 ]. The soluble fibre of OB acts through alteration of the food microstructure via restriction of starch gelatinisation because of its high-water absorption capacity which in turn limits water available to starch granules in the food matrix [ 3 , 15 ]. Wheat bran is composed of up to 58% insoluble dietary fibre which increases faecal bulk, reduces transit time in the small intestine and is resistant to enzymatic hydrolysis due to its heterogeneous structure [ 19 ].…”

“…Starch is the major carbohydrate found in food commodities such as maize, wheat, potato and rice [ 1 ]. It is a good source of energy for humans, however, its excessive consumption is of health concern, as it is a predisposing factor to other metabolic-related diseases like obesity, and diabetes—A projected leading cause of death by the year 2030 according to the World Health Organisation [ 2 , 3 ]. Moreover, the ability to predict and regulate postprandial glucose absorption of starchy food is vital to the global epidemic called diabesity [ 4 , 5 ].…”

Nutraceutical Targeting of Inflammation-Modulating microRNAs in Severe Forms of COVID-19: A Novel Approach to Prevent the Cytokine Storm

“…Green tea polyphenols (GTP) are the active compounds in green tea and they are also commonly known as catechins. The main ones are epigallocathechin gallate (EGCG), epicathechin gallate, epichatechins and flavanols, which are responsible for many of the biological activities of green tea including the antioxidant, anti-inflammatory, anti-angiogenesis, antidiabetic and anticarcinogenic effects (Otton et al, 2018;Torres et al, 2019;Yan et al, 2020). A 250 ml cup of brewed green tea provides approximately 25-60 mg of EGCG (roughly 50-60% of the catechins are EGCG).…”