Polymeric tannins significantly alter properties and in vitro digestibility of partially gelatinized intact starch granule

Abstract

Excess calorie intake is a growing global problem. This study investigated effect of complexing partially gelatinized starch with condensed tannins on in vitro starch digestibility. Extracts from tannin and non-tannin sorghum, and cellulose control, were reacted with normal and waxy maize starch in 30% (30E) and 50% ethanol (50E) solutions at 70°C/20min. More tannins complexed with the 30E than 50E starches (mean 6.2 vs 3.5mg/g, respectively). In the 30E treatments, tannins significantly increased crystallinity, pasting temperature, peak viscosity, and slow digesting starch (from 100 to 274mg/g) in normal, but not waxy starch, suggesting intragranular cross-linking with amylose. Tannins doubled resistant starch (RS) to approx. 300mg/g in both starches. In 50E treatments, tannins made both maize starches behave like raw potato starch (>90% RS), suggesting granule surface interactions dominated. Non-tannin treatments generally behaved similar to cellulose. Condensed tannins could be used to favorably alter starch digestion profile.

Tea polyphenols as a strategy to control starch digestion in bread: the effects of polyphenol type and gluten

“…It was reported that polyphenols can interact directly with starch through hydrophobic forces and hydrogen bonding, thus reducing the available surface of starch granules to react with enzymes. 24 The authors in particular speculated that the presence of polyphenols would block the access of amylase to pores and channels that are typical of cereal starches. This may have happened also in our bread system.…”

Sensory Characteristics and Volatile Components of Dry Dog Foods Manufactured with Sorghum Fractions

“…Sorghum represents one of the least utilized starch ingredients in pet foods [ 6 ]. Some studies found that in some sorghums may have some anti-nutritional properties, as condensed tannins may reduce feed efficiency due to interactions with starch [ 7 ] and protein digestibility [ 8 ]. Red sorghum is poorly utilized by the pet food industry because of the condensed tannin content, which is expected to impart bitterness to the products [ 9 ], and perhaps also because consumers often do not recognize this grain.…”

Polyphenolic inhibition of enterocytic starch digestion enzymes and glucose transporters for managing type 2 diabetes may be reduced in food systems

“…The stimulation of glucose transport into these tissue cells can also help reduce the blood sugar level. Some studies highlighting the impacts of polyphenols on starch digestion are summarized in Table 1. From literature, there is proof that molecular weight of polyphenols has a direct effect on the inhibition capacity with monomers of low molecular weight showing lesser inhibition than polymeric polyphenols such as tannins (Amoako and Awika, 2016a;Zhu, 2015). The structure of the tannins are more hydrophobic due to abundance of hydroxyl groups which strengthen the interactions with carbohydrates or enzymes through hydrogen bonding (Table 2) (Sun and Miao, 2019;Awika, 2016a, 2016b;Liu et al, 2017).…”