Removal of astringency from persimmon paste via polysaccharide treatment

Study on the mechanism of natural polysaccharides on the deastringent effect of Triphala extract

This present study investigated the masking effect of high methoxyl pectin, xanthan gum, and gum Arabic on the astringency of the traditional herbal formula Triphala and further examined the mechanism of polysaccharide reducing astringency. Results of sensory evaluation and electronic tongue illustrated that 0.6 % pectin, 0.3 % xanthan gum, and 2 % gum Arabic had a substantial deastringent effect. The polyphenols in Triphala are basically hydrolysable tannins, which with high degree of gallic acylation may be the main astringent component of Triphala. Moreover, the three polysaccharides can combine with β-casein through CO and NH groups to form soluble binary complexes and decrease the secondary structure of β-casein. When polysaccharides were added to the Triphala-protein system, polyphenol-protein precipitation was also diminished, and they were capable of forming soluble ternary complexes. Consequently, the competition between polysaccharides and polyphenols for binding salivary proteins and the formation of ternary complexes help decrease the astringency of Triphala.

Effect of Addition of Tannin Extract from Underutilized Resources on Allergenic Proteins, Color and Textural Properties of Egg White Gels

Tannins, present in numerous plants, exhibit a binding affinity for proteins. In this study, we aimed to exploit this property to reduce the concentration of allergenic egg white proteins. Tannins were extracted, using hot water, from the lyophilized powder of underutilized resources, such as chestnut inner skin (CIS), young persimmon fruit (YPF), and bayberry leaves (BBLs). These extracts were then incorporated into an egg white solution (EWS) to generate an egg white gel (EWG). Allergen reduction efficacy was assessed using electrophoresis and ELISA. Our findings revealed a substantial reduction in allergenic proteins across all EWGs containing a 50% tannin extract. Notably, CIS and BBL exhibited exceptional efficacy in reducing low allergen levels. The addition of tannin extract resulted in an increase in the total polyphenol content of the EWG, with the order of effectiveness being CIS > YPF > BBL. Minimal color alteration was observed in the BBL-infused EWG compared to the other sources. Additionally, the introduction of tannin extract heightened the hardness stress, with BBL demonstrating the most significant effect, followed by CIS and YPF. In conclusion, incorporating tannin extract during EWG preparation was found to decrease the concentration of allergenic proteins while enhancing antioxidant properties and hardness stress, with BBL being particularly effective in preventing color changes in EWG.

Low Allergenicity in Processed Wheat Flour Products Using Tannins from Agri-Food Wastes

The present study aimed to investigate the effect of the addition of tannins from unutilized resources on wheat allergen reduction, antioxidant properties, and quality by substituting 3%, 5%, and 10% of the flour with chestnut inner skin (CIS) and young persimmon fruit (YPF) powders to produce cookies. The enzyme-linked immunosorbent assay and Western blotting showed significantly lower wheat allergen content in CIS- or YPF-substituted cookies than in control cookies, and this effect was pronounced for CIS-substituted cookies. In addition, the tannin content and antioxidant properties of the CIS- or YPF-substituted cookies were markedly higher than those of the control cookies. Quality analysis of the CIS- and YPF-substituted cookies showed that the specific volume and spread factor, which are quality indicators for cookies, were slightly lower in the CIS- and YPF-substituted cookies than in the control cookies. Compared to the control, CIS substitution did not affect the breaking stress and total energy values of the cookies; however, YPF substitution at 10% increased these values. Color was also affected by the addition of CIS and YPF. The results suggest that the addition of CIS and YPF can reduce wheat allergens in cookies and improve tannin content and antioxidant properties.