Effect of ultrahigh pressure on structural and physicochemical properties of rice and corn starch in complexes with apple polyphenols

Effect of high hydrostatic pressure on the multi-scale structure and digestive properties of Lonicera caerulea berry polyphenol-wheat starch complex

Polyphenols increase resistant starch (RS) content and stabilize postprandial blood glucose levels. This study examined the effects of high hydrostatic pressure (HHP) technology on the multi-scale structure and digestibility of the Lonicera caerulea berry polyphenol-wheat starch (LPWS) complex in vitro and in vivo. The results showed that 200, 400, and 600 MPa HHP treatments promoted starch gelatinization, destroyed the grain structure of wheat starch (WS), significantly increased the particle size (P < 0.05), significantly increased the RS content by 1.60, 2.33, and 2.60 times (P < 0.05), and decreased the crystallinity and molecular weight. Under HHP, Lonicera caerulea berry polyphenols (LCBP) and WS formed A + V complex and the two interacted with each other through hydrogen bonding, leading to a further reduction in the gelatinization enthalpy (ΔH). The amount of glucose released by internal digestion in mice decreased significantly from 10.28 mmol/L to 8.87 mmol/L at 180 min (P < 0.05). Complex digestives appeared dense, which reduced WS digestion. This study provides a theoretical basis for the research and development of functional starch with stable postprandial blood glucose levels, and its use as a functional food ingredient.

Research progress on the regulation of starch-polyphenol interactions in food processing

Starch is a fundamental material in the food industry. However, the inherent structural constraints of starch impose limitations on its physicochemical properties, including thermal instability, viscosity, and retrogradation. To address these obstacles, polyphenols are extensively employed for starch modification owing to their distinctive structural characteristics and potent antioxidant capabilities. Interaction between the hydroxyl groups of polyphenols and starch results in the formation of inclusion or non-inclusion complexes, thereby inducing alterations in the multiscale structure of starch. These modifications lead to changes in the physicochemical properties of starch, while simultaneously enhancing its nutritional value. Recent studies have demonstrated that both thermal and non-thermal processing exert a significant influence on the formation of starch-polyphenol complexes. This review meticulously analyzes the techniques facilitating complex formation, elucidating the critical factors that dictate this process. Of noteworthy importance is the observation that thermal processing significantly boosts these interactions, whereas non-thermal processing enables more precise modifications. Thus, a profound comprehension and precise regulation of the production of starch-polyphenol complexes are imperative for optimizing their application in various starch-based food products. This in-depth study is dedicated to providing a valuable pathway for enhancing the quality of starchy foods through the strategic integration of suitable processing technologies.

Elucidating the influence and mechanism of different phenols on the properties, food quality and function of maize starch

This study discusses interaction differences between three phenols (protocatechuic acid, naringin and tannic acid) and starch helix, investigates influences of phenols at different doses on properties of maize starch, and further determines their effects on quality and function of maize-starchy foods. Simulated results indicate variations of phenolic structure (phenolic hydroxyl group amount, glycoside structure and steric hindrance) and dose induce phenols form different complexes with starch helix. Formation of different starch-phenols complexes alters gelatinization (1.65-5.63 J/g), pasting form, water binding capacity (8.83-12.69 g/g) and particle size distribution of starch. Meanwhile, differences in starch-phenols complexes are reflected in fingerprint area (R1045/1022: 0.920 to 1.047), crystallinity (8.3% to 17.0%), rheology and gel structure of starch. Additionally, phenols change texture and color of cold maize cake, giving them different antioxidant capacity and lower digestibility. Findings are beneficial for understanding interaction between starch and different phenols and their potential application.

Interaction of high amylose corn starch with polyphenols: Modulating the stability of polyphenols with different structure against thermal processing

Polyphenols are known to undergo thermal degradation and their bioactivity is reduced. In this study, the thermal degradation of polyphenols was modulated by the complexation between polyphenols and high amylose corn starch (HACS). The inclusion complex between ferulic acid with hydrophobic group methoxy and HACS had the highest encapsulation efficiency (EE = 26.15 %), loading efficiency (LE = 2.38 %) and thermal stability (DPPH radical scavenging activity was reduced by only 5.99 % after baking). After complexing with HACS, protocatechuic acid with ortho-position hydroxyl group had a higher encapsulation rate and thermal stability than 3, 5-dihydroxybenzoic acid with meta-position hydroxyl. In addition, soy isoflavone with the higher logarithmic value of octanol-water partition coefficient (Log P = 3.66) resulted in higher encapsulation rate and thermal stability than naringenin (Log P = 2.11). The results suggest that the complexation between polyphenols and starch protects the bioactivity of polyphenols and improves the processing suitability of polyphenols.

Tunable interactions in starch-anthocyanin complexes switched by high hydrostatic pressure

Native starches usually have poor polyphenol-binding efficiency despite remarkable architectural structures. In this study, the interaction between cyandin-3-O-glucose (C3G) and three starches under high hydrostatic pressure was investigated. Pressure (200-550 MPa) was found to promote the binding rate of potato starch from 31.6% to 47.0% but reduced that of corn and pea starch to below 10% at 550 MPa. Microscopy results showed that pressurized corn and pea starch-C3G complexes partially or completely lost spatial structures, whereas potato starch-C3G complexes retained structural integrity. The former had decreased zeta potentials and increased particle sizes at 550 MPa, suggesting surface charges and specific surface area losses caused poor binding. Potato starch-C3G complexes, however, exhibited unchanged zeta potential and particle size but the strongest fluorescence at 200 MPa, indicating a positive binding shift from surface to interior. Overall, high hydrostatic pressure can regulate the interactions of native starches with anthocyanins via spatial structural changes.

Starch modification through its combination with other molecules: Gums, mucilages, polyphenols and salts

Apart from its non-toxicity, biocompatibility and biodegradability, starch has demonstrated eminent functional characteristics, e.g., forming well-defined gels/films, stabilizing emulsions/foams, and thickening/texturizing foods, which make it a promising hydrocolloid for various food purposes. Nonetheless, because of the ever-increasing range of its applications, modification of starch via chemical and physical methods for expanding its capabilities is unavoidable. The probable detrimental impacts of chemical modification on human health have encouraged scientists to develop potent physical approaches for starch modification. In this category, in recent years, starch combination with other molecules (i.e., gums, mucilages, salts, polyphenols) has been an interesting platform for developing modified starches with unique attributes where the characteristics of the fabricated starch could be finely tuned via adjusting the reaction parameters, type of molecules reacting with starch and the concentration of the reactants. The modification of starch characteristics upon its complexation with gums, mucilages, salts, and polyphenols as common ingredients in food formulations is comprehensively overviewed in this study. Besides their potent impact on physicochemical, and techno-functional attributes, starch modification via complexation could also remarkably customize the digestibility of starch and provide new products with less digestibility.