Hierarchical structural modification of starch via non-thermal plasma: A state-of-the-art review

New insights into cold plasma-induced starch modification: A comparative analysis of microstructure and physicochemical properties in A-type and B-type starches

With the growing demand for clean labeling in food products, cold plasma (CP) has gained attention as an eco-friendly method for starch modification. This study evaluated various effects of CP treatment on A- and B-type starches by comparing their microstructure and physicochemical properties. CP treatment caused the deposition of precipitates on the starch surfaces. While it did not alter the crystalline type, it reduced the relative crystallinity, particularly in potato starch (PS), with a 6.5 % decrease. Amylopectin chain length analysis showed depolymerization as the dominant effect in PS, while corn starh (CS) experienced cross-linking and degradation. Furthermore, the formation of smaller particles through CP enhanced water-holding capacity. CP treatment induced lower digestibility in both raw and cooked starches, especially uncooked PS showed slowly-digestible and resistant starch content with 11.59 % and 59.69 %. These effects are linked to differences in crystal cell arrangement, offering potential for CP-modified starches with tailored industrial applications.

Effects of Porphyra haitanensis polysaccharides on the short-term retrogradation and simulated digestion in vitro of three crystalline starches

In this study, the effects of Porphyra haitanensis polysaccharides (PHP) (0.4 %, 0.8 % and 1.2 %) on the short-term retrogradation and simulated digestion in vitro properties of starches with corn starch (CS), potato starch (PS) and lotus seed starch (LS) and their potential mechanism of PHP were constructed. 0.4 % and 0.8 % PHP promoted the formation of ordered structures in PS, and all PHP suppressed short-range ordered structure rearrangements in CS and LS. PHP promoted PS-PHP complex while retarding water migration of CS-PHP and LS-PHP complex. XRD showed that all PHP inhibited the short-term retrogradation of CS and LS while facilitating PS. Finally, compared to native starch, CS-0.4%PHP, CS-0.8%PHP, LS-0.8%PHP and LS-1.2%PHP had higher hydrolysis rate, but PHP could decrease that of PS. All of PHP were decreased the RS proportion of CS and LS, especially CS-0.8%PHP, LS-0.8%PHP and LS-1.2%PHP. While PHP were increased that of PS. These results will provide a scientific basis for the development of starch-based foods.

Supramolecular structure and in vitro digestive properties of plasma-treated corn starches varying in amylose content

The effects of plasma treatment on the multi-scale structure and in vitro digestibility of maize starch with different amylose contents were systematically evaluated. The results demonstrated that all maize starches' molecular weights (MW) decreased when treated with plasma, among which the MW of waxy maize starch displayed the largest reduction. Plasma treatment led to an increase in the thickness of the semi-crystalline lamellae and double helix proportions of waxy and normal maize starches. However, high-amylose maize starch presented a less ordered structure by plasma treatment. Additionally, larger pores and channels were observed on the surface of plasma-treated waxy and normal maize starch granules. Moreover, deposits were displayed on the surface of high-amylose maize starch granules. These changes increased the in vitro digestibility and hydrolysis rate of three starches after plasma treatment. Notably, plasma treatment caused diverse alterations in the structure and functionality of maize starch varying in amylose content, leading to maize starch with better digestibility, therefore being used as an ingredient for functional foods.

Improving the quality and digestibility of wheat flour starch and protein for noodles through ultrasound, high hydrostatic pressure, and plasma technologies: A review

The production of high-quality noodles relies on using premium-quality wheat flour. There is growing interest in using nonthermal technologies (NTTs), like ultrasound, high hydrostatic pressure (HHP), and plasma techniques, to enhance the nutritional properties of wheat flour starch and protein, specifically its digestibility. This review compiles the impact of these nonthermal technologies on wheat flour characteristics for optimal noodle preparation. Ultrasound applications can modify protein networks and starch granules in wheat flour, resulting in improved consistency and texture of noodles. High hydrostatic pressure (HHP) treatments have been observed to effectively alter protein specificity, thereby forming desirable textural attributes such as hardness and firmness. Consequently, this process significantly contributes to the overall improvement in the quality of the noodles. Additionally, HHP treatments promote gelatinization within structures, improving noodle digestibility. On the other hand, plasma treatment modifies the structure and properties of gluten, enhancing dough rheology and stability and improving the texture, nutrition, and sensory attributes of noodles. The modifications induced by ultrasound HHP and plasma treatments in gluten structure enzymatic potential, starch granules, and protein functionality collectively enhance noodle characteristics. Furthermore, the modifications efficiently improve digestibility and increase nutrient availability during digestion, thereby increasing the overall nutritional value of noodles.

The properties of potato starch with different moisture content treated by cold plasma:Structure, physicochemical and digestive properties

To investigate the effect and mechanism of water on the structure, physicochemical properties, and in vitro digestibility of starch treated with CP, different moisture content (16.7 %, 28.6 %, 37.5 %, 44.4 %, and 50 %, w/w) were used, followed by treatment with CP (40 V, 1 A, 3 mins). Results show that CP treatment preserves the Maltese cross pattern, crystal morphology, and Fourier transform infrared spectroscopy spectra of potato starch. However, significant changes were observed in molecular weight, chain length distribution, average particle size, ordered structure, and relative crystallinity. As moisture content increased, the etching effect on the particle surface intensified, leading to further reductions in molecular weight and ordered structure. Concurrently, amylose content, solubility, relative crystallinity, and resistant starch content increased. At higher water levels, water molecules exhibited protective effects, mitigating CP-induced structural damage by reducing etching and loss of molecular weight. These findings suggest that the role of water in CP treatment is complex and provide insights into the interaction between CP and water in starch properties, highlighting its potential applications in starch-based foods.

The effect of cold plasma on starch: Structure and performance

The inherent side effects of the physico-chemical properties of native starches often severely limit their use in food and non-food industries. Plasma is a non-thermal technology that allows rapid improvement of functional properties. This review provides a comprehensive summary of the sources and mechanisms of action of cold plasma and assesses its effects on starch morphology, crystal structure, molecular chain structure and physicochemical properties. The complex relationship between structure and function of plasma-treated starch is also explored. Potential applications of plasma-modified starch are also discussed in detail. The outcome of the modification process is influenced by factors such as starch type and concentration, plasma source, intensity and duration. The properties of starch can be effectively optimised using plasma technology. Plasma-based technologies therefore have the potential to modify starch to create a range of functionalities to meet the growing market demand for clean label ingredients.

Formation, influencing factors, and applications of internal channels in starch: A review

Starch, a natural polymer, has a complex internal structure. Some starches, such as corn and wheat starches, have well-developed surface pores and internal channels. These channel structures are considered crucial in connecting surface stomata and internal cavities and have adequate space for loading guest molecules. After processing or modification, the starch-containing channel structures can be used for food and drug encapsulation and delivery. This article reviews the formation and determination of starch internal channels, and the influence of different factors (such as starch species and processing conditions) on the channel structure. It also discusses relevant starch preparation methods (physical, chemical, enzymatic, and synergistic), and the encapsulation effect of starch containing internal channels on different substances. In addition, the role of internal channels in regulating the starch digestion rate and other aspects is also discussed here. This review highlights the significant multifunctional applications of starch with a channel structure.

Multi-scale structural disruption induced by radio frequency air cold plasma accelerates enzymatic hydrolysis/ hydroxypropylation of tapioca starch

This study investigated the effects of radio frequency air cold plasma (RFACP) pretreatment on the multi-scale structures, physicochemical properties, enzymatic hydrolysis, and hydroxypropylation of tapioca starch. The results showed that cold plasma (CP) made starch granules rough on the surface and disrupted long- and short-range ordered structures, reducing relative crystallinity from 43.8 % to 37.4 % and R1047/1022 value from 0.992 to 0.934. Meanwhile, the starch molecules were depolymerized and oxidized by CP, reducing weight-average molecular weight from 9.64 × 107 to 2.17 × 107 g/mol, while increasing carbonyl and carboxyl groups by up to 118 % and 53 %. Additionally, CP-treated starches exhibited higher solubility and swelling power, along with lower gelatinization enthalpy. Short-time CP pretreatment (10 min) promoted the hydroxypropylation of starch and increased the molar substitution (0.081-0.112). Also, CP pretreatment accelerated enzymatic hydrolysis of starch, as indicated by the increase in hydrolysis rate (1.846 × 10-3-2.033 × 10-3 min-1) and degree of hydrolysis (51.45 % - 59.92 %). Overall, the multi-scale structural disruption induced by CP treatment facilitated the accessibility of enzymes/chemical reagents into starch granules and glucan chains. This study suggested that RFACP could be used for starch pretreatment to increase production efficiency in modified starch production, as well as in brewing and fermentation industries.