Effects of heat‐moisture and alkali treatment on the enzymatic hydrolysis of porous sago ( Metroxylon sagu ) starch

Effects of plasma-activated water combined with ultrasonic treatment of corn starch on structural, thermal, physicochemical, functional, and pasting properties

In this study, corn starch was used as the raw material, and modified starch was prepared using a method combining plasma-activated water and ultrasound treatment (PUL). This method was compared with treatments using plasma-activated water (PAW) and ultrasound (UL) alone. The structure, thermal, physicochemical, pasting, and functional properties of the native and treated starches were evaluated. The results indicated that PAW and UL treatments did not alter the shape of the starch granules but caused some surface damage. The PUL treatment increased the starch gelatinization temperature and enthalpy (from 11.22 J/g to 13.13 J/g), as well as its relative crystallinity (increased by 0.51 %), gel hardness (increased by 16.19 %) compared to untreated starch, without inducing a crystalline transition. The PUL treatment resulted in a whitening of the samples. The dual treatment enhanced the thermal stability of the starch paste, which can be attributed to the synergistic effect between PAW and ultrasound (PAW can modify the starch structure at a molecular level, while ultrasound can further disrupt the granule weak crystalline structures, leading to improved thermal properties). Furthermore, FTIR results suggested significant changes in the functional groups related to the water-binding capacity of starch, and the order of the double-helical structure was disrupted. The findings of this study suggest that PUL treatment is a promising new green modification technique for improving the starch structure and enhancing starch properties. However, further research is needed to tailor the approach based on the specific properties of the raw material.

The art and science of porous starch: understanding the preparation method and structure-function relationship

Porous starch (PS), a modified form of starch with unique properties, is attracting substantial attention for its diverse advantages and applications. Its intricate porous structure, crystalline and amorphous characteristics, and hydrophilic-hydrophobic properties stem from pore formation via physical, chemical, enzymatic, and combined synergistic methods. Porous starch offers benefits like improved gelatinization temperature, water absorption, increased surface area, tunable crystallinity, and enhanced functional properties, making it appealing for diverse food industry applications. To optimize its properties, determining the parameters governing porous structure formation is crucial. Factors such as processing conditions, starch source, and modification methods substantially impact porosity and the overall characteristics of the material. Understanding and controlling these parameters allows customization for specific applications, from pharmaceutical drug delivery systems to enhancing texture and moisture retention in food products. To date, studies shedding light on how porosity formation can be fine-tuned for specific applications are fewer. This review critically assesses the existing reports on porous starch, focusing on how preparation methods affect porosity formation, thereby influencing the product's crystallinity/hydrophilic-hydrophobic nature and overall applicability.

Porous corn starch obtained from combined cold plasma and enzymatic hydrolysis: Microstructure and physicochemical properties

The combined effect of cold plasma treatment and enzymatic hydrolysis was investigated on the physicochemical and microstructural properties of porous corn starch. Scanning electron microscopy (SEM) images depicted that the combined treatment led to the creation of deeper pores on the surface of starch granules. The combined treatment indicated the highest swelling power (19.49 g/g), solubility (10.08 %), specific surface area (2.97 m²/g) and total pore volume (10.47 cm³/g). According to the X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC), the combined treatment, compared with the enzymatic hydrolysis, decreased the starch crystallinity, the order of the double-helix structure, and the starch gelatinization enthalpy. The rapid visco analyzer (RVA) pasting profile revealed that the combined treatment elevated the breakdown and setback viscosities. This study indicated that cold plasma pretreatment, as a green non-thermal technology, facilitated the performance of enzymes, resulting in the production of a porous starch with a higher absorption capacity.