Structural and physicochemical properties of resistant starch from Chinese chestnut (Castanea mollissima ) prepared by autoclaving treatment and pullulanase hydrolysis

Abstract

The purpose of this study was to evaluate the properties of resistant starch (RS) from Chinese chestnut (Castanea mollissima), which was prepared by autoclaving treatment and pullulanase hydrolysis. Scanning electron microscopy (SEM) revealed that the chestnut resistant starch (CRS) granules had a cohesive structure, an irregular shape, and diameters ranging from 6.0 to 7.2 µm. The enzymatic and retrogradation processes increased the yield of RS, and also decreased its swelling power, water solubility, and viscosity. An increase in transparency was also observed. The percent syneresis of the two starches increased steadily over time. X‐ray diffraction (XRD) analyses revealed that autoclaving and pullulanase hydrolysis converted C‐type native starch into a B‐type pattern and increased the crystallinity. In addition, differential scanning calorimetry (DSC) results indicated a reduction in gelatinization temperature and enthalpy compared with native starch. The thermal properties of RS increased due to the retrogradation and recrystallization (p < .05). Practical applications Chinese chestnut (Castanea mollissima) is an important nut crop with high nutrition and planted in China widely. High water content in fresh chestnut leads to mildew attack easily, which will affect the chestnut market value and trade business. Therefore, it has great significance and practical demand to develop the deep processing technology and diversify its products. The resistant starch has been implemented as an ingredient for its resistant digestion properties for making flour food and functional food. However, the research and application of resistant starch from Chinese chestnut (Castanea mollissima) has been rarely seen. This study investigated the structural and physicochemical properties of chestnut resistant starch and provided a reference for the application of chestnut resistant starch in the food processing industries. For example, an increase in transparency and syneresis suggested chestnut resistant starch could be potentially used as a functional ingredient in jelly, beverages, and other food products, but not be possible for use in the frozen food industry.

Effect of Steaming Processing on Phenolic Profiles and Cellular Antioxidant Activities of Castanea mollissima

“…Previous studies have pointed out that the formation of phenolics in chestnut might be due to hydrolysis of tannins and lignin [ 24 , 29 ]. Additionally, Gu et al also stated that starch granules formed during autoclaving, also promote the combination of straight chain starch in chestnut kernels and the formation of hydrogen bonds [ 30 ]. These complex reactions might be involving in the release of bound phenolics.…”

Flow behavior and mechanical properties of water chestnut (Trapa natans) under steady shear as affected by acid and autoclave treatment

“…Among the autoclaved WCNFs, the AT‐72 showed higher peak intensity than AT‐24 and AT. The change in the internal structure and recrystallization of small regions by double‐helical chain displacement has been reported (Gu et al, 2018).…”

“…The granular structure is lost, and a gel-like matrix depicts that autoclaved samples have undergone gelatinization, and hence the morphology is lost. The damage in surface characteristics following agglomeration of the Chinese chestnut starch after autoclaving has been reported (Gu et al, 2018).…”

“…Autoclaving causes the rupture of granular structure and increases the hydrogen bonding sites that facilitate the gelatinization‐retrogradation process of starch particularly through recrystallization of amylose molecules to contribute to the resistant starch formation (Gu, Yao, & Wang, 2018). The modifications thus induced increases the interaction of polymer chains by disturbing the crystalline structure and disassociating the double‐helical structure (Astuti, Asiah, Setyowati, & Fitriawati, 2018; Li et al, 2020).…”

Valorisation of frozen chestnut by-products: technological challenges for the production of gluten-free flour

“…Besides the nutritional advantages, chestnut is a gluten-free fruit and therefore suitable for people suffering gluten-related disorders such as celiac disease, which treatment relies on absolute and lifelong dietary withdrawal of gluten [8]. Indeed, in the last years several works have reported the use of chestnut flour in the manufacture of gluten-free and functional food products, such as, bread, cookies, muffins, pasta, snacks and probiotic fermented milk supplemented with chestnut flour [7,[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. In fact, since most of the gluten-free cereal products contain low amounts of health beneficial components, it may be advantageous to use chestnut flour due to its nutritional value [23].…”