Abstract:Frying is a commonly used food processing method, and fried foods are very popular with consumers because of their unique color, flavor and taste. Starchy foods are common ingredients of fried foods. Starchy fried foods such as French fries, deep-fried dough sticks and instant noodles are common delicacies on the table. However, the frying process may produce harmful substances such as acrylamide, and excessive consumption of fried foods may cause overweight, obesity and other chronic diseases, which are harmful to our health. Therefore, new frying technologies have been developed to improve the quality of fried foods, and vacuum frying is one of the more mature technologies. This paper focuses on the principle and advantages of vacuum frying technology and its combination with other technologies, and describes its effects on starch properties and its applications in starchy foods in details. The purpose of this study is to provide reference for the further development of vacuum fried starchy foods, to create healthier starchy fried foods, and to reduce the incidence of diet-related chronic diseases.

Abstract:Whole grain is one of the most important sources of functional components such as dietary fiber and phenolic substances. Their Effective intake can reduce the risk of chronic diseases such as diabetes, hyperlipidemia, and hypertension in modern population. Whole grains have complex submacroscopic and multi-layer structures. Specially, the content of insoluble dietary fiber is high in the bran layer, and the phenols are covalently connected to the pectin and semi-fiber wall in bound state, resulting in the poor solubility and bad edible taste of whole grains as well as the great loss of functional and nutritional components during heating processes. This paper summarizes the contents and distributions, existing forms and potential health benefits of dietary fibers and phenolic substances in whole grains, as well as the effects of biological and physical green process technologies such as germination, fermentation, extrusion, 3D print and ultra-fine grinding on the macro/micro structure, sensory quality, dietary fibers, and phenolic substances of whole grain products.

Abstract:Resistant dextrin is an anti-digestion, low-calorie dietary fiber, effectively lowering blood sugar and blood lipids, preventing the rise of blood sugar, improving gastrointestinal function, and promoting probiotic proliferation. Pyrodextrin is the key intermediate product during the preparation of resistant dextrin, and it is also the major source of resistance. During the preparation, many new glycoside bonds are generated, which could not be degraded by human digestive enzymes, producing the 'anti-digestibility' of pyrodextrin and resistant dextrin. In this paper, the preparation, molecular structure, physicochemical properties, current main applications and future application development trends of pyrodextrin are reviewed in order to promote the sustainable and healthy development of the pyrodextrin industry.

Abstract:In recent years, more and more people realize that healthy diet is an effective mean to prevent and treat chronic diseases since the number of patients with chronic diseases increases year by year with the population tending to be younger. Low-calorie starch and its derivatives have been used more and more widely in food, medicine and other industries because of their functions of reducing blood glucose and lipids, improving intestinal environment, promoting absorption of trace elements and anti-digestion. At present, enzymatic preparation of low calorie starch and its derivatives has become a safe, green, healthy and efficient method. In this paper, the key enzymes, key technologies and functional applications of enzymatic preparation of low calorie starch and its derivatives were summarized, providing a reference for the optimization of preparation technology and the application of products in the future.

Abstract:Dietary starch is the main energy source of human body, and its bioavailability is closely related to the postprandial glycemia and insulin responses. The bioavailability is mainly affected by food matrix and the structure of starch itself. In the context of chronic disease pandemic, the digestion behavior of dietary starch has attracted extensive attention. In order to more efficiently study the digestion mechanism of dietary starch, several in vitro evaluation methods have been proposed. Compared with in vivo tests, in vitro methods could help guide food processing and consumption choices with higher efficiency, repeatability, lower costs and appropriate ethics. This review summarized the development status of methods for in vitro analysis of starch digestion, and their advantages and limitations were discussed. On the one hand, this review could provide references for developing in vitro digestion model fitting the meal pattern in China, and on the other hand, it could provide technical guidance for the classification of starchy food.

Abstract:Starch is the main component of human staple food and the main source of energy supply. The improvement of starch nutrition quality is of great value to human health. Enzymatic modification is an important method to improve the starch quality due to its advantages of high efficiency, high specificity, and compliance with clean label. This research mainly studied the synergistic modification effect of cyclodextrin glucosyltransferase (CGTase) and cyclodextrinase (CDase) on corn starch. The structure and digestibility of modified starch products were analyzed by adding CGTase alone, CGTase and CDase simultaneously, and CGTase and CDase sequentially. The results indicated that the dual-enzyme modification significantly increased the proportion of malto-oligosaccharides in the products, while that of cyclodextrins decreased significantly. After modified in three ways, the starch structure was significantly depolymerized. The chain length ratios of DP 13~24, DP 25~36 and DP > 37 decreased, while the chain length ratio of DP < 13 increased significantly. In addition, the content of resistant starch was significantly increased after enzymatic modification. Thus, dual-enzyme modification via CGTase and CDase has a good application prospect in improving the nutritional quality of starch.

Abstract:Polyphenol molecules can interact with starch molecules and this reaction can affect the digestibility of starch. In order to investigate the effect of interaction between starch molecules and polyphenol molecules on the starch digestibility, six polyphenols including genistein, quercetin, naringin, gallic acid, ferulic acid, and caffeic acid, and rice starch were used to prepare the starch-polyphenol complexes in this study, and the digestibility of the complexes was determined. The X-ray diffraction patterns of rice starch-polyphenol complexes showed diffraction peaks at 13.0° and 20.0°, which indicated that rice starch formed V-type complexes with the six polyphenols mentioned above. Differential scanning calorimetry analysis showed that the complexes exhibited an endothermic peak at 104~113 ℃, which further confirmed the formation of V-type starch-polyphenol inclusion complexes. The starch-polyphenol complex was spherical particles which were loosely aggregated. The molar contents of polyphenols in the complexes formed by rice starch and genistein, quercetin, naringin, gallic acid, ferulic acid, and caffeic acid were 5.59, 1.72, 5.40, 5.57, 2.77, and 6.52 mmol/g starch, which indicated that caffeic acid had the strongest ability to form complex with starch. However, the content of resistant starch in each complex was about 32% and insignificant difference was observed. The above results indicated that the resistance of starch-polyphenol complexes was not only dependent on the polyphenols content in complexes.

Abstract:To study the effect of different temperature of autoclaving on the granule structure and digestibility of starch with three different crystal forms (type A, type B, and type C) were investigated. Starch from corn, potato and pea were processed at 110 ℃, 120 ℃, and 130 ℃, respectively, and their physicochemical properties and digestibility before and after treatment were characterized by XRD, SEM, RVA, DSC and enzymatic hydrolysis. Results indicated that the gelatinization characteristics of starch changed significantly after autoclaving. The peak viscosity, recovery value, final viscosity and disintegration value decreased, while the gelatinization temperature increased. Microstructural analysis showed that moisture and thermal energy during autoclaving resulted in partial gelatinization of starch granules, and subsequently resulting in surface cavity on the granules. After autoclaving, the potato starch gradually lost the characteristic diffraction peak of type B crystal, while that of type A crystal appeared. Compared with the original pea starch, the crystal form of pea starch after autoclaving tended to change from type C to type A, however, the diffraction peaks of corn starch insignificantly changed. In addition, the content of resistant starch in different crystalline starch after autoclaving significantly increased(p<0.05). This study systematically revealed the changes in the structure and digestibility of different crystalline starches after autoclaving, providing a theoretical basis for the subsequent preparation of starch-based foods with lower digestion

Abstract:In order to improve the nutritional functions and sensory quality of pudding, chestnut flour after enzymatic hydrolysis coupled with wet heat treatment and pea protein were used as the main materials to prepare chestnut pudding (CSPP). The changes of digestibility, predicted glycaemic index (pGI), predicted glycaemic load (pGL), retrogradation, texture and sensory properties of CSPP were investigated during storage. Results showed that CSPP was rich in slowly digestible starch (SDS) and resistant starch (RS), which was classified as the medium pGL food. During storage, the enthalpy and retrogradation degree (RD) of CSPP were lower than those of the control group CSP with 50.84% reduction of RD, indicating that the interaction between starch and protein molecules could effectively inhibit the retrogradation of starch. Meanwhile, the hardness and chewiness of CSPP increased slightly, while the elasticity and resilience changed insignificantly, showing good texture characteristics and sensory quality.

Abstract:The changes in the enzyme activity and structure of α-amylase/λ-carrageenan complex during freeze-thawing were studied. The influences of complex on the properties of frozen dough and the steamed bread were analyzed through the fermentation performance, pore size distribution, and texture. The results showed that the fluorescence quenching was observed after three cycles of freeze-thaw and the α-amylase activity was significantly decreased to 54%. The formation of α-amylase/λ-carrageenan complex could further reduce the enzyme activity. The addition of α-amylase effectively changed the quality of steamed bread, such as increasing the specific volume, reducing the hardness, and improving the elasticity. But the complex of λ-carrageenan/α-amylase insignificantly affected the texture of steamed bread. The number of pores in steamed bread treated with α-amylase and complex was significantly higher than that in blank group, but pore wall became thicker, indicating that α-amylase and complex made the internal structure of steamed breads finer and more stable. In summary, α-amylase/λ-carrageenan complex did not improve the quality of steamed bread as well as the addition of α-amylase alone. The polysaccharide was speculated to mask the activity site of α-amylase and weaken the improvement effect on the quality of steamed bread after the formation of α-amylase and λ-carrageenan complex.

Abstract:Curdlan is a bacterial polysaccharide, which is also a dietary fiber. The retrogradation of Liangpi during storage was a bottleneck restricting its industrialization. In order to explore the effect of curdlan on the retrogradation of Liangpi, 0% ~ 1.0% curdlan was added to Liangpi. And it was stored at 4°C for 3 days to study the effect of curdlan on its preservation quality. The results showed that the hardness of Liangpi decreased from 273.18 g to 230.98 g, and the chewiness decreased from 122.74 to 91.96 with the amount of curdlan increased from 0% ~ 1.0%. Low-field nuclear magnetic (L-NMR) analysis showed that curdlan could bind water molecules more tightly and the water holding capacity of gel was enhanced. Scanning electron microscope showed that the internal structure of Liangpi became dense. The relative crystallinity decreased from 11.13% to 8.28%. The short-range order of Liangpi decreased and the enthalpy of retrogradation decreased from 5.2 J/g to 4.33 J/g as the amount of curdlan increased. The sensory score was the highest with 0.8% curdlan. The hardness of Liangpi was 15.5% lower than that of the control. The curdlan delayed the quality deterioration of Liangpi during refrigeration. This study provided a reference for the application of curdlan in anti-retrogradation of Liangpi and starch products.

Abstract:In recent years, study on starch-based hydrogels has attracted much attention, however, the application of natural starch hydrogels is limited by their high brittleness and low tensile properties. This work aimed to improve the gel properties of starch by modifying cassava starch with hydroxypropyl. A hydrogel was constructed using the obtained hydroxypropyl cassava starch compounded with corn starch to exploring the hydrogel properties. The results showed that the enthalpy of cassava starch after hydroxypropylation decreased from 14.885 J/g to 7.780 J/g, the crystallinity decreased from 28.2% to 22.1%, while the tensile strain of its hydrogel increased from 320% to 550%. The tensile strain of compounded starch gel was also improved, greatly expanding its application in industry, agriculture, food and other fields.

Abstract:Application of starch-based Pickering emulsion was widely investigated in food, medicine and cosmetics. In this study, ultrasonic-assisted octenyl succinic acidification and ball milling on millet starch were used to improve the emulsifying ability and stability. The corresponding mechanism was elucidated by measuring the degrees of substitution and hydrolysis, characteristic functional groups, crystal structure, micromorphology, particle size and emulsifying index. The results showed that ultrasonic treatment improved the reaction efficiency and substitution degree. The OSA groups were mainly grafted in the amorphous region of millet starch, and slightly entered into the crystalline region. Ball milling destroyed the particle morphology and crystal structure of OSA millet starch. The ability to form Pickering emulsion of OSA millet starch and the emulsion stability were significantly enhanced with the increase of ball milling duration and the amount of millet starch added. Ultrasound-assisted octenyl succinic acidification combined with ball milling is an effective technology to prepare starch-based Pickering emulsions with high emulsion stability, which is conducive to develop and utilize starch resources in the field of Pickering emulsion.