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Protein, as the second major component in starchy foods, is crucial for its influence on the physicochemical properties and digestibility of starch. However, the effect of different sources of protein on starch digestibility is still unclear. In this paper, the effects of different sources of proteins (rice protein: RP, soybean isolate protein: SPI, and whey concentrate protein: WPC) on structural features, digestibility, and enzyme activity of extruded rice starch were investigated. The addition of all three proteins reduced the starch digestibility of extrudates. Native SPI and WPC suppressed amyloglucosidase activity, and all three proteins exhibited stronger amyloglucosidase inhibition when hydrolyzed. The rheological properties and Fourier transform infrared spectroscopy results revealed the exogenous proteins and starch interacted through non‐covalent bonds and improved the ordered structures in the extrudates. The extrusion process also facilitated the formation of a V‐type structure. The sum of SDS and RS content of extrudates was negatively correlated with the content of leached amylose and positively correlated with the ratio of 1047/1022 cm−1. These findings suggest that the inclusion of exogenous proteins during extrusion can affect starch digestibility through mechanisms such as the interaction with starch molecules, as well as the inhibition of amylase activity. Practical Application: This result indicated that the addition of protein during extrusion not only increased the nutritional value of the extrudate, but also decreased the starch digestibility. Extrusion technology can efficiently produce extruded products with protein, expanding further applications of protein in food and providing new healthy staple food options for special populations, such as diabetic and overweight people. [ABSTRACT FROM AUTHOR]

Vaccinium bracteatum Thunb.leaves (VBTL) are a traditional Chinese herbal medicine with potential natural pigments and antioxidants. Its application information on extrusion is limited. In this study, to increase the usage of foods containing VBTL, rice‐based extrudates with VBTL were investigated. The extrusion was performed at a wide temperature range (60–140°C) and with different VBTL supplementations (3%–10%). The extrudates with 10% VBTL showed a significant decrease in total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity upon extrusion. TPC and TFC increased with the rise of barrel temperature. The VBTL color was stable during the wide‐temperature extrusion process. The bioactivities of the extrudates were positively correlated with the VBTLsupplement (R = 0.943–0.989). In addition, different addition levels of VBTL significantly changed the water absorption index (WAI), water solubility index (WSI), pasting properties, and in vitro starch digestibility of the extrudates. Moreover, extrudates with 3% VBTL showed the highest WAI and peak viscosity but the lowest in vitro starch digestibility. These results may suggest that rice extrudates with a low supplement of VBTL have an acceptable color and may be used as functional additives for high antioxidant and low glycemic response diets. Practical Application: The results showed that the Vaccinium bracteatum Thunb. leaves (VBTL) color and antioxidation were stable during the wide‐temperature extrusion process. Extrusion processing can be used to enlarge the usage of VBTL and simplify its traditional processing method. Applying VBTL to the process of extrusion appears to be a suitable method of producing value‐added and low glycemic response extrudates. [ABSTRACT FROM AUTHOR]

Abstract: Problems with rehydration and palatability are considered as unacceptable quality characteristics for the noodles produced using high‐strength extrusion technique. Thus, the aim of this study was to solve these problems by designing a novel method to create a porous structure for the high‐strength extruded noodles (HENs). The quality indices of HENs were significantly improved after adding to them thermostable α‐amylase (TαA) at 0.05% to 0.10%. The microstructure graphs showed that a well‐developed porous structures was successfully created throughout noodle strands. This indicated that the TαA has effectively worked on starch granules in spite of the high‐strength performance of the extrusion process. MALLS‐GFC, X‐ray diffraction, and differential scanning calorimeter investigations showed that the appearance of a porous structure was mainly attributed to the internal collapse of α‐1,4‐glycosidic bonds and the dissolution of water‐soluble degradation products, such as dextrin and oligosaccharides. Moreover, the slight inhibited effect of excess TαA on the starch gelatinization was because of the fact that the high enzyme concentration might cause TαA to adhere or overlay on it. Practical Application: The rehydration and palatability properties of HENs were greatly improved by creating a well‐developed or honeycomb‐like porous structure using TαA at low concentration. The findings of this study could be applied to enhance the quality characteristics of HENs and to encourage the research and development in the noodle industry. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Science (John Wiley & Sons, Inc.) is the property of John Wiley & Sons, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Food Science (John Wiley & Sons, Inc.) is the property of John Wiley & Sons, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Food Science (John Wiley & Sons, Inc.) is the property of John Wiley & Sons, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)