Starch retrogradation is a process in which disaggregated amylose and amylopectin chains in a gelatinized starch paste reassociate to form more ordered structures. Starch retrogradation has been the subject of intensive research over the last 50 years, mainly due to its detrimental effect on the sensory and storage qualities of many starchy foods. However, starch retrogadation is desirable for some starchy food products in terms of textural and nutritional properties. To better understand the effect of starch retrogradation on the quality of starchy foods, measurement methods of starch retrogradation and factors that influence starch retrogradation have been studied extensively. This article provides a comprehensive review of starch retrogradation including the definition of the process, molecular mechanisms of how it occurs, and measurement methods and factors that influence starch retrogradation. The review also discusses the effect of retrogradation on the in vitro enzyme digestibility of starch. Spectroscopic methods such as FTIR and Raman are considered to be very promising in characterizing starch retrogradation at a molecular level, although more studies are needed in the future.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/1541-4337.12143

Starch retrogradation: a comprehensive review

We report a study of self-assembled beta-pleated sheets in B. mori silk fibroin films using thermal analysis and infrared spectroscopy. B. mori silk fibroin may stand as an exemplar of fibrous proteins containing crystalline beta-sheets. Materials were prepared from concentrated solutions (2−5 wt % fibroin in water) and then dried to achieve a less ordered state without beta-sheets. Crystallization of beta-pleated sheets was effected either by heating the films above the glass transition temperature (Tg) and holding isothermally or by exposure to methanol. The fractions of secondary structural components including random coils, alpha-helices, beta-pleated sheets, turns, and side chains were evaluated using Fourier self-deconvolution (FSD) of the infrared absorbance spectra. The silk fibroin films were studied thermally using temperature-modulated differential scanning calorimetry (TMDSC) to obtain the reversing heat capacity. The increment of the reversing heat capacity ΔCp0(Tg) at the glass transition fo...

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Determining Beta Sheet Crystallinity in Fibrous Proteins by Thermal Analysis and Infrared Spectroscopy

In the 21st century, climate changes, water scarcity, increasing world population, rising food prices, and other socioeconomic impacts are expected to generate a great threat to agriculture and food security worldwide, especially for the poorest people who live in arid and subarid regions. These impacts present a challenge to scientists and nutritionists to investigate the possibilities of producing, processing, and utilizing other potential food sources to end hunger and poverty. Cereal grains are the most important source of the world's food and have a significant role in the human diet throughout the world. As one of the most important drought-resistant crops, millet is widely grown in the semiarid tropics of Africa and Asia and constitutes a major source of carbohydrates and proteins for people living in these areas. In addition, because of their important contribution to national food security and potential health benefits, millet grain is now receiving increasing interest from food scientists, technologists, and nutritionists. The aim of this work was to review the recent advances in research carried out to date for purposes of evaluation of nutritional quality and potential health benefits of millet grains. Processing technologies used for improving the edible and nutritional characteristics of millet as well as challenges, limitations, and future perspectives to promote millet utilization as food for a large and growing population are also discussed.

Millet Grains: Nutritional Quality, Processing, and Potential Health Benefits

Present trends towards technologies and processes that increase the use of residues make starchy vegetal biomass an important alternative material in various applications due to starch’s versatility, low cost and ease of use when its physicochemical properties are altered. Starch is increasingly used in many industrial applications and as a renewable energy resource. Starch can be modified to enhance its positive attributes and eliminate deficiencies in its native characteristics. In this article, the state of knowledge on conventional and unconventional starches and their properties, characteristics, modifications and applications are reviewed.

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Physicochemical properties, modifications and applications of starches from different botanical sources

Melanoidins produced by the Maillard reaction: Structure and biological activity

http://depa.fquim.unam.mx/amyd/archivero/4Maillardestyactantiox_14220.pdf

Structure and antioxidant activity of high molecular weight Maillard reaction products from casein-glucose

Effect of tea polyphenols on the retrogradation of rice starch

Some functional properties of oat bran protein concentrate modified by trypsin

Effects of pulsed electric fields (PEF) treatment (0–547 μs and 0–40 kV/cm) on physicochemical properties of soybean protein isolates (SPI) were studied. Solubility, surface free sulfhydryls (SHF) and hydrophobicity of SPI dispersions (20 mg/ml) increased with the increment of the PEF strength and treatment time at constant pulse width 2 μs, pulse frequency 500 pulse per second (pps) and sample flow rate (1 ml/s). When the PEF strength and treatment time were above 30 kV/cm and 288 μs, solubility, surface SHF, and hydrophobicity of SPI decreased due to denaturation and aggregation of SPI by hydrophobic interactions and disulfide bonds. Size-exclusion chromatography and laser light scattering analyses demonstrated further that stronger PEF treatment-induced dissociation, denaturation and reaggregation of SPI. Circular dichroism analysis showed that PEF treatment did not produce significant secondary structure changes of SPI. These results suggested that controlled PEF could be applied to process liquid food including soybean protein ingredient and to modify their structure and function in order to get desired products.

Effects of pulsed electric fields on physicochemical properties of soybean protein isolates

A new method, a magnetic resonance imaging (MRI) technique characterized by T(2) relaxation time, was developed to study the water migration mechanism between arabinoxylan (AX) gels and gluten matrix in a whole wheat dough (WWD) system prepared from whole wheat flour (WWF) of different particle sizes. The water sequestration of AX gels in wheat bran was verified by the bran fortification test. The evaluations of baking quality of whole wheat bread (WWB) made from WWF with different particle sizes were performed by using SEM, FT-IR, and RP-HPLC techniques. Results showed that the WWB made from WWF of average particle size of 96.99 μm had better baking quality than those of the breads made from WWF of two other particle sizes, 50.21 and 235.40 μm. T(2) relaxation time testing indicated that the decreased particle size of WWF increased the water absorption of AX gels, which led to water migration from the gluten network to the AX gels and resulted in inferior baking quality of WWB.

Zhengxing Chen

Papers

Structure and antioxidant activity of high molecular weight Maillard reaction products from casein-glucose

Effect of tea polyphenols on the retrogradation of rice starch

Some functional properties of oat bran protein concentrate modified by trypsin

Effects of pulsed electric fields on physicochemical properties of soybean protein isolates

Effect of water migration between arabinoxylans and gluten on baking quality of whole wheat bread detected by magnetic resonance imaging (MRI).