Summary
Fresh rice bran (RB) is susceptible to rancidity during storage and transportation and needs a stabilisation process to inactivate enzymes and retain maximum nutrients. Two stabilisation methods, i.e., dry‐heat and extrusion, were applied to study the changes in nutritional composition, volatile compounds, and storage stability of rice bran under varied conditions. Both methods stabilised phytic acid content at 0.55–0.60 μmol L−1; the overall oryzanol content was reduced and found to be less in untreated rice bran. The increase in dry‐heat treatment time and temperature accelerated the oryzanol loss and the loss rate was lower than untreated RB while the oryzanol content was higher at end of storage. Similarly, the reduction rate in oryzanol content by extrusion treatment was positively correlated with storage temperature. Both methods significantly increased the total dietary and soluble dietary fibre but reduced vitamin E content. The extrusion treatment was better at stabilising different volatile compounds (such as aldehydes and ketones) than the dry‐heat treatment in the rice bran. The most volatile substances were hydrocarbons. Dry heat and extrusion increase aldehydes and ketones, oxidising RB and reducing its quality while aldehydes and ketones decreased during storage.
Summary
Selenium (Se) is a nutrient related to human physiological processes and an essential trace element that has attracted considerable attention because of its antioxidant, immune and other functions. Se deficiency can cause all sorts of diseases and dysfunctions in the human tissues, but excessive intake of Se can also cause poisoning and injury. With lower toxicity and higher utilisation than inorganic Se, organic Se is recommended in the framework of a balanced diet. Compared with pharmaceutical supplementation, dietary Se supplementation is more acceptable to the masses. Thus, Se‐rich foods and selenoproteins enriched with organic Se have become a hot spot for current research. In living organisms, Se often exists in the form of selenoproteins (more than 25); for example, selenocysteine and selenomethionine are the common chemical forms of Se amino acids. And most of Se's physiological functions depend on the participation of selenoproteins. This paper reviews the physiological processes of Se, the development and utilisation of Se‐enriched foods, and the research on the properties of selenoproteins. Some suggestions and prospects for developing Se‐rich food in the future are also provided.
Peanuts are important
oil crops and plant protein source. This
study evaluated the influence of storage temperature (15, 25, and
35 °C) and time (0, 160, and 320 days) on the protein composition
and the molecular structure of peanuts through sodium dodecyl sulfate
polyacrylamide gel electrophoresis, particle size, total sulfhydryl
(−SH) contents, nanostructural characterization, surface morphology
microstructure, and spatial distribution of proteins and lipid analysis.
Results showed that the basic subunits and disulfide contents of peanut
protein were not affected by storage temperature and time. However,
the −SH contents decreased significantly (
P
< 0.05) in all samples except the 15 °C/160 day storage
group. The protein particle size and graininess increased when stored
at 25 and 35 °C for 160 and 320 days, respectively; however,
there was no significant change (
P
> 0.05) when
stored
at 15 °C. In addition, significant changes (
P
< 0.05) on the microscopic morphology and spatial distribution
of protein and lipids were observed when stored at 25 and 35 °C
for 320 days.
The effect of non-thermal treatment on the solubility and structural properties of rice bran protein was investigated. It was shown that the non-thermal treatment significantly improved the solubility of rice bran protein, in which, HHP and US increased it by 76.69% and 136.75%, respectively. The structural analysis showed that the non-thermal treatment reduced the β-sheet content and increased the content of free sulfhydryl groups on the surface, indicating that the inter-chain hydrogen and disulfide bonds of rice bran protein were broken and the protein structure shifted from order to disorder. And the internal chromogenic groups of the protein were exposed and tended to the hydrophilic environment, indicating the exposure of hydrophilic groups. This study provides a theoretical basis for non-thermal modification of rice bran protein and its processing and utilisation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.