Latent Anti-nutrients and Unintentional Breeding Consequences in Australian Sorghum bicolor Varieties

Sorghum Flour Features Related to Dry Heat Treatment and Milling

Heat treatment of sorghum kernels has the potential to improve their nutritional properties. The goal of this study was to assess the impact of dry heat treatment at two temperatures (121 and 140 °C) and grain fractionation, on the chemical and functional properties of red sorghum flour with three different particle sizes (small, medium, and large), for process optimization. The results showed that the treatment temperature had a positive effect on the water absorption capacity, as well as the fat, ash, moisture and carbohydrate content, whereas the opposite tendency was obtained for oil absorption capacity, swelling power, emulsion activity and protein and fiber content. Sorghum flour particle size had a positive impact on water absorption capacity, emulsion activity and protein, carbohydrate and fiber content, while oil absorption capacity, swelling power and fat, ash and moisture content were adversely affected. The optimization process showed that at the treatment temperature at 133 °C, an increase in fat, ash, fiber and carbohydrate content was experienced in the optimal fraction dimension of red sorghum grains. Moreover, the antioxidant performance showed that this fraction produced the best reducing capability when water was used as an extraction solvent. Starch digestibility revealed a 22.81% rise in resistant starch, while the thermal properties showed that gelatinization enthalpy was 1.90 times higher compared to the control sample. These findings may be helpful for researchers and the food industry in developing various functional foods or gluten-free bakery products.

Global Decrease in H3K9 Acetylation in Sorghum Seed Postgermination Stages

Sorghum seed germination is accompanied by increases in nutrient contents and reduced levels of antinutrients and is therefore being applied to food processing. However, the characterization of acetylated histone H3 at lysine residue 9 (H3K9ac) in sorghum postgermination has lagged. In this study, we performed chromatin immunoprecipitation sequencing (ChIP-seq) to identify H3K9ac enrichment and obtained transcriptome in postgermination stages. More than 10,000 hypoacetylated genes gained H3K9ac marks in the postgermination stages. In addition, we observed that the expression of the main histone deacetylase (HDAC) genes was elevated. The application of the HDAC inhibitor trichostatin A (TSA) resulted in seed growth arrest, suggesting that the repression of the H3K9ac modification is critical for postgermination. Additionally, we obtained a comprehensive view of abundant genomic changes in H3K9ac-marked regions and transcription between the mock and TSA treatment groups, which suggested that H3K9ac was required in the late stage of autotrophic seedling establishment. Metabolic profiling, transcriptome analyses, and ChIP-seq revealed that H3K9ac is enriched at genes involved in phenylpropanoid, including lignin and flavonoid, biosynthesis. Our results suggest important roles of H3K9ac in sorghum seed postgermination stages.

Effects of germination and lactic acid fermentation on nutritional and rheological properties of sorghum: A graphical review

Sorghum (Sorghum bicolor) is a nutritional grain considered an important source of micro- and macro-nutrients. Also, the flour obtained from sorghum is considered a suitable substitute for wheat flour for celiac disease patients due it is gluten-free. However, its use has some limitations due to anti-nutritional factors such as tannins, phytates, trypsin inhibitors, and protein crosslinkers. To prevent those effects, new strategies for sorghum processing have been explored. Germination of this grain has been shown to increase nutrient content further and reduce anti-nutrients. In addition, fermentation with lactic acid bacteria could modify starch and protein digestion in sorghum flour and increase their nutrient availability. Although there are many benefits to germination and fermentation, more research must be done to improve the products' texture and sensory properties to gain wider consumer acceptance. In this review, the mechanism behind changes in the nutritional and anti-nutritional profile of sorghum grain due to germination and fermentation treatments is shown, and the impact of these changes on dough rheological properties and bread quality.

Recent applications of metabolomics in plant breeding

Metabolites play a central role in maintaining organismal life and in defining crop phenotypes, such as nutritional value, fragrance, color, and stress resistance. Among the 'omes' in biology, the metabolome is the closest to the phenotype. Consequently, metabolomics has been applied to crop improvement as method for monitoring changes in chemical compositions, clarifying the mechanisms underlying cellular functions, discovering markers and diagnostics, and phenotyping for mQTL, mGWAS, and metabolite-genome predictions. In this review, 359 reports of the most recent applications of metabolomics to plant breeding-related studies were examined. In addition to the major crops, more than 160 other crops including rare medicinal plants were considered. One bottleneck associated with using metabolomics is the wide array of instruments that are used to obtain data and the ambiguity associated with metabolite identification and quantification. To further the application of metabolomics to plant breeding, the features and perspectives of the technology are discussed.

Concentration of Pro-Health Compound of Sorghum Grain-Based Foods

More than 35% of the world sorghum seed production is a human food source. The main ingredient of fully ripe sorghum grains is starch. Sorghum does not contain gluten, and it is also a rich source of antioxidant compounds other than vitamins or macro- and microelements, including phenolic acids, flavonoids, and sterols. The aim of this study was to determine the antioxidant activity and the content of selected bioactive compounds, i.e., total phenolic acids, total flavonoids, and total phytosterols, as well as determination of the qualitative and quantitative profile of phenolic acids, flavonoids, and phytosterols in various food products, the basic ingredient of which was sorghum grain. It was found that antioxidant activity is related to the total phenolic compounds content. The ABTS^•+ ranged from 319 to 885 µmol TROLOX/kg. However, white sorghum grain flour contained almost two times more polyphenols than red sorghum grain flour. The FPA ranged from 224 in raw pasta to 689 mgGAE/100 g in white sorghum grain. During this study, the quantitative profile of selected polyphenols in grain flour, wafers, pasta, and cookies containing sorghum grain was also investigated, as well as the content of 11 selected phenolic acids. Total content of the latter ranged from 445 to 2850 mg/kg. Phytosterols such as beta-sitosterol, campesterol, and stigmasterol were found in all the analyzed products. Based on this research, it was investigated that the products containing sorghum grains can be classified as functional food.

Potential food applications of sorghum (Sorghum bicolor) and rapid screening methods of nutritional traits by spectroscopic platforms

Sorghum is a drought-resistant crop widely spread in tropical regions of the American, African, and Asian continents. Sorghum flour is considered the main alternative for wheat flour, and it exhibits gluten-free nature. Generally, conventional wet chemical methods are used to analyze the nutritional profile of sorghum. Since many sorghum plants are available in breeding grounds, the application of conventional methods has limitations due to high cost and time consumption. Therefore, rapid screening protocols have been introduced as nondestructive alternatives. The current review highlights novel and portable devices that can be used to analyze the nutritional composition, color parameters, and pest resistance. Sorghum is often a traditional food item with minimal processing, and the review elaborates on emerging food applications and feasible food product developments from sorghum. The demand for gluten-free products has been rapidly increasing in developed countries. In order to develop food products according to market requirements, it is necessary to screen high-quality sorghum plants. Rapid analysis techniques effectively select the best sorghum types, and the novel tools have outperformed existing conventional methods.