Comparative Study of Physicochemical Properties and Starch Granule Structure in Seven Ginkgo Kernel Flours

Effects of the extraction temperatures on the protein contents, gelatin purities, physicochemical properties, and functional properties of tilapia scale gelatins

Herein, the effects of the extraction temperatures (45, 55, 65, 75, and 85 °C) on the protein contents, gelatin purities, physicochemical properties, and functional properties of tilapia scale gelatins were studied. Among these temperatures, 65 °C was the best extraction temperature to obtain good production yield (16.0 % ± 0.3 %), good protein contents (excellent total amino acid composition of 94.20 ± 0.76 g/100 g of gelatin, the highest hydrophobic amino acids percentage of 32.68 ± 0.24 g/100 g of gelatin), appropriate ATR-FTIR spectra peaks (Amides A, B, I, II, and III), high β-sheet percentage (38.2 % ± 1.3 %), the highest purity of the gelatin structures (280, 140, and 125 kDa), the lowest nanoparticle sizes in atomic force microscopy results, the highest water-holding capacity (25.3 % ± 0.9 %), the highest fat-binding capacity (16.9 % ± 0.1 %), high foaming properties (foaming capacity of 151.7 % ± 7.6 % and foaming stability of 145.8 % ± 6.3 %), the lowest interfacial tension (2.1 ± 0.2 mN/m), the lowest emulsifying activity index (16.5 % ± 0.9 %), the highest emulsifying stability index (88.9 % ± 5.1 %), highest emulsion viscosity (1462 ± 17 mPa·s at the rotary speed of 6 rpm), the lowest initial droplet sizes, and lowest emulsion creaming index (6.9 % ± 0.7 %). This work provided a useful guide to choosing extraction temperature for gelatin extraction and a useful theory on the relationship between compositions and properties of a protein sample.

Combined physicochemical and transcriptomic analyses reveal the effect of the OsGA20ox1 gene on the starch properties of germinated brown rice

Genes play a pivotal role in regulating the germination of cereal grains; however, there is limited research on the impact of germination genes on the physicochemical properties of germinated cereal starch. We investigated the effects of the OsGA20ox1 gene on the multiscale structural features and adhesion behavior of germinated brown rice starch. Compared to the knockout lines group, the wild type exhibited a decrease in double-helix content (62.74 %), relative crystallinity (47.39 %), and short-range molecular ordering (2.47 %), accompanied by enhanced erosion on the surface of starch granules. The damage to glycosidic bonds at the double-helix level and the heightened structural amorphization (90.95 %) led to reduced entanglement and interaction among starch molecules, ultimately resulting in reduced characteristic viscosity. Further transcriptomic analysis revealed that OsGA20ox1 could regulate the expression of starch-related enzyme genes in the starch metabolism pathway during germination of brown rice. This study contributes to understanding the role of germination genes in promoting the physicochemical properties of starch in germinated grains, thereby opening up new avenues for the improvement of plant-based starch, and paving the way for further research in this field.

Three-dimensional reconstruction and multiomics analysis reveal a unique pattern of embryogenesis in Ginkgo biloba

Ginkgo (Ginkgo biloba L.) is one of the earliest extant species in seed plant phylogeny. Embryo development patterns can provide fundamental evidence for the origin, evolution, and adaptation of seeds. However, the architectural and morphological dynamics during embryogenesis in G. biloba remain elusive. Herein, we obtained over 2,200 visual slices from 3 stages of embryo development using micro-computed tomography imaging with improved staining methods. Based on 3-dimensional (3D) spatiotemporal pattern analysis, we found that a shoot apical meristem with 7 highly differentiated leaf primordia, including apical and axillary leaf buds, is present in mature Ginkgo embryos. 3D rendering from the front, top, and side views showed 2 separate transport systems of tracheids located in the hypocotyl and cotyledon, representing a unique pattern of embryogenesis. Furthermore, the morphological dynamic analysis of secretory cavities indicated their strong association with cotyledons during development. In addition, we identified genes GbLBD25a (lateral organ boundaries domain 25a), GbCESA2a (cellulose synthase 2a), GbMYB74c (myeloblastosis 74c), GbPIN2 (PIN-FORMED 2) associated with vascular development regulation, and GbWRKY1 (WRKYGOK 1), GbbHLH12a (basic helix-loop-helix 12a), and GbJAZ4 (jasmonate zim-domain 4) potentially involved in the formation of secretory cavities. Moreover, we found that flavonoid accumulation in mature embryos could enhance postgerminative growth and seedling establishment in harsh environments. Our 3D spatial reconstruction technique combined with multiomics analysis opens avenues for investigating developmental architecture and molecular mechanisms during embryogenesis and lays the foundation for evolutionary studies of embryo development and maturation.

Dynamics of α-glucan from Agrocybe cylindracea water extract at different developmental stages and its structure characteristics

Polysaccharides are the important bioactive macromolecules in Agrocybe cylindracea, but their changes are as yet elusive during developmental process. This study investigated the dynamic changes of polysaccharides from A. cylindracea fruiting body water extract at four developmental stages and its structure characteristics. Results revealed that the polysaccharides from A. cylindracea water extract significantly increased at the pileus expansion stage and the increased fraction could be α-glucan. The further purification and identification indicated that this α-glucan was a glycogen. It had typical morphology of β particles with a molecular weight of 1375 kDa. Its backbone comprised α-D-(1 → 4)-Glcp and α-D-(1 → 4,6)-Glcp residues at a ratio of 5:1, terminated by α-D-Glcp residue. Rheological behavior suggested that it was a Newtonian fluid at the concentration of 1 %. In addition, despite both the glycogen and natural starch were composed of D-glucose, they exhibited the entirely distinct Maltese cross characteristic and unique crystalline structure. This study is the first to demonstrate the presence of abundant glycogen in the pileus expansion stage of A. cylindracea, which provides new insights on the change patterns of fungal polysaccharides.

Pulsed light treatment enhances starch hydrolysis and improves starch physicochemical properties of germinated brown rice

BACKGROUND

Recently, germinated brown rice (GBR) has gained substantial attention as a functional food because of its nutritional attributes. Notably, pulsed light technology (PLT) has emerged as a promising tool for enhancing rice germination and, consequently, has improved the nutritional and functional qualities of GBR-derived products. However, further research is required to comprehensively understand the impact of PLT on GBR physicochemical properties. The present study aimed to investigate the stimulating effects of PLT on starch hydrolysis, starch structure and functional properties of GBR.

RESULTS

The PLT substantially boosted α-amylase activity during brown rice germination, leading to a 10.9% reduction in total starch content and a 17.3% increase in reducing sugar content, accompanied by elevated free water levels. Structural analysis indicated no changes in starch crystalline types, whereas gelatinization temperature slightly increased. Pasting properties exhibited a significant drop in peak viscosity. Scanning electron microscopy showed surface erosion of starch granules with microstructural changes. Furthermore, correlation analysis established positive links between α-amylase activity, reducing sugar accumulation, starch structure and functional properties in GBR.

CONCLUSION

The present study demonstrates that PLT enhanced the physicochemical properties of GBR starch, significantly improving the stability of GBR products, thereby contributing to expanded applicability of rice starch in the food industry. © 2023 Society of Chemical Industry.

Morphological Characteristics, Ultrastructure, and Chemical Constituents of the Endotesta in Ginkgo (Ginkgo biloba L.)

Ginkgo biloba L. is a tree species of significant economic and ecological importance. Prior studies of the Ginkgo biloba seed coat have predominantly focused on the sarcotesta and sclerotesta, with less attention paid to the endotesta. In this study, the development and formation of Ginkgo endotesta were examined using light microscopy and transmission electron microscopy. The structural properties of the mature endotesta were analyzed using micro-CT imaging and scanning electron microscopy. The results indicate that the endotesta possess a membranous structure primarily originating from the inner bead peridium, a segment of bead core tissue, and the macrospore membrane. The endotesta from the middle constriction line to the chalazal end comprises a single layer with a greyish-white papery structure. In contrast, the endotesta was divided into two inner and two outer layers, from the middle constriction line to the micropylar end. The outer endosperm adheres closely to the sclerotesta, while the inner endosperm adheres to the seed kernel. The surface of the endotesta was irregularly raised, with thicker wax at the chalazal end, whereas the micropylar end demonstrated similar characteristics with thinner wax and tumor layers. The endotesta contained 17 amino acids, 18 fatty acids, 10 trace elements, and 7 vitamins. Overall, its nutritional value was relatively well balanced.

Ginkgo seed extract promotes longevity and stress resistance of Caenorhabditis elegans

Ginkgo seeds are a traditional food in China valued for their nutritional and health benefits. However, little is known about the anti-aging and health-promoting effects of ginkgo seed products. Here, we showed that ginkgo seed powder extract (GSP-E) is abundant in alkaloids and flavonoids, and can extend the lifespan of Caenorhabditis elegans. GSP-E improved most physiological indicators related to aging of C. elegans, including locomotor activity, reproductive capacity, and resistance to oxidation and heat. Moreover, GSP-E reduced the accumulation of lipofuscin and reactive oxygen species (ROS) in C. elegans. Further studies demonstrated that GSP-E improved longevity and stress resistance by mediating lipid metabolism and autophagy, as well as by regulating gene expression (e.g., FASN-1, POD-2, GPX-7, FAT-5). GSP-E has an anti-amyloid effect and delayed amyloid-induced paralysis of C. elegans. These findings could support the utilization of ginkgo seed as a potential dietary supplement for the health food industry, and provide a novel health-promoting resource against aging and aging-related diseases.