Soybean Sugar Research Articles

Correlation analysis between soluble sugars of soybean and mucus drawing length of fermented natto

Natto is a traditional fermented food from Japan that is made from soybean fermented by Bacillus subtilis natto. The mucus drawing length of natto determines the sensory quality of natto, and there are differences in the mucus drawing length and sensory quality of natto fermented with soybeans with different contents of soluble sugars. In this study, soybeans with different contents of soluble sugars were used to ferment natto, and the differences and correlations between the mucilage composition, the mucus drawing length and the sensory quality of natto were investigated. The contents of oligosaccharides and total sugars in soybean were significantly positively correlated with the mucus drawing length (R = 0.921, R = 0.956), and the correlation between the drawing length of mucilage and total sugars was stronger. Fermenting soybeans with high contents of total sugars could make mucus drawing of natto longer. The contents of oligosaccharides and total sugars in soybean were significantly positively correlated with the sensory index score (R = 0.886, R = 0.925). The natto fermented from soybean with high contents of soluble total sugars had better overall sensory quality. Soluble sugars had a positive influence on mucus drawing length and sensory quality of natto.

Laser light and magnetic field stimulation effect on biochemical, enzymes activities and chlorophyll contents in soybean seeds and seedlings during early growth stages

Laser and magnetic field bio-stimulation attracted the keen interest of scientific community in view of their potential to enhance seed germination, seedling growth, physiological, biochemical and yield attributes of plants, cereal crops and vegetables. Present study was conducted to appraise the laser and magnetic field pre-sowing seed treatment effects on soybean sugar, protein, nitrogen, hydrogen peroxide (H2O2) ascorbic acid (AsA), proline, phenolic and malondialdehyde (MDA) along with chlorophyll contents (Chl “a” “b” and total chlorophyll contents). Specific activities of enzymes such as protease (PRT), amylase (AMY), catalyst (CAT), superoxide dismutase (SOD) and peroxides (POD) were also assayed. The specific activity of enzymes (during germination and early growth), biochemical and chlorophyll contents were enhanced significantly under the effect of both laser and magnetic pre-sowing treatments. Magnetic field treatment effect was slightly higher than laser treatment except PRT, AMY and ascorbic acid contents. However, both treatments (laser and magnetic field) effects were significantly higher versus control (un-treated seeds). Results revealed that laser and magnetic field pre-sowing seed treatments have potential to enhance soybean biological moieties, chlorophyll contents and metabolically important enzymes (degrade stored food and scavenge reactive oxygen species). Future study should be focused on growth characteristics at later stages and yield attributes.

A Simple Analytical Method for High-Throughput Screening of Major Sugars from Soybean by Normal-Phase HPLC with Evaporative Light Scattering Detection

This paper presents a simple analytical method for determining sugars in soybean (Glycine max(L.) Merr.) tissues. Sample preparation was modified from several early published methods. High-performance liquid chromatography (HPLC) equipped with an evaporative light scattering detector (ELSD) was used to separate, identify, and quantify seven sugars, including glucose, galactose, fructose, sucrose, melibiose, raffinose, and stachyose. Two mobile phases were programed into a gradient elution. Mobile phase A is pure water and mobile phase B is a mixture of acetonitrile and acetone 75 : 25 (v/v). Total chromatographic retention time is less than 20 minutes. This method has been validated for detection limit, calibration range, and intraday and interday repeatability. This method has been used analyzing more than 5000 soybean samples in the experiments studying natural genetic variation of sugar contents and components in soybean seeds and other tissues.

Genetic Variability of Seed Sugar Content in Worldwide Soybean Germplasm Collections

Soluble sugar is an important quality trait in food‐grade soybeans [Glycine max (L.) Merr.]. Desirable sugars such as sucrose, glucose, and fructose can help improve the taste and flavor of soyfood including tofu, soymilk, and natto; whereas oligosaccharides including raffinose and stachyose are indigestible by humans and animals and often cause flatulence or diarrhea. In this study, 241 plant introductions (PIs) of three maturity groups (MGs) from 28 origins were investigated for seed sugar content including glucose, fructose, sucrose, raffinose, and stachyose. Variation was detected in individual and total sugars in soybean PIs from different origins and MGs. Sucrose and stachyose are the major sugars in soybean seed. The sucrose content ranged from 1.6 to 95.4 mg g−1 with 13 PIs containing greater than 70 mg g−1 and 14 PIs having less than 10 mg g−1 The stachyose content ranged from 0.2 to 69.6 mg g−1 with 14 PIs containing less than 10 mg g−1 stachyose. The high sucrose and low stachyose types are the most valuable for breeding specialty soybeans for soyfood and animal feed. In addition, 30 PIs were identified as having high concentrations of glucose or fructose as major sugars. This new class of high glucose or fructose has not been reported before. While soybean germplasm with unique sugar profiles may be useful for future breeding and genetic research, environmental effects on sugar stability will need to be further investigated.

Sugar Variation in Soybean Seed Assessed with a Rapid Extraction and Quantification Method

Sugar content in soybean [Glycine max(L) Merr.] seed is an important quality attribute for soyfood and feed. Rapid extraction and quantification of soluble sugars in soybean seed are essential for large-scale breeding selections. In this study, using water as extractant combined with a high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) system, variability and repeatability of sugar content were tested in 20 diverse soybean genotypes. Individual sugars were clearly resolved and identified, including sucrose, stachyose, raffinose, glucose, fructose, and verbascose. Analysis of variance (ANOVA) revealed a highly reproducible estimation of sucrose, stachyose, and raffinose. PI 243545 was confirmed as a unique germplasm with the highest sucrose (105.48 mg/g) and total sugar (148.76 mg/g) content. Two low-oligosaccharide accessions, PI 200508 and 03CB-14, were confirmed with extremely low concentrations of raffinose and stachyose. PI 417559 was identified as a high glucose and fructose germplasm. The identified germplasm with unique sugar profiles will be valuable in breeding specialty soybeans for improved sugar content. The sugar testing method will facilitate the screening of seed sugar profiles in a large-scale soybean breeding program.

Comparison of two HPLC systems and an enzymatic method for quantification of soybean sugars

Successful breeding programs need fast and reliable methods for analyzing sugar composition in new soybean ( Glycine max (L.) Merrill) lines. The efficiency to quantify the major sugars, including glucose, fructose, sucrose, raffinose, and stachyose, in five soybean lines with two HPLC systems and an enzymatic procedure were compared. Soluble sugars in soybean were extracted with water at a solvent-to-sample ratio of 5:1 at 50 °C for 15 min, and analyzed by high-performance size exclusion chromatography with refractive index detection (HPSEC-RI), high-performance anion-exchange chromatography with pulsed-amperometric detection (HPAEC-PAD), and a raffinose-series oligosaccharides assay procedure. All three methods produced comparable and reproducible results. The HPAEC-PAD method was more sensitive, faster and capable of separating all five major sugars in soybean with improved peak resolution compared with the HPSEC-RI method, and is recommended for soybean breeding programs. The enzymatic procedure required no expensive instrumentation and less sample preparation, but could not quantify individual raffinose and stachyose.

Effects of Solvent, Temperature, Time, Solvent‐to‐Sample Ratio, Sample Size, and Defatting on the Extraction of Soluble Sugars in Soybean

ABSTRACT Extraction solvent, temperature, time, and solvent‐to‐sample ratio were studied to identify the optimal conditions for extracting sugars from nondefatted soybean. Water and 10%, 50%, and 80% (v/v) ethanol were used as the solvents. Extraction temperatures of 25 °C, 50 °C, and 80 °C, for 15, 30, and 60 min and solvent‐to‐sample ratios of 5:1, 10:1, and 15:1 (v/w) were combined with different solvents. The sugar composition in the soybean extracts was analyzed by high‐performance anion‐exchange chromatography with pulsed amperometric detection. The sugar appropriate to be used as the standard in the phenol‐sulfuric acid method in sugar quantification, and effects of sample size and defatting on sugar extraction were also evaluated. The optimum extraction protocol concluded from this study includes the use of water as the solvent at a solvent‐to‐sample ratio of 5:1 at 25 °C or 50 °C for 15 min. Sucrose was shown to be the best sugar as the standard to quantify the total soluble sugars in soybean. Extractions from sample size of 1 g and 0.1 g yielded similar soluble sugars. A greater amount of sugars was extracted with the defatted soybean meal than with the nondefatted sample.

Seed Protein and its Relationship to Soluble Sugars in Soybean

Protein meal from soybean [Glycine max (L.) Merr.] contains the soluble sugars raffinose and stachyose. Because of these sugars, the quantity of soybean meal must be limited in rations to avoid flatulence in dogs (Canis familiaris) and digestive disturbances in baby pigs (Sus scrofa) and chicks (Gallus domesticus). Identifying soybean with a lower level of these sugars could lead to an increase in the quantity of soybean meal used in specific rations. As protein content of soybean seed is increased and oil is reduced, the total protein + oil + seed coat is greater than in standard type soybean. The residual portion is therefore reduced, and soluble sugars could account for a part of this reduction. Twenty standard type (high‐oil) soybean cultivars and breeding lines and 20 high‐protein breeding lines were grown in replicated trials on Sharkey clay (very‐fine, montmorillonitic, nonacid, thermic Vertic Haplaquept) at Stoneville in 1991 and 1992. Seed was analyzed for protein, oil, raffinose, stachyose, and sucrose. Range in protein content was from 387 to 537 g kg−1 dry seed and oil was from 145 to 216 g kg−1 dry seed. Range in g stachyose + raffinose kg−1 protein was 78.3 to 133.7. The correlation between protein and stachyose + raffinose was negative but nonsignificant. The g stachyose + raffinose kg−1 protein for the cultivar Forrest was used as a basis for comparison with the other genotypes evaluated. On this basis, the quantity of protein that might be used in a ration without changing the raffinose + stachyose level from that in Forrest ranged from 89 to 153%.