•The common response is the enhanced phytic acid degradation and antioxidant enzymes.•Up-regulated purple acid phosphatase and inositol-phosphate phosphatase were found.•The inhibition effect by SA is probably due to protein biosynthesis impairment.•Most of the differential proteins were involving carbohydrate and energy metabolism.•The molecular mechanisms that contributed to the growth regulation were complex.The effects of sodium citrate (SC), sodium acetate (SA) and sodium tartrate (ST) spraying on mung bean germination were investigated. Exogenous SC, ST and SA treatments significantly reduced the phytic acid content and increased the antioxidant enzyme activities. In this study, an iTRAQ-based proteomic approach was employed to explore the proteomes of mung bean sprouts, and 81, 101 and 90 differentially expressed proteins were identified in 4-day-old SC-, SA- and ST-treated mung bean sprouts, with 38 proteins present in all samples. Functional classification analysis showed that most of the differentially expressed proteins in mung bean sprouts subjected to the three treatments were involved in carbohydrate and energy metabolism. The inhibitory effect of the SA treatment was probably due to impairments in protein biosynthesis, whereas enhanced energy metabolism, accelerated reserve hydrolysis and protein processing were very important strategies for growth stimulation in response to ST and SC treatments.

•Enhanced FPC and BPC resulted in elevated antioxidant activities of germinated wheat.•Ferulic and p-coumaric acid were most abundant phenolic acids in germinated wheat.•Wheat varieties were differentiated by bound sinapic acid during early germination.•Antioxidant enzymes were synchronous activated with PAL during wheat germination.•Ferulic acid contributed the most to the BPC, bound DPPH and ABTS activities.Three typical Chinese wheat varieties have been studied monitoring their phenolic profiles, antioxidant capacity and relevant enzyme activity during germination. Results showed that free and bound phenolic contents significantly increased in germinated wheat and contributed to enhanced antioxidant capacity. Sumai188 showed the highest total phenolic contents and antioxidant capacity after 4-day germination. Ferulic acid and p-coumaric acid were most abundant in germinated wheat and mainly existed in the bound form. Meanwhile, the activated Phenylalanine ammonia-lyase could result in the phenolic accumulation and the activities of antioxidant enzymes peroxidase, catalase and ascorbate peroxidase were also enhanced in germinated wheat. Jimai 22 could be differentiated by bound sinapic acid in the early stage of germination compared with the other two varieties from principle component analysis. In addition, multiple linear regression studies led to the conclusion that ferulic acid contributed the most to the bound phenolic contents, bound DPPH and ABTS activities.

•Ca2+ increased ITCs by up-regulating gene expression on GL synthesis and hydrolysis.•Ca2+ increased ITCs by increasing MYR activity.•Ca2+ increased the relative content of 1-isothiocyanato-butane in ITCs.•ITCs contributed to total antioxidant capacity and DPPH• scavenging capacity.The effects of CaCl2 on metabolism of glucosinolates (GLs) and formation of isothiocyanates (ITCs), as well as the antioxidant capacity of broccoli sprouts, were investigated. The results showed that CaCl2 treatment enhanced BrST5b (sulfotransferase 5b) and limited AOP2 (2-oxoglutarate-dependent dioxygenase 2) expression, which increased GLs biosynthesis. CaCl2 also promoted the gene expression of myrosinase (MYR) and its activity, and thus increased ITCs formation. Three ITCs and two nitriles were found in the hydrolysate of broccoli sprouts. CaCl2 treatment increased the content of 1-isothiocyanato butane significantly. Then, CaCl2 increased the formation of ITCs by regulating gene expression and enzyme activity. After CaCl2 treatment, the antioxidant capacity of sprouts increased and the formed ITCs mainly contributed to total antioxidant capacity and DPPH• scavenging capacity.

•NO is an essential signaling molecule mediating UV-B-induced isoflavone production.•NO could up-regulate gene expression of isoflavone biosynthetic-enzymes.•NO could enhance antioxidant system under UV-B stress.•NO could regulate gene expression of enzymes involved in antioxidant system.•GSH and ASC induced by NO may up-regulate the isoflavone content under UV-B stress.In this study, we investigated the relationships between endogenous NO signal transduction pathways, the antioxidant system and isoflavone accumulation induced by UV-B radiation in soybean sprouts. Results showed that UV-B-triggered NO generation induced isoflavone accumulation by up-regulating the activity and gene expression of key enzymes (phenylalanine ammonia lyase, PAL; chalcone isomerase, CHI; chalcone synthase, CHS; isoflavone synthase, IFS) that participate in isoflavone biosynthesis and enhanced the antioxidant system by regulating levels of antioxidants (glutathione reductase, GR; glutathione S-transferase, GST; ascorbate peroxidase, APX; glutathione GSH; ascorbic acid, ASC), antioxidant enzyme activities (superoxide dismutase, SOD; peroxidase, POD; catalase, CAT) and their gene expression. These effects were inhibited by the addition of a specific NO-scavenger, carboxy-PTIO (cPTIO). The inhibition was reversed through application of the exogenous NO donor, SNP. Overall, NO is an essential signaling molecule, mediating UV-B-induced isoflavone accumulation and the antioxidant system enhancement in soybean sprouts.

Calcium lactate facilitates the growth and phytic acid degradation of soybean sprouts, but the mechanism is unclear. In this study, calcium lactate (Ca) and calcium lactate with lanthanum chloride (Ca+La) were used to treat soybean sprouts to reveal the relevant mechanism. Results showed that the phytic acid content decreased and the availability of phosphorus increased under Ca treatment. This must be due to the enhancement of enzyme activity related to phytic acid degradation. In addition, the energy metabolism was accelerated by Ca treatment. The energy status and energy metabolism-associated enzyme activity also increased. However, the transmembrane transport of calcium was inhibited by La3+ and concentrated in intercellular space or between the cell wall and cell membrane; thus, Ca+La treatment showed reverse results compared with those of Ca treatment. Interestingly, gene expression did not vary in accordance with their enzyme activity. These results demonstrated that calcium lactate increased the rate of phytic acid degradation by enhancing growth, phosphorus metabolism, and energy metabolism.

In this study, to investigate the role of inositol 1,4,5-trisphosphate (IP3) in nitric oxide–guanosine 3′,5′-cyclic monophosphate (NO-cGMP)-induced isoflavone accumulation in soybean sprouts under UV-B radiation, the sprouts were treated with donors and inhibitors of NO and cGMP as well as IP3 inhibitor. Results showed that NO, with cGMP as a second messenger, stimulates IP3 accumulation under UV-B radiation. Consistent with the increase in IP3 content, the up-regulation of gene and protein expression of phosphoinositide-specific phospholipase C (PI-PLC) in response to sodium nitroprusside (SNP) (exogenous NO donor) and 8-Br-cGMP (cGMP analogue) was also observed. In addition, protein kinase G (PKG) participated in NO-cGMP-induced IP3 production. IP3 induced by the NO-cGMP pathway was involved in isoflavone synthesis by elevating the activity and gene and protein expressions of chalcone synthase (CHS) and isoflavone synthase (IFS). Overall, IP3 mediates NO-cGMP-induced isoflavone accumulation in soybean sprouts under UV-B stress.Keywords: IP3; isoflavone; NO-cGMP; soybean sprouts; UV-B;

In this study, aliphatic glucosinolates and sulforaphane were accumulated in broccoli sprouts under the stresses of heat, hypoxia and heat plus hypoxia. Glucoraphanin content in 7-day-old broccoli sprouts under heat, hypoxia and heat plus hypoxia stresses enhanced by 1.39-, 1.10- and 1.16-fold compared with the control, respectively; meanwhile, glucoerucin content increased by 1.87-, 4.17- and 3.24-fold, respectively. Aliphatic glucosinolate content was enhanced by heat stress due to the increasing expression of Elong, CYP83A1 and FMOGS-OX1. However, under hypoxia and heat plus hypoxia stresses, the expression levels of Elong, CYP83A1, UGT74B1, ST5b and AOP2 related to aliphatic glucosinolates biosynthesis were dramatically up-regulated. Heat, hypoxia and heat plus hypoxia stresses enhanced sulforaphane formation in 7-day-old sprouts by 153.73, 95.15 and 86.95 % compared with the control, respectively. However, heat plus hypoxia stress did not exhibit the synergistic effect of heat and hypoxia stresses. These results indicated that heat and hypoxia stresses were feasible strategies to enhance the accumulation of aliphatic glucosinolates and sulforaphane in broccoli sprouts.

Fresh-cut water fennel was treated with a novel complex chemical solution and subsequently packaged prior to refrigerated storage. Chlorophyll degradation and lignification were investigated. The complex solution consisted of 1.16 g/L calcium lactate, 150 mg/L zinc acetate, and 15.29 mg/L salicylic acid. Chlorophyllase, Mg-dechelatase, and chlorophyll-degrading peroxidase activities of water fennel decreased after immersion in the complex solution, which delayed chlorophyll degradation and increased L* and a* values. Complex solution treatment also reduced phenylalanine ammonia-lyase (PAL) activity and, thus, inhibited accumulation of lignin. After the complex solution treatment, packaging in high-density polypropylene plastic bags further retained chlorophylls and alleviated lignification of water fennel. Treatment with a complex chemical solution and subsequent packaging can maintain the quality, delay senescence, and improve the shelf life of water fennel.

•80 proteins induced by calcium in cotyledons and 71 in embryos were identified.•Calcium enriched signal transduction and energy pathway and transportation.•Calcium increased the abundance of NDPK and antioxidant enzymes and their activities.•Calcium caused the accumulation of GABA and free PAs to reduce osmotic pressure.•Protein processing in E.R. plays an essential role in improving the salt stress by calcium.Calcium enhances salt stress tolerance of soybeans. Nevertheless, the molecular mechanism of calcium's involvement in resistance to salt stress is unclear. A comparative proteomic approach was used to investigate protein profiles in germinating soybeans under NaCl-CaCl2 and NaCl-LaCl3 treatments. A total of 80 proteins affected by calcium in 4-day-old germinating soybean cotyledons and 71 in embryos were confidently identified. The clustering analysis showed proteins were subdivided into 5 and 6 clusters in cotyledon and embryo, respectively. Among them, proteins involved in signal transduction and energy pathways, in transportation, and in protein biosynthesis were largely enriched while those involved in proteolysis were decreased. Abundance of nucleoside diphosphate kinase and three antioxidant enzymes were visibly increased by calcium. Accumulation of gamma-aminobutyric acid and polyamines was also detected after application of exogenous calcium. This was consistent with proteomic results, which showed that proteins involved in the glutamate and methionine metabolism were mediated by calcium. Calcium could increase the salt stress tolerance of germinating soybeans via enriching signal transduction, energy pathway and transportation, promoting protein biosynthesis, inhibiting proteolysis, redistributing storage proteins, regulating protein processing in endoplasmic reticulum, enriching antioxidant enzymes and activating their activities, accumulating secondary metabolites and osmolytes, and other adaptive responses.Biological significanceSoybean (Glycine max L.), as a traditional edible legume, is being targeted for designing functional foods. During soybean germination under stressful conditions especially salt stress, newly discovered functional components such as gamma-aminobutyric acid (GABA) are rapidly accumulated. However, soybean plants are relatively salt-sensitive and the growth, development and biomass of germinating soybeans are significantly suppressed under salt stress condition. According to previous studies, exogenous calcium counters the harmful effect of salt stress and increases the biomass and GABA content of germinating soybeans. Nevertheless, the precise molecular mechanism underlying the role of calcium in resistance to salt stress is still unknown. This paper is the first study employing comparative proteomic and physiological analyses to reveal the protective effect of exogenous calcium in the germinating soybean response to salt stress. Our study links the biological events with proteomic information and provides detailed peptide information on all identified proteins. The functions of those significantly changed proteins are also analyzed. The physiological and comparative proteomic analyses revealed the putative molecular mechanism of exogenous calcium treatment induced salt stress responses. The findings from this paper are beneficial to high GABA-rich germinating soybean biomass. Additionally, these findings also might be applicable to the genetic engineering of soybean plants to improve stress tolerance.

•ZnSO4 raised glucosinolate content of broccoli sprouts.•ZnSO4 enhanced myrosinase activity and its gene expression of broccoli sprouts.•ZnSO4 enhanced sulforaphane formation of broccoli sprouts via its stress effect.Broccoli sprouts have attracted much attention in recent years for their abundant phytochemicals such as glucosinolates and sulforaphane. In this study, zinc sulphate (ZnSO4) as a sulphur (S)-source was compared with potassium sulphate (K2SO4) and methionine (Met), significantly increased glucosinolates content and stimulated sulforaphane formation by enhancing myrosinase activity and gene expressions related to glucoraphanin biosynthesis and sulforaphane formation in broccoli sprouts. However, it resulted in a stress effect on sprout growth. Thus, ZnSO4 is a suitable S-source to improve sulforaphane formation in broccoli sprouts via its stress effect.

In order to improve the growth condition of broccoli sprouts under ZnSO4 application, exogenous CaCl2 was added in the cultural medium, and the growth profiles, key bioactive substances (glucosinolates, sulforaphane, ascorbic acid and phenolic compounds), antioxidant capacity, myrosinase activity and related genes expression of the broccoli sprouts were evaluated. Results showed that the stressful condition caused by ZnSO4 was effectively mitigated by CaCl2. Consequently, ascorbic acid and the total phenolics content as well as the antioxidant capacity of the broccoli sprouts decreased compared with that of the sole ZnSO4 treatment. However, sulforaphane formation increased because a higher glucoraphanin content, myrosinase activity and related gene expression was induced after the CaCl2 treatment. The glucoraphanin content and sulforaphane formation of the water-treated sprouts decreased steadily during germination. However, the sulforaphane formation of the sprouts treated with ZnSO4 plus CaCl2 increased after germinating for 2 days. These results suggest that CaCl2 could mitigate the stress caused by ZnSO4 and enhance the sulforaphane formation of broccoli sprouts.

Broccoli sprouts were directly frozen at −20 °C (DF-20), −40 °C (DF-40) and −80 °C (DF-80) or stored at −20 °C (LN-20), −40 °C (LN-40) and −80 °C (LN-80) after being frozen in liquid nitrogen for 5 min or always frozen in liquid nitrogen (LN). The effect of these treatments on glucoraphanin and ascorbic acid content, myrosinase activity, sulforaphane and sulforaphane nitrile formation in broccoli sprouts was investigated. The results showed that glucoraphanin content was not significantly affected by freezing. Treatments of DF-20, DF-40, LN-20 and LN-40 for 24 and 48 h enhanced myrosinase activity and decreased the ascorbic acid content. The enhancement of myrosinase activity after freezing was in parallel with more sulforaphane and less sulforaphane nitrile formation. Besides, freezing at −20 °C was more favorable for sulforaphane formation than −40 °C. Directly freezing at −20 °C increased the sulforaphane yield by 1.54–2.11 fold in the broccoli sprouts of the three cultivars investigated in this study.

•Growth temperature affected the contents of glucoraphanin, sulforaphane and nitrile.•Sulforaphane formation was highest in cotyledon and lowest in root.•Myrosinase activity in cotyledon was lower than that in hypocotyl and root.•The most abundant hydrolysis product in all organs except for root was sulforaphane.The effect of growth temperature on glucoraphanin, sulforaphane and myrosinase activity in germinating broccoli sprouts was firstly evaluated, and then their distributions in the cotyledon, hypocotyl and root at the optimum temperature were investigated. The profiles of isothiocyanates and nitrile in seeds, sprouts and different organs were also analyzed. Glucoraphanin content and sulforaphane formation declined with sprouts growth. Myrosinase activity in sprouts, stable for the first 3 days of germination, slowly increased threefold by day 7. The highest levels of glucoraphanin and sulforaphane were recorded in non-germinated seeds. Sprouts grown at 25 °C had higher glucoraphanin content and sulforaphane formation than that grown at 20 and 30 °C. In addition, cotyledon had significantly higher glucoraphanin content and sulforaphane formation than hypocotyl and root. Glucoraphanin and sulforaphane were barely detectable in root, despite its high myrosinase activity. The most abundant hydrolysis product in seeds and sprouts, cotyledon and hypocotyl was sulforaphane.

A comparative proteomic approach was employed to explore proteome expression patterns in germinating soybeans under NaCl stress and NaCl–aminoguanidine treatment. The proteins were extracted from 4-day-old germinating soybean cotyledons and noncotyledons (hypocotyl and radicle) and were separated using two-dimensional polyacrylamide gel electrophoresis. A total of 63 and 72 differentially expressed proteins were confidently identified by MALDI-TOF/TOF in the noncotyledons and cotyledons, respectively. These identified proteins were divided into ten functional groups and most of them were predicted to be cytoplasmic proteins in noncotyledons. Moreover, γ-aminobutyric acid was accumulated while the major allergen (Bd 30K protein) was reduced in the germinating soybeans. The proteins involved in energy metabolism and in protein processing in endoplasmic reticulum were enriched under NaCl stress. Meanwhile, the negative effect of stress was aggravated once polyamine degradation was inhibited. Redistribution of storage proteins under stress indicated that storage proteins might not only function as seed storage reserves but also have additional roles in plant defense.

Usually, ACTIN is used as an internal reference for the gene expression analysis. But in faba bean, its ACTIN gene sequence has not been obtained yet. In this study, RT-PCR was initially performed with mRNAs prepared from 5-day germinated faba bean using a pair of primers (degenerate primers). Then the 3′ and 5′ untranslated regions of VfActin were generated by 3′-RACE PCR and 5′-RACE PCR, and finally the full length gene of ACTIN in germinated faba bean was isolated. It was shown that VfActin cDNA of faba bean contains a 1,131 bp of open reading frame that encodes 377 amino-acid peptides with a calculated molecular mass of 41.79 kDa and a pI of 5.39 (GenBank: JX444700). This result supplied a convenient tool for further researches about the analysis of gene expression in faba bean.

Effects of calcium on soybean growth and gamma-aminobutyric acid (GABA) accumulation pathways in germinating soybean were investigated. The harmful effect of NaCl stress was alleviated by CaCl2 while was aggravated by LaCl3. Glutamate decarboxylase (GAD) activity increased significantly under NaCl plus CaCl2 treatment, while its gene expression levels had no significant changes compared with NaCl treatment. GAD and diamine oxidase (DAO) activities and their gene expression levels significantly decreased after LaCl3 was applied. When treated with AG, the soybean growth was suppressed and DAO activity was inhibited completely while DAO expression had no significant changes. Meanwhile, the GABA content decreased by 17.04 and 11.76 % in cotyledon and embryo under NaCl plus CaCl2 treatment compared with NaCl treatment, respectively. It can be concluded that CaCl2 addition changed the contribution ratio of GABA shunt and polyamine degradation pathway for GABA formation, and the increment of GABA in germinating soybean was mainly synthesized via GABA shunt.

Effects of NaCl stress and supplemental CaCl2 on soybean growth and gamma-aminobutyric acid (GABA) accumulation pathways in germinating soybean were investigated. Germinating under NaCl stress, GABA accumulation was caused not only by the activation of glutamate decarboxylase (GAD), diamine oxidase (DAO) and aminoaldehyde dehydrogenase (AMADH) existing in seed but also by their gene expression up-regulation during germination. However, after CaCl2 (6 mM) application, the harmful effect of NaCl stress (50 mM) was removed. GAD activity significantly increased, while its gene expression levels had no significant changes with the control, indicating that the increment in GAD activity was caused by the stimulation of exogenous Ca2+. Meanwhile, GABA was still accumulated although DAO and AMADH activities and their gene expression levels had no significant difference compared with the control. It can be concluded that CaCl2 addition decreased the contribution of polyamine degradation pathway to GABA accumulation compared with NaCl stress, and the increased GABA was mainly synthesized via GABA shunt.

GABA shunt and polyamine degradation pathway on γ-aminobutyric acid (GABA) accumulation in germinating fava bean under hypoxia was investigated. GABA content, GAD and DAO activity were significantly increased under hypoxia treatment. Glu and polyamine contents enhanced largely and thus supplied as sufficient substrates for GABA formation. In contrast, GABA content decreased, mainly in the embryo, after removing the hypoxia stress. DAO activity, Glu and polyamines contents decreased, while an increment of GAD activity was observed. This indicated that GAD activity can be not only regulated by hypoxia, but by the rapid growth of embryo after the recovery from hypoxia stress. When treated with AG, DAO activity was almost inhibited completely, and the GABA content decreased by 32.96% and 32.07% after treated for 3 and 5 days, respectively. Hence, it can be inferred that about 30% of GABA formed in germinating fava bean under hypoxia was supplied by polyamine degradation pathway.Highlights► Hypoxia is very helpful for accumulating GABA in germinating fava bean. ► The levels of Glu and polyamines were regulated by hypoxia treatment. ► GAD activity was regulated by hypoxia treatment and rapid growth of embryo. ► DAO was sensitive to hypoxia treatment. ► Polyamine degradation pathway supplied at least 30% of GABA formation under hypoxia.

•The enzymolysis conditions for isothiocyanates production from broccoli sprouts were optimized by RSM.•Isothiocyanates production was clearly enhanced by a suitable pH, addition content of EDTA and ascorbic acid.•Isothiocyanates profiles were firstly identified by GC/MS in broccoli sprouts.•Sulforaphane accounts the most in the total isothiocyanates.Isothiocyanates (ITCs) are proved as one of natural anticarcinogenic compounds, which are produced from the decomposition of glucosinolates by myrosinase. The present study optimized the enzymolysis conditions (pH, addition of EDTA and ascorbic acid) for ITCs production from glucosinolates in broccoli sprouts using response surface methodology. ITCs production was clearly enhanced by a suitable pH, addition content of EDTA and ascorbic acid. The optimal enzymolysis conditions were determined to be adding EDTA 0.02 mmol and 0.16 mg ascorbic acid to 4 ml of the homogenized phosphate–citrate buffer solution (pH 4.00). ITCs profiles were identified and seven kinds of individual ITCs were detected, among which sulforaphane accounted the most. Four kinds of individual ITCs including isobutyl isothiocyanate, 4-isothiocyanato-1-butene, 1-isothiocyanato-3-methyl-butane and 1-isothiocyanato-butane are firstly reported in broccoli sprouts.

γ-Aminobutyric acid (GABA) is a non-proteinous amino acid with some functions for human health. In this study, aminoaldehyde dehydrogenase (EC 1.2.1.19, AMADH) which has been proven to be an essential enzyme responsible for the GABA bioformation via polyamine degradation pathway was purified from 2-day germinated soybeans and characterized. The partially purified enzyme showed a single major band with a relative molecular mass of approximately 53.72 kDa-subunit using sodium dodecyl sulfate gel electrophoresis. AMADH exhibited the optimal activity at pH 8.0 and at 45 °C, respectively. The activity of purified AMADH was significantly inhibited by some heavy metal ions and sulfhydryl reagents. The cDNA of AMADH was sequenced by RT-PCR, which indicated 1,677 bp long and contained a 1,515 bp open reading frame that encoded 504 amino-acid peptides (GenBank accession number: KC478661).

Changes in physiological and biochemical metabolism as well as glucoraphanin and sulforaphane contents of germinating broccoli seeds and sprouts were investigated in this study. Sprout length, root length, and fresh weight increased with germination time. Dry weight varied from 2.5 to 3.0 mg per sprout. A rapid increase in respiratory rate of sprouts occurred between 24 and 36 h of germination and then stayed at a high level. HPLC analysis found that glucoraphanin content increased at the early stage (0–12 h) of germination, decreased to a low value of 3.02 mg/g at 48 h, and then reached the highest value of 6.30 mg/g at 72 h of germination. Sulforaphane content decreased dramatically during the first day of germination, then increased slowly, and reached a high value of 3.38 mg/g at 48 h before declining again.

Selenium-enriched brown rice (Se-BR) has been reported to accumulate Se mainly in its proteins. Purification of selenium-containing proteins (Se-Ps) from Se-BR and their in vitro antioxidant activities were investigated in this study. Sephadex G-100 gel filtration and diethylaminoethyl cellulose Sepharose Fast Flow anion-exchange chromatography were used to purify the major Se-Ps from the crude protein extract from Se-BR. Se content was measured after each step to determine the major Se-containing fraction for further separation. Three major Se-Ps with molecular weights of ~15 kDa, determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis, were isolated and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Their antioxidant activities were evaluated using three different free radical-scavenging assays, namely, the hydroxyl radical-, superoxide anion-, and 1,1-diphenyl-2-picrylhydrazyl-scavenging assays. Results indicate that Se-Ps purified from Se-BR exhibit antioxidant activities and may be used as potential antioxidants.

High levels of γ-aminobutyric acid (GABA) accumulate in plant tissues under various stresses and exogenous additives. The purpose of this research is to provide an effective finding that can prove a rapid accumulation of GABA in germinated soybean (Glycine max L.) in response to different additives under hypoxia. Hypoxia-induced GABA accumulation in soybean embryo resulted in part from polyamine oxidation. Response to different concentration of glutamate (Glu), pyridoxal phosphate, arginine, CuCl2, NaCl, and CaCl2, a significant difference including GABA accumulation, changes of Glutamate decarboxylase (GAD), and Diamine oxidase activity (DAO) activity in germinated soybean under hypoxia occurred (p < 0.05) and the maximum accumulation of GABA were 4.07, 3.02, 3.50, 3.26, 4.00, and 3.30 g kg−1 DW respectively, which were significantly higher than those germinated soybean under normal culture (CK) and hypoxia culture (CK0) (p < 0.05). The GAD and DAO have different distributions in cotyledon and embryo of germinated soybean, and the enzyme activity mainly located in embryo of germinated soybean. Germinated soybean is a good resource of GABA-rich food. Different additives have significant effects on GABA production, among which Glu and NaCl are ideal material for GABA accumulation.

This study investigated the compositions of anthocyanins in blackberry juice and the effect of heating (70, 80, and 90 °C) on individual anthocyanins, as well as its impact on antioxidant activity. The results showed that five anthocyanins were identified, including cyanidin (Cy)-3-O-glucoside (1), Cy-3-O-arabinoside (2), Cy-3-O-malonyl-glucoside (3), Cy-3-O-dioxalyl-glucoside (4), and the Cy derivative (5). The degradation rates of individual anthocyanins (1–4) followed the first-order reaction kinetics. Unexpectedly, the amount of the Cy derivative (5) was observed to slightly increase in temperature. At the same temperature, the half-lives (T1/2) values of each anthocyanin (1–4) significantly differed (P < 0.05). Maximum of the T1/2 values were observed with Cy-3-O-dioxalyl-glucoside (T1/2 values ranged 9.48–3.54 h) and exhibited relatively resistant stability. Moreover, the T1/2 values of Cy-3-O-glucoside were higher than Cy-3-O-arabinoside and Cy-3-O-malonyl-glucoside. The antioxidant activity of blackberry juice reduced with the decreasing of total anthocyanins. These results demonstrated that the time dependency of anthocyanins degradation and antioxidant capacity were strongly correlated in blackberry juice.

This study investigated the accumulation of selenium (Se) in protein fractions of albumin, globulin, prolamin and glutelin extracted from Se-enriched brown rice and the molecular weight distribution of Se-containing proteins. Results showed that the amount of total Se (T-Se) and protein-bound Se (PB-Se) in brown rice was significantly (P < 0.05) increased after germination with 10–60 μmol/l sodium selenite. Except prolamin, the amount of all the other three protein fractions decreased significantly (P < 0.05) with the increase of germination time. Low Se concentrations had promoting effects on degradation of albumin and globulin, while no significant effects were observed on prolamin and glutelin. The accumulation of T-Se and PB-Se were in the order of albumin > glutelin > globulin > prolamin. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS–PAGE) analysis showed that Se was distributed in all the proteins of which molecular weights varied from 13.6 to 121.4 kDa; however, 84.34% of Se was observed in the proteins whose molecular weights less than 36.3 kDa.Research highlights► The accumulation kinetics Se in brown rice during germination was investigated. ► Se accumulation capacity of various protein fractions of brown rice was studied. ► Determined molecular weights of Se-containing proteins in Se-enriched brown rice. ► A very non-uniform distribution of Se in Se-containing proteins was observed.

The incubation conditions of wheat germ for angiotensin I-converting enzyme inhibitory activity (ACEI) elevation and peptide accumulation were investigated, and five ACE inhibitory peptides were obtained. The effect of individual factors such as incubation time, temperature, initial pH, and liquid to solid ratio on ACEI and peptide concentration of incubation medium was evaluated, respectively. The combinations of four factors were further optimized using a Box−Behnken design. Under the best incubation condition (pH 4.4 with a liquid to solid ratio 8.14 mL/g at temperature 47 °C, for 7 h), maximum ACEI (92.16%) and peptide concentration (88.12 mg/g) were obtained, which were 6.2- and 2.4-fold, respectively, as compared to the unincubated wheat germ. After they were purified, five ACE inhibitory peptides, VEV, W, NPPSV, QV, and AMY, were identified by liquid chromatography/tandem mass spectrometry. The IC50 were 115.20, 94.87, 40.56, 26.82, and 5.86 μM, respectively.

Factors (germination time, spectra, temperature, pH, and chemical inhibitors) influencing diamine oxidase (DAO, EC 1.4.3.6) activity and γ-aminobutyric acid (GABA) content of fava bean (Vicia faba L.) during germination were investigated in this study. DAO activity significantly increased in germinating seeds but varied with different organs. The enzyme activity was higher in shoot than that in cotyledon, hypocotyl, and radicle. When seeds were germinated in the dark, DAO activity was 2.35-, 2.00-, 2.36-, 4.40-, and 1.67-fold of that under white, red, blue, green, and yellow spectra, respectively. The optimum germination temperature and pH value for increasing DAO activity were 30 °C and 3.0, respectively. The DAO activity was inhibited significantly by aminoguanidine and sodium ethylenediamine tetracetate, while it was activated by CuCl2 and CaCl2. Germinating at an appropriate temperature and pH, 30% of GABA formation was supplied by DAO. Calcium was related to the regulation of DAO activity and GABA accumulation.

Effects of soaking temperature, soaking time, opportunity of aeration treatment, culture temperature, pH value, and air flow rate on γ-aminobutyric acid (GABA) accumulation during germination of soybean (Glycine max (L.) Merr.) were investigated in this study. The objective of this study was to optimize the culture conditions of GABA production in germinated soybeans. Results showed that soaking at 30 °C for 4 h was found to be the most effective soaking ways that made soybean seeds have sufficient moisture, satisfactory germination, and GABA accumulation. The suitable stress opportunity was dark culture for 2 days with distilled water and then hypoxia stress in aerated culture medium for 2 days in a dark incubator at 30 °C. Under these conditions, the maximum GABA content (2.24 mg/g DW) was 3.5 times higher than the initial sample of aeration treatment (0 h) and 12.5 times higher than the raw material. Correlation analysis also revealed that GABA accumulation was significantly correlated to the corresponding physiochemical indexes (p < 0.01). Box-Behnken experimental analysis showed that the optimal condition with aeration treatment for GABA accumulation in germinated soybean was at a temperature of 30.5 °C, a pH value of 4.1, and an air flow rate of 0.9 L/min; the predicted highest GABA yield was 2.60 mg/g DW, which was 15.2 times higher than raw seeds. Analysis of variance and confirmatory trials for the regression model suggested that the model can quite exactly predict GABA accumulation in soybean during germination.

This study involved the development of the method for removing proteins impurities from lily non-starch polysaccharides (NSP) with fermentation of Saccharomyces cerevisiae, which was different from Sevag and trichloroacetic acid methods. We optimized the extraction conditions of NSP; meanwhile, the optimal deproteinization conditions were determined. Firstly, a Plackett–Burman design was utilized to evaluate the effects of variables on the NSP yield and the ratio of protein removed (RPR). Lily bulb powder, temperature, pH and KH2PO4 exerted significant effects on NSP yield (P < 0.05), whereas lily bulb powder and pH had significant effects (P < 0.01) on RPR. Subsequently, these four factors were optimized using response surface analysis. The analysis revealed that the optimum conditions were 60.0 g/L lily bulb powder, 1.50 g/L KH2PO4, pH4.8 and temperature 26.9 °C. In the verification experiments, the experimental NSP yield of 8.81 ± 0.18% and RPR of 91.71 ± 0.08% perfectly matched with the predicted values (8.99% for NSP yield and 91.70% for RPR), which verified the practicability of this optimum strategy.

The effects of glutamic acid (Glu), pyridoxal-5-phosphate (PLP) and calcium chloride (CaCl2) in culture medium on glutamate decarboxylase (GAD) activity and γ-aminobutyric acid (GABA) accumulation in foxtail millet (Setaria italica L.) during germination were investigated in this study. The components in culture medium for GABA accumulation were optimised using response surface methodology (RSM). Results showed that GAD activity and GABA yield were dependent on the addition of Glu, PLP and CaCl2 into the culture medium. Box–Behnken design indicated that the optimal culture components for GABA accumulation were: Glu at a concentration of 1.2 mg/ml, PLP at a concentration of 50 μM and CaCl2 at a concentration of 2.5 mM. Under the optimal conditions, the maximal production of GABA (42.9 mg/100 g FW) was obtained. Analysis of variance for the regression model suggested that the model can quite exactly predict GABA accumulation in millet during germination.

The goal of this paper was to study the accumulation of selenium (Se) in different cultivars of brown rice and its distribution in fractions. The results of the study showed that Se content in brown rice increased significantly (P < 0.01) as the external selenite or selenate concentrations increased from 10 to 180 μmol/L. In contrast, no significant influence (P > 0.05) on germination percentage and growth of sprouts was observed when the supplied Se was lower than 60 μmol/L. Moreover, selenite was easily transformed into selenoproteins to selenate. Based on this, ten brown rice cultivars were compared for Se accumulation. Likewise, significant difference (P < 0.01) was found among cultivars with respect to the capacity for Se accumulation. To understand the distribution of Se in selenized brown rice and its loss during milling, two cultivars with relatively higher ability to accumulate Se, namely, Zhendao 8 (Z8) and Xieyou 57 (X57), were selected for further study. The results showed that Se content was highest in the sprouts and decreased remarkably (P < 0.01) from the bran layers to the endosperm. In terms of Se loss during the milling procedure, 39.02% and 48.46% of Se were lost in Z8 and X57, respectively.

In this paper, a growth-promoting culture solution was developed to enhance the accumulation of peptides during brown rice germination. Among 11 variables investigated with Plackett–Burman design, gibberellic acid, NaCl, CuSO4 and MnSO4 were selected based on their statistically significant (P < 0.05) and positive effects on peptides content in germinated brown rice. Subsequently, uniform design was used for further optimization of these selected variables to improve the peptides content. By backward regression analysis, a second-order polynomial model was established to identify the relationship between those selected components in culture solution and peptides content, as well as protease activity. The three most effective components are GA3, NaCl and MnSO4 and the optimum concentrations were obtained as follows: 55 μmol/L, 6.0 mmol/L and 1.8 mmol/L respectively. An overall 1.90-fold increase in peptides accumulation was achieved in the optimized culture solution (10.53 mg/g) as compared with control (5.53 mg/g), and 2.52-fold increase as compared with ungerminated brown rice (4.18 mg/g).

Effects of culture conditions on the growth of mycelium and the production of intracellular cordycepin ofCordyceps militaris were investigated in this study. The natural medium which is a mixture of 53% brown rice paste, 6% beerwort and 42% soybean meal juice was used for the fermentation in shaking flasks. Fermentation temperature, pH and medium capacity, which had been proved to be significant factors, were optimized by Box-Behnken design. Results showed that dry mycelia weight (DMW) and cordycepin yield (CY) was varied with the transformation of culture conditions. The highest DMW (19.1 g/L) and CY (1.8 mg/g) would be obtained at the condition of fermentation temperature 28 °C, pH 6.2 and medium capacity 57 mL.

Effects of two buffer solutions—citrate solution and acetate solution—on γ-aminobutyric acid (GABA) accumulation during germination of foxtail millet (Setaria italica L.) and optimization of culture conditions, namely culture temperature, air flow rate and pH values, on GABA yield in germinated foxtail millet were investigated in this paper. The optimization processes were conducted using response surface methodology. The results showed that citrate buffer at 10 mmol L−1 was most effective as culture medium. Box–Behnken experimental design showed that the optimal conditions for GABA accumulation during millet germination were at a temperature of 33 °C; an air flow rate of 1.9 L/min; and a pH value of 5.8. Under these conditions, the maximal observed production of GABA (26.96 mg 100 g−1FW) was obtained. Analysis of variance for quadratic polynomial regression model indicated that the model was extremely significant (P < 0.0001), the determination coefficient (R2) was 0.9594, which implied that the model can forecast the changes of GABA accumulation during millet germination excellently.

Optimization of the conditions for extracting anthocyanins from the cob, a byproduct of purple corn (Zea mays L.), was investigated in this paper. A full factorial design (22 × 32) was used. The factors studied were type of solvent: ethanol or methanol; solvent/water mixture: 100, 90, 80% v/v; type of acid: citric acid or acetic acid; and concentrations of acid: 0.25, 0.5, 1% v/v. Tristimulus colorimetry was employed to evaluate the yield and quality of anthocyanins extracts. The results showed that the maximum yield (5.90 mg/g dw) was obtained with the combination of 80% (v/v) methanol and 1% (v/v) citric acid, and that the relatively high chroma (C* = 23.60) and hue angle (h = 16.63) values of the anthocyanins extract were observed under the same conditions. Eight kinds of anthocyanins in the cob were detected by HPLC–DAD, most the anthocyanins were non-acylated.

Proteins in brown rice (BR), white rice (WR) and rice bran (RB) were extracted from the same paddy rice and investigated for their components, functional properties and chemical characteristics by SDS-PAGE methodology. BR and WR proteins possessed a poor solubility under weak acid conditions due to a high content of glutenin and richness in higher molecular-weight (MW) protein fractions. Rice bran protein contained significantly lower molecular-weight components (MWs < 50 kDa) than those in WR and BR. Nitrogen solubility, foaming and emulsification properties of their rice protein preparations were affected not only by pH (3–11), but also by the concentrations of NaCl (0.4–2.0%) and sucrose (4.0–20.0%). All of them, particularly rice bran protein, had favorable functional properties in the medium with a high salt or sugar concentration. Therefore, they have a good potential for development in the food industry.

Sulforaphane is a type of sulfur-containing isothiocyanates hydrolyzed from glucosinolates by myrosinase found in Brassica plants. Sulforaphane is a naturally occurring inducer of phase II enzymes in human and animal bodies to detoxify cancer-causing chemicals. Glucoraphanin is the precursor of sulforaphane and its content is greatly influenced by plant species and genotype, plant organs, pre-harvest factors, and post-harvest processing, thus sulforaphane formation is also directly influenced. Here, we review the formation mechanism of sulforaphane and the factors influencing sulforaphane formation. In the end, the future directions are also discussed.

Gamma-aminobutyric acid (GABA), a nonproteinous amino acid with some benefits on human health, is synthesized by GABA-shunt and the polyamine degradation pathway in plants. The regulation of Ca2+ and aminoguanidine on GABA accumulation in germinating soybean (Glycine max L.) under hypoxia-NaCl stress was investigated in this study. Exogenous Ca2+ increased GABA content significantly by enhancing glutamate decarboxylase gene expression and its activity. Addition of ethylene glycol tetra-acetic acid into the culture solution reduced GABA content greatly due to the inhibition of glutamate decarboxylase activity. Aminoguanidine reduced over 85% of diamine oxidase activity, and 33.28% and 36.35% of GABA content in cotyledon and embryo, respectively. Under hypoxia–NaCl stress, the polyamine degradation pathway contributed 31.61–39.43% of the GABA formation in germinating soybean.

Studies were carried out to identify edible mushrooms that are able to release ferulic acid from wheat bran. In the five samples tested in the present studies, cultured mycelia of four mushroom species were found to release ferulic acid, with Hericium erinaceus producing the highest ferulic acid yield at 4 d of culture, reach 95.51 mg/l in wheat bran broth. Enzymes detection showed that H. erinaceus secreted a large amount of ferulic acid esterase and cellulase. Ferulic acid esterase activity could get up to 2.04 ± 0.23 mU/ml. It was reported that ferulic acid eaterase is the key enzyme responsible for the release of ferulic acid. However, cellulase, which could decompose cell walls to release ferulic acid of wheat bran, was the only enzyme detected in the fermentation of the other mushrooms; the activities were variable between different mushroom species and fermentation time.

•CaCl2 were added during soybean sprout production by three ways.•Soybean sprout length and yield were improved by supplemental CaCl2.•CaCl2 improved Zn, Fe and Ca bioavailability by decreasing phytic acid content.•Free amino acid, GABA and isoflavone content of CaCl2-treated sprouts were improved.Effects of supplemental Ca2+ on growth and selected qualities of soybean sprout were investigated. Ca2+-treated sprouts had 40 ∼ 47% higher length and 31 ∼ 39% higher yield than water-treated ones. Increment of endogenous indoleacetic acid and gibberellin in Ca2+-treated soybean sprouts possibly contributed to the improved growth. Metabolism of selected anti-nutritional factor and bioactive substances in soybean sprouts was strengthened by Ca2+. Phytic acid content of Ca2+-treated soybean sprouts was 33 ∼ 49% lower than that of the control. Supplemental Ca2+ increased content of gamma-aminobutyric acid and isoflavone by improving activity of diamine oxidase and isoflavone synthetase, respectively. Soybean sprouts produced by soaking Ca2+ and spraying Ca2+ contained more ascorbic acid and phenolics and hence exhibited enhanced antioxidant capacity compared to the control. Besides, no adverse change on protein content and amino acid composition was observed in Ca2+-treated sprouts. These findings indicate that supplemental Ca2+ can increase soybean sprout yield and improve its nutrition qualities.

•Dough under frozen storage and freeze/thaw showed different degradation kinetics.•Dough weight loss contributed most to reduced bread loaf volume under frozen storage.•GMP depolymerization dominated in degraded bread loaf volume under freeze/thaw.Successive freeze/thaw (FT) cycle was a widely used empirical approach to shorten the experimental period since it could accelerate frozen dough deterioration compared with frozen storage (FS). In order to compare the effect of FS and FT cycle on deterioration procedure of chemical-leavened steamed bread dough, kinetic studies of bread quality indices were performed and the relationships between bread quality and dough components were further established. Results showed that degradation of steamed bread loaf volume and firmness followed first-order kinetics during FS and zero-order kinetics during FT, respectively. Glutenin macropolymers (GMP) depolymerization and dough weight loss occurred steadily throughout FS and FT. Significant enhancement of damaged starch and crystallinity were observed at the later FS period and FT cycle. Multiple regression study led to the conclusion that dough weight loss contributed the most to the reduced bread loaf volume under FS whereas GMP depolymerization dominated under FT condition.

•Chemical leavened dough showed higher freeze stability in steamed bread quality.•Gassing power of frozen yeast leavened dough decreased due to yeast viability loss.•Frozen chemical leavened dough showed stable gassing power and faster release rate.•Gluten depolymerization and secondary structure conversion indicated its degradation.•Chemical leavener was conducive to the more freeze-tolerant gluten network.The present study comparatively evaluated the evolution of yeast and chemical leavened steamed bread dough (YLD/CLD) quality during freeze/thaw (FT) cycles. The steamed bread quality of CLD was more freeze-stable than that of the YLD after 3 FT cycles. Decreased yeast viability contributed to the loss of gassing power in YLD while no significant differences were observed for CLD during FT cycles. However, faster gas release rate in frozen CLD indicated gas retention loss due to the distortion of gluten network. Glutenin macropolymers (GMP) depolymerization via breakage of inter-chain disulfide (SS) bonds and conversions of α-helix and β-turn to β-sheet structures were the main indicators of gluten deterioration. Gluten network was more vulnerable in frozen YLD, resulting in detectable loss of viscoelasticity. The results suggested that supplement of chemical leavener contributed to a more freeze-tolerant gluten network besides its stable gassing power.