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Highlights: [•] 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. [Copyright &y& Elsevier]

Highlights: [•] 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. [Copyright &y& Elsevier]

Abstract: 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 5days, respectively. Hence, it can be inferred that about 30% of GABA formed in germinating fava bean under hypoxia was supplied by polyamine degradation pathway. [Copyright &y& Elsevier]

Abstract: Gamma-aminobutyric acid (GABA) is a non-protein amino acid with bioactive functions in humans. In this work, glutamate decarboxylase (EC 4.1.1.15, GAD) which is key in the GABA bioformation was purified from 5-day germinated faba beans and characterized. A single band was observed at 58kDa using sodium dodecyl sulphate gel electrophoresis. GAD optimal activity was at pH 6.0 at 40°C with a K m value for glutamic acid (Glu) of 2.63mM. The enzyme was inhibited significantly by Cu2+, Fe3+, Mg2+, Ba2+, aminoxyacetate, EGTA, Na2EDTA, l-cysteine and beta-mercaptoethanol; and activated at low Ca2+ 0.2mM. Using RT-PCR, the GAD cDNA was sequenced which indicated 1787bp long, containing a 1527bp open reading frame (ORF) that encoded 509 amino-acid peptides with a calculated molecular weight of 57.74kDa and a pI of 5.41 (GenBank accession number: JX444699). [Copyright &y& Elsevier]