ABSTRACT
BACKGROUND: Pseudocereals are nutrient-rich grains with high mineral content but also phytate content. Phytate is a mineral absorption inhibitor. The study's aim was to evaluate phytate degradation during spontaneous fermentation and during Lactobacillus plantarum 299v® fermentation of quinoa, canihua, and amaranth grains and flours. It also aimed to evaluate the accessibility of iron, zinc, and calcium and to estimate their bioavailability before and after the fermentation of flours with starter culture. Lactic acid, pH, phytate, and mineral content were analyzed during fermentation. RESULTS: Higher phytate degradation was found during the fermentation of flours (64-93%) than during that of grains (12-51%). Results suggest that phytate degradation was mainly due to endogenous phytase activity in different pseudocereals rather than the phytase produced by added microorganisms. The addition of Lactobacillus plantarum 299v® resulted in a higher level of lactic acid (76.8-82.4 g kg-1 DM) during fermentation, and a relatively quicker reduction in pH to 4 than in spontaneous fermentation. Mineral accessibility was increased (1.7-4.6-fold) and phytate : mineral molar ratios were reduced (1.5-4.2-fold) in agreement with phytate degradation (1.8-4.2-fold) in fermented flours. The reduced molar ratios were still above the threshold value for the improved estimated mineral bioavailability of mainly iron. CONCLUSION: Fermentation proved to be effective for degrading phytate in pseudocereal flours, but less so in grains. Fermentation with Lactobacillus plantarum 299v® improved mineral accessibility and estimated bioavailability in flours. © 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Subject(s)
Amaranthus/microbiology , Chenopodium quinoa/microbiology , Chenopodium/microbiology , Lactobacillus plantarum/metabolism , Minerals/analysis , Phytic Acid/metabolism , Amaranthus/chemistry , Amaranthus/metabolism , Chenopodium/chemistry , Chenopodium/metabolism , Chenopodium quinoa/chemistry , Chenopodium quinoa/metabolism , Edible Grain/chemistry , Edible Grain/metabolism , Edible Grain/microbiology , Fermentation , Flour/analysis , Gastrointestinal Tract/metabolism , Humans , Minerals/metabolism , Phytic Acid/analysisABSTRACT
Ulocladium subcucurbitae and U. brassicae are described and illustrated. These species were isolated from diseased leaves of Chenopodium glaucum and Brassica pekinensis from Guizhou and Yunnan provinces of China respectively.
Subject(s)
Ascomycota/classification , Ascomycota/isolation & purification , Ascomycota/cytology , Chenopodium/microbiology , China , Microscopy , Plant Diseases/microbiology , Plant Leaves/microbiology , Spores, Fungal/cytologyABSTRACT
About 20 species of Peronospora have been reported to cause downy mildew on Chenopodium, but, particularly in plant pathology literature, only one species, P. farinosa, is considered to be involved. We performed sequence analysis of the ITS rDNA to reveal the phylogenetic relationships of Peronospora specimens from five species of Chenopodium, viz. C. album, C. ambrosioides, C. bonus-henricus, C. hybridum, and C. polyspermum. The five clades corresponded to particular Chenopodium species, and showed a high level of sequence divergence. Differences in the morphology of the conidia and ultimate branchlets also supported the separation of the five groups at the host species level. These results suggest that the names P. variabilis, P. boni-henrici, P. chenopodii, and P. chenopodii-polyspermi should be used for the four downy mildew pathogens specific to C. album, C. bonus-henricus, C. hybridum, and C. polyspermum, respectively. The Peronospora on C. ambrosioides was found to be an independent species.
