Daiva Vidmantiene

Solid state fermentation with lactic acid bacteria to improve the nutritional quality of lupin and soya bean

BACKGROUND The ability of bacteriocin-like inhibitory substance (BLIS)-producing lactic acid bacteria (LAB) to degrade biogenic amines as well as to produce L(+) and D(-)-lactic acid during solid state fermentation (SSF) of lupin and soya bean was investigated. In addition, the protein digestibility and formation of organic acids during SSF of legume were investigated. RESULTS Protein digestibility of fermented lupin and soya bean was found higher on average by 18.3% and 15.9%, respectively, compared to untreated samples. Tested LAB produced mainly L-lactic acid in soya bean and lupin (D/L ratio 0.38-0.42 and 0.35-0.54, respectively), while spontaneous fermentation gave almost equal amounts of both lactic acid isomers (D/L ratio 0.82-0.98 and 0.92, respectively). Tested LAB strains were able to degrade phenylethylamine, spermine and spermidine, whereas they were able to produce putrescine, histamine and tyramine. CONCLUSIONS SSF improved lupin and soya bean protein digestibility. BLIS-producing LAB in lupin and soya bean medium produced a mixture of D- and L-lactic acid with a major excess of the latter isomer. Most toxic histamine and tyramine in fermented lupin and soya bean were found at levels lower those causing adverse health effects. Selection of biogenic amines non-producing bacteria is essential in the food industry to avoid the risk of amine formation.

Effect of lactic acid fermentation of lupine wholemeal on acrylamide content and quality characteristics of wheat-lupine bread

Abstract The effect of supplementing wheat flour at a level of 15% with lupine (Lupinus angustifolius L.) wholemeal fermented by different lactic acid bacteria on acrylamide content in bread crumb as well as on bread texture and sensory characteristics was analysed. The use of fermented lupine resulted in a lower specific volume and crumb porosity of bread on an average by 14.1% and 10.5%, respectively, while untreated lupine lowered the latter parameters at a higher level (30.8% and 20.7%, respectively). The addition of lupine resulted in a higher by 43.3% acrylamide content compared to wheat bread (19.4 µg/kg dry weight (d.w.)). Results showed that acrylamide was significantly reduced using proteolytic Lactobacillus sakei and Pediococcus pentosaceus 10 strains for lupine fermentation. Although the bread supplemented with lupine spontaneous sourdough had the lowest level of acrylamide (15.6 µg/kg d.w.), it had the malodorous flavour and was unacceptable to the consumers. The lactofermentation could increase the potential use of lupine as a food ingredient while reducing acrylamide formation and enriching bread with high quality proteins.

Influence of diets to Wistar rats supplemented with soya, flaxseed and lupine products treated by lactofermentation to improve their gut health

Abstract The present study proposes the contribution of lactic acid bacteria and plants rich in bioactive substances and high-quality proteins as alternative products for human diets in improving the gut environment as potential against pathogenic bacteria. The effect of diets supplemented with soya, flaxseed and lupine flours fermented with a Pediococcus acidilactici KTU05-7 probiotic strain in the gastrointestinal tract (GIT) of Wistar rats were analyzed. In vivo experiments showed a positive effect of long time lactofermentation of plant material on the body weight of rats. Diets with fermented yellow lupine resulted in enhanced activities of α-glucosidase, β-galactosidases, as well as high levels of lactic acid bacteria, bifidobacteria and enterococci in the GIT were determined. Lactofermentation of analyzed plant products had a significantly lowering effect on Escherichia coli compared with the control group. The dominant flora of large intestines like Bifidobacterium and anaerobic cocci were found in high levels after diets with fermented lupine.

Benefits of β‐xylanase for wheat biomass conversion to bioethanol

BACKGROUND The efficiency of bioethanol production from wheat biomass is related to the quality of end products as well as to safety criteria of co-products such as distillers dried grains with solubles (DDGS). The inclusion of a new biocatalyst for non-starch polysaccharide degradation in fermentation processes could be one of the solutions. The objective of this study was to evaluate the influence of β-xylanases in combination with traditional amylolytic enzymes on the efficiency of bioethanol production and DON detoxification during fermentation of Fusarium-contaminated wheat biomass with high concentration of deoxynivalenol (DON; 3.95 mg kg(-1)). RESULTS The results showed that the negative effect of Fusarium spp. on yield and quality of bioethanol could be eliminated by the application of Trichoderma reesei xylanase in combination with amylolytic enzymes. This technological solution allowed to increase the concentration of ethanol in the fermented wort by 35.3% and to improve the quality of bioethanol by decreasing the concentrations of methanol, methyl acetate, isoamyl and isobutyl alcohols. Mass balance calculations showed that DDGS was the main source of DON contamination, comprising 74% of toxin found in wheat biomass. By using new enzyme combination for wheat biomass saccharification, a higher level of detoxification (41%) of DON was achieved during the fermentation process. CONCLUSION The addition of Trichoderma reesei xylanase played a positive role in bioethanol production from Fusarium-contaminated wheat biomass, indicating that the yeast-growing medium was enriched during the enzymatic treatment.

Nutritional quality of fermented defatted soya and flaxseed flours and their effect on texture and sensory characteristics of wheat sourdough bread

The use of soya and flaxseed flours fermented with Pediococcus acidilactici for wheat sourdough bread production was investigated. The protein digestibility, biogenic amine contents of soya and flaxseed sourdoughs, texture and sensory features of bread were studied. The fermentation with P. acidilactici significantly improved soya and flaxseed protein extraction and increased protein digestibility on an average by 13.5%. The concentrations of histamine (3.8 ± 2.3 and 4.0 ± 0.2 mg/kg), tyramine (4.6 ± 0.7 and 19.3 ± 1.8 mg/kg) and putrescine (66.4 ± 1.3 and 11.3 ± 3.0 mg/kg) do not present a health risk for consumers due to their relatively low levels in fermented plant products. The flaxseed sourdoughs influenced a 17.5% higher specific volume and a 4.6% lower crumb hardness of bread than those of soya sourdoughs, and did not disimprove sensory properties of bread. However, the fermented soya additives decreased acceptability of bread because of intensive taste and odour.

Acoustic sensing of deoxynivalenol in co-occurrence with zearalenone and T-2/HT-2 toxin in winter wheat cultivar Sirvinta from Lithuania

A fast acoustic screening method in combination with an ELISA method was applied for the detection of deoxynivalenol (DON) in co-occurrence with some trichothecenes such as zearalenone (ZEA) and T-2/HT-2 toxins in winter wheat grains (Triticum aestivum L.) of the most popular Lithuanian cultivar Sirvinta. Strong correlations between the amplitude of the acoustic signal that penetrated the wheat samples and DON as well as total amount of mentioned trichothecenes quantified by ELISA method were found (R2=0.787 and R2=0.794, respectively). It turned out that weak correlations between the acoustic signal and the concentrations of ZEA and T-2/HT-2 were found. These correlations suggest that DON is the marker of the Fusarium infected wheat grain. This statement is also strengthened by the fact that DON is the most significant trichothecene contaminant of cereal grains in the world and levels are generally higher in the wetter climates. The dependency determined between the acoustic signal and structural physica...

Recent advances in the rapid acoustic screening of deoxynivalenol in wheat grains

Deoxynivalenol (DON) is a natural and ubiquitous toxic metabolite produced by filamentous fungi of the genus Fusarium. Approximately one quarter of the worlds food crops (mainly cereals) are affected by mycotoxins such as DON. A rapid and non-destructive method to evaluate the quality and safety of grains is therefore required to eliminate these toxins from the food chain. The first portable acoustic device that predicts the concentration of DON in cereal grains has been developed using a broadband capacitive ultrasonic transducer. An acoustic method was optimised for the rapid prediction of DON in wheat. To measure the performance of this method, a model system comprising 0-100% scabby wheat grains was prepared and a single laboratory validation was carried out. The best regression model between DON concentrations determined by the reference ELISA method and the acoustic technique was obtained at an acoustic frequency of 32.2 kHz, with a correlation coefficient of 0.9852 and a repeatability coefficient ...

Seed treatment with lactic acid bacteria against seed-borne pathogens of spring wheat

Antifungal potential of lactic acid bacteria (LAB) such as Lactobacillus sakei KTU05-6, Pediococcus acidilactici KTU05-7 and Pediococcus pentosaceus KTU05-8, KTU05-9 and KTU05-10 was tested on naturally contaminated wheat seeds. LAB influence on fungal growth on kernels, seedling diseases and seed germination was examined by laboratory and field experiments. KTU05-10 was selected and later used for seed treatment as solitary strain and in two- or three-component mixtures with KTU05-7 and KTU05-6. The occurrence of Fusarium spp. on wheat kernels in agar plate assays was decreased by seed treatment with all LAB cultures, and the efficacy of each strain depended on incubation temperature. Inoculation of wheat kernels with strains of solitary KTU05-10 and in mixtures with KTU05-7 and KTU05-6 significantly reduced the incidence of Fusarium spp., Bipolaris sorokiniana and Alternaria spp. LAB influence on seed germination and seedling diseases was observed in laboratory and field experiments, but in most cases, this influence was insignificant.

A Rapid Quantitative Acoustic Technique to Screen for DON in Grain

ABSTRACT Mycotoxins in food and feed are considered as an important safety issue of growing concern. One of the most important mycotoxins both from an economic as well as from a health point of view is deoxynivalenol (DON), a toxin produced by fungi of the genus Fusarium occurring mainly on grains. DON occurs in grain in concentrations up to 10.000 μg/kg. Costly invasive wet chemistry methods and sampling procedures for grain, which cannot be considered as representative, have to safeguard the consumer. Not seldom, however, the Tolerable Daily Intake (TDI) of 1 μg/kg body weight as determined by the Joined Expert Committee of Food Additives (JECFA) is exceeded, which puts the population at risk. Recently a rapid acoustic technique with in-line capabilities has been tested for the quantitative determination of DON in wheat. It can be used to screen for DON in contaminated wheat at the point of harvest and with promising precision. Because it is fit for monitoring, this technique meets part of the problems previously associated with sampling and analysis.