Changes in the free amino acids and the biogenic amine contents during lactic acid fermentation of different lupin species

The aim of the work was to evaluate the profile of free amino acids (FAA) as the possible precursors of biogenic amines (BAs) in different varieties and hybrid lines of Lupinus luteus and Lupinus angustifolius and its changes during fermentation. Lupins have high amounts of FAA, and therefore, significant contents of BAs by the action of bacterial amino acid decarboxylases can be formed. In view of this, the effect of three Pediococcus pentosaceus strains KTU05‐8, KTU05‐9 and KTU05‐10 on BA formation during lupin fermentation was studied. The formation of BAs was monitored during 48‐h fermentation at solid‐state conditions and compared with that in samples after submerged fermentation and in the control nonfermented samples. The lupin variety, fermentation conditions and the Pediococcus strain were found to have the significant effect on the FAA profile and BA contents in fermented lupin; the interaction between analysed factors was F(5.989) = 1755.321 (P < 0.0001) and F(5.660) = 130.736 (P < 0.0001), respectively. A weak correlation was found between amino acid His and histamine (r = 0.3709; P = 0.0005) and between Phe and phenylethylamine (r = 0.3914, P = 0.0002) in lupin samples, but the significant correlations between amino acid Tyr and tyramine and between Lys and cadaverine were not found. By optimising the fermentation technology, it is possible to increase the nutritional value and functionality of lupin.     

Occurrence and risk assessment of mycotoxins,acrylamide, and furan in Latvian beer

This work reports data on the occurrence of nine mycotoxins and two food processing contaminants – acrylamide and furan – in a total of 100 beers produced in Latvia. Mycotoxins were detected by high-performance liquid chromatography (HPLC) coupled with time-of-flight mass spectrometry, acrylamide by HPLC coupled with quadrupole-Orbitrap mass spectrometry, and furan by headspace gas chromatography-mass spectrometry. The most frequently occurring mycotoxins were HT-2 and deoxynivalenol (DON), which were detected in 52% and 51% of the analysed samples. The highest content was observed for DON, reaching the maximum of 248 µg kg^?1. Furan was ubiquitous, and 74% of the samples contained acrylamide. In terms of the estimated exposure, the biggest potential risk was identified for HT-2 representing more than 11% of tolerable weekly intake. The margin of exposure approach indicated the exposure to furan through beer as significant, this parameter being close to the critical limit.     

Modulation of the nutritional value of lupine wholemeal and protein isolates using submerged and solid‐state fermentation with Pediococcus pentosaceus strains

The influence of different factors (submerged and/or solid‐state fermentation, pediococci strain, lupine variety and protein isolation process) on the protein digestibility, total phenolic compounds (TPC) content and radical scavenging activity of Lupinus luteus and angustifolius wholemeal and protein isolates was evaluated. As safety factor, biogenic amines (Bas) formation was analysed. The Pediococcus pentosaceus strains No. 8, No. 9 and No. 10 are suitable starters for lupine wholemeal fermentation and both applied processes (fermentation and protein isolation) increase protein digestibility (by 10%). Higher TPC content in fermented wholemeal can be obtained, compare to isolates. In SMF isolates by 58.3%, 68.2%, 95.6%, 76.6%, lower content of phenylethylamine, putrescine, cadaverine and histamine, respectively was found. The highest protein digestibility and the lowest BAs content using submerged fermentation with pediococcus No. 8 in lupine variety Vilnius protein isolates can be obtained and this technology for high‐quality lupine proteins preparation can be recommended.     

Polycyclic aromatic hydrocarbons in meat smoked with different types of wood

The influence of the wood used for the smoking of meat on the formation of polycyclic aromatic hydrocarbons (PAH) has been studied. Ten types of wood and charcoal were used for preparation of smoked meat samples. The analytical sample preparation method implied extraction of PAH with cyclohexane, liquid–liquid extraction with N,N-dimethylformamide/water, back extraction with cyclohexane, followed by clean-up on silica solid phase extraction (SPE) column and quantification by gas chromatography–mass spectrometry. It was found that the type of wood has a significant influence on the amount of PAH in smoked meat. The samples smoked with apple-tree and alder contained the smallest PAH concentrations. The samples smoked with spruce had the highest concentrations of PAH. The difference in content of benzo[a]pyrene (from 6.04 till 35.07 μg/kg) and total PAH (from 47.94 till 470.91 μg/kg) indicates that choice of wood for smoking is one of the critical parameter to be controlled in order to diminish the contamination of food products.     

Improved sensitivity of ochratoxin A analysis in coffee using high-performance liquid chromatography with hybrid triple quadrupole-linear ion trap mass spectrometry (LC-QqQLIT-MS/MS)

A novel and sensitive method utilising high-performance liquid chromatography coupled to triple quadrupole-linear ion trap mass spectrometry (LC-QqQLIT-MS/MS) was developed in order to analyse the content of ochratoxin A (OTA) in coffee samples. The introduction of the triple-stage MS scanning mode (MS³) has been shown to increase greatly sensitivity and selectivity by eliminating the high chromatographic baseline caused by interference of complex coffee matrices. The analysis included the sample preparation procedure involving extraction of OTA using a methanol–water mixture and clean-up by immunoaffinity columns and detection using the MS³ scanning mode of LC-QqQLIT-MS/MS. The proposed method offered a good linear correlation (r² > 0.998), excellent precision (RSD < 2.9%) and recovery (94%). The limit of quantification (LOQ) for coffee beans and espresso beverages was 0.010 and 0.003 µg kg^?1, respectively. The developed procedure was compared with traditional methods employing liquid chromatography coupled to fluorescent and tandem quadrupole detectors in conjunction with QuEChERS and solid-phase extraction. The proposed method was successfully applied to the determination of OTA in 15 samples of coffee beans and in 15 samples of espresso coffee beverages obtained from the Latvian market. OTA was found in 10 samples of coffee beans and in two samples of espresso in the ranges of 0.018–1.80 µg kg^?1 and 0.020–0.440 µg l^?1, respectively. No samples exceeded the maximum permitted level of OTA in the European Union (5.0 µg kg^?1).     

Influence of the addition of Helianthus tuberosus L. fermented with different lactobacilli on acrylamide content in biscuits

The aim of the study was to investigate the effect of the addition of Helianthus tuberosus L. fermented with different lactobacilli (Lactobacillus sakei KTU05‐6, Pediococcus acidilactici KTU05‐7 and Pediococcus pentosaceus KTU05‐9) on acrylamide content in biscuits. Results of study indicated that submerged fermented Helianthus tuberosus L. tubers had the significantly (P ≤ 0.05) lower pH, higher total titratable acidity and from 1.2 to 1.3 times higher protease and from 1.2 to 2.0 higher alpha‐amylase activities compared with treated by solid‐state fermentation. The acrylamide content in all biscuit samples enriched with submerged fermented Helianthus tuberosus L. was measured lower than 10 μg kg^?1. Submerged fermentation with selected lactobacilli provided specific characteristics of fermented Helianthus tuberosus products which had effect on the asparagine reduction in plant additives, thus reducing acrylamide content in biscuits enriched with Helianthus tuberosus L.     

The effects of ultrasonication,fermentation with Lactobacillus sp., and dehydration on the chemical composition and microbial contamination of bovine colostrum

The aim of this study was to evaluate the influence of ultrasonication, fermentation with Lactobacillus plantarum LUHS135 and Lactobacillus paracasei LUHS244, and different methods of dehydration on the chemical composition of bovine colostrum (BC), including the fatty acid and free amino acid profile and the content of micro- and macroelements. In addition, we analyzed the changes in lactic acid bacteria count, microbial contamination (aerobic mesophilic spore-forming bacteria, enterobacteria including Escherichia coli, and fungi/yeasts), the abundance of biogenic amines, and the concentration of nucleotide monophosphates. Significant effects of different treatments on the free amino acid profile were established, and an increase of lysine concentration by 1.2 to 95.9% was observed in treated BC. All of the treatments reduced the concentration of cadaverine, histamine, and tyramine in BC. The concentrations of macro- and microelements in BC followed the following order Ca > Na > K > Mg and Zn > Fe > Sr > Ba > Mn > Cu > Al > Se > Mo > Cr > Ni > Sn > Co > Pb > Cd. By combining the fermentation with Lactobacillus plantarum strain LUHS135 and vacuum drying, it was possible to increase the abundance of nucleotide monophosphates by more than 100%. All of the treatments reduced the microbial contamination of BC. Thus, the combination of ultrasonication, fermentation, and dehydration can be used for improving the properties and safety of BC.     

Occurrence of glyphosate in beer from the Latvian market

A sensitive LC-MS/MS method for the determination of glyphosate in beer has been developed, validated, and applied to analyse 100 beer samples from 24 different producers and distributors in Latvia. The selected samples represented most beer brands and varieties sold in local supermarkets. Different procedures for sample preparation and chromatographic separation were compared. The final version of the method consisted of solid phase extraction, chromatographic separation on aminopropyl stationary phase, and detection using tandem mass spectrometry. The concentration of glyphosate in beer varied from below the LOD of 0.2 μg kg^?1 up to 150 μg kg^?1, higher than previously reported. Significantly higher (p < 0.01) content of glyphosate was observed in beers that did not have the country of production disclosed on the label and were sold in local supermarkets by distributors from Latvia (1.8 μg kg^?1 median concentration in locally produced beer, 6.7 μg kg^?1 in beer of undisclosed origin).     

Nutraceuticals in gummy candies form prepared from lacto‐fermented lupine protein concentrates,as high‐quality protein source,incorporated with Citrus paradise L. essential oil and xylitol

As an addition to a normal diet, the use of food enriched with functional compounds has become increasingly popular. Alternatively, functional ingredients can be incorporated into nutraceuticals in gummy candies (GC) form. This study aimed to adapt lacto‐fermented lupine protein concentrates, as high‐quality protein and genistein sources, with Citrus paradise essential oil (EO), an antimicrobial and bean taste masking agent, and xylitol, a low glycaemic index sweetener, for preparation of nutraceuticals in GC form. For GC preparation, submerged fermentation with Lactobacillus sakei lupine variety Vilniai protein concentrate was selected, which had the highest protein content (90.11%), protein digestibility (89.94%) and genistein content (30.93 μg g^?1) and the lowest trypsin inhibitors activity (19.40%), among the concentrates assessed. GC formulated with xylitol, ascorbic acid, grapefruit EO (up to 0.2%) and lupine protein concentrate (up to 13.0%) allowed obtaining products that exhibited a good texture, high overall acceptability and contained desirable functional compounds.