Solid-State Fermentation Reduces Phytic Acid Level, Improves the Profile of Myo-Inositol Phosphates and Enhances the Availability of Selected Minerals in Flaxseed Oil Cake

U radu su ispitani in vitro sljedeći parametri: udjel fitata (InsP6), svojstva mioinozitol fosfata i iskoristivost esencijalnih mineralnih tvari iz lanene pogače fermentirane s pomoću gljivice Rhizopus oligosporus (DSM 1964 i ATCC 64063). Maseni udjel fitata u lanenoj pogači bio je 13,9 mg/g, nakon 96 sati fermentacije s pomoću R. oligosporus DSM 1964 smanjen je za 48 %, a s pomoću R. oligosporus ATCC 64063 za 33 %. Fermentacijom s pomoću soja DSM 1964 postignuti su bolji rezultati, jer je dobiven dominantni mioinozitol InsP3-5, dok je fermentacijom s pomoću soja ATCC 64603 dobiven uglavnom InsP5-6. Fermentacijom na čvrstoj podlozi od lanene pogače poboljšana je in vitro iskoristivost kalcija za 14 %, magnezija za 3,3 % i fosfora za 2-4 %.Flaxseed oil cake was subjected to fermentation with Rhizopus oligosporus (DSM 1964 a nd ATCC 64063), and the phytate (InsP6) content, myo-inositol phosphate profile and in vitro bioavailability of essential minerals were studied. Flaxseed oil cake had a phytate mass fraction of 13.9 mg/g. A 96-hour fermentation of flaxseed oil cake by R. oligo sporus DSM 1964 and R. oligosporus ATCC 64063 decreased the InsP6 content by 48 and 33 %, respectively. The strains had different phytate-degrading activities: fermentation of flaxseed oil cake with R. oligosporus DSM 1964 was more advantageous, yielding InsP3-5 as a predominating myo-inositol compound, while fermentation with R. oligosporus ATCC 64603 produced predominantly InsP5-6. Solid-state fermentation of flaxseed oil cake enhanced in vitro bioavailability of calcium by 14, magnesium by 3.3 and phosphorus by 2–4 %

Brewing with 10% and 20% Malted Lentils—Trials on Laboratory and Pilot Scales

Lentils, a popular foodstuff worldwide, are gaining more interest for their use in alternative diets. In addition, we are observing an ever-growing demand for new raw materials in the malting and brewing industry and an overall rising interest in a low-gluten lifestyle. Therefore, in this study, malt was produced from green lentils and used in both laboratory- and pilot-scale brewing trials. Malted lentils were used as 10% and 20% adjuncts at the laboratory scale, following the Congress mash procedure, and the most important parameters (e.g., filtration time, pH, color, extract, fermentability) of the wort and beer samples were analyzed with a special focus on the concentrations of metal ions (Mg2+, Ca2+, Zn2+, Fe) in wort. The production of beer with lentil malt as an adjunct was then scaled up to 1 hl, and several beer parameters were analyzed, including the gluten content and foam stability. The results showed that the gluten content was decreased by circa 35% and foam stability was enhanced by approximately 6% when adding 20% lentil malt. Furthermore, the use of lentil malt reduced the filtration time by up to 17%. A trained panel evaluated the sensorial qualities of the produced beers. Overall, the use of green lentil malt shows promising results for its potential use in brewing

Chemical Composition of Sour Beer Resulting from Supplementation the Fermentation Medium with Magnesium and Zinc Ions

The bioavailability of minerals, such as zinc and magnesium, has a significant impact on the fermentation process. These metal ions are known to influence the growth and metabolic activity of yeast, but there are few reports on their effects on lactic acid bacteria (LAB) metabolism during sour brewing. This study aimed to evaluate the influence of magnesium and zinc ions on the metabolism of Lactobacillus brevis WLP672 during the fermentation of brewers’ wort. We carried out lactic acid fermentations using wort with different mineral compositions: without supplementation; supplemented with magnesium at 60 mg/L and 120 mg/L; and supplemented with zinc at 0.4 mg/L and 2 mg/L. The concentration of organic acids, pH of the wort and carbohydrate use was determined during fermentation, while aroma compounds, real extract and ethanol were measured after the mixed fermentation. The addition of magnesium ions resulted in the pH of the fermenting wort decreasing more quickly, an increase in the level of L-lactic acid (after 48 h of fermentation) and increased concentrations of some volatile compounds. While zinc supplementation had a negative impact on the L. brevis strain, resulting in a decrease in the L-lactic acid content and a higher pH in the beer. We conclude that zinc supplementation is not recommended in sour beer production using L. brevis WLP672

Connecting yeast proteome and metabolome

Numerous factors, e.g. temperature, yeast pitching rate or wort composition, can alter the yeast proteome and thus the final beer characteristics. The understanding of yeast response to diverse environmental parameters requires detailed analysis of proteome variations, assimilation of wort components (e.g. carbohydrates, amino acids and metal ions) as well as production of metabolites (e.g. glycerol, esters, organic acids, diacetyl, ethanol and higher alcohols). Shotgun proteomics via liquid chromatography mass spectrometry was applied to quantify the yeast proteome during beer fermentation. Ale yeast was pitched into standard wort and monitored for 120h. Proteins of interest were quantified by relative abundance of proteins, in essence the quantity of a specific protein per total quantity of proteins obtained. More than 1000 yeast proteins were identified and 25 were carefully investigated due to their role in substrate consumption or metabolites production. The majority of the selected enzymes involved in the glycolysis and fermentation correlated with the profile of the cell growth curve; exponentially increasing between 12h and 48h. The relative abundance of aldehyde dehydrogenase 6 (responsible for reduction of acetaldehyde to acetic acid) declined between 48h and 120h; whereas the presence of heat shock protein 26 increased during the stationary phase. The relative abundance of alcohol dehydrogenase (ADH1, responsible for the reduction of acetaldehyde to ethanol) slowly decreased during the lag phase (until 6h) and raised exponentially until reaching the stationary phase. The trend in ethanol content was similar when compared to ADH1 throughout the entire fermentation. In conclusion, the findings of this study give a better understanding of the impact of fermentation conditions on the yeast proteome and might be used in future studies aiming at the improved control of the fermentation proces